docs: restructure org for per-function literate prose

37 per-function code blocks with prose explaining design reasoning,
edge cases, and CL traps. Combined tangle blocks at end for actual
compilation.

New scripts/tangle.py: reliable Python tangler (emacs --batch failed).
Added: %split-string, %join-lines, tangle helper.

CL traps documented in org prose:
- defstruct generates keyword constructors (no :constructor needed)
- case with strings uses EQL — use cond + string=
- CL strings: no \n escape — use (string #\Newline)
- FiveAM closure capture — use list boxing
- read-byte is package-locked — use read-raw-byte
- ASDF compile-file stricter than LOAD — debug with LOAD

60 tests, 100% GREEN.

README.org

@@ -50,3 +50,4 @@ See ~docs/ROADMAP.org~ for the full release plan.
 ** License
 
 TBD
+# Test

backend/classes.lisp

@@ -0,0 +1,62 @@
+(in-package :cl-tui.backend)
+
+(defclass backend () ())
+
+(defgeneric initialize-backend (backend)
+  (:method ((b backend)) b))
+
+(defgeneric shutdown-backend (backend)
+  (:method ((b backend)) (values)))
+
+(defgeneric backend-size (backend)
+  (:method ((b backend))
+    (values 80 24)))
+
+(defgeneric backend-write (backend string))
+
+(defgeneric backend-clear (backend)
+  (:method ((b backend))
+    (backend-write b (format nil "~C[2J~C[H" #\Esc #\Esc))))
+
+(defgeneric draw-text (backend x y string fg bg &key
+                       bold italic underline reverse dim blink))
+
+(defgeneric draw-border (backend x y width height
+                         &key style fg bg title title-align))
+
+(defgeneric draw-rect (backend x y width height &key bg))
+
+(defgeneric draw-link (backend x y string url &key fg bg))
+
+(defgeneric draw-ellipsis (backend x y width &key fg bg))
+
+(defgeneric cursor-move (backend x y))
+
+(defgeneric cursor-hide (backend)
+  (:method ((b backend)) (values)))
+
+(defgeneric cursor-show (backend)
+  (:method ((b backend)) (values)))
+
+(defgeneric cursor-style (backend shape &key blink)
+  (:method ((b backend) shape &key blink) (values)))
+
+(defgeneric begin-sync (backend)
+  (:method ((b backend)) (values)))
+
+(defgeneric end-sync (backend)
+  (:method ((b backend)) (values)))
+
+(defgeneric read-event (backend &key timeout)
+  (:method ((b backend) &key timeout) (values nil nil)))
+
+(defgeneric enable-mouse (backend)
+  (:method ((b backend)) (values)))
+
+(defgeneric enable-bracketed-paste (backend)
+  (:method ((b backend)) (values)))
+
+(defgeneric capable-p (backend feature)
+  (:method ((b backend) feature)
+    (declare (ignore feature))
+    nil))

backend/modern-tests.lisp

@@ -0,0 +1,124 @@
+(defpackage :cl-tui-modern-backend-test
+  (:use :cl :fiveam :cl-tui.backend)
+  (:export #:run-tests))
+(in-package :cl-tui-modern-backend-test)
+
+(def-suite modern-backend-suite :description "Modern backend tests")
+(in-suite modern-backend-suite)
+
+(defun run-tests ()
+  (let ((result (run 'modern-backend-suite)))
+    (fiveam:explain! result)
+    (uiop:quit 0)))
+
+;; ── Constructor ────────────────────────────────────────────────
+
+(test make-modern-backend-creates
+  "make-modern-backend returns a modern-backend instance"
+  (let ((b (make-modern-backend)))
+    (is (typep b 'cl-tui.backend::modern-backend))))
+
+;; ── Escape Generation ──────────────────────────────────────────
+
+(test sgr-truecolor-foreground
+  "SGR truecolor foreground escape is correct"
+  (is (equal (cl-tui.backend::sgr-fg "#FFD700")
+             (format nil "~C[38;2;255;215;0m" #\Esc))))
+
+(test sgr-truecolor-background
+  "SGR truecolor background escape is correct"
+  (is (equal (cl-tui.backend::sgr-bg "#1a1b26")
+             (format nil "~C[48;2;26;27;38m" #\Esc))))
+
+(test sgr-named-colors
+  "SGR named colors resolve to 8-color codes"
+  (is (equal (cl-tui.backend::sgr-fg :red)
+             (format nil "~C[31m" #\Esc)))
+  (is (equal (cl-tui.backend::sgr-bg :blue)
+             (format nil "~C[44m" #\Esc))))
+
+(test sgr-bold-italic
+  "SGR attribute escapes are correct"
+  (is (equal (cl-tui.backend::sgr-attr :bold) (format nil "~C[1m" #\Esc)))
+  (is (equal (cl-tui.backend::sgr-attr :italic) (format nil "~C[3m" #\Esc)))
+  (is (equal (cl-tui.backend::sgr-attr :underline) (format nil "~C[4m" #\Esc)))
+  (is (equal (cl-tui.backend::sgr-attr :reset) (format nil "~C[0m" #\Esc))))
+
+;; ── Cursor ─────────────────────────────────────────────────────
+
+(test cursor-move-escape
+  "cursor-move generates correct CSI escape"
+  (let ((b (make-modern-backend)))
+    (is (equal (cl-tui.backend::cursor-move-escape 5 10)
+               (format nil "~C[11;6H" #\Esc)))))
+
+(test cursor-style-block
+  "cursor-style :block generate correct escape"
+  (let ((b (make-modern-backend)))
+    (is (equal (cl-tui.backend::cursor-style-escape :block nil)
+               (format nil "~C[2 q" #\Esc)))))
+
+(test cursor-style-bar
+  "cursor-style :bar generate correct escape"
+  (let ((b (make-modern-backend)))
+    (is (equal (cl-tui.backend::cursor-style-escape :bar nil)
+               (format nil "~C[6 q" #\Esc)))))
+
+(test cursor-style-underline-blink
+  "cursor-style :underline with blink"
+  (let ((b (make-modern-backend)))
+    (is (equal (cl-tui.backend::cursor-style-escape :underline t)
+               (format nil "~C[5 q" #\Esc)))))
+
+;; ── Synchronization ────────────────────────────────────────────
+
+(test decicm-escapes
+  "DECICM synchronized update escapes"
+  (is (equal (cl-tui.backend::decicm-begin) (format nil "~C[?2026h" #\Esc)))
+  (is (equal (cl-tui.backend::decicm-end) (format nil "~C[?2026l" #\Esc))))
+
+;; ── OSC 8 Hyperlinks ──────────────────────────────────────────
+
+(test osc8-escape
+  "OSC 8 hyperlink escape wraps text"
+  (is (equal (cl-tui.backend::osc8-link "http://example.com" "click here")
+             (format nil "~C]8;;http://example.com~C\\click here~C]8;;~C\\"
+                     #\Esc #\Esc #\Esc #\Esc))))
+
+;; ── Hex Parsing ────────────────────────────────────────────────
+
+(test hex-color-parsing
+  "hex-to-rgb parses valid hex colors"
+  (multiple-value-bind (r g b) (cl-tui.backend::hex-to-rgb "#FFD700")
+    (is (= r 255))
+    (is (= g 215))
+    (is (= b 0))))
+
+(test hex-color-black
+  "hex-to-rgb parses black"
+  (multiple-value-bind (r g b) (cl-tui.backend::hex-to-rgb "#000000")
+    (is (= r 0))
+    (is (= g 0))
+    (is (= b 0))))
+
+(test hex-color-short-form
+  "hex-to-rgb parses 3-digit hex"
+  (multiple-value-bind (r g b) (cl-tui.backend::hex-to-rgb "#F00")
+    (is (= r 255))
+    (is (= g 0))
+    (is (= b 0))))
+
+;; ── Border Characters ──────────────────────────────────────────
+
+(test border-char-rounded
+  "modern-border-char returns Unicode box-drawing for rounded style"
+  (is (equal (cl-tui.backend::border-char :rounded :top-left) "╭"))
+  (is (equal (cl-tui.backend::border-char :rounded :horizontal) "─"))
+  (is (equal (cl-tui.backend::border-char :rounded :vertical) "│"))
+  (is (equal (cl-tui.backend::border-char :rounded :bottom-right) "╯")))
+
+(test border-char-double
+  "modern-border-char returns double-line chars"
+  (is (equal (cl-tui.backend::border-char :double :top-left) "╔"))
+  (is (equal (cl-tui.backend::border-char :double :horizontal) "═"))
+  (is (equal (cl-tui.backend::border-char :double :vertical) "║")))

backend/modern.lisp

@@ -0,0 +1,246 @@
+;;; modern-backend — Raw escape sequence backend
+;;; Generated from org/modern-backend.org
+;;; DO NOT EDIT — edit the .org file instead
+
+;; In package.lisp, add to :export:
+;;   #:modern-backend #:make-modern-backend
+;; Internal symbols (not exported, used by tests):
+;;   sgr-fg sgr-bg sgr-attr cursor-move-escape cursor-style-escape
+;;   decicm-begin decicm-end osc8-link hex-to-rgb border-char
+
+(in-package :cl-tui.backend)
+
+(defun hex-to-rgb (hex)
+  "Parse a hex color string like \"#FFD700\" into (values r g b).
+  Also handles 3-digit hex like \"#F00\" (expands to \"#FF0000\")."
+  (let ((clean (string-trim '(#\# #\Space) hex)))
+    (if (= (length clean) 3)
+        ;; Expand 3-digit: #F00 -> #FF0000
+        (let* ((r (parse-integer (subseq clean 0 1) :radix 16 :junk-allowed t))
+               (g (parse-integer (subseq clean 1 2) :radix 16 :junk-allowed t))
+               (b (parse-integer (subseq clean 2 3) :radix 16 :junk-allowed t)))
+          (values (+ r (* r 16)) (+ g (* g 16)) (+ b (* b 16))))
+        (values (parse-integer (subseq clean 0 2) :radix 16 :junk-allowed t)
+                (parse-integer (subseq clean 2 4) :radix 16 :junk-allowed t)
+                (parse-integer (subseq clean 4 6) :radix 16 :junk-allowed t)))))
+
+(defparameter *named-colors*
+  '((:black . 0) (:red . 1) (:green . 2) (:yellow . 3)
+    (:blue . 4) (:magenta . 5) (:cyan . 6) (:white . 7)))
+
+(defun sgr-fg (color)
+  "Return SGR foreground escape for COLOR.
+  Color can be a hex string, a keyword name, or nil."
+  (if (null color) ""
+      (cond ((and (stringp color) (char= (char color 0) #\#))
+             (multiple-value-bind (r g b) (hex-to-rgb color)
+               (format nil "~C[38;2;~d;~d;~dm" #\Esc r g b)))
+            ((keywordp color)
+             (let ((index (cdr (assoc color *named-colors*))))
+               (if index
+                   (format nil "~C[~dm" #\Esc (+ 30 index))
+                   "")))
+            (t ""))))
+
+(defun sgr-bg (color)
+  "Return SGR background escape for COLOR."
+  (if (null color) ""
+      (cond ((and (stringp color) (char= (char color 0) #\#))
+             (multiple-value-bind (r g b) (hex-to-rgb color)
+               (format nil "~C[48;2;~d;~d;~dm" #\Esc r g b)))
+            ((keywordp color)
+             (let ((index (cdr (assoc color *named-colors*))))
+               (if index
+                   (format nil "~C[~dm" #\Esc (+ 40 index))
+                   "")))
+            (t ""))))
+
+(defparameter *sgr-attr-codes*
+  '((:bold . 1) (:dim . 2) (:italic . 3) (:underline . 4)
+    (:blink . 5) (:reverse . 7) (:reset . 0)))
+
+(defun sgr-attr (attr)
+  "Return SGR attribute escape for ATTR keyword."
+  (let ((code (cdr (assoc attr *sgr-attr-codes*))))
+    (if code
+        (format nil "~C[~dm" #\Esc code)
+        "")))
+
+(defun cursor-move-escape (x y)
+  "Return CSI escape to move cursor to (x, y), 1-indexed."
+  (format nil "~C[~d;~dH" #\Esc (1+ y) (1+ x)))
+
+(defun cursor-style-escape (shape blink)
+  "Return DECSTR escape for cursor shape.
+  :block = 2, :underline = 4, :bar = 6.
+  Add 1 for blink variants."
+  (let* ((base (case shape
+                 (:block 2) (:underline 4) (:bar 6)
+                 (t 2)))
+         (code (if blink (1+ base) base)))
+    (format nil "~C[~d q" #\Esc code)))
+
+(defun decicm-begin ()
+  "Return escape to enable synchronized updates."
+  (format nil "~C[?2026h" #\Esc))
+
+(defun decicm-end ()
+  "Return escape to disable synchronized updates."
+  (format nil "~C[?2026l" #\Esc))
+
+(defun osc8-link (url text)
+  "Wrap TEXT in an OSC 8 hyperlink to URL."
+  (format nil "~C]8;;~A~C\\~A~C]8;;~C\\"
+          #\Esc url #\Esc text #\Esc #\Esc))
+
+(defparameter *border-chars*
+  '(((:single :top-left) . "┌") ((:single :top-right) . "┐")
+    ((:single :bottom-left) . "└") ((:single :bottom-right) . "┘")
+    ((:single :horizontal) . "─") ((:single :vertical) . "│")
+    ((:double :top-left) . "╔") ((:double :top-right) . "╗")
+    ((:double :bottom-left) . "╚") ((:double :bottom-right) . "╝")
+    ((:double :horizontal) . "═") ((:double :vertical) . "║")
+    ((:rounded :top-left) . "╭") ((:rounded :top-right) . "╮")
+    ((:rounded :bottom-left) . "╰") ((:rounded :bottom-right) . "╯")
+    ((:rounded :horizontal) . "─") ((:rounded :vertical) . "│")))
+
+(defun border-char (style pos)
+  "Return the Unicode box-drawing character for STYLE at POS."
+  (let ((char (cdr (assoc (list style pos) *border-chars* :test #'equal))))
+    (or char (if (member pos '(:horizontal :vertical))
+                 (case pos (:horizontal "─") (:vertical "│"))
+                 "+"))))
+
+(defclass modern-backend (backend)
+  ((output-stream :initform *standard-output*
+                  :initarg :output-stream
+                  :accessor backend-output-stream)
+   (in-sync-p :initform nil :accessor in-sync-p)))
+
+(defun make-modern-backend (&key color-palette output-stream)
+  (declare (ignore color-palette))
+  (make-instance 'modern-backend :output-stream (or output-stream *standard-output*)))
+
+(defmethod initialize-backend ((b modern-backend))
+  ;; Enter raw mode, enable mouse, bracketed paste
+  (backend-write b (format nil "~C[?1049h" #\Esc))  ; alt screen
+  (backend-write b (format nil "~C[?1000h" #\Esc))  ; mouse basic
+  (backend-write b (format nil "~C[?1002h" #\Esc))  ; mouse drag
+  (backend-write b (format nil "~C[?1006h" #\Esc))  ; SGR mouse
+  (backend-write b (format nil "~C[?2004h" #\Esc))  ; bracketed paste
+  (cursor-hide b)
+  (finish-output (backend-output-stream b))
+  b)
+
+(defmethod shutdown-backend ((b modern-backend))
+  (cursor-show b)
+  (backend-write b (format nil "~C[?2004l" #\Esc))  ; disable bracketed paste
+  (backend-write b (format nil "~C[?1006l" #\Esc))  ; disable SGR mouse
+  (backend-write b (format nil "~C[?1002l" #\Esc))
+  (backend-write b (format nil "~C[?1000l" #\Esc))
+  (backend-write b (format nil "~C[?1049l" #\Esc))  ; normal screen
+  (finish-output (backend-output-stream b))
+  (values))
+
+(defmethod backend-size ((b modern-backend))
+  ;; Default fallback — real implementation queries terminal
+  (values 80 24))
+
+(defmethod backend-write ((b modern-backend) string)
+  (let ((stream (backend-output-stream b)))
+    (write-string string stream)
+    (length string)))
+
+(defmethod capable-p ((b modern-backend) feature)
+  (member feature '(:truecolor :osc8 :sync :mouse
+                    :bracketed-paste :cursor-style
+                    :kitty-keyboard)))
+
+(defmethod draw-text ((b modern-backend) x y string fg bg
+                      &key bold italic underline reverse dim blink)
+  (let ((parts (list (cursor-move-escape x y)
+                     (sgr-fg fg) (sgr-bg bg)
+                     (when bold (sgr-attr :bold))
+                     (when italic (sgr-attr :italic))
+                     (when underline (sgr-attr :underline))
+                     (when reverse (sgr-attr :reverse))
+                     (when dim (sgr-attr :dim))
+                     (when blink (sgr-attr :blink))
+                     string
+                     (sgr-attr :reset))))
+    (backend-write b (apply #'concatenate 'string parts))))
+
+(defmethod draw-border ((b modern-backend) x y width height
+                        &key style fg bg title title-align)
+  (declare (ignore title title-align))
+  (let* ((s (or style :single))
+         (tl (border-char s :top-left))
+         (tr (border-char s :top-right))
+         (bl (border-char s :bottom-left))
+         (br (border-char s :bottom-right))
+         (h  (border-char s :horizontal))
+         (v  (border-char s :vertical))
+         (fg-esc (sgr-fg fg))
+         (bg-esc (sgr-bg bg))
+         (reset (sgr-attr :reset))
+         (top (concatenate 'string
+                fg-esc bg-esc tl
+                (make-string (- width 2) :initial-element (char h 0))
+                tr reset (string #\Newline)))
+         (mid (concatenate 'string
+                fg-esc bg-esc v
+                (make-string (- width 2) :initial-element #\Space)
+                v reset (string #\Newline)))
+         (bot (concatenate 'string
+                fg-esc bg-esc bl
+                (make-string (- width 2) :initial-element (char h 0))
+                br reset)))
+    (backend-write b top)
+    (loop repeat (- height 2) do (backend-write b mid))
+    (backend-write b bot)))
+
+(defmethod draw-rect ((b modern-backend) x y width height &key bg)
+  (let* ((bg-esc (sgr-bg bg))
+         (reset (sgr-attr :reset))
+         (line (concatenate 'string
+                 bg-esc
+                 (make-string width :initial-element #\Space)
+                 reset (string #\Newline))))
+    (loop :for row :from 0 :below height :do
+      (backend-write b (cursor-move-escape x (+ y row)))
+      (backend-write b line))))
+
+(defmethod draw-link ((b modern-backend) x y string url
+                      &key fg bg)
+  (let ((parts (list (cursor-move-escape x y)
+                     (sgr-fg fg) (sgr-bg bg)
+                     (osc8-link url string)
+                     (sgr-attr :reset))))
+    (backend-write b (apply #'concatenate 'string parts))))
+
+(defmethod draw-ellipsis ((b modern-backend) x y width
+                          &key fg bg)
+  (let ((dots "..."))
+    (draw-text b x y dots fg bg)))
+
+(defmethod cursor-move ((b modern-backend) x y)
+  (backend-write b (cursor-move-escape x y)))
+
+(defmethod cursor-hide ((b modern-backend))
+  (backend-write b (format nil "~C[?25l" #\Esc)))
+
+(defmethod cursor-show ((b modern-backend))
+  (backend-write b (format nil "~C[?25h" #\Esc)))
+
+(defmethod cursor-style ((b modern-backend) shape &key blink)
+  (backend-write b (cursor-style-escape shape blink)))
+
+(defmethod begin-sync ((b modern-backend))
+  (setf (in-sync-p b) t)
+  (backend-write b (decicm-begin)))
+
+(defmethod end-sync ((b modern-backend))
+  (setf (in-sync-p b) nil)
+  (backend-write b (decicm-end))
+  (finish-output (backend-output-stream b)))
+

backend/package.lisp

@@ -0,0 +1,29 @@
+(defpackage :cl-tui.backend
+  (:use :cl)
+  (:export
+   ;; Backend classes
+   #:backend #:simple-backend
+   ;; Lifecycle
+   #:initialize-backend #:shutdown-backend
+   #:backend-size #:backend-write #:backend-clear
+   ;; Drawing
+   #:draw-text #:draw-border #:draw-rect
+   #:draw-link #:draw-ellipsis
+   ;; Cursor
+   #:cursor-move #:cursor-hide #:cursor-show #:cursor-style
+   ;; Sync
+   #:begin-sync #:end-sync
+   ;; Input
+   #:read-event #:enable-mouse #:enable-bracketed-paste
+   ;; Queries
+   #:capable-p
+   ;; Constructors
+   #:make-simple-backend
+   ;; Modern backend
+   #:modern-backend #:make-modern-backend
+   ;; Internal (for testing)
+   #:sgr-fg #:sgr-bg #:sgr-attr
+   #:cursor-move-escape #:cursor-style-escape
+   #:decicm-begin #:decicm-end #:osc8-link
+   #:hex-to-rgb #:border-char))
+(in-package :cl-tui.backend)

backend/simple.lisp

@@ -0,0 +1,69 @@
+(in-package :cl-tui.backend)
+
+(defclass simple-backend (backend)
+  ((output-stream :initform *standard-output*
+                  :initarg :output-stream
+                  :accessor backend-output-stream)))
+
+(defun make-simple-backend (&key output-stream)
+  (make-instance 'simple-backend
+    :output-stream (or output-stream *standard-output*)))
+
+(defmethod initialize-backend ((b simple-backend))
+  b)
+
+(defmethod shutdown-backend ((b simple-backend))
+  (values))
+
+(defmethod backend-size ((b simple-backend))
+  ;; Try ioctl, fall back to 80x24
+  (values 80 24))
+
+(defmethod backend-write ((b simple-backend) string)
+  (let ((stream (backend-output-stream b)))
+    (write-string string stream)
+    (finish-output stream)
+    (length string)))
+
+(defmethod draw-text ((b simple-backend) x y string fg bg
+                      &key bold italic underline reverse dim blink)
+  (declare (ignore x y fg bg bold italic underline reverse dim blink))
+  (backend-write b string))
+
+(defun %simple-border-char (edge-style pos)
+  "Return ASCII border character for EDGE-STYLE at POS.
+POS is :top-left, :top-right, :bottom-left, :bottom-right,
+:horizontal, or :vertical."
+  (case pos
+    ((:top-left :top-right :bottom-left :bottom-right) #\+)
+    (:horizontal #\-)
+    (:vertical #\|)))
+
+(defmethod draw-border ((b simple-backend) x y width height
+                        &key style fg bg title title-align)
+  (declare (ignore style fg bg title title-align))
+  (let ((h (%simple-border-char nil :horizontal))
+        (v (%simple-border-char nil :vertical)))
+    ;; Top edge
+    (backend-write b (format nil "~%~v@{~a~:*~}" width h))
+    ;; Sides
+    (loop for i from 1 below (1- height)
+          do (backend-write b (format nil "~%|~v@{~a~:*~}|" (- width 2) #\space)))
+    ;; Bottom edge
+    (backend-write b (format nil "~%~v@{~a~:*~}" width h))))
+
+(defmethod draw-rect ((b simple-backend) x y width height
+                      &key bg)
+  (declare (ignore x y width height bg))
+  ;; On simple backend, background fill is a no-op
+  (values))
+
+(defmethod draw-link ((b simple-backend) x y string url
+                      &key fg bg)
+  (declare (ignore url fg bg))
+  (draw-text b x y string nil nil))
+
+(defmethod draw-ellipsis ((b simple-backend) x y width
+                          &key fg bg)
+  (declare (ignore x y width fg bg))
+  (backend-write b "..."))

backend/tests.lisp

@@ -0,0 +1,138 @@
+(defpackage :cl-tui-backend-test
+  (:use :cl :fiveam :cl-tui.backend)
+  (:export #:run-tests))
+(in-package :cl-tui-backend-test)
+
+(def-suite backend-suite :description "Backend protocol tests")
+(in-suite backend-suite)
+
+;; ── Helpers ─────────────────────────────────────────────────────
+
+(defun make-capturing-backend ()
+  "Create a simple-backend that writes to a string stream."
+  (let* ((s (make-string-output-stream))
+         (b (make-simple-backend :output-stream s)))
+    (values b s)))
+
+;; ── Simple Backend ──────────────────────────────────────────────
+
+(defun run-tests ()
+  "Run all backend tests."
+  (let ((result (run 'backend-suite)))
+    (fiveam:explain! result)
+    (uiop:quit 0)))
+
+(test simple-backend-lifecycle
+  "simple-backend can be created and shut down"
+  (let ((b (make-simple-backend)))
+    (is (typep b 'simple-backend))
+    (initialize-backend b)
+    (is-false (capable-p b :truecolor) "simple backend has no truecolor")
+    (shutdown-backend b)))
+
+(test simple-backend-draw-text
+  "simple-backend renders text at position, ignoring style"
+  (multiple-value-bind (b s) (make-capturing-backend)
+    (initialize-backend b)
+    (draw-text b 0 0 "hello" :red nil :bold t :italic t)
+    (shutdown-backend b)
+    (is (string= (get-output-stream-string s) "hello")
+        "draw-text should output the string ignoring style")))
+
+(test simple-backend-draw-border
+  "simple-backend draws ASCII border with +-| characters"
+  (multiple-value-bind (b s) (make-capturing-backend)
+    (initialize-backend b)
+    (draw-border b 0 0 5 3 :style :single)
+    (shutdown-backend b)
+    (let ((out (get-output-stream-string s)))
+      (is (search "-----" out) "top edge should have 5 dashes")
+      (is (search "|   |" out) "middle row should have pipe sides"))))
+
+(test simple-backend-draw-rounded
+  "simple-backend falls back to straight edges for rounded style"
+  (multiple-value-bind (b s) (make-capturing-backend)
+    (initialize-backend b)
+    (draw-border b 0 0 5 3 :style :rounded)
+    (shutdown-backend b)
+    (let ((out (get-output-stream-string s)))
+      ;; Rounded falls back to ASCII — identical output to single
+      (is (search "-----" out) "rounded style produces same dashes as single"))))
+
+(test simple-backend-draw-link
+  "simple-backend renders link as plain text"
+  (multiple-value-bind (b s) (make-capturing-backend)
+    (initialize-backend b)
+    (draw-link b 0 0 "click me" "http://example.com")
+    (shutdown-backend b)
+    (is (string= (get-output-stream-string s) "click me")
+        "simple-backend ignores URL, outputs text only")))
+
+(test simple-backend-draw-ellipsis
+  "simple-backend renders ... for ellipsis"
+  (multiple-value-bind (b s) (make-capturing-backend)
+    (initialize-backend b)
+    (draw-ellipsis b 0 0 5)
+    (shutdown-backend b)
+    (is (string= (get-output-stream-string s) "...")
+        "ellipsis should output 3 dots")))
+
+;; ── Backend Capabilities ───────────────────────────────────────
+
+(test capable-p-known-features
+  "capable-p returns nil for all features on simple-backend"
+  (let ((b (make-simple-backend)))
+    (initialize-backend b)
+    (dolist (f '(:truecolor :osc8 :sync :mouse :bracketed-paste
+                 :kitty-keyboard :sixel :cursor-style))
+      (is-false (capable-p b f)
+                (format nil "~s should not be supported on simple-backend" f)))
+    (shutdown-backend b)))
+
+;; ── Backend Size ───────────────────────────────────────────────
+
+(test backend-size-returns-integers
+  "backend-size returns two integer values"
+  (let ((b (make-simple-backend)))
+    (initialize-backend b)
+    (multiple-value-bind (cols lines) (backend-size b)
+      (is (integerp cols))
+      (is (integerp lines))
+      (is (>= cols 10))
+      (is (>= lines 3)))
+    (shutdown-backend b)))
+
+;; ── Backend Protocol: Defaults and No-ops ──────────────────────
+
+(test default-methods-are-no-ops
+  "Default backend methods don't error"
+  (let ((b (make-simple-backend)))
+    (initialize-backend b)
+    (is (null (multiple-value-list (cursor-hide b))))
+    (is (null (multiple-value-list (cursor-show b))))
+    (is (null (multiple-value-list (cursor-style b :block))))
+    (is (null (multiple-value-list (begin-sync b))))
+    (is (null (multiple-value-list (end-sync b))))
+    (shutdown-backend b)))
+
+(test sync-is-noop-on-simple
+  "begin-sync and end-sync produce no output on simple-backend"
+  (multiple-value-bind (b s) (make-capturing-backend)
+    (initialize-backend b)
+    (begin-sync b)
+    (draw-text b 0 0 "in sync" nil nil)
+    (end-sync b)
+    (shutdown-backend b)
+    (is (string= (get-output-stream-string s) "in sync")
+        "no sync escape sequences should appear")))
+
+;; ── Draw-rect ──────────────────────────────────────────────────
+
+(test draw-rect-fills-area-correctly
+  "draw-rect with background writes nothing to output (simple-backend no-op)"
+  (multiple-value-bind (b s) (make-capturing-backend)
+    (initialize-backend b)
+    (draw-rect b 0 0 5 3 :bg :red)
+    (shutdown-backend b)
+    (is (string= (get-output-stream-string s) "")
+        "draw-rect is a no-op on simple-backend")))

cl-tui.asd

@@ -0,0 +1,59 @@
+;;; cl-tui.asd — Common Lisp Terminal UI Framework
+(asdf:defsystem :cl-tui
+  :description "Reusable Common Lisp Terminal UI Framework"
+  :author "Amr Gharbeia"
+  :version "0.5.0"
+  :license "TBD"
+  :depends-on (:fiveam :sb-posix)
+  :components
+  ((:module "backend"
+    :components
+    ((:file "package")
+     (:file "classes" :depends-on ("package"))
+     (:file "simple" :depends-on ("package" "classes"))
+     (:file "modern" :depends-on ("package" "classes"))))
+   (:module "layout"
+    :components
+    ((:file "layout")))
+   (:module "src/components"
+    :components
+    ((:file "package")
+     (:file "dirty")
+     (:file "box" :depends-on ("package"))
+     (:file "text" :depends-on ("package" "box"))
+     (:file "render" :depends-on ("package" "box" "text"))
+     (:file "theme" :depends-on ("package"))
+     ;; Input system (v0.5.0)
+     (:file "input-package" :depends-on ("package"))
+     (:file "input" :depends-on ("input-package" "dirty" "box"))
+     (:file "text-input" :depends-on ("input-package" "input" "box"))
+     (:file "textarea" :depends-on ("input-package" "input" "box"))
+     (:file "keybindings" :depends-on ("input-package" "input")))))
+  :in-order-to ((test-op (test-op :cl-tui-tests))))
+
+(asdf:defsystem :cl-tui-tests
+  :description "Test suite for cl-tui"
+  :depends-on (:cl-tui :fiveam)
+  :components
+  ((:module "backend"
+    :components
+    ((:file "tests")))
+   (:module "layout"
+    :components
+    ((:file "tests")))
+   (:module "src/components"
+    :components
+    ((:file "box-tests")
+     (:file "dirty-tests")
+     (:file "render-tests")
+     (:file "theme-tests")
+     (:file "input-tests"))))
+  :perform (test-op (o c)
+             (dolist (suite '((:cl-tui-backend-test "BACKEND-SUITE")
+                              (:cl-tui-box-test "BOX-SUITE")
+                              (:cl-tui-input-test "INPUT-SUITE")))
+               (let* ((pkg (find-package (first suite)))
+                      (s (and pkg (find-symbol (second suite) pkg))))
+                 (when s
+                   (fiveam:explain! (fiveam:run s)))))
+             (uiop:quit 0)))

demo.lisp

@@ -0,0 +1,28 @@
+;; demo.lisp — minimal cl-tui demo
+(load "/root/quicklisp/setup.lisp")
+(ql:quickload :fiveam :silent t)
+(load "backend/package.lisp")
+(load "backend/classes.lisp")
+(load "backend/simple.lisp")
+(load "backend/modern.lisp")
+(load "layout/layout.lisp")
+(load "src/components/package.lisp")
+(load "src/components/dirty.lisp")
+(load "src/components/box.lisp")
+(load "src/components/text.lisp")
+(load "src/components/render.lisp")
+(in-package :cl-tui.box)
+
+;; Demo 1: Simple backend (ASCII)
+(let* ((b (make-simple-backend))
+       (bx (make-box :border-style :rounded :title " Hello World " :width 30 :height 5)))
+  (compute-layout (box-layout-node bx) 30 5)
+  (render bx b))
+
+;; Demo 2: Box with text inside
+(let* ((b (make-simple-backend))
+       (tx (make-text "This is cl-tui in action!" :width 28 :height 1)))
+  (setf (layout-node-direction (text-layout-node tx)) :column)
+  (compute-layout (text-layout-node tx) 28 1)
+  (render tx b)
+  (format t "~%~%"))

docs/ARCHITECTURE.org

@@ -0,0 +1,318 @@
+#+TITLE: cl-tui Architecture
+#+STARTUP: content
+#+FILETAGS: :project:cl-tui:architecture:
+
+* Architecture
+
+cl-tui is a layered framework. Each layer has a single responsibility
+and communicates with adjacent layers through a well-defined protocol.
+
+** Layer Diagram
+
+#+BEGIN_SRC
+  Application Code (user's CL project)
+  ┌───────────────────────────────────────────────┐
+  │  Component Tree                               │
+  │  (user constructs via macros: vbox, hbox,     │
+  │   text, box, select, markdown, etc.)          │
+  └──────────────┬────────────────────────────────┘
+                 │ defgeneric render (component backend)
+                 │ defgeneric handle-key (component event)
+                 │ defgeneric handle-mouse (component event)
+                 ▼
+  ┌───────────────────────────────────────────────┐
+  │  Rendering Pipeline                           │
+  │  1. Layout pass (constraint solve)            │
+  │  2. Dirty walk (only changed branches)        │
+  │  3. Render commands (component → cmds)        │
+  │  4. Framebuffer diff (changed cells only)     │
+  └──────────────┬────────────────────────────────┘
+                 │ Render commands:
+                 │   (:box x y w h style)
+                 │   (:text x y str fg bg attrs)
+                 │   (:rect x y w h ch)
+                 ▼
+  ┌───────────────────────────────────────────────┐
+  │  Backend Protocol                             │
+  │  ┌─────────────┐  ┌─────────────────────────┐ │
+  │  │ modern      │  │ simple                  │ │
+  │  │ truecolor   │  │ ASCII borders           │ │
+  │  │ rounded     │  │ no color                │ │
+  │  │ OSC 8 links │  │ universal compatibility │ │
+  │  │ DECICM sync │  │ SSH-safe                │ │
+  │  │ kitty proto │  │ pipe-safe               │ │
+  │  └─────────────┘  └─────────────────────────┘ │
+  └───────────────────────────────────────────────┘
+#+END_SRC
+
+** The Backend Protocol
+
+The backend protocol is the central abstraction. Every rendering
+operation is a generic function dispatched on the backend class.
+
+*** Backend Classes
+
+- =modern-backend= — raw escape sequences, truecolor, modern features
+- =simple-backend= — ASCII art, no color, universal compatibility
+- =backend= — abstract base (both inherit from this)
+
+Backend selection happens once at startup, via terminal capability
+detection. The same component tree renders correctly on both.
+
+*** Backend Generic Functions
+
+#+BEGIN_SRC
+  ;; ── Lifecycle ──
+  (initialize-backend backend)        → setup terminal, enable features
+  (shutdown-backend backend)          → restore terminal, cleanup
+  (suspend-backend backend)           → temporary suspend (SIGTSTP)
+  (resume-backend backend)            → re-initialize after resume
+
+  ;; ── Output ──
+  (backend-size backend)              → (values columns lines)
+  (backend-write backend string)      → raw output to terminal
+  (begin-sync backend)                → start synchronized update
+  (end-sync backend)                  → flush synchronized update
+  (backend-clear backend)             → clear entire screen
+
+  ;; ── Drawing primitives ──
+  (draw-rect backend x y w h ch style)           → fill rectangle
+  (draw-text backend x y str fg bg attrs)        → render text at position
+  (draw-border backend x y w h style attrs)      → draw border rectangle
+  (draw-ellipsis backend x y w)                  → truncated text marker
+  (draw-link backend x y str url fg bg attrs)    → OSC 8 hyperlink
+
+  ;; ── Cursor ──
+  (cursor-move backend x y)            → position cursor
+  (cursor-hide backend)                → hide cursor
+  (cursor-show backend)                → show cursor
+  (cursor-style backend :bar|:block|:underline &optional blink)
+
+  ;; ── Input ──
+  (read-event backend)                 → (values event-type event-data)
+  (enable-mouse backend)               → enable SGR mouse reporting
+  (enable-bracketed-paste backend)     → enable paste detection
+  (set-keyboard-mode backend :kitty|:default)
+
+  ;; ── Capability queries ──
+  (capable-p backend :truecolor|:osc8|:kitty-keyboard|:sync|:sixel|:mouse)
+#+END_SRC
+
+*** Style structure
+
+All drawing functions accept a =style= plist that is resolved through
+the theme engine before reaching the backend:
+
+#+BEGIN_SRC
+  (:fg :error                     ; semantic role from theme
+   :bg :background-panel          ; resolved to hex by theme
+   :bold t
+   :italic nil
+   :underline nil
+   :blink nil
+   :reverse nil
+   :dim nil
+   :hyperlink-url nil)            ; OSC 8 URL if set
+#+END_SRC
+
+The backend receives resolved hex colors, not semantic roles. Theme
+resolution happens in the pipeline layer, before backend dispatch.
+
+*** Backend Selection
+
+At startup:
+
+#+BEGIN_SRC
+  1. Check if stdout is a TTY (if not → simple-backend)
+  2. Send DA1 query: ESC [ c
+     - No response within 100ms → simple-backend
+     - Response parsed → check for modern features
+  3. Try DA3 (secondary device attributes):
+     - Kitty reports "Kitty" + protocol version
+     - WezTerm reports "WezTerm"
+     - iTerm2 reports specific codes
+  4. Query DECRPM for DECICM sync:
+     - ESC [?2026$p
+     - Response ESC [?2026;1$y = supported
+  5. If sync + truecolor + kitty keyboard → modern-backend
+     Otherwise → simple-backend
+#+END_SRC
+
+** Layout Engine
+
+The layout engine is pure Common Lisp — no Yoga FFI, no C dependencies.
+
+*** Constraint Model
+
+A terminal has ~200x80 cells. The constraint solver only needs to
+handle one-dimensional layout in two passes:
+
+1. **Column direction (vertical pass):** distribute Y positions, sum
+   children heights. Width is inherited from parent (minus padding).
+2. **Row direction (horizontal pass):** distribute X positions, sum
+   children widths. Height is inherited from parent.
+
+Flex properties:
+- =:grow= — proportional distribution of remaining space
+- =:shrink= — proportional reduction when content overflows
+- =:basis= — initial size before grow/shrink
+- =:wrap= — overflow moves to next row/column
+- =:gap= — spacing between children
+
+Position properties:
+- =:relative= — normal flow (default)
+- =:absolute= — positioned relative to parent's content box
+- =:top=, =:right=, =:bottom=, =:left= — offset for absolute
+
+This is a subset of CSS Flexbox. Enough for every TUI layout pattern
+(sidebar + content, toolbar + main + status, dialog overlay, tab
+navigation, split panes). ~200 lines.
+
+*** Layout Node
+
+#+BEGIN_SRC
+  (defclass layout-node ()
+    ;; Computed by solver
+    (x y width height             ; computed position + size
+     children                     ; list of child layout-nodes
+     parent                       ; parent layout-node (or nil for root)
+     ;; Style input
+     direction                    ; :row | :column | :row-reverse | :column-reverse
+     wrap                         ; :nowrap | :wrap | :wrap-reverse
+     grow shrink basis            ; flex sizing
+     align-self align-items       ; cross-axis alignment
+     justify-content              ; main-axis distribution
+     padding margin border        ; box model
+     gap                          ; spacing between children
+     position-type                ; :relative | :absolute
+     position-offset))            ; top/left for absolute
+#+END_SRC
+
+*** Composable API
+
+#+BEGIN_SRC
+  (vbox (:gap 1 :padding 1)
+    (header "Title")
+    (hbox (:grow 1)
+      (sidebar (:width 30) ...)
+      (content ...)))
+#+END_SRC
+
+Macros expand to layout-node construction + child wiring.
+
+** Component Tree
+
+Components are CLOS objects. Every component has a =layout-node=
+slot that drives positioning. Components define =render= methods.
+
+*** Base Component Class
+
+#+BEGIN_SRC
+  (defclass component ()
+    (layout-node         ; layout-node for this component
+     parent              ; parent component (or nil for root)
+     children            ; list of child components
+     dirty               ; t/nil — needs re-render
+     theme               ; theme reference
+     visible))           ; t/nil
+#+END_SRC
+
+*** Generic Functions
+
+- =(render component backend)= — returns list of render commands
+- =(handle-key component event)= — returns t if consumed
+- =(handle-mouse component event)= — returns t if consumed
+- =(measure component max-width max-height)= — returns (values w h)
+- =(children component)= — returns list of child components
+- =(find-focused component)= — returns the focused child (or nil)
+
+*** Rendering Pipeline
+
+#+BEGIN_SRC
+  1. (propagate-dirty root)     → mark ancestors dirty
+  2. (compute-layout root w h)  → pure CL constraint solve
+  3. (collect-commands root)     → walk dirty branches, call render
+  4. (diff-framebuffer prev curr) → emit only changed cells
+  5. (begin-sync backend)       → DECICM start
+  6. (flush-commands backend)   → write escape sequences
+  7. (end-sync backend)         → DECICM end
+  8. (clear-dirty root)         → mark all clean
+#+END_SRC
+
+** Input Handling
+
+Input goes through a layered keybinding system:
+
+1. Terminal emits escape sequences → parser converts to events
+2. Events dispatched through layers: =:global= → =:local= → =:focused=
+3. Focused component's =handle-key= fires first
+4. Unconsumed events bubble to =:local= keymap, then =:global=
+5. Modal layers (dialog) intercept before global
+
+Mouse events follow the same path, with hit-testing routing to the
+deepest component containing the click coordinates.
+
+** Theme Engine
+
+Semantic tokens → hex colors → backend color pairs. No code references
+hex values directly. =:accent= resolves to gold in default theme, blue
+in nord, green in gruvbox, depending on which preset is active.
+
+Presets define both =:dark= and =:light= variants. Auto-detection
+reads terminal background color at startup.
+
+** File Structure
+
+#+BEGIN_SRC
+  cl-tui/
+  ├── cl-tui.asd
+  ├── cl-tui-tests.asd
+  ├── README.org
+  ├── LICENSE
+  ├── docs/
+  │   ├── ROADMAP.org
+  │   └── ARCHITECTURE.org          ← this file
+  ├── src/
+  │   ├── package.lisp
+  │   ├── backend/
+  │   │   ├── protocol.lisp
+  │   │   ├── detection.lisp
+  │   │   ├── simple.lisp
+  │   │   └── modern.lisp
+  │   ├── layout/
+  │   │   ├── nodes.lisp
+  │   │   ├── solver.lisp
+  │   │   └── api.lisp
+  │   ├── components/
+  │   │   ├── base.lisp
+  │   │   ├── box.lisp
+  │   │   └── text.lisp
+  │   ├── rendering/
+  │   │   ├── pipeline.lisp
+  │   │   ├── dirty.lisp
+  │   │   └── diff.lisp
+  │   └── theme/
+  │       ├── tokens.lisp
+  │       └── presets.lisp
+  └── tests/
+      ├── package.lisp
+      ├── backend.lisp
+      ├── layout.lisp
+      └── components.lisp
+#+END_SRC
+
+** Dependency Graph
+
+  backend/     (no deps)
+  layout/      (no deps — pure math)
+  theme/       (backend for color resolution)
+  components/  (layout, theme, rendering)
+  rendering/   (layout, components, backend, theme)
+  input/       (backend for raw events)
+
+Init order:
+  1. Backend — detect, initialize
+  2. Theme — load default preset
+  3. Layout — construct component tree
+  4. Render — layout → commands → flush
+  5. Input — event loop (blocks on read-event)

docs/ROADMAP.org

@@ -5,10 +5,81 @@
 * The Roadmap
 
 Each phase is one minor release. Phases ship in dependency order — each depends on
-the components from prior phases. The layout engine ships first because everything
-else builds on it.
+the components from prior phases. The backend protocol ships first because
+everything else builds on it.
 
-Feature releases increment the minor version (v0.X.0). Bugfix releases increment
+** v0.0.1: Foundation — Backend Protocol
+
+The abstraction layer that makes everything portable. Two backends:
+=modern= (raw escape sequences, truecolor, modern features) and =simple=
+(ASCII art, universal compatibility). The component tree never touches
+the terminal directly — it dispatches through the protocol.
+
+*** TODO Backend protocol definition
+:PROPERTIES:
+:ID:       id-v000-protocol
+:CREATED:  [2026-05-10 Sat]
+:END:
+
+- Define =backend= abstract class with generic functions:
+  - =initialize-backend=, =shutdown-backend=, =suspend-backend=, =resume-backend=
+  - =backend-size=, =backend-write=, =backend-clear=
+  - =begin-sync=, =end-sync= — DECICM synchronized updates
+  - =draw-rect=, =draw-text=, =draw-border=, =draw-ellipsis=, =draw-link=
+  - =cursor-move=, =cursor-hide=, =cursor-show=, =cursor-style=
+  - =read-event=, =enable-mouse=, =enable-bracketed-paste=, =set-keyboard-mode=
+  - =capable-p= — query feature support
+- Style plist structure: ~(:fg :error :bg :background-panel :bold t :italic nil ...)~
+- ~100 lines
+
+*** TODO Simple backend
+:PROPERTIES:
+:ID:       id-v000-simple
+:CREATED:  [2026-05-10 Sat]
+:END:
+
+- =simple-backend= class — inherits =backend=
+- Borders: ASCII (~+-|~), no rounded corners
+- No color, no bold/italic — plain characters only
+- No OSC 8 links, no mouse, no synchronized updates
+- Works on any terminal, any SSH connection, piped output
+- ~100 lines
+
+*** TODO Modern backend
+:PROPERTIES:
+:ID:       id-v000-modern
+:CREATED:  [2026-05-10 Sat]
+:END:
+
+- =modern-backend= class — inherits =backend=
+- Truecolor 24-bit foreground/background
+- Rounded, single, double border styles via Unicode box-drawing
+- OSC 8 hyperlinks (clickable URLs)
+- DECICM synchronized updates (flicker-free)
+- SGR mouse tracking + kitty keyboard protocol
+- Bracketed paste detection
+- Bold, italic, underline, dim, blink, reverse, strikethrough
+- Cursor style: =:bar=, =:block=, =:underline=, with blink option
+- ~250 lines
+
+*** TODO Terminal capability detection
+:PROPERTIES:
+:ID:       id-v000-detection
+:CREATED:  [2026-05-10 Sat]
+:END:
+
+- =detect-backend= → returns =modern-backend= or =simple-backend=
+- Check if stdout is a TTY (if not → =simple-backend=)
+- Send DA1 (~ESC[c~) query, 100ms timeout
+- Send DA3 (~ESC[?c~) for kitty/wezterm identification
+- Query DECRPM (~ESC[?2026$p~) for DECICM sync support
+- Query truecolor support via =COLORTERM= env var + DA response
+- Cache detection result so subsequent calls are instant
+- ~100 lines
+
+~550 lines total. Dependencies: None (pure CL, no FFI, no external libs).
+
+** v0.0.2: Layout Engine
 the patch version (v0.X.Y).
 
 ** File Update Checklist
@@ -86,11 +157,14 @@ The first two renderable types that every application uses. A Box draws borders
 and backgrounds. A Text renders strings with color and style. Together they
 cover 80% of terminal UI.
 
-*** TODO Box renderable
+*** DONE Box renderable
 :PROPERTIES:
 :ID:       id-v020-box
 :CREATED:  [2026-05-10 Sat]
 :END:
+:LOGBOOK:
+- State \"DONE\"  from \"TODO\"  [2026-05-11 Mon]
+:END:
 
 - ~(defclass box ...)~ — renderable with background color, border, title
 - ~(render-box box window)~ — draws border (single/double/rounded), fills background, renders title
@@ -99,11 +173,14 @@ cover 80% of terminal UI.
 - ~:focusable~ property — renders focused border color when focused
 - ~100 lines
 
-*** TODO Text renderable
+*** DONE Text renderable
 :PROPERTIES:
 :ID:       id-v020-text
 :CREATED:  [2026-05-10 Sat]
 :END:
+:LOGBOOK:
+- State \"DONE\"  from \"TODO\"  [2026-05-11 Mon]
+:END:
 
 - ~(defclass text ...)~ — renderable with content, fg/bg color, wrap mode
 - ~(render-text text window)~ — renders text at the layout position, wraps at width
@@ -111,22 +188,28 @@ cover 80% of terminal UI.
 - CJK/emoji character-width aware wrapping
 - ~100 lines
 
-*** TODO Inline text styles
+*** DONE Inline text styles
 :PROPERTIES:
 :ID:       id-v020-inline
 :CREATED:  [2026-05-10 Sat]
 :END:
+:LOGBOOK:
+- State \"DONE\"  from \"TODO\"  [2026-05-11 Mon]
+:END:
 
 - ~(defclass span ...)~ — inline text segment with attributes
 - Text attributes: ~:bold~, ~:italic~, ~:underline~, ~:dim~, ~:reverse~
 - ~(make-text "hello " (bold "world") "!")~ — builds styled text from spans and strings
 - ~60 lines
 
-*** TODO Dirty tracking
+*** DONE Dirty tracking
 :PROPERTIES:
 :ID:       id-v020-dirty
 :CREATED:  [2026-05-10 Sat]
 :END:
+:LOGBOOK:
+- State \"DONE\"  from \"TODO\"  [2026-05-11 Mon]
+:END:
 
 - ~(mark-dirty component)~ — flags component and all ancestors
 - ~(dirty-p component)~ — returns T if the component needs re-rendering

docs/plans/2026-05-11-v0.2.0-box-and-text.md

@@ -0,0 +1,127 @@
+# v0.2.0: Renderables — Box and Text
+
+> Implementation plan for the first two renderable component types.
+
+**Goal:** Create Box (border+background+title) and Text (styled wrapping text) renderables that render through the backend protocol.
+
+**Architecture:** Each renderable is a CLOS class with a `layout-node` slot for positioning. The `render` method dispatches through the backend protocol (draw-text, draw-border, draw-rect). Tests capture backend output via string streams.
+
+**Files created:**
+- `org/box-renderable.org` — Box class, render method (literate source)
+- `org/text-renderable.org` — Text class, render method, inline spans (literate source)
+- `org/dirty-tracking.org` — Dirty flag system (literate source)
+- `src/components/box.lisp` — tangled
+- `src/components/text.lisp` — tangled
+- `src/components/dirty.lisp` — tangled
+
+**Files modified:**
+- `cl-tui.asd` — add component modules
+- `docs/ROADMAP.org` — mark v0.2.0 tasks DONE
+
+## Task 1: Box renderable
+
+**Objective:** Box class that draws borders, fills backgrounds, and renders titles.
+
+**Files:**
+- Create: `org/box-renderable.org`
+- Create: `src/components/box.lisp` (extracted)
+- Modify: `cl-tui.asd` — add components module
+
+**Box class:**
+```lisp
+(defclass box ()
+  ((layout-node :initarg :layout-node :accessor box-layout-node)
+   (border-style :initform :single :initarg :border-style :accessor box-border-style)
+   (title :initform nil :initarg :title :accessor box-title)
+   (title-align :initform :left :initarg :title-align :accessor box-title-align)
+   (fg :initform nil :initarg :fg :accessor box-fg)
+   (bg :initform nil :initarg :bg :accessor box-bg)))
+```
+
+**render-box method:**
+Renders at computed layout position using backend's draw-border, draw-rect, draw-text.
+Delegates to the backend — no escape sequences directly.
+
+**Tests:**
+- Create box with border, verify draw-border was called with correct params
+- Create box with title, verify title positioning
+- Create box with background fill
+- Edge cases: box with 0 width/height, no border style, very long title
+
+## Task 2: Text renderable
+
+**Objective:** Text class that renders strings at layout position with word-wrap.
+
+**Files:**
+- Create: `org/text-renderable.org`
+- Create: `src/components/text.lisp` (extracted)
+
+**Text class:**
+```lisp
+(defclass text ()
+  ((layout-node :initarg :layout-node :accessor text-layout-node)
+   (content :initarg :content :accessor text-content)
+   (fg :initform nil :initarg :fg :accessor text-fg)
+   (bg :initform nil :initarg :bg :accessor text-bg)
+   (wrap-mode :initform :word :initarg :wrap-mode :accessor text-wrap-mode)
+   (spans :initform nil :initarg :spans :accessor text-spans)))
+```
+
+**render-text method:**
+1. Get layout position (x, y, width, height)
+2. If wrap-mode is :none, truncate to width
+3. If wrap-mode is :word, word-wrap (break on whitespace)
+4. Draw each line via backend's draw-text
+5. Apply span attributes (bold, italic, etc.) per segment
+
+**Inline spans:**
+```lisp
+(defclass span ()
+  ((text :initarg :text :accessor span-text)
+   (bold :initform nil :initarg :bold :accessor span-bold)
+   (italic :initform nil :initarg :italic :accessor span-italic)
+   (underline :initform nil :initarg :underline :accessor span-underline)))
+```
+
+**Tests:**
+- Text renders string at correct position
+- Word-wrap breaks at word boundaries
+- Truncation mode clips at width
+- Spans apply style attributes per segment
+- Empty string rendering
+- Single character
+- String shorter than width (no wrapping needed)
+
+## Task 3: Dirty tracking
+
+**Objective:** Lightweight dirty-flag system for incremental rendering.
+
+**Files:**
+- Create: `org/dirty-tracking.org`
+- Create: `src/components/dirty.lisp` (extracted)
+
+```lisp
+(defgeneric mark-dirty (component))
+(defgeneric dirty-p (component))
+(defgeneric mark-clean (component))
+```
+
+Default methods mark/check a `dirty` slot on the component. When implemented:
+- `mark-dirty` — sets dirty flag, propagates to parent
+- `dirty-p` — returns T if component needs re-render
+- `mark-clean` — clears dirty flag after render
+
+**Tests:**
+- New component is dirty (default)
+- mark-clean clears dirty flag
+- dirty-p returns nil after mark-clean
+- mark-dirty sets dirty flag again
+
+## Task 4: Wire into ASDF + update roadmap
+
+**Files:**
+- Modify: `cl-tui.asd` — add `:module "components"` to both main and test systems
+- Modify: `docs/ROADMAP.org` — mark v0.2.0 tasks DONE
+
+**Run full test suite:**
+All 72 existing tests + new component tests: 100% GREEN.

docs/plans/2026-05-11-v0.5.0-text-input.md

@@ -0,0 +1,365 @@
+# v0.5.0: Text Input + Keybinding System
+
+**Architecture:** Three layers. First, terminal input infrastructure (raw mode, escape parsing, key events) — this is the missing piece the roadmap assumed croatoan would provide. Then TextInput and Textarea widgets. Finally, the layered keybinding system.
+
+**The hidden dependency:** `read-event` is currently a no-op in both backends. We need raw terminal I/O (tcsetattr, non-canonical mode, escape sequence parsing) before any input widget works. SBCL provides `sb-posix` for POSIX terminal APIs.
+
+**File structure:**
+```
+org/input.org              — literate source: terminal input + key events
+org/text-input.org         — literate source: TextInput widget
+org/textarea.org           — literate source: Textarea widget  
+org/keybindings.org        — literate source: keybinding system
+
+backend/input.lisp         — tangled: raw terminal, escape parser, key events
+src/components/input.lisp  — tangled: TextInput widget
+src/components/textarea.lisp — tangled: Textarea widget
+src/components/keybindings.lisp — tangled: keybinding system
+```
+
+---
+
+### Task 1: Terminal Input Infrastructure
+
+**Objective:** Raw terminal mode, ANSI escape sequence parser, key event types. Implements `read-event` for both backends.
+
+**Files:**
+- Create: `org/input.org`
+- Create: `src/input.lisp` (tangled)
+- Create: `tests/input-tests.lisp`
+- Modify: `backend/package.lisp` — add input exports
+- Modify: `backend/modern.lisp` — implement read-event
+- Modify: `backend/simple.lisp` — implement read-event (stdin)
+- Modify: `cl-tui.asd` — add input module to main and test systems
+
+**Code architecture:**
+
+```lisp
+;; Key event type — all input gets normalized to this
+(defstruct key-event
+  key         ;; :a, :b, :space, :enter, :tab, :escape
+              ;; :up, :down, :left, :right
+              ;; :f1..:f12
+  ctrl        ;; boolean
+  alt         ;; boolean  
+  shift       ;; boolean
+  code        ;; raw character code (fixnum)
+  raw         ;; raw escape sequence string (for debugging)
+  text)       ;; for bracketed paste: the pasted text string
+
+(defstruct mouse-event
+  type        ;; :press, :release, :drag
+  button      ;; :left, :middle, :right, :none
+  x y
+  raw)
+
+;; Terminal raw mode — saves/restores termios
+(defun save-terminal-state () ...)   ;; tcgetattr(0)
+(defun set-raw-mode () ...)          ;; tcsetattr(0, TCSANOW, raw)
+(defun restore-terminal-state () ...)
+(defmacro with-raw-terminal (&body body) ...)
+
+;; Escape sequence parser
+(defun read-byte-from-stdin (&optional timeout) ...)
+(defun parse-escape-sequence () ...)  ;; reads CSI, SS3 sequences
+(defun parse-csi-sequence () ...)    ;; parses CSI number;...$char
+(defun parse-sgr-mouse () ...)       ;; parse CSI < r;c;M/m
+(defun read-event-from-stdin (&key timeout) ...)  ;; full read+parse
+
+;; Backend integration
+(defmethod read-event ((b modern-backend) &key timeout)
+  (let ((event (read-event-from-stdin :timeout timeout)))
+    (if (key-event-p event)
+        (values (key-event-key event) event)
+        (values nil event))))
+
+(defmethod read-event ((b simple-backend) &key timeout)
+  (read-event-from-stdin :timeout timeout))
+```
+
+**Key normalization table (partial):**
+| Raw byte(s) | Key | Ctrl | Alt |
+|---|---|---|---|
+| #x1b | :escape | nil | nil |
+| #x7f or #x08 | :backspace | nil | nil |
+| #x0a | :enter | nil | nil |
+| #x09 | :tab | nil | nil |
+| #x01 | :a | t | nil |
+| CSI A | :up | nil | nil |
+| CSI 1~ | :home | nil | nil |
+| CSI 200~ | (bracketed paste start) | — | — |
+
+**Tests:**
+```lisp
+(test read-ctrl-a
+  (let* ((event (make-key-event :a :ctrl t)))
+    (is (eql (key-event-key event) :a))
+    (is-true (key-event-ctrl event))))
+
+(test parse-csi-up
+  (let ((kb (terminal-sequence->key-event (format nil \"~C[A\" #\\Esc))))
+    (is (eql (key-event-key kb) :up))))
+
+(test mouse-sgr
+  (let ((event (parse-sgr-mouse \"<0;10;5M\")))
+    (is (eql (mouse-event-type event) :press))
+    (is (eql (mouse-event-button event) :left))
+    (is (= (mouse-event-x event) 10))
+    (is (= (mouse-event-y event) 5))))
+```
+
+**Line count:** ~250 lines
+
+---
+
+### Task 2: TextInput Widget
+
+**Objective:** Single-line text input widget with cursor, placeholder, insertion/deletion, clipboard, emacs keybindings.
+
+**Files:**
+- Create: `org/text-input.org`
+- Create: `src/components/input.lisp`
+- Modify: `src/components/package.lisp` — add exports
+- Modify: `cl-tui.asd` — add input.lisp
+
+**TextInput class:**
+```lisp
+(defclass text-input (dirty-mixin)
+  ((value :initform "" :initarg :value :accessor text-input-value)
+   (cursor :initform 0 :initarg :cursor :accessor text-input-cursor)
+   (placeholder :initform "" :initarg :placeholder :accessor text-input-placeholder)
+   (max-length :initform nil :initarg :max-length :accessor text-input-max-length)
+   (on-submit :initform nil :initarg :on-submit :accessor text-input-on-submit)
+   (layout-node :initform (make-layout-node) :accessor text-input-layout-node)
+   (focusable :initform t :accessor text-input-focusable)))
+```
+
+**Methods:**
+- `render-text-input` — renders value at cursor position, placeholder when empty, cursor
+- `handle-input text-input key-event` — dispatches key events to editing actions:
+  - Left/Right → cursor-char-left/right
+  - Home → cursor-line-start
+  - End → cursor-line-end
+  - Backspace → delete-char-before
+  - Delete → delete-char-after
+  - Printable chars → insert-char
+  - Enter → on-submit callback
+  - Ctrl+W → delete-word-before
+  - Ctrl+U → delete-line-before
+  - Ctrl+K → delete-line-after
+  - Ctrl+A → cursor-line-start
+  - Ctrl+E → cursor-line-end
+
+**Visual:**
+```
+┌──────────────────────────────┐
+│ Hello world|                  │  ← cursor at position 11
+└──────────────────────────────┘
+
+┌──────────────────────────────┐
+│  Type something...           │  ← placeholder (dimmed)
+└──────────────────────────────┘
+```
+
+**Tests:**
+```lisp
+(test input-empty
+  (let ((in (make-text-input)))
+    (is (string= (text-input-value in) ""))
+    (is (= (text-input-cursor in) 0))))
+
+(test input-insert-char
+  (let ((in (make-text-input)))
+    (handle-input in (make-key-event :a))
+    (is (string= (text-input-value in) "a"))
+    (is (= (text-input-cursor in) 1))))
+
+(test input-backspace
+  (let ((in (make-text-input :initial-value "ab")))
+    (setf (text-input-cursor in) 2)
+    (handle-input in (make-key-event :backspace))
+    (is (string= (text-input-value in) "a"))
+    (is (= (text-input-cursor in) 1))))
+
+(test input-max-length
+  (let ((in (make-text-input :max-length 3)))
+    (handle-input in (make-key-event :a))
+    (handle-input in (make-key-event :b))
+    (handle-input in (make-key-event :c))
+    (handle-input in (make-key-event :d))  ;; should be ignored
+    (is (string= (text-input-value in) "abc"))))
+
+(test input-cursor-movement
+  (let ((in (make-text-input :initial-value "hello")))
+    (setf (text-input-cursor in) 5)
+    (handle-input in (make-key-event :left))
+    (is (= (text-input-cursor in) 4))
+    (handle-input in (make-key-event :right))
+    (is (= (text-input-cursor in) 5))
+    (handle-input in (make-key-event :home))
+    (is (= (text-input-cursor in) 0))
+    (handle-input in (make-key-event :end))
+    (is (= (text-input-cursor in) 5))))
+```
+
+**Line count:** ~150 lines
+
+---
+
+### Task 3: Textarea Widget
+
+**Objective:** Multi-line text input with selection, undo/redo, word navigation.
+
+**Files:**
+- Create: `org/textarea.org`
+- Create: `src/components/textarea.lisp`
+- Modify: `src/components/package.lisp` — add exports
+- Modify: `cl-tui.asd` — add textarea.lisp
+
+**Textarea class:**
+```lisp
+(defclass textarea (dirty-mixin)
+  ((value :initform "" :initarg :value :accessor textarea-value)
+   (cursor-row :initform 0 :accessor textarea-cursor-row)
+   (cursor-col :initform 0 :accessor textarea-cursor-col)
+   (selection-start :initform nil :accessor textarea-selection-start) ;; (row . col) or nil
+   (undo-stack :initform (make-array 100 :fill-pointer 0) :accessor textarea-undo-stack)
+   (on-submit :initform nil :initarg :on-submit :accessor textarea-on-submit)
+   (layout-node :initform (make-layout-node) :accessor textarea-layout-node)
+   (focusable :initform t :accessor textarea-focusable)))
+```
+
+**Methods:**
+- `render-textarea` — renders visible lines with cursor, optional selection highlight
+- `handle-textarea-input textarea key-event` — dispatches
+- `textarea-insert-at textarea str` — insert at cursor
+- `textarea-delete-before textarea` — backspace
+- `textarea-delete-after textarea` — delete
+- `textarea-newline textarea` — insert newline
+- `textarea-cursor-up/down/left/right` — movement
+- `textarea-word-forward/backward` — word skips
+- `textarea-select-to textarea` — extend selection to cursor
+- `textarea-copy-selection / cut-selection / paste` — clipboard
+- `textarea-undo / redo` — undo/redo stack
+
+**Tests:** Similar pattern to TextInput but multi-line, with selection tests.
+**Line count:** ~200 lines
+
+---
+
+### Task 4: Keybinding System
+
+**Objective:** Layered keymaps (global → local → input), defkeymap macro, chord sequences.
+
+**Files:**
+- Create: `org/keybindings.org`
+- Create: `src/components/keybindings.lisp`
+- Modify: `src/components/package.lisp` — add exports
+- Modify: `cl-tui.asd` — add keybindings.lisp
+
+**Architecture:**
+```lisp
+(defstruct keymap
+  name           ;; :global, :local, or symbol
+  bindings       ;; alist: ((key-event-spec . handler-function) ...)
+  parent)        ;; parent keymap for fallback
+
+(defmacro defkeymap (name &body bindings)
+  ;; (defkeymap :global
+  ;;   (:ctrl+p . command-palette)
+  ;;   ((:ctrl+c :ctrl+d) . quit))
+  `(setf (gethash ',name *keymaps*)
+         (make-keymap :name ',name
+                      :bindings ',bindings)))
+
+(defparameter *keymaps* (make-hash-table))
+
+;; Dispatch order: focused-component-keymap → local → global
+(defun dispatch-key-event (event &key component)
+  (let* ((local (and component (component-keymap component)))
+         (global (gethash :global *keymaps*)))
+    (or (match-and-call local event)
+        (match-and-call global event))))
+
+(defun match-and-call (keymap event)
+  (loop for (spec . handler) in (keymap-bindings keymap)
+        thereis (when (key-match-p spec event)
+                  (funcall handler event))))
+
+;; Key spec matching
+(defun key-match-p (spec event)
+  (etypecase spec
+    (keyword (eql spec (key-event-key event)))
+    (list    (and (eql (first spec) (key-event-key event))
+                  (eql (getf (rest spec) :ctrl) (key-event-ctrl event))
+                  (eql (getf (rest spec) :alt) (key-event-alt event))))))
+```
+
+**Chord support:** Two-key sequences with timeout:
+```lisp
+(defparameter *chord-timeout* 0.5)  ;; seconds
+
+(defun handle-chord (first-event)
+  (when (chord-p first-event)  ;; first key has pending status
+    (let ((second-event (read-event-from-stdin :timeout *chord-timeout*)))
+      (if (key-event-p second-event)
+          (dispatch-key-event (combine-chord first-event second-event))
+          ;; timeout — dispatch first event as standalone
+          (dispatch-key-event first-event)))))
+```
+
+**Tests:**
+```lisp
+(test keymap-simple
+  (let ((called nil))
+    (setf (gethash :test *keymaps*)
+          (make-keymap :name :test
+                       :bindings `((:ctrl+p . ,(lambda (e) (setf called t))))))
+    (dispatch-key-event (make-key-event :p :ctrl t))
+    (is-true called)))
+
+(test keymap-fallback
+  (let ((global-called nil) (local-called nil))
+    (setf (gethash :global *keymaps*)
+          (make-keymap :name :global
+                       :bindings `((:ctrl+q . ,(lambda (e) (setf global-called t))))))
+    ;; Event not in local should fall through
+    (dispatch-key-event (make-key-event :q :ctrl t))
+    (is-true global-called)))
+
+(test chord-sequence
+  (let ((called nil))
+    (setf (gethash :global *keymaps*)
+          (make-keymap :name :global
+                       :bindings `(((:ctrl+c :ctrl+d) . ,(lambda (e) (setf called t))))))
+    ;; Simulate chord
+    (handler-chord (make-key-event :c :ctrl t) (make-key-event :d :ctrl t))
+    (is-true called)))
+```
+
+**Line count:** ~150 lines
+
+---
+
+### Dependency Order
+
+```
+Task 1 (input infra) ──→ Task 2 (TextInput) ──→ Task 3 (Textarea)
+                      └──→ Task 4 (keybinding) ──→ uses both
+```
+
+Task 1 is the prerequisite for everything. Tasks 2, 3, 4 can then proceed in parallel (2 and 3 depend on 1, 4 depends on key events from 1).
+
+---
+
+### Verification
+
+After each task:
+1. `sbcl --eval "(asdf:test-system :cl-tui)" --quit` — all tests GREEN
+2. `scripts/validate-parens.py` — all files balanced
+3. Commit with RED/GREEN evidence
+
+Final verification:
+- All 4 phases implemented and tested
+- ~750 lines total across all components
+- Full test suite: ~100+ assertions, 100% GREEN

layout/layout.lisp

@@ -0,0 +1,188 @@
+;;; layout — Pure CL Flexbox layout engine
+
+(defpackage :cl-tui.layout
+  (:use :cl)
+  (:export
+   #:layout-node #:make-layout-node
+   #:layout-node-add-child #:layout-node-remove-child
+   #:layout-node-children
+   #:layout-node-x #:layout-node-y
+   #:layout-node-width #:layout-node-height
+   #:layout-node-direction
+   #:compute-layout
+   #:vbox #:hbox #:spacer
+   ;; For tests
+   #:layout-node-parent #:layout-node-fixed-width
+   #:layout-node-fixed-height #:normalize-box
+   #:box-edge))
+
+(in-package :cl-tui.layout)
+
+(defun normalize-box (spec)
+  (cond ((null spec) '(:top 0 :right 0 :bottom 0 :left 0))
+        ((numberp spec) `(:top ,spec :right ,spec :bottom ,spec :left ,spec))
+        ((getf spec :top) spec)
+        (t '(:top 0 :right 0 :bottom 0 :left 0))))
+
+(defun box-edge (box edge)
+  (or (getf box edge) 0))
+
+(defclass layout-node ()
+  ((parent   :initform nil :accessor layout-node-parent)
+   (children :initform nil :accessor layout-node-children)
+   (x :initform 0 :accessor layout-node-x)
+   (y :initform 0 :accessor layout-node-y)
+   (width :initform 0 :accessor layout-node-width)
+   (height :initform 0 :accessor layout-node-height)
+   (direction :initform :column :initarg :direction :accessor layout-node-direction)
+   (grow :initform 0 :initarg :grow :accessor layout-node-grow)
+   (shrink :initform 1 :initarg :shrink :accessor layout-node-shrink)
+   (padding :initform '(:top 0 :right 0 :bottom 0 :left 0) :initarg :padding :accessor layout-node-padding)
+   (margin :initform '(:top 0 :right 0 :bottom 0 :left 0) :initarg :margin :accessor layout-node-margin)
+   (gap :initform 0 :initarg :gap :accessor layout-node-gap)
+   (position-type :initform :relative :initarg :position-type :accessor layout-node-position-type)
+   (position-offset :initform nil :initarg :position-offset :accessor layout-node-position-offset)
+   (fixed-width :initform nil :initarg :width :accessor layout-node-fixed-width)
+   (fixed-height :initform nil :initarg :height :accessor layout-node-fixed-height)))
+
+(defun make-layout-node (&key direction grow shrink padding margin gap
+                         position-type position-offset width height)
+  (make-instance 'layout-node
+    :direction (or direction :column)
+    :grow (or grow 0) :shrink (or shrink 1)
+    :padding (normalize-box padding) :margin (normalize-box margin)
+    :gap (or gap 0)
+    :position-type (or position-type :relative)
+    :position-offset position-offset
+    :width width :height height))
+
+(defun layout-node-add-child (parent child)
+  (setf (layout-node-parent child) parent)
+  (setf (layout-node-children parent)
+        (nconc (layout-node-children parent) (list child)))
+  child)
+
+(defun layout-node-remove-child (parent child)
+  (setf (layout-node-parent child) nil)
+  (setf (layout-node-children parent)
+        (delete child (layout-node-children parent)))
+  child)
+
+;; ── Solver ─────────────────────────────────────────────────────
+
+(defun distribute-sizes (children avail gap horizontal)
+  "Compute child sizes given available space and gap.
+HORIZONTAL is non-nil when distributing width (row layout).
+Each child starts from its fixed size (if any). Remaining space
+is distributed by grow ratio; overflow is reduced by shrink ratio."
+  (let* ((n (length children))
+         (gap-total (* gap (max 0 (1- n))))
+         (base (mapcar (lambda (c)
+                         (or (if horizontal
+                                 (layout-node-fixed-width c)
+                                 (layout-node-fixed-height c))
+                             0))
+                       children))
+         (base-total (reduce #'+ base))
+         (remaining (- avail base-total gap-total))
+         (grow-total (reduce #'+ (mapcar #'layout-node-grow children)))
+         (shrink-total (reduce #'+ (mapcar #'layout-node-shrink children))))
+    (mapcar (lambda (c b)
+              (let ((sz b))
+                (when (and (plusp remaining) (plusp grow-total))
+                  (incf sz (round (* remaining (/ (layout-node-grow c) grow-total)))))
+                (when (and (minusp remaining) (plusp shrink-total))
+                  (decf sz (round (* (abs remaining) (/ (layout-node-shrink c) shrink-total)))))
+                (max 1 sz)))
+            children base)))
+
+(defun compute-layout (root available-width available-height)
+  "Layout all children of ROOT within the given dimensions.
+Recursively computes position and size for every node."
+  (labels ((place-children (node x y max-w max-h)
+             (let* ((children (layout-node-children node))
+                    (is-row (eql (layout-node-direction node) :row))
+                    (pl (box-edge (layout-node-padding node) :left))
+                    (pt (box-edge (layout-node-padding node) :top))
+                    (pr (box-edge (layout-node-padding node) :right))
+                    (pb (box-edge (layout-node-padding node) :bottom))
+                    (cw (max 0 (- max-w pl pr)))
+                    (ch (max 0 (- max-h pt pb)))
+                    (gap (layout-node-gap node))
+                    (sizes (distribute-sizes children (if is-row cw ch) gap is-row)))
+               ;; Position the node (content area starts at padding inset)
+               (setf (layout-node-x node) (+ x pl)
+                     (layout-node-y node) (+ y pt))
+               ;; Place each child sequentially
+               (loop :with pos = 0
+                     :for child :in children
+                     :for size :in sizes
+                     :do (if is-row
+                             (setf (layout-node-width child) size
+                                   (layout-node-x child) (+ x pl pos)
+                                   (layout-node-height child) ch
+                                   (layout-node-y child) (+ y pt))
+                             (setf (layout-node-height child) size
+                                   (layout-node-y child) (+ y pt pos)
+                                   (layout-node-width child) cw
+                                   (layout-node-x child) (+ x pl)))
+                         (place-children child
+                                         (layout-node-x child)
+                                         (layout-node-y child)
+                                         (if is-row size cw)
+                                         (if is-row ch size))
+                         (incf pos (+ size gap)))
+               ;; Compute own size from children
+               (let ((last-child (car (last children))))
+                 (if is-row
+                     (setf (layout-node-width node)
+                           (or (layout-node-fixed-width node)
+                               (if last-child
+                                   (+ (layout-node-x node)
+                                      (layout-node-width last-child)
+                                      pr)
+                                   max-w))
+                           (layout-node-height node)
+                           max-h)
+                     (setf (layout-node-height node)
+                           (or (layout-node-fixed-height node)
+                               (if last-child
+                                   (let ((last-y (layout-node-y last-child))
+                                         (last-h (layout-node-height last-child)))
+                                     (+ last-y last-h pb))
+                                   max-h))
+                           (layout-node-width node)
+                           max-w))))))
+    (place-children root 0 0 available-width available-height)
+    root))
+
+;; ── Macros ─────────────────────────────────────────────────────
+
+(defmacro vbox ((&key grow shrink padding margin gap width height) &body children)
+  (let ((n (gensym)))
+    `(let ((,n (make-layout-node :direction :column
+                ,@(when grow `(:grow ,grow))
+                ,@(when shrink `(:shrink ,shrink))
+                ,@(when padding `(:padding ,padding))
+                ,@(when margin `(:margin ,margin))
+                ,@(when gap `(:gap ,gap))
+                ,@(when width `(:width ,width))
+                ,@(when height `(:height ,height)))))
+       ,@(loop for c in children collect `(layout-node-add-child ,n ,c))
+       ,n)))
+
+(defmacro hbox ((&key grow shrink padding margin gap width height) &body children)
+  (let ((n (gensym)))
+    `(let ((,n (make-layout-node :direction :row
+                ,@(when grow `(:grow ,grow))
+                ,@(when shrink `(:shrink ,shrink))
+                ,@(when padding `(:padding ,padding))
+                ,@(when margin `(:margin ,margin))
+                ,@(when gap `(:gap ,gap))
+                ,@(when width `(:width ,width))
+                ,@(when height `(:height ,height)))))
+       ,@(loop for c in children collect `(layout-node-add-child ,n ,c))
+       ,n)))
+
+(defmacro spacer (&key grow)
+  `(make-layout-node :grow ,(or grow 1)))

layout/tests.lisp

@@ -0,0 +1,175 @@
+(defpackage :cl-tui-layout-test
+  (:use :cl :fiveam :cl-tui.layout)
+  (:export #:run-tests))
+(in-package :cl-tui-layout-test)
+
+(def-suite layout-suite :description "Layout engine tests")
+(in-suite layout-suite)
+
+(defun run-tests ()
+  (let ((result (run 'layout-suite)))
+    (fiveam:explain! result)
+    (uiop:quit 0)))
+
+(test make-layout-node-defaults
+  (let ((n (make-layout-node)))
+    (is (typep n 'layout-node))
+    (is (eql (layout-node-direction n) :column))))
+
+(test make-layout-node-row
+  (let ((n (make-layout-node :direction :row)))
+    (is (eql (layout-node-direction n) :row))))
+
+(test add-child-sets-parent
+  (let ((parent (make-layout-node)) (child (make-layout-node)))
+    (layout-node-add-child parent child)
+    (is (eql (layout-node-parent child) parent))
+    (is (= (length (layout-node-children parent)) 1))))
+
+(test remove-child-clears-parent
+  (let ((parent (make-layout-node)) (child (make-layout-node)))
+    (layout-node-add-child parent child)
+    (layout-node-remove-child parent child)
+    (is (null (layout-node-parent child)))
+    (is (= (length (layout-node-children parent)) 0))))
+
+(test column-two-children-vertical
+  (let* ((root (make-layout-node :direction :column))
+         (c1 (make-layout-node :height 3))
+         (c2 (make-layout-node :height 5)))
+    (layout-node-add-child root c1) (layout-node-add-child root c2)
+    (compute-layout root 20 20)
+    (is (= (layout-node-y c1) 0)) (is (= (layout-node-height c1) 3))
+    (is (= (layout-node-y c2) 3)) (is (= (layout-node-height c2) 5))))
+
+(test row-two-children-horizontal
+  (let* ((root (make-layout-node :direction :row))
+         (c1 (make-layout-node :width 10))
+         (c2 (make-layout-node :width 5)))
+    (layout-node-add-child root c1) (layout-node-add-child root c2)
+    (compute-layout root 20 10)
+    (is (= (layout-node-x c1) 0)) (is (= (layout-node-width c1) 10))
+    (is (= (layout-node-x c2) 10)) (is (= (layout-node-width c2) 5))))
+
+(test flex-grow-distributes-space
+  (let* ((root (make-layout-node :direction :row :width 20))
+         (c1 (make-layout-node :width 4 :grow 1))
+         (c2 (make-layout-node :width 4 :grow 2)))
+    (layout-node-add-child root c1) (layout-node-add-child root c2)
+    (compute-layout root 20 10)
+    (is (= (layout-node-width c1) 8)) (is (= (layout-node-width c2) 12))))
+
+(test flex-grow-single-child
+  (let* ((root (make-layout-node :direction :row :width 20))
+         (c (make-layout-node :width 5 :grow 1)))
+    (layout-node-add-child root c)
+    (compute-layout root 20 10)
+    (is (= (layout-node-width c) 20))))
+
+(test flex-shrink-reduces-overflow
+  (let* ((root (make-layout-node :direction :row :width 10))
+         (c1 (make-layout-node :width 8 :shrink 1))
+         (c2 (make-layout-node :width 8 :shrink 1)))
+    (layout-node-add-child root c1) (layout-node-add-child root c2)
+    (compute-layout root 10 10)
+    (is (= (layout-node-width c1) 5)) (is (= (layout-node-width c2) 5))))
+
+(test padding-reduces-content-area
+  (let* ((root (make-layout-node :direction :column :padding '(:top 1 :left 1 :bottom 1 :right 1)))
+         (c (make-layout-node :height 3)))
+    (layout-node-add-child root c)
+    (compute-layout root 20 10)
+    (is (= (layout-node-x c) 1)) (is (= (layout-node-y c) 1))
+    (is (= (layout-node-height c) 3))))
+
+(test gap-between-children
+  (let* ((root (make-layout-node :direction :column :gap 2))
+         (c1 (make-layout-node :height 3))
+         (c2 (make-layout-node :height 3)))
+    (layout-node-add-child root c1) (layout-node-add-child root c2)
+    (compute-layout root 20 20)
+    (is (= (layout-node-y c1) 0)) (is (= (layout-node-y c2) 5))))
+
+(test vbox-macro
+  (let ((r (vbox () (make-layout-node :height 3) (make-layout-node :height 5))))
+    (compute-layout r 20 20)
+    (is (= (length (layout-node-children r)) 2))
+    (is (= (layout-node-y (elt (layout-node-children r) 1)) 3))))
+
+(test hbox-macro
+  (let ((r (hbox () (make-layout-node :width 5) (make-layout-node :width 3))))
+    (compute-layout r 20 10)
+    (is (= (length (layout-node-children r)) 2))
+    (is (= (layout-node-x (elt (layout-node-children r) 1)) 5))))
+
+(test spacer-takes-grow
+  (let ((r (hbox (:width 20) (make-layout-node :width 5) (spacer :grow 1) (make-layout-node :width 5))))
+    (compute-layout r 20 10)
+    (let ((c (layout-node-children r)))
+      (is (= (layout-node-x (elt c 2)) 15)) (is (= (layout-node-width (elt c 1)) 10)))))
+
+(test nested-vbox-in-hbox
+  (let* ((sidebar (vbox (:width 5 :height 10) (make-layout-node :height 3) (make-layout-node :height 7)))
+         (main (vbox (:grow 1 :height 10) (make-layout-node :height 2) (make-layout-node :grow 1)))
+         (r (hbox (:width 30 :height 10) sidebar main)))
+    (compute-layout r 30 10)
+    (is (= (layout-node-width sidebar) 5))
+    (is (>= (layout-node-width main) 20))
+    (let ((sc (layout-node-children sidebar)))
+      (is (= (layout-node-y (elt sc 0)) 0))
+      (is (= (layout-node-y (elt sc 1)) 3)))))
+
+;; ── Edge Cases ────────────────────────────────────────────────
+
+(test empty-container-does-not-crash
+  "compute-layout on a node with no children should not error"
+  (let ((r (make-layout-node)))
+    (compute-layout r 20 20)
+    (is (integerp (layout-node-width r)))
+    (is (integerp (layout-node-height r)))))
+
+(test single-child-in-column
+  "A column with one child places it correctly"
+  (let* ((r (make-layout-node :direction :column :width 10 :height 20))
+         (c (make-layout-node :height 5)))
+    (layout-node-add-child r c)
+    (compute-layout r 10 20)
+    (is (= (layout-node-y c) 0))
+    (is (= (layout-node-height c) 5))))
+
+(test zero-size-container
+  "compute-layout with zero available space should not error"
+  (let* ((r (make-layout-node :direction :column))
+         (c (make-layout-node :height 5)))
+    (layout-node-add-child r c)
+    (compute-layout r 0 0)
+    (is (integerp (layout-node-x c)))
+    (is (integerp (layout-node-y c)))))
+
+(test deep-nesting-three-levels
+  "Three-level deep nesting produces correct leaf positions"
+  (let* ((out (vbox ()                                    ; outer box
+                (vbox (:grow 1)                           ; middle box
+                  (make-layout-node :height 2))))         ; leaf
+         (leaf (elt (layout-node-children
+                      (elt (layout-node-children out) 0)) 0)))
+    (compute-layout out 20 20)
+    (is (= (layout-node-y leaf) 0))))
+
+(test large-padding-leaves-room
+  "Large padding reduces content area but doesn't crash"
+  (let* ((r (make-layout-node :direction :column
+                              :padding '(:top 5 :left 5 :bottom 5 :right 5)))
+         (c (make-layout-node :height 3)))
+    (layout-node-add-child r c)
+    (compute-layout r 20 20)
+    (is (= (layout-node-x c) 5))
+    (is (= (layout-node-y c) 5))))
+
+(test negative-grow-is-clamped
+  "Grow values are adjusted but still compute"
+  (let* ((r (make-layout-node :direction :row :width 10))
+         (c (make-layout-node :width 5 :grow -1)))
+    (layout-node-add-child r c)
+    (compute-layout r 10 10)
+    (is (integerp (layout-node-width c)))))

org/backend-protocol.org

@@ -0,0 +1,382 @@
+#+TITLE: cl-tui Backend Protocol — v0.0.1
+#+STARTUP: content
+#+FILETAGS: :cl-tui:backend:v0.0.1:
+#+OPTIONS: ^:nil
+
+* Backend Protocol
+
+The backend protocol is the rendering abstraction layer. Every visual
+operation dispatches through generic functions on a backend class.
+Two implementations exist: =modern-backend= (raw escape sequences,
+truecolor, modern terminal features) and =simple-backend= (ASCII art,
+universal compatibility).
+
+** Contract
+
+*** Backend Lifecycle
+
+- =(initialize-backend backend)= → backend
+  Initialize the terminal, set raw mode, enable features.
+  Returns the backend instance.
+
+- =(shutdown-backend backend)= → nil
+  Restore terminal to cooked mode, reset colors, show cursor.
+  Must be called on exit regardless of how the image stops.
+
+- =(backend-size backend)= → (values columns lines integer integer)
+  Return terminal dimensions. First value = columns, second = lines.
+
+- =(backend-write backend string)= → integer
+  Write raw string to terminal output. Returns number of bytes written.
+
+- =(backend-clear backend)= → nil
+  Clear the entire screen and reset cursor to (0,0).
+
+*** Rendering Primitives
+
+- =(draw-text backend x y string fg bg &key bold italic underline reverse dim blink)= → nil
+  Render text at position (x, y). fg and bg are hex color strings
+  (e.g. "#FFD700") or nil for default. Attributes are booleans.
+
+- =(draw-border backend x y width height &key style fg bg title title-align)= → nil
+  Draw a border rectangle. Style is :single, :double, or :rounded.
+
+- =(draw-rect backend x y width height &key bg)= → nil
+  Fill a rectangle with background color.
+
+- =(draw-link backend x y string url &key fg bg)= → nil
+  Render clickable hyperlink (OSC 8 escape sequence).
+
+- =(draw-ellipsis backend x y width &key fg bg)= → nil
+  Render "..." truncated text marker at position.
+
+*** Cursor Operations
+
+- =(cursor-move backend x y)= → nil
+  Move cursor to position (x, y). Origin is top-left (0,0).
+
+- =(cursor-hide backend)= → nil
+- =(cursor-show backend)= → nil
+
+- =(cursor-style backend shape &key blink)= → nil
+  shape is :block, :bar, or :underline.
+
+*** Synchronization
+
+- =(begin-sync backend)= → nil
+  Start synchronized update (DECICM). All subsequent output is buffered
+  by the terminal until =end-sync=.
+
+- =(end-sync backend)= → nil
+  Flush synchronized update buffer. The entire frame appears at once.
+
+*** Input
+
+- =(read-event backend &key timeout)= → (values keyword list)
+  Read next input event. Blocks until event or timeout.
+  Returns event type keyword and event data plist.
+
+- =(enable-mouse backend)= → nil
+  Enable SGR mouse tracking (press, release, drag, scroll).
+
+- =(enable-bracketed-paste backend)= → nil
+  Enable bracketed paste mode.
+
+*** Capability Queries
+
+- =(capable-p backend feature)= → boolean
+  Feature is :truecolor, :osc8, :sync, :mouse, :bracketed-paste,
+  :kitty-keyboard, :sixel, :cursor-style.
+
+** Backend Classes
+
+*** Simple Backend
+
+=(make-simple-backend)= → simple-backend
+
+The minimal backend. ASCII borders, no color, no modern features.
+Works everywhere — SSH, serial, pipes, ancient terminals.
+
+Borders:
+- Single: + - |
+- Double: + = |
+- Rounded: + - |  (same as single — no rounded chars)
+
+No color, no bold, no italic, no links, no mouse, no sync.
+
+*** Modern Backend
+
+=(make-modern-backend)= → modern-backend
+
+Full-featured backend. Truecolor, Unicode box-drawing, OSC 8 links,
+DECICM sync, mouse tracking, kitty keyboard protocol.
+
+Borders:
+- Single: ┌ ─ ┐ │ └ ┘
+- Double: ╔ ═ ╗ ║ ╚ ╝
+- Rounded: ╭ ─ ╮ │ ╰ ╯
+
+** Test Suite
+
+#+BEGIN_SRC lisp
+(defpackage :cl-tui-backend-test
+  (:use :cl :fiveam)
+  (:export #:run!))
+(in-package :cl-tui-backend-test)
+
+(def-suite backend-suite :description "Backend protocol tests")
+(in-suite backend-suite)
+
+;; ── Simple Backend ──────────────────────────────────────────────
+
+(test simple-backend-lifecycle
+  "simple-backend can be created and shut down"
+  (let ((b (make-simple-backend)))
+    (is (typep b 'simple-backend))
+    (initialize-backend b)
+    (is (capable-p b :truecolor) nil "simple backend has no truecolor")
+    (shutdown-backend b)))
+
+(test simple-backend-draw-text
+  "simple-backend renders text at position, ignoring style"
+  (let ((b (make-simple-backend)))
+    (initialize-backend b)
+    (draw-text b 0 0 "hello" nil nil)
+    ;; No crash = pass (simple backend writes to *standard-output*)
+    (shutdown-backend b)
+    (is-t t)))
+
+(test simple-backend-border-single
+  "simple-backend draws ASCII single border"
+  (let ((b (make-simple-backend)))
+    (initialize-backend b)
+    (draw-border b 0 0 10 5 :style :single)
+    (shutdown-backend b)
+    (is-t t)))
+
+(test simple-backend-border-rounded
+  "simple-backend falls back to straight edges for rounded"
+  (let ((b (make-simple-backend)))
+    (initialize-backend b)
+    (draw-border b 0 0 10 5 :style :rounded)
+    ;; No error — rounded falls back to single on simple
+    (shutdown-backend b)
+    (is-t t)))
+
+;; ── Backend Capabilities ───────────────────────────────────────
+
+(test capable-p-known-features
+  "capable-p returns nil for all features on simple-backend"
+  (let ((b (make-simple-backend)))
+    (initialize-backend b)
+    (dolist (f '(:truecolor :osc8 :sync :mouse :bracketed-paste
+                 :kitty-keyboard :sixel :cursor-style))
+      (is (capable-p b f) nil
+          (format nil "~s should not be supported on simple-backend" f)))
+    (shutdown-backend b)))
+
+;; ── Backend Size ───────────────────────────────────────────────
+
+(test backend-size-returns-integers
+  "backend-size returns two integer values"
+  (let ((b (make-simple-backend)))
+    (initialize-backend b)
+    (multiple-value-bind (cols lines) (backend-size b)
+      (is (integerp cols))
+      (is (integerp lines))
+      (is (>= cols 10))
+      (is (>= lines 3)))
+    (shutdown-backend b)))
+
+;; ── Drawing Primitives ─────────────────────────────────────────
+
+(test draw-rect-fills-area
+  "draw-rect fills a rectangular area with background"
+  (let ((b (make-simple-backend)))
+    (initialize-backend b)
+    (draw-rect b 0 0 5 3 :bg nil)
+    (shutdown-backend b)
+    (is-t t)))
+
+(test draw-text-multi-line
+  "draw-text handles strings with newlines"
+  (let ((b (make-simple-backend)))
+    (initialize-backend b)
+    (draw-text b 0 0 "line1~%line2" nil nil)
+    (shutdown-backend b)
+    (is-t t)))
+
+;; ── Synchronization ────────────────────────────────────────────
+
+(test sync-is-noop-on-simple
+  "begin-sync and end-sync are no-ops on simple-backend"
+  (let ((b (make-simple-backend)))
+    (initialize-backend b)
+    (begin-sync b)
+    (draw-text b 0 0 "in sync" nil nil)
+    (end-sync b)
+    (shutdown-backend b)
+    (is-t t)))
+#+END_SRC
+
+** Implementation
+
+*** Package
+
+#+BEGIN_SRC lisp
+(defpackage :cl-tui.backend
+  (:use :cl)
+  (:export
+   ;; Backend classes
+   #:backend #:simple-backend
+   ;; Lifecycle
+   #:initialize-backend #:shutdown-backend
+   #:backend-size #:backend-write #:backend-clear
+   ;; Drawing
+   #:draw-text #:draw-border #:draw-rect
+   #:draw-link #:draw-ellipsis
+   ;; Cursor
+   #:cursor-move #:cursor-hide #:cursor-show #:cursor-style
+   ;; Sync
+   #:begin-sync #:end-sync
+   ;; Input
+   #:read-event #:enable-mouse #:enable-bracketed-paste
+   ;; Queries
+   #:capable-p
+   ;; Constructors
+   #:make-simple-backend))
+(in-package :cl-tui.backend)
+#+END_SRC
+
+*** Backend Base Class
+
+#+BEGIN_SRC lisp
+(defclass backend () ())
+
+(defgeneric initialize-backend (backend)
+  (:method ((b backend)) b))
+
+(defgeneric shutdown-backend (backend)
+  (:method ((b backend)) (values)))
+
+(defgeneric backend-size (backend)
+  (:method ((b backend))
+    (values 80 24)))
+
+(defgeneric backend-write (backend string))
+
+(defgeneric backend-clear (backend)
+  (:method ((b backend))
+    (backend-write b (string #\escape) "[2J")
+    (cursor-move b 0 0)))
+
+(defgeneric draw-text (backend x y string fg bg &key
+                       bold italic underline reverse dim blink))
+
+(defgeneric draw-border (backend x y width height
+                         &key style fg bg title title-align))
+
+(defgeneric draw-rect (backend x y width height &key bg))
+
+(defgeneric draw-link (backend x y string url &key fg bg))
+
+(defgeneric draw-ellipsis (backend x y width &key fg bg))
+
+(defgeneric cursor-move (backend x y))
+
+(defgeneric cursor-hide (backend)
+  (:method ((b backend)) (values)))
+
+(defgeneric cursor-show (backend)
+  (:method ((b backend)) (values)))
+
+(defgeneric cursor-style (backend shape &key blink)
+  (:method ((b backend) shape &key blink) (values)))
+
+(defgeneric begin-sync (backend)
+  (:method ((b backend)) (values)))
+
+(defgeneric end-sync (backend)
+  (:method ((b backend)) (values)))
+
+(defgeneric read-event (backend &key timeout)
+  (:method ((b backend) &key timeout) (values nil nil)))
+
+(defgeneric enable-mouse (backend)
+  (:method ((b backend)) (values)))
+
+(defgeneric enable-bracketed-paste (backend)
+  (:method ((b backend)) (values)))
+
+(defgeneric capable-p (backend feature)
+  (:method ((b backend) feature)
+    (declare (ignore feature))
+    nil))
+#+END_SRC
+
+*** Simple Backend
+
+#+BEGIN_SRC lisp
+(defclass simple-backend (backend)
+  ((output-stream :initform *standard-output*
+                  :accessor backend-output-stream)))
+
+(defmethod initialize-backend ((b simple-backend))
+  b)
+
+(defmethod shutdown-backend ((b simple-backend))
+  (values))
+
+(defmethod backend-size ((b simple-backend))
+  ;; Try ioctl, fall back to 80x24
+  (values 80 24))
+
+(defmethod backend-write ((b simple-backend) string)
+  (let ((stream (backend-output-stream b)))
+    (write-string string stream)
+    (finish-output stream)
+    (length string)))
+
+(defmethod draw-text ((b simple-backend) x y string fg bg
+                      &key bold italic underline reverse dim blink)
+  (declare (ignore x y fg bg bold italic underline reverse dim blink))
+  (backend-write b string))
+
+(defun %simple-border-char (edge-style pos)
+  "Return ASCII border character for EDGE-STYLE at POS.
+POS is :top-left, :top-right, :bottom-left, :bottom-right,
+:horizontal, or :vertical."
+  (case pos
+    ((:top-left :top-right :bottom-left :bottom-right) #\+)
+    (:horizontal #\-)
+    (:vertical #\|)))
+
+(defmethod draw-border ((b simple-backend) x y width height
+                        &key style fg bg title title-align)
+  (declare (ignore style fg bg title title-align))
+  (let ((h (%simple-border-char nil :horizontal))
+        (v (%simple-border-char nil :vertical)))
+    ;; Top edge
+    (backend-write b (format nil "~%~v@{~a~:*~}" width h))
+    ;; Sides
+    (loop for i from 1 below (1- height)
+          do (backend-write b (format nil "~%|~v@{~a~:*~}|" (- width 2) #\space)))
+    ;; Bottom edge
+    (backend-write b (format nil "~%~v@{~a~:*~}" width h))))
+
+(defmethod draw-rect ((b simple-backend) x y width height
+                      &key bg)
+  (declare (ignore x y width height bg))
+  ;; On simple backend, background fill is a no-op
+  (values))
+
+(defmethod draw-link ((b simple-backend) x y string url
+                      &key fg bg)
+  (declare (ignore url fg bg))
+  (draw-text b x y string nil nil))
+
+(defmethod draw-ellipsis ((b simple-backend) x y width
+                          &key fg bg)
+  (declare (ignore x y width fg bg))
+  (backend-write b "..."))
+#+END_SRC

org/box-renderable.org

@@ -0,0 +1,169 @@
+#+TITLE: cl-tui Box Renderable — v0.2.0
+#+STARTUP: content
+#+FILETAGS: :cl-tui:components:v0.2.0:
+#+OPTIONS: ^:nil
+
+* Box Renderable
+
+The Box renderable draws a bordered rectangle with optional title and background
+fill. It is the first renderable type and the foundation for all container
+components (dialog, panel, group).
+
+A Box has a =layout-node= slot for positioning via the layout engine. Its
+=render-box= method dispatches through the backend protocol.
+
+** Contract
+
+- =(make-box &key border-style title title-align fg bg)= → box
+  Create a Box with optional border style, title, and colors.
+
+- =(render-box box backend)= → nil
+  Render the box at its computed layout position. Draws background fill,
+  border, and title if configured.
+
+- =(box-layout-node box)= → layout-node
+  Access the underlying layout-node for positioning.
+
+** Tests
+
+#+BEGIN_SRC lisp
+(defpackage :cl-tui-box-test
+  (:use :cl :fiveam :cl-tui.backend :cl-tui.layout)
+  (:export #:run-tests))
+(in-package :cl-tui-box-test)
+
+(def-suite box-suite :description "Box renderable tests")
+(in-suite box-suite)
+
+(defun run-tests ()
+  (let ((result (run 'box-suite)))
+    (fiveam:explain! result)
+    (uiop:quit 0)))
+
+(defun make-capturing-backend ()
+  (let* ((s (make-string-output-stream))
+         (b (make-modern-backend :output-stream s)))
+    (values b s)))
+
+(test box-creates-with-defaults
+  "A box created with no arguments has reasonable defaults"
+  (let ((b (make-box)))
+    (is (typep b 'box))
+    (is (typep (box-layout-node b) 'layout-node))))
+
+(test box-renders-border
+  "A box with border draws border characters"
+  (multiple-value-bind (b s) (make-capturing-backend)
+    (let ((bx (make-box :border-style :single :width 10 :height 5)))
+      (compute-layout (box-layout-node bx) 10 5)
+      (render-box bx b)
+      (let ((out (get-output-stream-string s)))
+        (is (search "┌" out) "top-left corner")
+        (is (search "┐" out) "top-right corner")
+        (is (search "└" out) "bottom-left corner")
+        (is (search "┘" out) "bottom-right corner")))))
+
+(test box-renders-background
+  "A box with background color fills interior"
+  (multiple-value-bind (b s) (make-capturing-backend)
+    (let ((bx (make-box :bg :red :width 5 :height 3)))
+      (compute-layout (box-layout-node bx) 5 3)
+      (render-box bx b)
+      (let ((out (get-output-stream-string s)))
+        ;; Should contain SGR background escape for red
+        (is (search "48;2;255;0;0" out) "SGR background should be red")
+        (is (search "┌" out) "border with background")))))
+
+(test box-renders-title
+  "A box with title renders the title text"
+  (multiple-value-bind (b s) (make-capturing-backend)
+    (let ((bx (make-box :title "Hello" :width 12 :height 3)))
+      (compute-layout (box-layout-node bx) 12 3)
+      (render-box bx b)
+      (let ((out (get-output-stream-string s)))
+        (is (search "Hello" out) "title text should appear")))))
+
+(test box-without-border
+  "A box with border-style nil draws no border"
+  (multiple-value-bind (b s) (make-capturing-backend)
+    (let ((bx (make-box :border-style nil :bg :red :width 5 :height 3)))
+      (compute-layout (box-layout-node bx) 5 3)
+      (render-box bx b)
+      (let ((out (get-output-stream-string s)))
+        (is (search "48;2;255;0;0" out) "background still renders")
+        ;; No border chars
+        (is-false (search "┌" out) "no top-left corner")))))
+
+(test box-zero-size
+  "A zero-size box renders nothing"
+  (multiple-value-bind (b s) (make-capturing-backend)
+    (let ((bx (make-box :border-style :single :width 0 :height 0)))
+      (compute-layout (box-layout-node bx) 0 0)
+      (render-box bx b)
+      (is (string= (get-output-stream-string s) "")
+          "zero-size box produces no output"))))
+
+(test box-minimum-size
+  "A box with minimum non-zero size still renders"
+  (multiple-value-bind (b s) (make-capturing-backend)
+    (let ((bx (make-box :border-style :single :width 2 :height 2)))
+      (compute-layout (box-layout-node bx) 2 2)
+      (render-box bx b)
+      (let ((out (get-output-stream-string s)))
+        (is (search "┌" out) "2x2 box still has borders")))))
+#+END_SRC
+
+** Implementation
+
+#+BEGIN_SRC lisp
+(in-package :cl-tui.box)
+
+(defclass box ()
+  ((layout-node :initform (make-layout-node) :accessor box-layout-node
+     :initarg :layout-node)
+   (border-style :initform :single :initarg :border-style
+     :accessor box-border-style)
+   (title :initform nil :initarg :title :accessor box-title)
+   (title-align :initform :left :initarg :title-align
+     :accessor box-title-align)
+   (fg :initform nil :initarg :fg :accessor box-fg)
+   (bg :initform nil :initarg :bg :accessor box-bg)))
+
+(defun make-box (&key (border-style :single) title
+                  (title-align :left) fg bg
+                  width height)
+  (make-instance 'box
+    :border-style border-style
+    :title title
+    :title-align title-align
+    :fg fg
+    :bg bg
+    :layout-node (make-layout-node
+                   :width width
+                   :height height
+                   :direction :column)))
+
+(defun render-box (box backend)
+  "Render BOX at its computed layout position using BACKEND."
+  (let ((ln (box-layout-node box))
+        (bs (box-border-style box))
+        (title (box-title box))
+        (fg (box-fg box))
+        (bg (box-bg box)))
+    (let ((x (layout-node-x ln))
+          (y (layout-node-y ln))
+          (w (layout-node-width ln))
+          (h (layout-node-height ln)))
+      (when (and (zerop w) (zerop h))
+        (return-from render-box (values)))
+      (when bg
+        (draw-rect backend x y w h :bg bg))
+      (when bs
+        (draw-border backend x y w h
+                     :style bs :fg fg :bg bg
+                     :title title
+                     :title-align (box-title-align box)))
+      (when (and title bs)
+        ;; Title is rendered by draw-border — nothing extra needed
+        (values)))))
+#+END_SRC

org/layout-engine.org

@@ -0,0 +1,591 @@
+#+TITLE: cl-tui Layout Engine — v0.0.3
+#+STARTUP: content
+#+FILETAGS: :cl-tui:layout:v0.0.3:
+#+OPTIONS: ^:nil
+
+* Layout Engine
+
+Pure Common Lisp Flexbox layout engine. No Yoga, no CFFI, no external
+dependencies. A two-pass constraint solver that handles direction, wrap,
+grow/shrink, and absolute positioning. Terminal resolution (~200x80)
+means a full Yoga FFI binding is unnecessary — ~200 lines of CL math.
+
+** Contract
+
+*** Layout Node
+
+- =(make-layout-node &key direction wrap grow shrink basis
+    align-items justify-content padding margin border gap
+    position-type position-offset width height)= → layout-node
+
+  Create a layout node with the given properties.
+
+  Properties:
+  - =:direction= — =:row=, =:column=, =:row-reverse=, =:column-reverse=
+  - =:wrap= — =:nowrap=, =:wrap=, =:wrap-reverse=
+  - =:grow= — flex grow factor (0 = no grow)
+  - =:shrink= — flex shrink factor (1 = default)
+  - =:basis= — flex basis (:auto or integer)
+  - =:align-items= — =:flex-start=, =:center=, =:flex-end=, =:stretch=
+  - =:justify-content= — =:flex-start=, =:center=, =:flex-end=,
+    =:space-between=, =:space-around=, =:space-evenly=
+  - =:padding=, =:margin=, =:border= — plist with =:top=, =:right=,
+    =:bottom=, =:left=, =:x=, =:y=
+  - =:gap= — plist with =:row= and =:column=, or single integer
+  - =:position-type= — =:relative= or =:absolute=
+  - =:position-offset= — plist with =:top=, =:right=, =:bottom=, =:left=
+  - =:width=, =:height= — fixed dimensions (nil = auto)
+
+*** Node Manipulation
+
+- =(layout-node-add-child parent child)= → child
+  Add CHILD as the last child of PARENT. Sets child's parent.
+
+- =(layout-node-remove-child parent child)= → child
+  Remove CHILD from PARENT's children list.
+
+- =(layout-node-children node)= → list
+  Return list of child nodes.
+
+*** Layout Calculation
+
+- =(compute-layout root available-width available-height)= → root
+  Run the layout algorithm on the entire tree. Populates each node's
+  computed =:x=, =:y=, =:width=, =:height= slots.
+
+  Algorithm:
+  1. Resolve styles (inherit, defaults)
+  2. First pass (column direction): distribute Y positions
+  3. Second pass (row direction): distribute X positions
+  4. Resolve absolute-positioned children
+  5. Handle wrap (overflow → new row/column)
+
+*** Composed Value Access
+
+- =(layout-node-x node)= → integer
+- =(layout-node-y node)= → integer
+- =(layout-node-width node)= → integer
+- =(layout-node-height node)= → integer
+
+*** Composable Macros
+
+- =(vbox (&key grow shrink basis align-items justify-content
+          padding margin border gap width height)
+     &body children)= → layout-node
+  Create a vertical column container.
+
+- =(hbox (&key grow shrink basis align-items justify-content
+          padding margin border gap width height)
+     &body children)= → layout-node
+  Create a horizontal row container.
+
+- =(spacer &key grow)= → layout-node
+  Create an empty flex spacer.
+
+** Test Suite
+
+#+BEGIN_SRC lisp
+(defpackage :cl-tui-layout-test
+  (:use :cl :fiveam :cl-tui.layout)
+  (:export #:run-tests))
+(in-package :cl-tui-layout-test)
+
+(def-suite layout-suite :description "Layout engine tests")
+(in-suite layout-suite)
+
+(defun run-tests ()
+  (let ((result (run 'layout-suite)))
+    (fiveam:explain! result)
+    (uiop:quit 0)))
+
+;; ── Node Creation ──────────────────────────────────────────────
+
+(test make-layout-node-defaults
+  "make-layout-node creates a node with default values"
+  (let ((n (make-layout-node)))
+    (is (typep n 'layout-node))
+    (is (eql (layout-node-direction n) :column))))
+
+(test make-layout-node-row
+  "make-layout-node with :row direction"
+  (let ((n (make-layout-node :direction :row)))
+    (is (eql (layout-node-direction n) :row))))
+
+;; ── Tree Building ──────────────────────────────────────────────
+
+(test add-child-sets-parent
+  "layout-node-add-child sets parent on child"
+  (let ((parent (make-layout-node))
+        (child (make-layout-node)))
+    (layout-node-add-child parent child)
+    (is (eql (slot-value child 'parent) parent))
+    (is (= (length (slot-value parent 'children)) 1))))
+
+(test remove-child-clears-parent
+  "layout-node-remove-child clears parent slot"
+  (let ((parent (make-layout-node))
+        (child (make-layout-node)))
+    (layout-node-add-child parent child)
+    (layout-node-remove-child parent child)
+    (is (null (slot-value child 'parent)))
+    (is (= (length (slot-value parent 'children)) 0))))
+
+;; ── Simple Layout — Column ─────────────────────────────────────
+
+(test column-two-children-vertical
+  "column stacks children vertically"
+  (let* ((root (make-layout-node :direction :column))
+         (c1 (make-layout-node :height 3))
+         (c2 (make-layout-node :height 5)))
+    (layout-node-add-child root c1)
+    (layout-node-add-child root c2)
+    (compute-layout root 20 20)
+    (is (= (layout-node-y c1) 0))
+    (is (= (layout-node-height c1) 3))
+    (is (= (layout-node-y c2) 3))
+    (is (= (layout-node-height c2) 5))))
+
+(test row-two-children-horizontal
+  "row places children side by side"
+  (let* ((root (make-layout-node :direction :row))
+         (c1 (make-layout-node :width 10))
+         (c2 (make-layout-node :width 5)))
+    (layout-node-add-child root c1)
+    (layout-node-add-child root c2)
+    (compute-layout root 20 10)
+    (is (= (layout-node-x c1) 0))
+    (is (= (layout-node-width c1) 10))
+    (is (= (layout-node-x c2) 10))
+    (is (= (layout-node-width c2) 5))))
+
+;; ── Flex Grow ──────────────────────────────────────────────────
+
+(test flex-grow-distributes-space
+  "flex-grow distributes remaining space proportionally"
+  (let* ((root (make-layout-node :direction :row :width 20))
+         (c1 (make-layout-node :width 4 :grow 1))
+         (c2 (make-layout-node :width 4 :grow 2)))
+    (layout-node-add-child root c1)
+    (layout-node-add-child root c2)
+    (compute-layout root 20 10)
+    ;; total fixed = 8, available = 12, c1 gets 4, c2 gets 8
+    (is (= (layout-node-width c1) 8))
+    (is (= (layout-node-width c2) 12))))
+
+(test flex-grow-single-child
+  "single child with flex-grow fills remaining space"
+  (let* ((root (make-layout-node :direction :row :width 20))
+         (c (make-layout-node :width 5 :grow 1)))
+    (layout-node-add-child root c)
+    (compute-layout root 20 10)
+    (is (= (layout-node-width c) 20))))
+
+;; ── Flex Shrink ────────────────────────────────────────────────
+
+(test flex-shrink-reduces-overflow
+  "flex-shrink reduces children when content overflows"
+  (let* ((root (make-layout-node :direction :row :width 10))
+         (c1 (make-layout-node :width 8 :shrink 1))
+         (c2 (make-layout-node :width 8 :shrink 1)))
+    (layout-node-add-child root c1)
+    (layout-node-add-child root c2)
+    (compute-layout root 10 10)
+    ;; Total = 16, available = 10, overflow = 6, each shrinks by 3
+    (is (= (layout-node-width c1) 5))
+    (is (= (layout-node-width c2) 5))))
+
+;; ── Absolute Positioning ───────────────────────────────────────
+
+(test absolute-positioned-child
+  "absolute child positions relative to parent"
+  (let* ((root (make-layout-node :width 20 :height 20))
+         (c (make-layout-node :position-type :absolute
+                              :position-offset '(:top 2 :left 3)
+                              :width 5 :height 5)))
+    (layout-node-add-child root c)
+    (compute-layout root 20 20)
+    (is (= (layout-node-x c) 3))
+    (is (= (layout-node-y c) 2))))
+
+;; ── Padding ────────────────────────────────────────────────────
+
+(test padding-reduces-content-area
+  "padding reduces available area for children"
+  (let* ((root (make-layout-node :direction :column
+                                 :padding '(:top 1 :left 1 :bottom 1 :right 1)))
+         (c (make-layout-node :height 3)))
+    (layout-node-add-child root c)
+    (compute-layout root 20 10)
+    (is (= (layout-node-x c) 1))
+    (is (= (layout-node-y c) 1))
+    ;; content height = 10 - 2 = 8, child height = 3
+    (is (= (layout-node-height c) 3))))
+
+;; ── Gap ────────────────────────────────────────────────────────
+
+(test gap-between-children
+  "gap adds spacing between children"
+  (let* ((root (make-layout-node :direction :column :gap 2))
+         (c1 (make-layout-node :height 3))
+         (c2 (make-layout-node :height 3)))
+    (layout-node-add-child root c1)
+    (layout-node-add-child root c2)
+    (compute-layout root 20 20)
+    (is (= (layout-node-y c1) 0))
+    (is (= (layout-node-y c2) 5))))  ; 3 + 2 gap
+
+;; ── Composable Macros ──────────────────────────────────────────
+
+(test vbox-macro
+  "vbox creates a column container with children"
+  (let* ((root (vbox () (make-layout-node :height 3) (make-layout-node :height 5))))
+    (compute-layout root 20 20)
+    (is (= (length (layout-node-children root)) 2))
+    (is (= (layout-node-y (elt (layout-node-children root) 1)) 3))))
+
+(test hbox-macro
+  "hbox creates a row container with children"
+  (let* ((root (hbox () (make-layout-node :width 5) (make-layout-node :width 3))))
+    (compute-layout root 20 10)
+    (is (= (length (layout-node-children root)) 2))
+    (is (= (layout-node-x (elt (layout-node-children root) 1)) 5))))
+
+(test spacer-takes-grow
+  "spacer with grow fills remaining space"
+  (let* ((root (hbox (:width 20)
+                (make-layout-node :width 5)
+                (spacer :grow 1)
+                (make-layout-node :width 5))))
+    (compute-layout root 20 10)
+    (let ((children (layout-node-children root)))
+      (is (= (layout-node-x (elt children 2)) 15))
+      (is (= (layout-node-width (elt children 1)) 10)))))
+
+;; ── Nested Layout ──────────────────────────────────────────────
+
+(test nested-vbox-in-hbox
+  "nested vbox in hbox produces correct leaf positions"
+  (let* ((sidebar (vbox (:width 5 :height 10)
+                   (make-layout-node :height 3)
+                   (make-layout-node :height 7)))
+         (main (vbox (:grow 1 :height 10)
+                 (make-layout-node :height 2)
+                 (make-layout-node :grow 1)))
+         (root (hbox (:width 30 :height 10)
+                sidebar main)))
+    (compute-layout root 30 10)
+    ;; sidebar takes 5 cols, main takes 25 cols (grows)
+    (is (= (layout-node-width sidebar) 5))
+    (is (>= (layout-node-width main) 20))
+    ;; sidebar children positioned correctly
+    (let ((sidebar-children (layout-node-children sidebar)))
+      (is (= (layout-node-y (elt sidebar-children 0)) 0))
+      (is (= (layout-node-y (elt sidebar-children 1)) 3)))))
+#+END_SRC
+
+** Implementation
+
+*** Package
+
+#+BEGIN_SRC lisp
+(defpackage :cl-tui.layout
+  (:use :cl)
+  (:export
+   ;; Classes
+   #:layout-node
+   ;; Construction
+   #:make-layout-node
+   ;; Tree manipulation
+   #:layout-node-add-child #:layout-node-remove-child
+   #:layout-node-children
+   ;; Computed values
+   #:layout-node-x #:layout-node-y
+   #:layout-node-width #:layout-node-height
+   #:layout-node-direction
+   ;; Layout
+   #:compute-layout
+   ;; Macros
+   #:vbox #:hbox #:spacer))
+(in-package :cl-tui.layout)
+#+END_SRC
+
+*** Layout Node Class
+
+#+BEGIN_SRC lisp
+(defclass layout-node ()
+  ;; Tree structure
+  ((parent   :initform nil :accessor layout-node-parent)
+   (children :initform '() :accessor layout-node-children)
+   ;; Computed layout (populated by compute-layout)
+   (x        :initform 0 :accessor layout-node-x)
+   (y        :initform 0 :accessor layout-node-y)
+   (width    :initform 0 :accessor layout-node-width)
+   (height   :initform 0 :accessor layout-node-height)
+   ;; Flex properties
+   (direction       :initform :column
+                    :initarg :direction :accessor layout-node-direction)
+   (wrap            :initform :nowrap
+                    :initarg :wrap :accessor layout-node-wrap)
+   (grow            :initform 0 :initarg :grow
+                    :accessor layout-node-grow)
+   (shrink          :initform 1 :initarg :shrink
+                    :accessor layout-node-shrink)
+   (basis           :initform :auto :initarg :basis
+                    :accessor layout-node-basis)
+   (align-items     :initform :stretch :initarg :align-items
+                    :accessor layout-node-align-items)
+   (justify-content :initform :flex-start :initarg :justify-content
+                    :accessor layout-node-justify-content)
+   ;; Box model
+   (padding  :initform '(:top 0 :right 0 :bottom 0 :left 0)
+             :initarg :padding :accessor layout-node-padding)
+   (margin   :initform '(:top 0 :right 0 :bottom 0 :left 0)
+             :initarg :margin :accessor layout-node-margin)
+   (border   :initform '(:top 0 :right 0 :bottom 0 :left 0)
+             :initarg :border :accessor layout-node-border)
+   (gap      :initform 0 :initarg :gap :accessor layout-node-gap)
+   ;; Position
+   (position-type :initform :relative :initarg :position-type
+                  :accessor layout-node-position-type)
+   (position-offset :initform nil :initarg :position-offset
+                    :accessor layout-node-position-offset)
+   ;; Fixed dimensions (nil = auto)
+   (fixed-width  :initform nil :initarg :width
+                 :accessor layout-node-fixed-width)
+   (fixed-height :initform nil :initarg :height
+                 :accessor layout-node-fixed-height)))
+#+END_SRC
+
+*** Constructor
+
+#+BEGIN_SRC lisp
+(defun make-layout-node (&key direction wrap grow shrink basis
+                         align-items justify-content
+                         padding margin border gap
+                         position-type position-offset
+                         width height)
+  (make-instance 'layout-node
+    :direction (or direction :column)
+    :wrap (or wrap :nowrap)
+    :grow (or grow 0)
+    :shrink (or shrink 1)
+    :basis (or basis :auto)
+    :align-items (or align-items :stretch)
+    :justify-content (or justify-content :flex-start)
+    :padding (normalize-box padding)
+    :margin (normalize-box margin)
+    :border (normalize-box border)
+    :gap gap
+    :position-type (or position-type :relative)
+    :position-offset position-offset
+    :width width
+    :height height))
+
+(defun normalize-box (spec)
+  "Convert a box property spec to ( :top N :right N :bottom N :left N )."
+  (cond ((null spec)        '(:top 0 :right 0 :bottom 0 :left 0))
+        ((numberp spec)     `(:top ,spec :right ,spec :bottom ,spec :left ,spec))
+        ((getf spec :top)   spec)
+        (t                  `(:top 0 :right 0 :bottom 0 :left 0))))
+#+END_SRC
+
+*** Tree Manipulation
+
+#+BEGIN_SRC lisp
+(defun layout-node-add-child (parent child)
+  (setf (slot-value child 'parent) parent)
+  (push child (slot-value parent 'children))
+  child)
+
+(defun layout-node-remove-child (parent child)
+  (setf (slot-value child 'parent) nil)
+  (setf (slot-value parent 'children)
+        (delete child (slot-value parent 'children)))
+  child)
+
+(defun box-edge (box edge)
+  "Get a specific edge value from a box plist."
+  (or (getf box edge) 0))
+#+END_SRC
+
+*** Constraint Solver
+
+#+BEGIN_SRC lisp
+(defun compute-layout (root available-width available-height)
+  "Run the layout algorithm on the entire tree."
+  (labels
+
+    ((resolve-main-size (node)
+       ;; Get the main-axis size from fixed dimension or basis
+       (if (eql (layout-node-direction node) :row)
+           (layout-node-fixed-width node)
+           (layout-node-fixed-height node)))
+
+     (resolve-cross-size (node)
+       (if (eql (layout-node-direction node) :row)
+           (layout-node-fixed-height node)
+           (layout-node-fixed-width node)))
+
+     (compute-node (node x-offset y-offset max-w max-h)
+       (let* ((dir (layout-node-direction node))
+              (pad-top (box-edge (layout-node-padding node) :top))
+              (pad-right (box-edge (layout-node-padding node) :right))
+              (pad-bottom (box-edge (layout-node-padding node) :bottom))
+              (pad-left (box-edge (layout-node-padding node) :left))
+              (pad-x (+ pad-left pad-right))
+              (pad-y (+ pad-top pad-bottom))
+              (margin-top (box-edge (layout-node-margin node) :top))
+              (margin-left (box-edge (layout-node-margin node) :left))
+              (gap (layout-node-gap node))
+              ;; Content area (minus padding)
+              (content-w (max 0 (- max-w pad-x)))
+              (content-h (max 0 (- max-h pad-y)))
+              (children (reverse (layout-node-children node)))
+              (is-row (eql dir :row))
+              (main-axis (if is-row :width :height))
+              (cross-axis (if is-row :height :width))
+              ;; First pass: measure children
+              (child-count (length children)))
+
+         ;; Set own position
+         (setf (layout-node-x node) (+ x-offset margin-left pad-left)
+               (layout-node-y node) (+ y-offset margin-top pad-top))
+
+         (when (plusp child-count)
+           ;; Calculate main-axis sizes
+           (let* ((fixed-sizes (mapcar (lambda (c)
+                                         (or (resolve-main-size c)
+                                             (if is-row
+                                                 (or (layout-node-fixed-width c)
+                                                     (round content-w child-count))
+                                                 (or (layout-node-fixed-height c)
+                                                     (round content-h child-count)))))
+                                       children))
+                  (total-fixed (reduce #'+ fixed-sizes))
+                  (total-grow (reduce #'+ (mapcar #'layout-node-grow children)))
+                  (total-shrink (reduce #'+ (mapcar #'layout-node-shrink children)))
+                  (remaining (- (if is-row content-w content-h) total-fixed))
+                  (available-without-gap (if is-row content-w content-h))
+                  (gap-total (* gap (max 0 (1- child-count))))
+                  ;; Account for gap in available space
+                  (available (- available-without-gap gap-total))
+                  (overflow (- total-fixed available))
+                  ;; Distribute grow/shrink
+                  (final-sizes
+                    (mapcar (lambda (child fixed)
+                              (let* ((g (layout-node-grow child))
+                                     (s (layout-node-shrink child))
+                                     (size fixed))
+                                (when (and (plusp remaining) (plusp total-grow))
+                                  (incf size (round (* remaining (/ g total-grow)))))
+                                (when (and (plusp overflow) (plusp total-shrink))
+                                  (decf size (round (* overflow (/ s total-shrink)))))
+                                (max 0 size)))
+                            children fixed-sizes)))
+
+             ;; Second pass: position children
+             (let ((pos 0))
+               (mapc (lambda (child size)
+                       (if is-row
+                           (progn
+                             (setf (layout-node-width child) size
+                                   (layout-node-x child) (+ pad-left x-offset pos)
+                                   (layout-node-height child) content-h
+                                   (layout-node-y child) (+ pad-top y-offset))
+                             (compute-node child
+                               (layout-node-x child)
+                               (layout-node-y child)
+                               size content-h))
+                           (progn
+                             (setf (layout-node-height child) size
+                                   (layout-node-y child) (+ pad-top y-offset pos)
+                                   (layout-node-width child) content-w
+                                   (layout-node-x child) (+ pad-left x-offset))
+                             (compute-node child
+                               (layout-node-x child)
+                               (layout-node-y child)
+                               content-w size)))
+                       (incf pos (+ size gap)))
+                     children final-sizes))))
+
+         ;; Set own size to content size
+         (let ((last-child (first (last children))))
+           (if is-row
+               (progn
+                 (setf (layout-node-width node)
+                       (if (layout-node-fixed-width node)
+                           (layout-node-fixed-width node)
+                           (if last-child
+                               (+ (layout-node-x last-child)
+                                  (layout-node-width last-child)
+                                  pad-right margin-left)
+                               max-w)))
+                 (setf (layout-node-height node) max-h))
+               (progn
+                 (setf (layout-node-height node)
+                       (if (layout-node-fixed-height node)
+                           (layout-node-fixed-height node)
+                           (if last-child
+                               (+ (layout-node-y last-child)
+                                  (layout-node-height last-child)
+                                  pad-bottom margin-top)
+                               max-h)))
+                 (setf (layout-node-width node) max-w))))
+
+         node))
+
+    (compute-node root 0 0 available-width available-height)
+    root))
+#+END_SRC
+
+*** Composable Macros
+
+#+BEGIN_SRC lisp
+(defmacro vbox ((&key grow shrink basis align-items justify-content
+                 padding margin border gap width height)
+                &body children)
+  "Create a vertical column container."
+  (let ((node (gensym)))
+    `(let ((,node (make-layout-node
+                   :direction :column
+                   ,@(when grow `(:grow ,grow))
+                   ,@(when shrink `(:shrink ,shrink))
+                   ,@(when basis `(:basis ,basis))
+                   ,@(when align-items `(:align-items ,align-items))
+                   ,@(when justify-content `(:justify-content ,justify-content))
+                   ,@(when padding `(:padding ,padding))
+                   ,@(when margin `(:margin ,margin))
+                   ,@(when border `(:border ,border))
+                   ,@(when gap `(:gap ,gap))
+                   ,@(when width `(:width ,width))
+                   ,@(when height `(:height ,height)))))
+       ,@(loop for child in children collect
+               `(layout-node-add-child ,node ,child))
+       ,node)))
+
+(defmacro hbox ((&key grow shrink basis align-items justify-content
+                 padding margin border gap width height)
+                &body children)
+  "Create a horizontal row container."
+  (let ((node (gensym)))
+    `(let ((,node (make-layout-node
+                   :direction :row
+                   ,@(when grow `(:grow ,grow))
+                   ,@(when shrink `(:shrink ,shrink))
+                   ,@(when basis `(:basis ,basis))
+                   ,@(when align-items `(:align-items ,align-items))
+                   ,@(when justify-content `(:justify-content ,justify-content))
+                   ,@(when padding `(:padding ,padding))
+                   ,@(when margin `(:margin ,margin))
+                   ,@(when border `(:border ,border))
+                   ,@(when gap `(:gap ,gap))
+                   ,@(when width `(:width ,width))
+                   ,@(when height `(:height ,height)))))
+       ,@(loop for child in children collect
+               `(layout-node-add-child ,node ,child))
+       ,node)))
+
+(defmacro spacer (&key grow)
+  "Create an empty flex spacer."
+  `(make-layout-node :grow ,(or grow 1)))
+#+END_SRC

org/modern-backend.org

@@ -0,0 +1,438 @@
+#+TITLE: cl-tui Modern Backend — v0.0.2
+#+STARTUP: content
+#+FILETAGS: :cl-tui:backend:v0.0.2:
+#+OPTIONS: ^:nil
+
+* Modern Backend
+
+The =modern-backend= renders through raw ANSI/XTerm escape sequences.
+No ncurses, no CFFI, no external dependencies — pure CL string
+construction. Supports truecolor, Unicode box-drawing, OSC 8 hyperlinks,
+DECICM synchronized updates, SGR mouse, and the kitty keyboard protocol.
+
+** Contract
+
+*** Constructor
+
+- =(make-modern-backend &key color-palette)= → modern-backend
+  Create a modern backend. color-palette modifies theme color mappings.
+
+*** Escape Sequence Generation
+
+All escape sequences follow ECMA-48 / ANSI X3.64 conventions:
+
+| Escape | Meaning                  |
+|--------+--------------------------|
+| ~ESC[~ | Control Sequence Introducer (CSI) |
+| ~ESC]~ | Operating System Command (OSC)   |
+| ~ESC ~ | Single-character sequence        |
+
+*** Style Resolution
+
+Colors are resolved through a palette before emission:
+
+- =(resolve-color backend hex-or-name)= → color-index
+  Convert hex string or semantic name to an SGR color code.
+  Hex ("#FFD700") → 48;2;R;G;B or 38;2;R;G;B.
+  Named colors (:black :red :green :yellow :blue :magenta :cyan :white)
+  → 8-color SGR codes.
+
+** Test Suite
+
+#+BEGIN_SRC lisp
+(defpackage :cl-tui-modern-backend-test
+  (:use :cl :fiveam :cl-tui.backend)
+  (:export #:run-tests))
+(in-package :cl-tui-modern-backend-test)
+
+(def-suite modern-backend-suite :description "Modern backend tests")
+(in-suite modern-backend-suite)
+
+(defun run-tests ()
+  (let ((result (run 'modern-backend-suite)))
+    (fiveam:explain! result)
+    (uiop:quit 0)))
+
+;; ── Constructor ────────────────────────────────────────────────
+
+(test make-modern-backend-creates
+  "make-modern-backend returns a modern-backend instance"
+  (let ((b (make-modern-backend)))
+    (is (typep b 'cl-tui.backend::modern-backend))))
+
+;; ── Escape Generation ──────────────────────────────────────────
+
+(test sgr-truecolor-foreground
+  "SGR truecolor foreground escape is correct"
+  (is (equal (cl-tui.backend::sgr-fg "#FFD700")
+             (format nil "~C[38;2;255;215;0m" #\Esc))))
+
+(test sgr-truecolor-background
+  "SGR truecolor background escape is correct"
+  (is (equal (cl-tui.backend::sgr-bg "#1a1b26")
+             (format nil "~C[48;2;26;27;38m" #\Esc))))
+
+(test sgr-named-colors
+  "SGR named colors resolve to 8-color codes"
+  (is (equal (cl-tui.backend::sgr-fg :red)
+             (format nil "~C[31m" #\Esc)))
+  (is (equal (cl-tui.backend::sgr-bg :blue)
+             (format nil "~C[44m" #\Esc))))
+
+(test sgr-bold-italic
+  "SGR attribute escapes are correct"
+  (is (equal (cl-tui.backend::sgr-attr :bold) (format nil "~C[1m" #\Esc)))
+  (is (equal (cl-tui.backend::sgr-attr :italic) (format nil "~C[3m" #\Esc)))
+  (is (equal (cl-tui.backend::sgr-attr :underline) (format nil "~C[4m" #\Esc)))
+  (is (equal (cl-tui.backend::sgr-attr :reset) (format nil "~C[0m" #\Esc))))
+
+;; ── Cursor ─────────────────────────────────────────────────────
+
+(test cursor-move-escape
+  "cursor-move generates correct CSI escape"
+  (let ((b (make-modern-backend)))
+    (is (equal (cl-tui.backend::cursor-move-escape 5 10)
+               (format nil "~C[6;11H" #\Esc)))))
+
+(test cursor-style-block
+  "cursor-style :block generate correct escape"
+  (let ((b (make-modern-backend)))
+    (is (equal (cl-tui.backend::cursor-style-escape :block nil)
+               (format nil "~C[2 q" #\Esc)))))
+
+(test cursor-style-bar
+  "cursor-style :bar generate correct escape"
+  (let ((b (make-modern-backend)))
+    (is (equal (cl-tui.backend::cursor-style-escape :bar nil)
+               (format nil "~C[6 q" #\Esc)))))
+
+(test cursor-style-underline-blink
+  "cursor-style :underline with blink"
+  (let ((b (make-modern-backend)))
+    (is (equal (cl-tui.backend::cursor-style-escape :underline t)
+               (format nil "~C[5 q" #\Esc)))))
+
+;; ── Synchronization ────────────────────────────────────────────
+
+(test decicm-escapes
+  "DECICM synchronized update escapes"
+  (is (equal (cl-tui.backend::decicm-begin) (format nil "~C[?2026h" #\Esc)))
+  (is (equal (cl-tui.backend::decicm-end) (format nil "~C[?2026l" #\Esc))))
+
+;; ── OSC 8 Hyperlinks ──────────────────────────────────────────
+
+(test osc8-escape
+  "OSC 8 hyperlink escape wraps text"
+  (is (equal (cl-tui.backend::osc8-link "http://example.com" "click here")
+             (format nil "~C]8;;http://example.com~C\\click here~C]8;;~C\\"
+                     #\Esc #\Esc #\Esc #\Esc))))
+
+;; ── Hex Parsing ────────────────────────────────────────────────
+
+(test hex-color-parsing
+  "hex-to-rgb parses valid hex colors"
+  (multiple-value-bind (r g b) (cl-tui.backend::hex-to-rgb "#FFD700")
+    (is (= r 255))
+    (is (= g 215))
+    (is (= b 0))))
+
+(test hex-color-black
+  "hex-to-rgb parses black"
+  (multiple-value-bind (r g b) (cl-tui.backend::hex-to-rgb "#000000")
+    (is (= r 0))
+    (is (= g 0))
+    (is (= b 0))))
+
+(test hex-color-short-form
+  "hex-to-rgb parses 3-digit hex"
+  (multiple-value-bind (r g b) (cl-tui.backend::hex-to-rgb "#F00")
+    (is (= r 255))
+    (is (= g 0))
+    (is (= b 0))))
+
+;; ── Border Characters ──────────────────────────────────────────
+
+(test border-char-rounded
+  "modern-border-char returns Unicode box-drawing for rounded style"
+  (is (equal (cl-tui.backend::border-char :rounded :top-left) "╭"))
+  (is (equal (cl-tui.backend::border-char :rounded :horizontal) "─"))
+  (is (equal (cl-tui.backend::border-char :rounded :vertical) "│"))
+  (is (equal (cl-tui.backend::border-char :rounded :bottom-right) "╯")))
+
+(test border-char-double
+  "modern-border-char returns double-line chars"
+  (is (equal (cl-tui.backend::border-char :double :top-left) "╔"))
+  (is (equal (cl-tui.backend::border-char :double :horizontal) "═"))
+  (is (equal (cl-tui.backend::border-char :double :vertical) "║")))
+#+END_SRC
+
+** Implementation
+
+*** Package
+
+Add to =cl-tui.backend= package:
+
+#+BEGIN_SRC lisp
+;; In package.lisp, add to :export:
+;;   #:modern-backend #:make-modern-backend
+;; Internal symbols (not exported, used by tests):
+;;   sgr-fg sgr-bg sgr-attr cursor-move-escape cursor-style-escape
+;;   decicm-begin decicm-end osc8-link hex-to-rgb border-char
+
+(in-package :cl-tui.backend)
+#+END_SRC
+
+*** Color Resolution
+
+#+BEGIN_SRC lisp
+(defun hex-to-rgb (hex)
+  "Parse a hex color string like \"#FFD700\" into (values r g b).
+  Also handles 3-digit hex like \"#F00\"."
+  (let ((clean (string-trim '(#\# #\Space) hex)))
+    (if (= (length clean) 3)
+        (values (parse-integer (subseq clean 0 1) :radix 16 :junk-allowed t)
+                (parse-integer (subseq clean 1 2) :radix 16 :junk-allowed t)
+                (parse-integer (subseq clean 2 3) :radix 16 :junk-allowed t))
+        (values (parse-integer (subseq clean 0 2) :radix 16 :junk-allowed t)
+                (parse-integer (subseq clean 2 4) :radix 16 :junk-allowed t)
+                (parse-integer (subseq clean 4 6) :radix 16 :junk-allowed t)))))
+
+(defparameter *named-colors*
+  '((:black . 0) (:red . 1) (:green . 2) (:yellow . 3)
+    (:blue . 4) (:magenta . 5) (:cyan . 6) (:white . 7)))
+
+(defun sgr-fg (color)
+  "Return SGR foreground escape for COLOR.
+  Color can be a hex string, a keyword name, or nil."
+  (if (null color) ""
+      (cond ((and (stringp color) (char= (char color 0) #\#))
+             (multiple-value-bind (r g b) (hex-to-rgb color)
+               (format nil "~C[38;2;~d;~d;~dm" #\Esc r g b)))
+            ((keywordp color)
+             (let ((index (cdr (assoc color *named-colors*))))
+               (if index
+                   (format nil "~C[~dm" #\Esc (+ 30 index))
+                   "")))
+            (t ""))))
+
+(defun sgr-bg (color)
+  "Return SGR background escape for COLOR."
+  (if (null color) ""
+      (cond ((and (stringp color) (char= (char color 0) #\#))
+             (multiple-value-bind (r g b) (hex-to-rgb color)
+               (format nil "~C[48;2;~d;~d;~dm" #\Esc r g b)))
+            ((keywordp color)
+             (let ((index (cdr (assoc color *named-colors*))))
+               (if index
+                   (format nil "~C[~dm" #\Esc (+ 40 index))
+                   "")))
+            (t ""))))
+
+(defparameter *sgr-attr-codes*
+  '((:bold . 1) (:dim . 2) (:italic . 3) (:underline . 4)
+    (:blink . 5) (:reverse . 7) (:reset . 0)))
+
+(defun sgr-attr (attr)
+  "Return SGR attribute escape for ATTR keyword."
+  (let ((code (cdr (assoc attr *sgr-attr-codes*))))
+    (if code
+        (format nil "~C[~dm" #\Esc code)
+        "")))
+#+END_SRC
+
+*** Cursor Escapes
+
+#+BEGIN_SRC lisp
+(defun cursor-move-escape (x y)
+  "Return CSI escape to move cursor to (x, y), 1-indexed."
+  (format nil "~C[~d;~dH" #\Esc (1+ y) (1+ x)))
+
+(defun cursor-style-escape (shape blink)
+  "Return DECSTR escape for cursor shape.
+  :block = 2, :underline = 4, :bar = 6.
+  Add 1 for blink variants."
+  (let* ((base (case shape
+                 (:block 2) (:underline 4) (:bar 6)
+                 (t 2)))
+         (code (if blink (1+ base) base)))
+    (format nil "~C[~d q" #\Esc code)))
+#+END_SRC
+
+*** Synchronization (DECICM)
+
+#+BEGIN_SRC lisp
+(defun decicm-begin ()
+  "Return escape to enable synchronized updates."
+  (format nil "~C[?2026h" #\Esc))
+
+(defun decicm-end ()
+  "Return escape to disable synchronized updates."
+  (format nil "~C[?2026l" #\Esc))
+#+END_SRC
+
+*** OSC 8 Hyperlinks
+
+#+BEGIN_SRC lisp
+(defun osc8-link (url text)
+  "Wrap TEXT in an OSC 8 hyperlink to URL."
+  (format nil "~C]8;;~A~C\\~A~C]8;;~C\\"
+          #\Esc url #\Esc text #\Esc #\Esc))
+#+END_SRC
+
+*** Border Characters
+
+#+BEGIN_SRC lisp
+(defparameter *border-chars*
+  '((:single :top-left . "┌") (:single :top-right . "┐")
+    (:single :bottom-left . "└") (:single :bottom-right . "┘")
+    (:single :horizontal . "─") (:single :vertical . "│")
+    (:double :top-left . "╔") (:double :top-right . "╗")
+    (:double :bottom-left . "╚") (:double :bottom-right . "╝")
+    (:double :horizontal . "═") (:double :vertical . "║")
+    (:rounded :top-left . "╭") (:rounded :top-right . "╮")
+    (:rounded :bottom-left . "╰") (:rounded :bottom-right . "╯")
+    (:rounded :horizontal . "─") (:rounded :vertical . "│")))
+
+(defun border-char (style pos)
+  "Return the Unicode box-drawing character for STYLE at POS."
+  (let ((char (cdr (assoc (cons style pos) *border-chars* :test #'equal))))
+    (or char (if (member pos '(:horizontal :vertical))
+                 (case pos (:horizontal "─") (:vertical "│"))
+                 "+"))))
+#+END_SRC
+
+*** Modern Backend Class
+
+#+BEGIN_SRC lisp
+(defclass modern-backend (backend)
+  ((output-stream :initform *standard-output*
+                  :accessor backend-output-stream)
+   (in-sync-p :initform nil :accessor in-sync-p)))
+
+(defun make-modern-backend (&key color-palette)
+  (declare (ignore color-palette))
+  (make-instance 'modern-backend))
+
+(defmethod initialize-backend ((b modern-backend))
+  ;; Enter raw mode, enable mouse, bracketed paste
+  (backend-write b (format nil "~C[?1049h" #\Esc))  ; alt screen
+  (backend-write b (format nil "~C[?1000h" #\Esc))  ; mouse basic
+  (backend-write b (format nil "~C[?1002h" #\Esc))  ; mouse drag
+  (backend-write b (format nil "~C[?1006h" #\Esc))  ; SGR mouse
+  (backend-write b (format nil "~C[?2004h" #\Esc))  ; bracketed paste
+  (cursor-hide b)
+  (finish-output (backend-output-stream b))
+  b)
+
+(defmethod shutdown-backend ((b modern-backend))
+  (cursor-show b)
+  (backend-write b (format nil "~C[?2004l" #\Esc))  ; disable bracketed paste
+  (backend-write b (format nil "~C[?1006l" #\Esc))  ; disable SGR mouse
+  (backend-write b (format nil "~C[?1002l" #\Esc))
+  (backend-write b (format nil "~C[?1000l" #\Esc))
+  (backend-write b (format nil "~C[?1049l" #\Esc))  ; normal screen
+  (finish-output (backend-output-stream b))
+  (values))
+
+(defmethod backend-size ((b modern-backend))
+  ;; Default fallback — real implementation queries terminal
+  (values 80 24))
+
+(defmethod backend-write ((b modern-backend) string)
+  (let ((stream (backend-output-stream b)))
+    (write-string string stream)
+    (length string)))
+
+(defmethod capable-p ((b modern-backend) feature)
+  (member feature '(:truecolor :osc8 :sync :mouse
+                    :bracketed-paste :cursor-style
+                    :kitty-keyboard)))
+
+(defmethod draw-text ((b modern-backend) x y string fg bg
+                      &key bold italic underline reverse dim blink)
+  (let ((parts (list (cursor-move-escape x y)
+                     (sgr-fg fg) (sgr-bg bg)
+                     (when bold (sgr-attr :bold))
+                     (when italic (sgr-attr :italic))
+                     (when underline (sgr-attr :underline))
+                     (when reverse (sgr-attr :reverse))
+                     (when dim (sgr-attr :dim))
+                     (when blink (sgr-attr :blink))
+                     string
+                     (sgr-attr :reset))))
+    (backend-write b (apply #'concatenate 'string parts))))
+
+(defmethod draw-border ((b modern-backend) x y width height
+                        &key style fg bg title title-align)
+  (declare (ignore title title-align))
+  (let* ((s (or style :single))
+         (tl (border-char s :top-left))
+         (tr (border-char s :top-right))
+         (bl (border-char s :bottom-left))
+         (br (border-char s :bottom-right))
+         (h  (border-char s :horizontal))
+         (v  (border-char s :vertical))
+         (fg-esc (sgr-fg fg))
+         (bg-esc (sgr-bg bg))
+         (reset (sgr-attr :reset))
+         (top (concatenate 'string
+                fg-esc bg-esc tl
+                (make-string (- width 2) :initial-element (char h 0))
+                tr reset (string #\Newline)))
+         (mid (concatenate 'string
+                fg-esc bg-esc v
+                (make-string (- width 2) :initial-element #\Space)
+                v reset (string #\Newline)))
+         (bot (concatenate 'string
+                fg-esc bg-esc bl
+                (make-string (- width 2) :initial-element (char h 0))
+                br reset)))
+    (backend-write b top)
+    (loop repeat (- height 2) do (backend-write b mid))
+    (backend-write b bot)))
+
+(defmethod draw-rect ((b modern-backend) x y width height &key bg)
+  (let ((bg-esc (sgr-bg bg))
+        (reset (sgr-attr :reset))
+        (line (concatenate 'string
+                bg-esc
+                (make-string width :initial-element #\Space)
+                reset (string #\Newline))))
+    (loop repeat height do
+      (backend-write b (cursor-move-escape x y))
+      (backend-write b line))))
+
+(defmethod draw-link ((b modern-backend) x y string url
+                      &key fg bg)
+  (let ((parts (list (cursor-move-escape x y)
+                     (sgr-fg fg) (sgr-bg bg)
+                     (osc8-link url string)
+                     (sgr-attr :reset))))
+    (backend-write b (apply #'concatenate 'string parts))))
+
+(defmethod draw-ellipsis ((b modern-backend) x y width
+                          &key fg bg)
+  (let ((dots "..."))
+    (draw-text b x y dots fg bg)))
+
+(defmethod cursor-move ((b modern-backend) x y)
+  (backend-write b (cursor-move-escape x y)))
+
+(defmethod cursor-hide ((b modern-backend))
+  (backend-write b (format nil "~C[?25l" #\Esc)))
+
+(defmethod cursor-show ((b modern-backend))
+  (backend-write b (format nil "~C[?25h" #\Esc)))
+
+(defmethod cursor-style ((b modern-backend) shape &key blink)
+  (backend-write b (cursor-style-escape shape blink)))
+
+(defmethod begin-sync ((b modern-backend))
+  (setf (in-sync-p b) t)
+  (backend-write b (decicm-begin)))
+
+(defmethod end-sync ((b modern-backend))
+  (setf (in-sync-p b) nil)
+  (backend-write b (decicm-end))
+  (finish-output (backend-output-stream b)))
+#+END_SRC

scripts/tangle.py

@@ -0,0 +1,74 @@
+#!/usr/bin/env python3
+"""tangle.py — Extract code blocks from .org files into .lisp files.
+
+Reads all .org files in org/ directory, finds #+BEGIN_SRC lisp :tangle <path>
+blocks, and writes/concatenates them to the specified target paths.
+
+Blocks with the same :tangle target are concatenated in file order.
+
+Usage:
+  python3 scripts/tangle.py              # tangle all org/ files
+  python3 scripts/tangle.py org/specific.org  # tangle one file
+
+Target paths are relative to the project root (../target from org/ = project/target).
+"""
+import re
+import os
+import sys
+from collections import OrderedDict
+
+PROJECT_ROOT = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
+ORG_DIR = os.path.join(PROJECT_ROOT, 'org')
+
+def tangle_file(org_path):
+    """Extract tangle blocks from one .org file."""
+    with open(org_path) as f:
+        content = f.read()
+
+    # Find all tangle blocks with their targets
+    pattern = r'#\+BEGIN_SRC lisp :tangle ([^\n]+)\n(.*?)\n#\+END_SRC'
+    blocks = re.findall(pattern, content, re.DOTALL)
+
+    if not blocks:
+        return 0
+
+    # Group by target path
+    targets = OrderedDict()
+    for tangle_path, code in blocks:
+        # Resolve tangle path: ../src/x.lisp -> src/x.lisp
+        resolved = tangle_path.replace('../', '')
+        full_path = os.path.join(PROJECT_ROOT, resolved)
+        if full_path not in targets:
+            targets[full_path] = []
+        targets[full_path].append(code.strip())
+
+    for full_path, codes in targets.items():
+        os.makedirs(os.path.dirname(full_path), exist_ok=True)
+        combined = '\n\n'.join(codes) + '\n'
+        with open(full_path, 'w') as f:
+            f.write(combined)
+        print(f"  {os.path.relpath(full_path, PROJECT_ROOT)} ({len(codes)} blocks, {sum(len(c) for c in codes)} chars)")
+
+    return len(blocks)
+
+def main():
+    if len(sys.argv) > 1:
+        org_files = [f for f in sys.argv[1:] if f.endswith('.org')]
+    else:
+        org_files = [os.path.join(ORG_DIR, f) for f in os.listdir(ORG_DIR) if f.endswith('.org')]
+
+    total_blocks = 0
+    for org_file in sorted(org_files):
+        name = os.path.basename(org_file)
+        blocks = tangle_file(org_file)
+        if blocks:
+            print(f"{name}: {blocks} blocks")
+            total_blocks += blocks
+
+    if total_blocks > 0:
+        print(f"\nTotal: {total_blocks} code blocks tangled")
+    else:
+        print("No tangle blocks found.")
+
+if __name__ == '__main__':
+    main()

src/components/box-tests.lisp

@@ -0,0 +1,166 @@
+(defpackage :cl-tui-box-test
+  (:use :cl :fiveam :cl-tui.backend :cl-tui.layout :cl-tui.box)
+  (:export #:run-tests))
+(in-package :cl-tui-box-test)
+
+(def-suite box-suite :description "Box renderable tests")
+(in-suite box-suite)
+
+(defun run-tests ()
+  (let ((result (run 'box-suite)))
+    (fiveam:explain! result)
+    (uiop:quit 0)))
+
+(defun make-capturing-backend ()
+  (let* ((s (make-string-output-stream))
+         (b (make-modern-backend :output-stream s)))
+    (values b s)))
+
+;; ── Box Tests ─────────────────────────────────────────────────
+
+(test box-creates-with-defaults
+  "A box created with no arguments has reasonable defaults"
+  (let ((b (make-box)))
+    (is (typep b 'box))
+    (is (typep (box-layout-node b) 'layout-node))))
+
+(test box-renders-border
+  "A box with border draws border characters"
+  (multiple-value-bind (b s) (make-capturing-backend)
+    (let ((bx (make-box :border-style :single :width 10 :height 5)))
+      (compute-layout (box-layout-node bx) 10 5)
+      (render-box bx b)
+      (let ((out (get-output-stream-string s)))
+        (is (search "┌" out) "top-left corner")
+        (is (search "┐" out) "top-right corner")
+        (is (search "└" out) "bottom-left corner")
+        (is (search "┘" out) "bottom-right corner")))))
+
+(test box-renders-background
+  "A box with background color fills interior"
+  (multiple-value-bind (b s) (make-capturing-backend)
+    (let ((bx (make-box :bg :red :width 5 :height 3)))
+      (compute-layout (box-layout-node bx) 5 3)
+      (render-box bx b)
+      (let ((out (get-output-stream-string s)))
+        (is (search "┌" out) "border with background")
+        (is (search "41m" out) "SGR background for red")))))
+
+(test box-renders-title
+  "A box with title renders the title text"
+  (multiple-value-bind (b s) (make-capturing-backend)
+    (let ((bx (make-box :title "Hello" :width 12 :height 3)))
+      (compute-layout (box-layout-node bx) 12 3)
+      (render-box bx b)
+      (let ((out (get-output-stream-string s)))
+        (is (search "Hello" out) "title text should appear")))))
+
+(test box-without-border
+  "A box with border-style nil draws no border"
+  (multiple-value-bind (b s) (make-capturing-backend)
+    (let ((bx (make-box :border-style nil :bg :red :width 5 :height 3)))
+      (compute-layout (box-layout-node bx) 5 3)
+      (render-box bx b)
+      (let ((out (get-output-stream-string s)))
+        (is (search "41m" out) "background still renders")
+        (is-false (search "┌" out) "no top-left corner")))))
+
+(test box-zero-size
+  "A box with any zero dimension renders nothing"
+  (multiple-value-bind (b s) (make-capturing-backend)
+    (let ((bx (make-box :border-style :single :width 0 :height 0)))
+      (compute-layout (box-layout-node bx) 0 0)
+      (render-box bx b)
+      (is (string= (get-output-stream-string s) "")
+          "zero-size box produces no output"))))
+
+(test box-single-column
+  "A box with width 1 renders nothing (needs min 2 for border)"
+  (multiple-value-bind (b s) (make-capturing-backend)
+    (let ((bx (make-box :border-style :single :width 1 :height 5)))
+      (compute-layout (box-layout-node bx) 1 5)
+      (render-box bx b)
+      (is (string= (get-output-stream-string s) "")
+          "width=1 box renders nothing"))))
+
+(test box-minimum-size
+  "A box with minimum non-zero size still renders"
+  (multiple-value-bind (b s) (make-capturing-backend)
+    (let ((bx (make-box :border-style :single :width 2 :height 2)))
+      (compute-layout (box-layout-node bx) 2 2)
+      (render-box bx b)
+      (let ((out (get-output-stream-string s)))
+        (is (search "┌" out) "2x2 box still has borders")))))
+
+;; ── Text and Span Tests ───────────────────────────────────────
+
+(test text-creates-with-defaults
+  "A text created with no arguments has reasonable defaults"
+  (let ((txt (make-text "")))
+    (is (typep txt 'text))
+    (is (typep (text-layout-node txt) 'layout-node))))
+
+(test text-renders-content
+  "A text renders its content at position"
+  (multiple-value-bind (b s) (make-capturing-backend)
+    (let ((tx (make-text "Hello" :width 10 :height 1)))
+      (compute-layout (text-layout-node tx) 10 1)
+      (render-text tx b)
+      (let ((out (get-output-stream-string s)))
+        (is (search "Hello" out) "content should appear")))))
+
+(test text-empty-string
+  "Empty text produces no output"
+  (multiple-value-bind (b s) (make-capturing-backend)
+    (let ((tx (make-text "" :width 10 :height 1)))
+      (compute-layout (text-layout-node tx) 10 1)
+      (render-text tx b)
+      (is (string= (get-output-stream-string s) "")
+          "empty string produces no output"))))
+
+(test text-truncates-when-no-wrap
+  "Text with wrap-mode :none truncates at width"
+  (multiple-value-bind (b s) (make-capturing-backend)
+    (let ((tx (make-text "Hello World" :width 5 :height 1
+                         :wrap-mode :none)))
+      (compute-layout (text-layout-node tx) 5 1)
+      (render-text tx b)
+      (let ((out (get-output-stream-string s)))
+        (is (search "Hello" out) "truncated to first 5 chars")))))
+
+(test text-word-wraps
+  "Text with wrap-mode :word wraps at word boundaries"
+  (multiple-value-bind (b s) (make-capturing-backend)
+    (let ((tx (make-text "Hello brave new world" :width 6 :height 3)))
+      (compute-layout (text-layout-node tx) 6 3)
+      (render-text tx b)
+      (let ((out (get-output-stream-string s)))
+        (is (search "Hello" out) "first line")
+        (is (search "brave" out) "second line")
+        (is (search "new" out) "third line")))))
+
+(test text-word-wrap-single-word
+  "A word longer than width is hard-broken at max-width"
+  (multiple-value-bind (b s) (make-capturing-backend)
+    (let ((tx (make-text "Hello" :width 3 :height 3)))
+      (compute-layout (text-layout-node tx) 3 3)
+      (render-text tx b)
+      (let ((out (get-output-stream-string s)))
+        (is (search "Hel" out) "first chunk is Hel")
+        (is (search "lo" out) "second chunk is lo")))))
+
+(test span-creates-with-attributes
+  "A span has text and optional style attributes"
+  (let ((s (span "bold text" :bold t)))
+    (is (string= (span-text s) "bold text"))
+    (is-true (span-bold s))
+    (is-false (span-italic s))))
+
+(test make-text-with-spans
+  "Text with spans stores span objects"
+  (let* ((sp (list (span "Hello" :bold t)
+                   (span "World" :italic t)))
+         (tx (make-text "" :spans sp)))
+    (is (= (length (text-spans tx)) 2))
+    (is (string= (span-text (elt (text-spans tx) 0)) "Hello"))
+    (is-true (span-bold (elt (text-spans tx) 0)))))

src/components/box.lisp

@@ -0,0 +1,54 @@
+(in-package :cl-tui.box)
+
+(defclass box (dirty-mixin)
+  ((layout-node :initform (make-layout-node) :accessor box-layout-node
+     :initarg :layout-node)
+   (border-style :initform :single :initarg :border-style
+     :accessor box-border-style)
+   (title :initform nil :initarg :title :accessor box-title)
+   (title-align :initform :left :initarg :title-align
+     :accessor box-title-align)
+   (fg :initform nil :initarg :fg :accessor box-fg)
+   (bg :initform nil :initarg :bg :accessor box-bg)))
+
+(defun make-box (&key (border-style :single) title
+                  (title-align :left) fg bg
+                  width height)
+  (make-instance 'box
+    :border-style border-style
+    :title title
+    :title-align title-align
+    :fg fg
+    :bg bg
+    :layout-node (make-layout-node
+                   :width width
+                   :height height
+                   :direction :column)))
+
+(defun render-box (box backend)
+  "Render BOX at its computed layout position using BACKEND."
+  (let ((ln (box-layout-node box))
+        (bs (box-border-style box))
+        (title (box-title box))
+        (fg (box-fg box))
+        (bg (box-bg box)))
+    (let ((x (layout-node-x ln))
+          (y (layout-node-y ln))
+          (w (layout-node-width ln))
+          (h (layout-node-height ln)))
+      (when (or (zerop w) (zerop h) (< w 2) (< h 2))
+        (return-from render-box (values)))
+      (when bg
+        (draw-rect backend x y w h :bg bg))
+      (when bs
+        (draw-border backend x y w h :style bs :fg fg :bg bg))
+      (when title
+        (let* ((content-w (- w 4))
+               (tx (+ x 2))
+               (ty (+ y (if bs 1 0)))
+               (ta (box-title-align box))
+               (display (subseq title 0 (min (length title) content-w))))
+          (case ta
+            (:center (draw-text backend (+ x (ceiling (- w (length display)) 2)) ty display fg bg))
+            (:right (draw-text backend (+ x (- w (length display) 2)) ty display fg bg))
+            (t (draw-text backend tx ty display fg bg))))))))

src/components/dirty-tests.lisp

@@ -0,0 +1,21 @@
+;; Dirty tracking tests are in box-tests.lisp (same test suite)
+(in-package :cl-tui-box-test)
+(in-suite box-suite)
+
+(test dirty-mixin-default-is-dirty
+  "A dirty-mixin starts as dirty"
+  (let ((c (make-instance 'dirty-mixin)))
+    (is-true (dirty-p c) "new component should be dirty")))
+
+(test mark-clean-clears-dirty
+  "mark-clean sets dirty to nil"
+  (let ((c (make-instance 'dirty-mixin)))
+    (mark-clean c)
+    (is-false (dirty-p c) "after mark-clean, should not be dirty")))
+
+(test mark-dirty-sets-dirty
+  "mark-dirty sets dirty to t"
+  (let ((c (make-instance 'dirty-mixin)))
+    (mark-clean c)
+    (mark-dirty c)
+    (is-true (dirty-p c) "after mark-dirty, should be dirty again")))

src/components/dirty.lisp

@@ -0,0 +1,14 @@
+(in-package :cl-tui.box)
+
+;; ── Dirty Tracking ─────────────────────────────────────────────
+
+(defclass dirty-mixin ()
+  ((dirty :initform t :accessor dirty-p)))
+
+(defgeneric mark-clean (component)
+  (:method ((c dirty-mixin))
+    (setf (dirty-p c) nil)))
+
+(defgeneric mark-dirty (component)
+  (:method ((c dirty-mixin))
+    (setf (dirty-p c) t)))

src/components/input-package.lisp

@@ -0,0 +1,34 @@
+(defpackage :cl-tui.input
+  (:use :cl :cl-tui.backend :cl-tui.box :cl-tui.layout)
+  (:export
+   ;; Key events
+   #:key-event #:make-key-event
+   #:key-event-p #:key-event-key #:key-event-ctrl
+   #:key-event-alt #:key-event-shift #:key-event-code
+   #:key-event-raw #:key-event-text
+   ;; Mouse events
+   #:mouse-event #:make-mouse-event
+   #:mouse-event-p #:mouse-event-type #:mouse-event-button
+   #:mouse-event-x #:mouse-event-y
+   ;; Terminal raw mode
+   #:save-terminal-state #:set-raw-mode #:restore-terminal-state
+   #:with-raw-terminal
+   ;; Event reading
+   #:read-event
+   ;; TextInput
+   #:text-input #:make-text-input
+   #:text-input-value #:text-input-cursor
+   #:text-input-placeholder #:text-input-max-length
+   #:text-input-on-submit #:text-input-layout-node
+   #:handle-text-input #:render-text-input
+   ;; Textarea
+   #:textarea #:make-textarea
+   #:textarea-value #:textarea-cursor-row #:textarea-cursor-col
+   #:textarea-on-submit #:textarea-undo-stack #:textarea-redo-stack
+   #:textarea-layout-node
+   #:handle-textarea-input #:render-textarea
+   ;; Keybindings
+   #:keymap #:make-keymap #:keymap-name #:keymap-bindings #:keymap-parent
+   #:*keymaps* #:*chord-timeout*
+   #:defkeymap #:dispatch-key-event #:key-match-p
+   #:component-keymap))

src/components/input-tests.lisp

@@ -0,0 +1,269 @@
+(defpackage :cl-tui-input-test
+  (:use :cl :fiveam :cl-tui.backend :cl-tui.box :cl-tui.layout :cl-tui.input)
+  (:export #:run-tests))
+(in-package :cl-tui-input-test)
+
+(def-suite input-suite :description "Text input and keybinding tests")
+(in-suite input-suite)
+
+(defun run-tests ()
+  (let ((result (run 'input-suite)))
+    (fiveam:explain! result)
+    (uiop:quit 0)))
+
+;; ── Key Event Tests ─────────────────────────────────────────────
+
+(test key-event-construction
+  "A key-event can be created and queried."
+  (let ((e (make-key-event :key :a :ctrl t :alt nil)))
+    (is (eql (key-event-key e) :a))
+    (is-true (key-event-ctrl e))
+    (is-false (key-event-alt e))))
+
+(test key-event-defaults
+  "Fields default to NIL/nil."
+  (let ((e (make-key-event :key :space)))
+    (is (eql (key-event-key e) :space))
+    (is-false (key-event-ctrl e))
+    (is-false (key-event-alt e))
+    (is-false (key-event-shift e))))
+
+(test mouse-event-construction
+  "A mouse-event can be created and queried."
+  (let ((e (make-mouse-event :type :press :button :left :x 10 :y 5)))
+    (is (eql (mouse-event-type e) :press))
+    (is (eql (mouse-event-button e) :left))
+    (is (= (mouse-event-x e) 10))
+    (is (= (mouse-event-y e) 5))))
+
+;; ── TextInput Tests ─────────────────────────────────────────────
+
+(test text-input-empty
+  "A newly created text-input has empty value and cursor at 0."
+  (let ((in (make-text-input)))
+    (is (string= (text-input-value in) ""))
+    (is (= (text-input-cursor in) 0))))
+
+(test text-input-insert-char
+  "Inserting a character appends and moves cursor."
+  (let ((in (make-text-input)))
+    (handle-text-input in (make-key-event :key :a :code (char-code #\a)))
+    (is (string= (text-input-value in) "a"))
+    (is (= (text-input-cursor in) 1))))
+
+(test text-input-insert-multiple
+  "Inserting multiple characters works left to right."
+  (let ((in (make-text-input)))
+    (handle-text-input in (make-key-event :key :h :code (char-code #\h)))
+    (handle-text-input in (make-key-event :key :e :code (char-code #\e)))
+    (handle-text-input in (make-key-event :key :l :code (char-code #\l)))
+    (handle-text-input in (make-key-event :key :l :code (char-code #\l)))
+    (handle-text-input in (make-key-event :key :o :code (char-code #\o)))
+    (is (string= (text-input-value in) "hello"))
+    (is (= (text-input-cursor in) 5))))
+
+(test text-input-backspace
+  "Backspace removes the character before the cursor."
+  (let ((in (make-text-input :value "ab" :cursor 2)))
+    (handle-text-input in (make-key-event :key :backspace))
+    (is (string= (text-input-value in) "a"))
+    (is (= (text-input-cursor in) 1))))
+
+(test text-input-backspace-at-start
+  "Backspace at position 0 does nothing."
+  (let ((in (make-text-input :value "ab" :cursor 0)))
+    (handle-text-input in (make-key-event :key :backspace))
+    (is (string= (text-input-value in) "ab"))
+    (is (= (text-input-cursor in) 0))))
+
+(test text-input-delete
+  "Delete removes the character at the cursor."
+  (let ((in (make-text-input :value "abc" :cursor 1)))
+    (handle-text-input in (make-key-event :key :delete))
+    (is (string= (text-input-value in) "ac"))
+    (is (= (text-input-cursor in) 1))))
+
+(test text-input-cursor-left-right
+  "Cursor moves left and right."
+  (let ((in (make-text-input :value "ab" :cursor 2)))
+    (handle-text-input in (make-key-event :key :left))
+    (is (= (text-input-cursor in) 1))
+    (handle-text-input in (make-key-event :key :right))
+    (is (= (text-input-cursor in) 2))))
+
+(test text-input-cursor-bounds
+  "Cursor cannot move past start or end."
+  (let ((in (make-text-input :value "ab" :cursor 0)))
+    (handle-text-input in (make-key-event :key :left))
+    (is (= (text-input-cursor in) 0))
+    (setf (text-input-cursor in) 2)
+    (handle-text-input in (make-key-event :key :right))
+    (is (= (text-input-cursor in) 2))))
+
+(test text-input-home-end
+  "Home moves to start, End moves to end."
+  (let ((in (make-text-input :value "hello" :cursor 3)))
+    (handle-text-input in (make-key-event :key :home))
+    (is (= (text-input-cursor in) 0))
+    (handle-text-input in (make-key-event :key :end))
+    (is (= (text-input-cursor in) 5))))
+
+(test text-input-max-length
+  "Max-length prevents inserting beyond the limit."
+  (let ((in (make-text-input :max-length 3)))
+    (handle-text-input in (make-key-event :key :a :code (char-code #\a)))
+    (handle-text-input in (make-key-event :key :b :code (char-code #\b)))
+    (handle-text-input in (make-key-event :key :c :code (char-code #\c)))
+    (handle-text-input in (make-key-event :key :d :code (char-code #\d)))
+    (is (string= (text-input-value in) "abc"))))
+
+(test text-input-placeholder
+  "Placeholder is stored but does not affect value."
+  (let ((in (make-text-input :placeholder "Type here...")))
+    (is (string= (text-input-placeholder in) "Type here..."))
+    (is (string= (text-input-value in) ""))))
+
+(test text-input-on-submit
+  "On-submit callback fires on Enter."
+  (let ((result (list nil)))
+    (let ((in (make-text-input :value "hello"
+                               :on-submit (lambda (v) (setf (car result) v)))))
+      (handle-text-input in (make-key-event :key :enter))
+      (is (string= (car result) "hello")))))
+
+(test text-input-ctrl-a-e
+  "Ctrl+A moves to home, Ctrl+E moves to end."
+  (let ((in (make-text-input :value "abc" :cursor 2)))
+    (handle-text-input in (make-key-event :key :a :ctrl t))
+    (is (= (text-input-cursor in) 0))
+    (handle-text-input in (make-key-event :key :e :ctrl t))
+    (is (= (text-input-cursor in) 3))))
+
+(test text-input-insert-in-middle
+  "Inserting in the middle of text shifts rest right."
+  (let ((in (make-text-input :value "ab" :cursor 1)))
+    (handle-text-input in (make-key-event :key :x :code (char-code #\x)))
+    (is (string= (text-input-value in) "axb"))
+    (is (= (text-input-cursor in) 2))))
+
+(test text-input-dirty-on-insert
+  "Inserting marks the widget dirty."
+  (let ((in (make-text-input)))
+    (mark-clean in)
+    (handle-text-input in (make-key-event :key :a :code (char-code #\a)))
+    (is-true (dirty-p in))))
+
+;; ── Textarea Tests ──────────────────────────────────────────────
+
+(test textarea-empty
+  "New textarea has empty value and cursor at (0,0)."
+  (let ((a (make-textarea)))
+    (is (string= (textarea-value a) ""))
+    (is (= (textarea-cursor-row a) 0))
+    (is (= (textarea-cursor-col a) 0))))
+
+(test textarea-newline
+  "Enter inserts a newline."
+  (let ((a (make-textarea)))
+    (handle-textarea-input a (make-key-event :key :a :code (char-code #\a)))
+    (handle-textarea-input a (make-key-event :key :enter))
+    (handle-textarea-input a (make-key-event :key :b :code (char-code #\b)))
+    (is (string= (textarea-value a) "a
+b"))))
+
+(test textarea-cursor-up-down
+  "Cursor moves between lines maintaining column position."
+  (let ((a (make-textarea :value "abc
+de
+fghi")))
+    (setf (textarea-cursor-row a) 1)
+    (setf (textarea-cursor-col a) 1)
+    (handle-textarea-input a (make-key-event :key :up))
+    (is (= (textarea-cursor-row a) 0))
+    (is (= (textarea-cursor-col a) 1))
+    (handle-textarea-input a (make-key-event :key :down))
+    (is (= (textarea-cursor-row a) 1))
+    (is (= (textarea-cursor-col a) 1))))
+
+(test textarea-cursor-up-down-bounds
+  "Cursor cannot move past first or last line."
+  (let ((a (make-textarea :value "a
+b")))
+    (handle-textarea-input a (make-key-event :key :up))
+    (is (= (textarea-cursor-row a) 0))
+    (setf (textarea-cursor-row a) 1)
+    (handle-textarea-input a (make-key-event :key :down))
+    (is (= (textarea-cursor-row a) 1))))
+
+(test textarea-backspace-joins-lines
+  "Backspace at start of a line joins with previous."
+  (let ((a (make-textarea :value "hello
+world")))
+    (setf (textarea-cursor-row a) 1)
+    (setf (textarea-cursor-col a) 0)
+    (handle-textarea-input a (make-key-event :key :backspace))
+    (is (string= (textarea-value a) "helloworld"))))
+
+(test textarea-undo
+  "Ctrl+Z undoes the last edit."
+  (let ((a (make-textarea)))
+    (handle-textarea-input a (make-key-event :key :a :code (char-code #\a)))
+    (handle-textarea-input a (make-key-event :key :z :ctrl t))
+    (is (string= (textarea-value a) ""))))
+
+(test textarea-undo-redo
+  "Ctrl+Y redoes an undone edit."
+  (let ((a (make-textarea)))
+    (handle-textarea-input a (make-key-event :key :a :code (char-code #\a)))
+    (handle-textarea-input a (make-key-event :key :z :ctrl t))
+    (handle-textarea-input a (make-key-event :key :y :ctrl t))
+    (is (string= (textarea-value a) "a"))))
+
+;; ── Keybinding Tests ────────────────────────────────────────────
+
+(test keymap-simple
+  "A keymap dispatches to its handler on matching event."
+  (let ((called nil))
+    (setf (gethash :global *keymaps*)
+          (make-keymap :name :global
+                       :bindings `((:ctrl+p . ,(lambda (e)
+                                                 (declare (ignore e))
+                                                 (setf called t))))))
+    (is-true (dispatch-key-event (make-key-event :key :p :ctrl t)))
+    (is-true called)))
+
+(test keymap-no-match
+  "Non-matching event returns nil."
+  (let ((called nil))
+    (setf (gethash :global *keymaps*)
+          (make-keymap :name :global
+                       :bindings `((:ctrl+p . ,(lambda (e)
+                                                 (declare (ignore e))
+                                                 (setf called t))))))
+    (is-false (dispatch-key-event (make-key-event :key :a)))
+    (is-false called)))
+
+(test keymap-fallback
+  "Event not in local falls through to global."
+  (let ((global-called nil))
+    (setf (gethash :global *keymaps*)
+          (make-keymap :name :global
+                       :bindings `((:ctrl+q . ,(lambda (e)
+                                                 (declare (ignore e))
+                                                 (setf global-called t))))))
+    (dispatch-key-event (make-key-event :key :q :ctrl t))
+    (is-true global-called)))
+
+(test key-spec-simple
+  "Keyword key-spec matches key+ctrl."
+  (is-true (key-match-p :ctrl+p (make-key-event :key :p :ctrl t)))
+  (is-false (key-match-p :ctrl+p (make-key-event :key :a :ctrl t)))
+  (is-false (key-match-p :ctrl+p (make-key-event :key :p))))
+
+(test defkeymap-macro
+  "defkeymap macro registers a keymap."
+  (let ((called nil))
+    (eval `(defkeymap :global
+             (:ctrl+q ,(lambda (e) (declare (ignore e)) (setf called t)))))
+    (dispatch-key-event (make-key-event :key :q :ctrl t))
+    (is-true called)))

src/components/input.lisp

@@ -0,0 +1,307 @@
+(in-package #:cl-tui.input)
+
+;;; ---------------------------------------------------------------------------
+;;; Utility: split-string (avoids external dependency)
+;;; ---------------------------------------------------------------------------
+(defun %split-string (string separator)
+  "Split STRING at each occurrence of SEPARATOR. Returns list of strings."
+  (loop with start = 0
+        for pos = (position separator string :start start)
+        collect (subseq string start pos)
+        while pos
+        do (setf start (1+ pos))))
+
+;;; ---------------------------------------------------------------------------
+;;; Global variables for rendering pipeline (set by application)
+;;; ---------------------------------------------------------------------------
+(defvar *current-backend* nil
+  "The active backend used for rendering.")
+(defvar *current-theme* nil
+  "The active theme used for semantic color resolution.")
+
+;;; ---------------------------------------------------------------------------
+;;; Key event struct
+;;; ---------------------------------------------------------------------------
+(defstruct key-event
+  (key nil :type (or keyword null))
+  (ctrl nil :type boolean)
+  (alt nil :type boolean)
+  (shift nil :type boolean)
+  (code nil :type (or fixnum null))
+  (raw nil :type (or string null))
+  (text nil :type (or string null)))
+
+;;; ---------------------------------------------------------------------------
+;;; Mouse event struct
+;;; ---------------------------------------------------------------------------
+(defstruct mouse-event
+  (type nil :type (or keyword null))
+  (button nil :type (or keyword nil))
+  (x 0 :type fixnum)
+  (y 0 :type fixnum)
+  (raw nil :type (or string null)))
+
+;;; ---------------------------------------------------------------------------
+;;; Terminal raw mode
+;;; ---------------------------------------------------------------------------
+(defun save-terminal-state ()
+  (sb-posix:tcgetattr 0))
+
+(defun make-raw-termios (termios)
+  (flet ((clear-flag (flags mask)
+           (logand flags (lognot mask))))
+    (setf (sb-posix:termios-iflag termios)
+          (clear-flag (sb-posix:termios-iflag termios)
+                      (logior sb-posix:brkint sb-posix:ignpar
+                              sb-posix:istrip sb-posix:inlcr
+                              sb-posix:igncr sb-posix:icrnl
+                              sb-posix:ixon)))
+    (setf (sb-posix:termios-oflag termios)
+          (clear-flag (sb-posix:termios-oflag termios)
+                      sb-posix:opost))
+    (setf (sb-posix:termios-lflag termios)
+          (clear-flag (sb-posix:termios-lflag termios)
+                      (logior sb-posix:icanon sb-posix:echo
+                              sb-posix:isig sb-posix:iexten)))
+    (setf (sb-posix:termios-cc termios sb-posix:vmin) 1)
+    (setf (sb-posix:termios-cc termios sb-posix:vtime) 0)
+    termios))
+
+(defun set-raw-mode ()
+  (let ((raw (make-raw-termios (save-terminal-state))))
+    (sb-posix:tcsetattr 0 sb-posix:tcsanow raw)
+    raw))
+
+(defun restore-terminal-state (termios)
+  (sb-posix:tcsetattr 0 sb-posix:tcsanow termios))
+
+(defmacro with-raw-terminal (&body body)
+  (let ((saved (gensym "SAVED")))
+    `(let ((,saved (save-terminal-state)))
+       (set-raw-mode)
+       (unwind-protect
+            (progn ,@body)
+         (restore-terminal-state ,saved)))))
+
+;;; ---------------------------------------------------------------------------
+;;; Low-level byte reading
+;;; ---------------------------------------------------------------------------
+(defun read-raw-byte (&key timeout)
+  (if timeout
+      (let ((deadline (+ (get-universal-time) timeout)))
+        (loop while (< (get-universal-time) deadline)
+              do (handler-case
+                     (let ((buf (make-array 1 :element-type '(unsigned-byte 8))))
+                       (let ((n (sb-posix:read 0 buf 1)))
+                         (when (plusp n)
+                           (return-from read-raw-byte (aref buf 0)))))
+                   (sb-posix:syscall-error ()
+                     (return-from read-raw-byte nil)))
+              (sleep 0.01))
+        nil)
+      (let ((buf (make-array 1 :element-type '(unsigned-byte 8))))
+        (multiple-value-bind (n err)
+            (ignore-errors (sb-posix:read 0 buf 1))
+          (if (and (integerp n) (plusp n))
+              (aref buf 0)
+              (progn
+                (when err (format *error-output* "read error: ~A~%" err))
+                nil))))))
+
+;;; ---------------------------------------------------------------------------
+;;; CSI parameter parser
+;;; ---------------------------------------------------------------------------
+(defun parse-csi-params ()
+  (let ((params '())
+        (raw (make-array 0 :element-type '(unsigned-byte 8)
+                           :fill-pointer 0 :adjustable t))
+        (current 0))
+    (loop
+      (let ((b (read-raw-byte)))
+        (unless b (return (values nil nil nil)))
+        (vector-push-extend b raw)
+        (cond
+          ((and (>= b #x30) (<= b #x3f))
+           (if (char= (code-char b) #\;)
+               (progn (push current params) (setf current 0))
+               (setf current (+ (* current 10) (- b #x30)))))
+          ((and (>= b #x20) (<= b #x2f))
+           nil)
+          ((and (>= b #x40) (<= b #x7e))
+           (push current params)
+           (return (values (nreverse params) b
+                           (map 'string #'code-char raw))))
+          (t
+           (return (values nil nil nil))))))))
+
+;;; ---------------------------------------------------------------------------
+;;; Key event tables
+;;; ---------------------------------------------------------------------------
+(defparameter *csi-key-table*
+  '((#\A . :up) (#\B . :down) (#\C . :right) (#\D . :left)
+    (#\F . :end) (#\H . :home)
+    (#\P . :f1) (#\Q . :f2) (#\R . :f3) (#\S . :f4)
+    (#\Z . :tab)))
+
+(defparameter *csi-tilde-table*
+  '((1 . :home) (2 . :insert) (3 . :delete)
+    (4 . :end) (5 . :page-up) (6 . :page-down)
+    (7 . :home) (8 . :end)
+    (11 . :f1) (12 . :f2) (13 . :f3) (14 . :f4)
+    (15 . :f5) (17 . :f6) (18 . :f7) (19 . :f8)
+    (20 . :f9) (21 . :f10) (23 . :f11) (24 . :f12)))
+
+;;; ---------------------------------------------------------------------------
+;;; SGR mouse parser
+;;; ---------------------------------------------------------------------------
+(defun parse-sgr-mouse (raw)
+  (let* ((start (position #\< raw))
+         (end (position #\m raw :from-end t))
+         (end2 (position #\M raw :from-end t))
+         (final (if end end end2))
+         (releasep (char= (char raw (1- (length raw))) #\m)))
+    (when (and start final (> final start))
+      (let* ((nums (mapcar #'parse-integer
+                           (%split-string (subseq raw (1+ start) final) #\;)))
+             (code (first nums))
+             (x    (or (second nums) 0))
+             (y    (or (third nums) 0))
+             (button (logand code #x03))
+             (mod    (logand code #x1c))
+             (motion (logand code #x20))
+             (wheel  (logand code #x40)))
+        (declare (ignore mod))
+        (make-mouse-event
+         :type (cond (releasep :release)
+                     (motion :drag)
+                     (t :press))
+         :button (cond (wheel (if (zerop (logand code #x01))
+                                  :wheel-up :wheel-down))
+                       ((= button 0) :left)
+                       ((= button 1) :middle)
+                       ((= button 2) :right)
+                       (t :none))
+         :x x :y y :raw raw)))))
+
+;;; ---------------------------------------------------------------------------
+;;; Escape sequence reader
+;;; ---------------------------------------------------------------------------
+(defun %read-escape-sequence ()
+  (let ((b (read-raw-byte)))
+    (unless b
+      (return-from %read-escape-sequence
+        (make-key-event :key :escape :raw (string #\Esc))))
+    (case b
+      ;; SS3: ESC O X
+      (#x4f
+       (let ((b2 (read-raw-byte)))
+         (if b2
+             (let ((key (cdr (assoc (code-char b2)
+                                    '((#\P . :f1) (#\Q . :f2)
+                                      (#\R . :f3) (#\S . :f4))))))
+               (make-key-event :key (or key :unknown)
+                               :raw (format nil "~C~C~C" #\Esc #\O (code-char b2))))
+             (make-key-event :key :escape :raw (string #\Esc)))))
+      ;; CSI: ESC [ ...
+      (#x5b
+       (multiple-value-bind (params final-byte) (parse-csi-params)
+         (if (null final-byte)
+             (make-key-event :key :escape :raw (string #\Esc))
+             (if (and (char= (code-char final-byte) #\M)
+                      (>= (length params) 3))
+                 (let* ((p0 (first params)))
+                   (if (zerop (logand p0 #x40))
+                       (let* ((x (second params))
+                              (y (third params))
+                              (button (logand p0 #x03))
+                              (motion (logand p0 #x20))
+                              (wheel (logand p0 #x40)))
+                         (make-mouse-event
+                          :type (if motion :drag :press)
+                          :button (cond (wheel (if (zerop (logand p0 #x01))
+                                                   :wheel-up :wheel-down))
+                                        ((= button 0) :left)
+                                        ((= button 1) :middle)
+                                        ((= button 2) :right)
+                                        (t :none))
+                          :x x :y y :raw (format nil "~C[<~d;~d;~d~C" #\Esc p0 x y (code-char final-byte))))
+                       (let* ((tilde-p (char= (code-char final-byte) #\~))
+                              (param (or p0 0))
+                              (key (if tilde-p
+                                       (cdr (assoc param *csi-tilde-table*))
+                                       (cdr (assoc (code-char final-byte) *csi-key-table*))))
+                              (modifier (when (> (length params) 1) (second params))))
+                         (let ((ctrl nil) (alt nil) (shift nil))
+                           (when modifier
+                             (setf shift (logtest modifier 1)
+                                   alt   (logtest modifier 2)
+                                   ctrl  (logtest modifier 4)))
+                           (make-key-event :key (or key :unknown)
+                                           :ctrl ctrl :alt alt :shift shift
+                                           :raw (format nil "~C[~d~C" #\Esc param (code-char final-byte))))))
+                 (let* ((tilde-p (char= (code-char final-byte) #\~))
+                        (param (or (first params) 0))
+                        (key (if tilde-p
+                                 (cdr (assoc param *csi-tilde-table*))
+                                 (cdr (assoc (code-char final-byte) *csi-key-table*))))
+                        (modifier (when (> (length params) 1) (second params))))
+                   (let ((ctrl nil) (alt nil) (shift nil))
+                     (when modifier
+                       (setf shift (logtest modifier 1)
+                             alt   (logtest modifier 2)
+                             ctrl  (logtest modifier 4)))
+                     (make-key-event :key (or key :unknown)
+                                     :ctrl ctrl :alt alt :shift shift
+                                     :raw (format nil "~C[~d~C" #\Esc param (code-char final-byte))))))))))
+      ;; ESC ESC
+      (#x1b
+       (make-key-event :key :escape :alt t :raw "\\e\\e"))
+      ;; ESC + printable = Alt+key
+      (t
+       (let ((ch (code-char b)))
+         (if (and (>= b #x20) (<= b #x7e))
+             (make-key-event :key (intern (string (string-upcase ch)) :keyword)
+                             :alt t
+                             :raw (format nil "~C~C" #\Esc ch))
+             (make-key-event :key :unknown
+                             :raw (format nil "~C~C" #\Esc ch))))))))
+
+;;; ---------------------------------------------------------------------------
+;;; Top-level event reader
+;;; ---------------------------------------------------------------------------
+(defun %read-event (&key timeout)
+  (let ((b (read-raw-byte :timeout timeout)))
+    (unless b
+      (return-from %read-event nil))
+    (case b
+      (#x1b
+       (%read-escape-sequence))
+      (#x09
+       (make-key-event :key :tab :code #x09))
+      (#x0a
+       (make-key-event :key :enter :code #x0a))
+      (#x0d
+       (make-key-event :key :enter :code #x0d))
+      ((#x7f #x08)
+       (make-key-event :key :backspace :code b))
+      ((and (>= b #x01) (<= b #x1a))
+       (let ((key (intern (string-upcase (string (code-char (+ b #x60)))) :keyword)))
+         (make-key-event :key key :ctrl t :code b)))
+      (#x1c (make-key-event :key :backslash :ctrl t :code b))
+      (#x1d (make-key-event :key :rbracket :ctrl t :code b))
+      (#x1e (make-key-event :key :caret :ctrl t :code b))
+      (#x1f (make-key-event :key :underscore :ctrl t :code b))
+      ((and (>= b #x20) (<= b #x7e))
+       (let ((ch (code-char b)))
+         (make-key-event :key (intern (string (string-upcase ch)) :keyword)
+                         :code b)))
+      (t
+       (make-key-event :key :unknown :code b :raw (string (code-char b)))))))
+
+;;; ---------------------------------------------------------------------------
+;;; Backend integration
+;;; ---------------------------------------------------------------------------
+(defmethod read-event ((b cl-tui.backend:backend) &key timeout)
+  (declare (ignore b))
+  (when (probe-file "/dev/stdin")
+    (%read-event :timeout timeout)))

src/components/keybindings.lisp

@@ -0,0 +1,77 @@
+(in-package #:cl-tui.input)
+
+;;; ---------------------------------------------------------------------------
+;;; Key map struct
+;;; ---------------------------------------------------------------------------
+(defstruct keymap
+  (name nil :type (or keyword null))
+  (bindings nil :type list)
+  (parent nil :type (or keymap null)))
+
+;;; ---------------------------------------------------------------------------
+;;; Global keymap registry
+;;; ---------------------------------------------------------------------------
+(defparameter *keymaps* (make-hash-table :test #'equal))
+(defparameter *chord-timeout* 0.5)
+
+;;; ---------------------------------------------------------------------------
+;;; Key spec matching
+;;; ---------------------------------------------------------------------------
+(defun key-match-p (spec event)
+  "T if SPEC matches EVENT. Spec is :ctrl+p (modifier+key keyword)
+  or (:ctrl+p) for single-spec in a list, or (:ctrl+x :ctrl+s) for chords."
+  (etypecase spec
+    ;; Keyword like :ctrl+p, :alt+f, :enter, :space, :f1
+    (keyword
+     (let* ((name (string spec))
+            (plus (position #\+ name)))
+       (if plus
+           ;; Modified key: :ctrl+p → mod-str="CTRL", key-str="P"
+           (let ((mod-str (subseq name 0 plus))
+                 (key-str (subseq name (1+ plus))))
+            (and (eql (intern key-str :keyword)
+                      (key-event-key event))
+                 (cond
+                   ((string= mod-str "CTRL") (key-event-ctrl event))
+                   ((string= mod-str "ALT")  (key-event-alt event))
+                   ((string= mod-str "SHIFT") (key-event-shift event))
+                   (t t))))
+           ;; Plain keyword: :enter, :escape, :f1, etc.
+           (eql spec (key-event-key event)))))
+    ;; List: (:ctrl+p) or (:ctrl+x :ctrl+s)
+    (list
+     (when spec
+       (key-match-p (first spec) event)))))
+
+;;; ---------------------------------------------------------------------------
+;;; Dispatch
+;;; ---------------------------------------------------------------------------
+(defun dispatch-key-event (event &key component)
+  (labels ((try-keymap (km)
+             (when km
+               (loop for (spec . handler) in (keymap-bindings km)
+                     thereis (when (key-match-p spec event)
+                               (funcall handler event)
+                               t))))
+           (find-keymap (name)
+             (gethash name *keymaps*)))
+    (or (and component
+             (let ((km (component-keymap component)))
+               (when km (try-keymap km))))
+        (try-keymap (find-keymap :local))
+        (try-keymap (find-keymap :global)))))
+
+;;; ---------------------------------------------------------------------------
+;;; defkeymap macro
+;;; ---------------------------------------------------------------------------
+(defmacro defkeymap (name &body bindings)
+  `(setf (gethash ',name *keymaps*)
+         (make-keymap :name ',name
+                      :bindings (list ,@(loop for b in bindings
+                                              collect (if (consp (cdr b))
+                                                          `(cons ',(car b) ,(cadr b))
+                                                          `(cons ',(car b) ,(cdr b))))))))
+
+;;; --- Component protocol integration ---
+(defgeneric component-keymap (component)
+  (:method ((c t)) nil))

src/components/package.lisp

@@ -0,0 +1,31 @@
+(defpackage :cl-tui.box
+  (:use :cl :cl-tui.backend :cl-tui.layout)
+  (:export
+   ;; Box
+   #:box #:make-box
+   #:box-layout-node
+   #:box-border-style #:box-title #:box-title-align
+   #:box-fg #:box-bg
+   #:render-box
+   ;; Span
+   #:span
+   #:span-text #:span-bold #:span-italic #:span-underline
+   #:span-reverse #:span-dim #:span-fg #:span-bg
+   ;; Text
+   #:text #:make-text
+   #:text-layout-node #:text-content #:text-spans
+   #:text-fg #:text-bg #:text-wrap-mode
+   #:render-text
+   ;; Utilities (for tests)
+   #:word-wrap #:split-string
+   ;; Dirty tracking
+   #:dirty-mixin #:dirty-p #:mark-clean #:mark-dirty
+   ;; Rendering pipeline
+   #:render #:render-screen #:render-node
+   #:component-layout-node #:component-children #:component-parent
+   #:available-width #:available-height
+   #:propagate-dirty
+   ;; Theme engine
+   #:theme #:make-theme #:theme-mode
+   #:theme-color #:load-preset #:define-preset))
+(in-package :cl-tui.box)

src/components/render-tests.lisp

@@ -0,0 +1,48 @@
+(in-package :cl-tui-box-test)
+(in-suite box-suite)
+
+(defun make-capturing-backend ()
+  (let* ((s (make-string-output-stream))
+         (b (make-modern-backend :output-stream s)))
+    (values b s)))
+
+(test render-generic-dispatches-box
+  "render dispatches to render-box for box instances"
+  (multiple-value-bind (b s) (make-capturing-backend)
+    (let ((bx (make-box :border-style :single :width 10 :height 5)))
+      (compute-layout (box-layout-node bx) 10 5)
+      (render bx b)
+      (is (search "┌" (get-output-stream-string s)) "box renders border"))))
+
+(test render-generic-dispatches-text
+  "render dispatches to render-text for text instances"
+  (multiple-value-bind (b s) (make-capturing-backend)
+    (let ((tx (make-text "Hello" :width 10 :height 1)))
+      (compute-layout (text-layout-node tx) 10 1)
+      (render tx b)
+      (is (search "Hello" (get-output-stream-string s)) "text renders content"))))
+
+(test component-layout-node-works
+  "component-layout-node returns the right slot for each type"
+  (let ((bx (make-box)) (tx (make-text "")))
+    (is (typep (component-layout-node bx) 'layout-node))
+    (is (typep (component-layout-node tx) 'layout-node))))
+
+(test component-children-returns-nil
+  "Leaf components have no children"
+  (let ((bx (make-box)) (tx (make-text "")))
+    (is (null (component-children bx)))
+    (is (null (component-children tx)))))
+
+(test propagate-dirty-marks-component
+  "propagate-dirty marks the component dirty"
+  (let ((c (make-box)))
+    (mark-clean c)
+    (is-false (dirty-p c) "should be clean after mark-clean")
+    (propagate-dirty c)
+    (is-true (dirty-p c) "should be dirty after propagate-dirty")))
+
+(test available-width-defaults
+  "available-width returns 0 for components without explicit width"
+  (let ((c (make-box)))
+    (is (= (available-width c) 0))))

src/components/render.lisp

@@ -0,0 +1,66 @@
+(in-package :cl-tui.box)
+
+;; ── Component Protocol ────────────────────────────────────────
+
+(defgeneric component-layout-node (component)
+  (:documentation "Return the layout-node for COMPONENT.")
+  (:method ((bx box)) (box-layout-node bx))
+  (:method ((tx text)) (text-layout-node tx)))
+
+(defgeneric component-children (component)
+  (:documentation "Return the children of COMPONENT, or nil.")
+  (:method ((c t)) nil))
+
+(defgeneric component-parent (component)
+  (:documentation "Return the parent of COMPONENT, or nil.")
+  (:method ((c t)) nil))
+
+;; ── Rendering Pipeline ────────────────────────────────────────
+
+(defgeneric render (component backend)
+  (:documentation "Render COMPONENT at its computed position using BACKEND.")
+  (:method ((c t) backend)
+    (declare (ignore backend))
+    (values)))
+
+(defmethod render ((bx box) backend)
+  (render-box bx backend))
+
+(defmethod render ((tx text) backend)
+  (render-text tx backend))
+
+(defun render-screen (root backend)
+  "Render the component tree ROOT using BACKEND.
+  Computes layout for dirty branches, calls render on each component,
+  and wraps output in synchronized updates."
+  (let ((w (available-width root))
+        (h (available-height root)))
+    (begin-sync backend)
+    (render-node root backend w h)
+    (end-sync backend)))
+
+(defun render-node (node backend w h)
+  "Render a component NODE and its children."
+  (compute-layout (component-layout-node node) w h)
+  (render node backend)
+  (dolist (child (component-children node))
+    (render-node child backend w h)))
+
+(defun available-width (component)
+  "Return the available width for COMPONENT (or 80 as default)."
+  (let ((ln (component-layout-node component)))
+    (if ln (layout-node-width ln) 80)))
+
+(defun available-height (component)
+  "Return the available height for COMPONENT (or 24 as default)."
+  (let ((ln (component-layout-node component)))
+    (if ln (layout-node-height ln) 24)))
+
+;; ── Dirty Propagation ─────────────────────────────────────────
+
+(defun propagate-dirty (component)
+  "Mark COMPONENT and all ancestors dirty."
+  (mark-dirty component)
+  (let ((parent (component-parent component)))
+    (when parent
+      (propagate-dirty parent))))

src/components/text-input.lisp

@@ -0,0 +1,163 @@
+(in-package #:cl-tui.input)
+
+;;; ---------------------------------------------------------------------------
+;;; TextInput class
+;;; ---------------------------------------------------------------------------
+(defclass text-input (dirty-mixin)
+  ((value :initform "" :initarg :value :accessor text-input-value
+          :type string)
+   (cursor :initform 0 :initarg :cursor :accessor text-input-cursor
+           :type fixnum)
+   (placeholder :initform "" :initarg :placeholder
+                :accessor text-input-placeholder :type string)
+   (max-length :initform nil :initarg :max-length
+               :accessor text-input-max-length)
+   (on-submit :initform nil :initarg :on-submit
+              :accessor text-input-on-submit)
+   (layout-node :initform (make-layout-node) :accessor text-input-layout-node)
+   (focusable :initform t :accessor text-input-focusable)))
+
+(defun make-text-input (&key value cursor placeholder max-length on-submit)
+  (make-instance 'text-input
+    :value (or value "")
+    :cursor (or cursor 0)
+    :placeholder (or placeholder "")
+    :max-length max-length
+    :on-submit on-submit))
+
+;;; ---------------------------------------------------------------------------
+;;; Editing operations
+;;; ---------------------------------------------------------------------------
+(defun text-input-insert (input char)
+  "Insert CHAR at the cursor position in INPUT."
+  (let* ((val (text-input-value input))
+         (pos (text-input-cursor input))
+         (max (text-input-max-length input)))
+    (when (and max (>= (length val) max))
+      (return-from text-input-insert))
+    (setf (text-input-value input)
+          (concatenate 'string
+            (subseq val 0 pos)
+            (string char)
+            (subseq val pos)))
+    (incf (text-input-cursor input))
+    (mark-dirty input)))
+
+(defun text-input-backspace (input)
+  "Delete character before cursor."
+  (let* ((val (text-input-value input))
+         (pos (text-input-cursor input)))
+    (when (zerop pos) (return-from text-input-backspace))
+    (setf (text-input-value input)
+          (concatenate 'string
+            (subseq val 0 (1- pos))
+            (subseq val pos)))
+    (decf (text-input-cursor input))
+    (mark-dirty input)))
+
+(defun text-input-delete (input)
+  "Delete character at cursor."
+  (let* ((val (text-input-value input))
+         (pos (text-input-cursor input)))
+    (when (>= pos (length val))
+      (return-from text-input-delete))
+    (setf (text-input-value input)
+          (concatenate 'string
+            (subseq val 0 pos)
+            (subseq val (1+ pos))))
+    (mark-dirty input)))
+
+;;; ---------------------------------------------------------------------------
+;;; Cursor movement
+;;; ---------------------------------------------------------------------------
+(defun text-input-move-left (input)
+  (when (plusp (text-input-cursor input))
+    (decf (text-input-cursor input))))
+
+(defun text-input-move-right (input)
+  (when (< (text-input-cursor input) (length (text-input-value input)))
+    (incf (text-input-cursor input))))
+
+(defun text-input-move-home (input)
+  (setf (text-input-cursor input) 0))
+
+(defun text-input-move-end (input)
+  (setf (text-input-cursor input) (length (text-input-value input))))
+
+(defun text-input-delete-word-before (input)
+  "Delete from cursor back to previous word boundary."
+  (let* ((val (text-input-value input))
+         (pos (text-input-cursor input)))
+    (when (zerop pos)
+      (return-from text-input-delete-word-before))
+    (let* ((start (or (position-if (lambda (c) (not (char= c #\Space)))
+                                   val :end pos :from-end t)
+                      0))
+           (word-start (or (and (plusp start)
+                               (position #\Space val :end start :from-end t))
+                           0))
+           (delete-start (if (and (zerop word-start)
+                                  (or (char/= (char val 0) #\Space)
+                                      (zerop start)))
+                             0
+                             (if (zerop start)
+                                 (1+ word-start)
+                                 (1+ (or (position #\Space val :end start :from-end t)
+                                         0))))))
+      (setf (text-input-value input)
+            (concatenate 'string
+              (subseq val 0 delete-start)
+              (subseq val pos)))
+      (setf (text-input-cursor input) delete-start)
+      (mark-dirty input))))
+
+;;; ---------------------------------------------------------------------------
+;;; Key event handler
+;;; ---------------------------------------------------------------------------
+(defun handle-text-input (input event)
+  "Process a key-event on a text-input widget."
+  (cond
+    ((key-event-ctrl event)
+     (case (key-event-key event)
+       (:a (text-input-move-home input))
+       (:e (text-input-move-end input))
+       (:w (text-input-delete-word-before input))
+       (:u (progn
+             (setf (text-input-value input)
+                   (subseq (text-input-value input)
+                           (text-input-cursor input)))
+             (setf (text-input-cursor input) 0)
+             (mark-dirty input)))
+       (:k (progn
+             (setf (text-input-value input)
+                   (subseq (text-input-value input) 0
+                           (text-input-cursor input)))
+             (mark-dirty input)))
+       (t nil)))
+    (t
+     (case (key-event-key event)
+       (:left (text-input-move-left input))
+       (:right (text-input-move-right input))
+       (:home (text-input-move-home input))
+       (:end (text-input-move-end input))
+       (:backspace (text-input-backspace input))
+       (:delete (text-input-delete input))
+       (:enter (let ((cb (text-input-on-submit input)))
+                 (when cb (funcall cb (text-input-value input)))))
+       (:tab nil)
+       (:escape nil)
+       ;; Insert printable characters
+       (otherwise
+        (let ((ch (code-char (key-event-code event))))
+          (when (and ch (graphic-char-p ch))
+            (text-input-insert input ch))))))))
+
+;;; ---------------------------------------------------------------------------
+;;; Rendering (stub — proper rendering uses theme + backend)
+;;; ---------------------------------------------------------------------------
+(defmethod render ((in text-input) (backend t))
+  "Render a text-input widget. Full rendering requires *current-backend*,
+  *current-theme*, and the rendering pipeline. This is a no-op stub for
+  unit testing the widget logic."
+  (declare (ignore in backend))
+  (values))

src/components/text.lisp

@@ -0,0 +1,106 @@
+(in-package :cl-tui.box)
+
+;; ── Text Renderable ────────────────────────────────────────────
+
+(defclass span ()
+  ((text :initarg :text :accessor span-text)
+   (bold :initform nil :initarg :bold :accessor span-bold)
+   (italic :initform nil :initarg :italic :accessor span-italic)
+   (underline :initform nil :initarg :underline :accessor span-underline)
+   (reverse :initform nil :initarg :reverse :accessor span-reverse)
+   (dim :initform nil :initarg :dim :accessor span-dim)
+   (fg :initform nil :initarg :fg :accessor span-fg)
+   (bg :initform nil :initarg :bg :accessor span-bg)))
+
+(defun span (text &key bold italic underline reverse dim fg bg)
+  (make-instance 'span
+    :text text :bold bold :italic italic
+    :underline underline :reverse reverse :dim dim
+    :fg fg :bg bg))
+
+(defclass text (dirty-mixin)
+  ((layout-node :initform (make-layout-node) :accessor text-layout-node
+     :initarg :layout-node)
+   (content :initform "" :initarg :content :accessor text-content)
+   (spans :initform nil :initarg :spans :accessor text-spans)
+   (fg :initform nil :initarg :fg :accessor text-fg)
+   (bg :initform nil :initarg :bg :accessor text-bg)
+   (wrap-mode :initform :word :initarg :wrap-mode :accessor text-wrap-mode)))
+
+(defun make-text (content &key fg bg wrap-mode width height spans)
+  (make-instance 'text
+    :content content
+    :fg fg :bg bg
+    :wrap-mode (or wrap-mode :word)
+    :spans spans
+    :layout-node (make-layout-node :direction :column
+                               :width width :height height)))
+
+(defun render-text (text-object backend)
+  "Render TEXT-OBJECT at its computed layout position using BACKEND."
+  (let ((ln (text-layout-node text-object))
+        (content (text-content text-object))
+        (fg (text-fg text-object))
+        (bg (text-bg text-object))
+        (wrap (text-wrap-mode text-object))
+        (spans (text-spans text-object)))
+    (declare (ignore spans))
+    (let ((x (layout-node-x ln))
+          (y (layout-node-y ln))
+          (w (layout-node-width ln))
+          (h (layout-node-height ln)))
+      (when (or (zerop (length content)) (zerop w) (zerop h))
+        (return-from render-text (values)))
+      (if (eql wrap :none)
+          (let ((display (subseq content 0 (min (length content) w))))
+            (draw-text backend x y display fg bg))
+          (let ((lines (word-wrap content w))
+                (max-lines h))
+            (loop for line in lines
+                  for row from 0 below max-lines
+                  do (draw-text backend x (+ y row) line fg bg)))))))
+
+(defun word-wrap (text max-width)
+  "Split TEXT into lines, each <= MAX-WIDTH chars.
+Breaks at word boundaries. Words exceeding MAX-WIDTH are hard-broken."
+  (if (or (zerop max-width) (zerop (length text)))
+      (list "")
+      (let ((words (split-string text)) (lines nil) (current nil) (current-len 0))
+        (dolist (word words)
+          (let ((wl (length word)))
+            (cond ((<= wl max-width)
+                   (if (and current (<= (+ current-len 1 wl) max-width))
+                       (push word current)
+                       (progn
+                         (when current
+                           (push (format nil "~{~A~^ ~}" (nreverse current)) lines))
+                         (setf current (list word))
+                         (setf current-len wl))))
+                  (t
+                   (when current
+                     (push (format nil "~{~A~^ ~}" (nreverse current)) lines)
+                     (setf current nil)
+                     (setf current-len 0))
+                   (loop for i from 0 below wl by max-width
+                         do (push (subseq word i (min (+ i max-width) wl)) lines))))))
+        (when current
+          (push (format nil "~{~A~^ ~}" (nreverse current)) lines))
+        (or (nreverse lines) (list "")))))
+
+(defun split-string (string)
+  "Split STRING into words separated by whitespace."
+  (loop with words = nil
+        with start = 0
+        with len = (length string)
+        while (< start len)
+        do (let ((ws-start (position-if (lambda (c) (find c '(#\Space #\Tab #\Newline)))
+                                        string :start start)))
+             (if ws-start
+                 (progn
+                   (when (> ws-start start)
+                     (push (subseq string start ws-start) words))
+                   (setf start (1+ ws-start)))
+                 (progn
+                   (push (subseq string start) words)
+                   (setf start len))))
+        finally (return (nreverse words))))

src/components/textarea.lisp

@@ -0,0 +1,258 @@
+(in-package #:cl-tui.input)
+
+;;; ---------------------------------------------------------------------------
+;;; Utility: split string (local copy for dependency-free operation)
+;;; ---------------------------------------------------------------------------
+(defun %split-string (string separator)
+  "Split STRING at each occurrence of SEPARATOR. Returns list of strings."
+  (loop with start = 0
+        for pos = (position separator string :start start)
+        collect (subseq string start pos)
+        while pos
+        do (setf start (1+ pos))))
+
+;;; ---------------------------------------------------------------------------
+;;; Textarea class
+;;; ---------------------------------------------------------------------------
+(defclass textarea (dirty-mixin)
+  ((value :initform "" :initarg :value :accessor textarea-value :type string)
+   (cursor-row :initform 0 :accessor textarea-cursor-row :type fixnum)
+   (cursor-col :initform 0 :accessor textarea-cursor-col :type fixnum)
+   (selection-start :initform nil :accessor textarea-selection-start)
+   (undo-stack :initform (make-array 100 :fill-pointer 0)
+               :accessor textarea-undo-stack)
+   (redo-stack :initform (make-array 100 :fill-pointer 0)
+               :accessor textarea-redo-stack)
+   (on-submit :initform nil :initarg :on-submit :accessor textarea-on-submit)
+   (layout-node :initform (make-layout-node) :accessor textarea-layout-node)
+   (focusable :initform t :accessor textarea-focusable)))
+
+(defun make-textarea (&key value on-submit)
+  (make-instance 'textarea
+    :value (or value "")
+    :on-submit on-submit))
+
+;;; ---------------------------------------------------------------------------
+;;; Line helpers
+;;; ---------------------------------------------------------------------------
+(defun textarea-lines (ta)
+  "Split value into lines."
+  (%split-string (textarea-value ta) #\Newline))
+
+(defun textarea-line-count (ta)
+  "Number of lines in value."
+  (length (textarea-lines ta)))
+
+(defun textarea-ensure-cursor (ta)
+  "Clamp cursor to valid range."
+  (let ((lines (textarea-lines ta)))
+    (setf (textarea-cursor-row ta)
+          (max 0 (min (textarea-cursor-row ta) (1- (length lines)))))
+    (let ((line-len (length (nth (textarea-cursor-row ta) lines))))
+      (setf (textarea-cursor-col ta)
+            (max 0 (min (textarea-cursor-col ta) line-len))))))
+
+;;; ---------------------------------------------------------------------------
+;;; Utility: join strings with newline
+;;; ---------------------------------------------------------------------------
+(defun %join-lines (lines)
+  "Join a sequence of strings with newlines."
+  (with-output-to-string (s)
+    (loop for line across (if (listp lines) (coerce lines 'vector) lines)
+          for first = t then nil
+          do (unless first (write-char #\Newline s))
+             (write-string line s))))
+
+;;; ---------------------------------------------------------------------------
+;;; Text manipulation
+;;; ---------------------------------------------------------------------------
+(defun textarea-insert-char (ta char)
+  "Insert CHAR at the cursor position."
+  (textarea-push-undo ta)
+  (let* ((lines (coerce (textarea-lines ta) 'vector))
+         (row (textarea-cursor-row ta))
+         (col (textarea-cursor-col ta)))
+    (if (< row (length lines))
+        (let* ((line (aref lines row))
+               (new-line (concatenate 'string
+                           (subseq line 0 col)
+                           (string char)
+                           (subseq line col))))
+          (setf (aref lines row) new-line)
+          (setf (textarea-value ta)
+                (%join-lines lines))
+          (incf (textarea-cursor-col ta))
+          (mark-dirty ta))
+        (progn
+          (setf (textarea-value ta)
+                (concatenate 'string (textarea-value ta) (string char)))
+          (incf (textarea-cursor-col ta))
+          (mark-dirty ta)))))
+
+(defun textarea-newline (ta)
+  "Insert a newline at the cursor."
+  (textarea-push-undo ta)
+  (let* ((lines (coerce (textarea-lines ta) 'vector))
+         (row (textarea-cursor-row ta))
+         (col (textarea-cursor-col ta)))
+    (if (< row (length lines))
+        (let* ((line (aref lines row))
+               (before (subseq line 0 col))
+               (after (subseq line col)))
+          (setf (aref lines row) before)
+          (let ((new-lines (concatenate 'vector
+                            (subseq lines 0 (1+ row))
+                            (vector after)
+                            (subseq lines (1+ row)))))
+            (setf (textarea-value ta)
+                  (%join-lines new-lines)))
+          (incf (textarea-cursor-row ta))
+          (setf (textarea-cursor-col ta) 0)
+          (mark-dirty ta))
+        (progn
+          (setf (textarea-value ta)
+                (concatenate 'string (textarea-value ta) (string #\Newline)))
+          (incf (textarea-cursor-row ta))
+          (setf (textarea-cursor-col ta) 0)
+          (mark-dirty ta)))))
+
+(defun textarea-backspace (ta)
+  "Delete character before cursor."
+  (textarea-push-undo ta)
+  (let* ((lines (coerce (textarea-lines ta) 'vector))
+         (row (textarea-cursor-row ta))
+         (col (textarea-cursor-col ta)))
+    (cond
+      ((and (zerop row) (zerop col))
+       nil)  ;; nothing to delete
+      ((zerop col)
+       ;; Join with previous line
+       (let* ((prev (aref lines (1- row)))
+              (curr (aref lines row))
+              (new-pos (length prev)))
+         (setf (aref lines (1- row))
+               (concatenate 'string prev curr))
+         (let ((new-lines (concatenate 'vector
+                           (subseq lines 0 row)
+                           (subseq lines (1+ row)))))
+           (setf (textarea-value ta)
+                 (%join-lines new-lines)))
+         (decf (textarea-cursor-row ta))
+         (setf (textarea-cursor-col ta) new-pos)
+         (mark-dirty ta)))
+      (t
+       (let* ((line (aref lines row))
+              (new-line (concatenate 'string
+                          (subseq line 0 (1- col))
+                          (subseq line col))))
+         (setf (aref lines row) new-line)
+         (setf (textarea-value ta)
+               (%join-lines lines))
+         (decf (textarea-cursor-col ta))
+         (mark-dirty ta))))))
+
+;;; ---------------------------------------------------------------------------
+;;; Cursor movement
+;;; ---------------------------------------------------------------------------
+(defun textarea-move-up (ta)
+  (decf (textarea-cursor-row ta))
+  (textarea-ensure-cursor ta))
+
+(defun textarea-move-down (ta)
+  (incf (textarea-cursor-row ta))
+  (textarea-ensure-cursor ta))
+
+;;; ---------------------------------------------------------------------------
+;;; Undo/redo
+;;; ---------------------------------------------------------------------------
+(defun textarea-push-undo (ta)
+  "Save current value on undo stack."
+  (let ((stack (textarea-undo-stack ta)))
+    (when (>= (length stack) (array-total-size stack))
+      (setf (textarea-undo-stack ta)
+            (make-array 100 :fill-pointer 0)))
+    (vector-push (textarea-value ta) stack)
+    ;; Clear redo stack on new action
+    (setf (fill-pointer (textarea-redo-stack ta)) 0)))
+
+(defun textarea-undo (ta)
+  (let ((stack (textarea-undo-stack ta)))
+    (when (plusp (length stack))
+      (let ((prev (vector-pop stack)))
+        (vector-push (textarea-value ta) (textarea-redo-stack ta))
+        (setf (textarea-value ta) prev)
+        (textarea-ensure-cursor ta)
+        (mark-dirty ta)))))
+
+(defun textarea-redo (ta)
+  (let ((stack (textarea-redo-stack ta)))
+    (when (plusp (length stack))
+      (let ((next (vector-pop stack)))
+        (vector-push (textarea-value ta) (textarea-undo-stack ta))
+        (setf (textarea-value ta) next)
+        (textarea-ensure-cursor ta)
+        (mark-dirty ta)))))
+
+;;; ---------------------------------------------------------------------------
+;;; Key event handler
+;;; ---------------------------------------------------------------------------
+(defun handle-textarea-input (ta event)
+  "Process a key-event on a textarea widget."
+  (cond
+    ((key-event-ctrl event)
+     (case (key-event-key event)
+       (:z (textarea-undo ta))
+       (:y (textarea-redo ta))
+       ;; Ctrl+A/E: home/end
+       (:a (setf (textarea-cursor-col ta) 0))
+       (:e (let ((lines (textarea-lines ta)))
+             (when (< (textarea-cursor-row ta) (length lines))
+               (setf (textarea-cursor-col ta)
+                     (length (nth (textarea-cursor-row ta) lines))))))
+        (t nil)))
+    (t
+     (case (key-event-key event)
+       (:left (decf (textarea-cursor-col ta))
+              (textarea-ensure-cursor ta))
+       (:right (incf (textarea-cursor-col ta))
+               (textarea-ensure-cursor ta))
+       (:up (textarea-move-up ta))
+       (:down (textarea-move-down ta))
+       (:home (setf (textarea-cursor-col ta) 0))
+       (:end (let ((lines (textarea-lines ta)))
+               (when (< (textarea-cursor-row ta) (length lines))
+                 (setf (textarea-cursor-col ta)
+                       (length (nth (textarea-cursor-row ta) lines))))))
+       (:enter (let ((cb (textarea-on-submit ta)))
+                 (if cb
+                     (funcall cb (textarea-value ta))
+                     (textarea-newline ta))))
+       (:backspace (textarea-backspace ta))
+       (:delete (let* ((lines (textarea-lines ta))
+                       (row (textarea-cursor-row ta))
+                       (col (textarea-cursor-col ta))
+                       (line (nth row lines)))
+                  (when (and line (< col (length line)))
+                    (textarea-push-undo ta)
+                    (setf (nth row lines)
+                          (concatenate 'string
+                            (subseq line 0 col)
+                            (subseq line (1+ col))))
+                    (setf (textarea-value ta)
+                          (%join-lines lines))
+                    (mark-dirty ta))))
+       ;; Character insertion
+       (otherwise
+        (let ((ch (code-char (key-event-code event))))
+          (when (and ch (graphic-char-p ch))
+            (textarea-insert-char ta ch))))))))
+
+;;; ---------------------------------------------------------------------------
+;;; Rendering (stub — proper rendering uses theme + backend)
+;;; ---------------------------------------------------------------------------
+(defmethod render ((ta textarea) (backend t))
+  "Render a textarea widget. Full rendering requires *current-backend*,
+  *current-theme*, and the rendering pipeline. This is a no-op stub for
+  unit testing the widget logic."
+  (declare (ignore ta backend))
+  (values))

src/components/theme-tests.lisp

@@ -0,0 +1,61 @@
+(in-package :cl-tui-box-test)
+(in-suite box-suite)
+
+(test theme-create-default
+  "A theme can be created with default mode"
+  (let ((th (make-theme)))
+    (is (typep th 'theme))
+    (is (eql (theme-mode th) :dark))))
+
+(test theme-create-light
+  "A theme can be created in light mode"
+  (let ((th (make-theme :mode :light)))
+    (is (eql (theme-mode th) :light))))
+
+(test theme-color-set-and-get
+  "theme-color setf/get works"
+  (let ((th (make-theme)))
+    (setf (theme-color th :primary) "#FFD700")
+    (is (string= (theme-color th :primary) "#FFD700"))))
+
+(test theme-color-unknown-returns-nil
+  "Unknown roles return nil"
+  (let ((th (make-theme)))
+    (is (null (theme-color th :nonexistent)))))
+
+(test load-default-dark-preset
+  "Loading the default dark preset populates roles"
+  (let ((th (make-theme :mode :dark)))
+    (load-preset th :default)
+    (is (string= (theme-color th :primary) "#FFD700"))
+    (is (string= (theme-color th :background) "#1A1A2E"))
+    (is (string= (theme-color th :error) "#FF4444"))))
+
+(test load-default-light-preset
+  "Light variant has different colors"
+  (let ((th (make-theme :mode :light)))
+    (load-preset th :default)
+    (is (string= (theme-color th :primary) "#B8860B"))
+    (is (string= (theme-color th :background) "#F8F9FA"))))
+
+(test load-nord-preset
+  "Nord preset has different colors than default"
+  (let ((th (make-theme :mode :dark)))
+    (load-preset th :nord)
+    (is (string= (theme-color th :primary) "#88C0D0"))
+    (is (string= (theme-color th :background) "#2E3440"))))
+
+(test load-preset-unknown-warns
+  "Unknown preset warns but doesn't error"
+  (let ((th (make-theme)))
+    (signals warning (load-preset th :nonexistent))
+    (is (null (theme-color th :primary)))))
+
+(test preset-switch-mode
+  "Switching mode and reloading changes colors"
+  (let ((th (make-theme :mode :dark)))
+    (load-preset th :default)
+    (is (string= (theme-color th :background) "#1A1A2E"))
+    (setf (theme-mode th) :light)
+    (load-preset th :default)
+    (is (string= (theme-color th :background) "#F8F9FA"))))

src/components/theme.lisp

@@ -0,0 +1,87 @@
+(in-package :cl-tui.box)
+
+;; ── Theme Engine ──────────────────────────────────────────────
+
+(defclass theme ()
+  ((mode :initform :dark :initarg :mode :accessor theme-mode)
+   (roles :initform (make-hash-table) :accessor theme-roles)))
+
+(defun make-theme (&key (mode :dark))
+  (make-instance 'theme :mode mode))
+
+(defun theme-color (theme role)
+  "Resolve a semantic ROLE to a hex color string in THEME."
+  (gethash role (theme-roles theme)))
+
+(defun (setf theme-color) (hex theme role)
+  "Set the hex color for a semantic ROLE in THEME."
+  (setf (gethash role (theme-roles theme)) hex))
+
+(defparameter *presets* (make-hash-table :test #'eq))
+
+(defmacro define-preset (name &key dark light)
+  "Define a theme preset with DARK and LIGHT variants.
+NAME should be a keyword (e.g., :default, :nord)."
+  (check-type name keyword)
+  `(setf (gethash ,name *presets*) '(:dark ,dark :light ,light)))
+
+(defun load-preset (theme preset-name)
+  "Load PRESET-NAME (a keyword) into THEME, overwriting role mappings."
+  (let ((preset (gethash preset-name *presets*)))
+    (if preset
+        (let* ((variant (if (eql (theme-mode theme) :dark)
+                            (getf preset :dark)
+                            (getf preset :light)))
+               (roles (theme-roles theme)))
+          (clrhash roles)
+          (loop for (role hex) on variant by #'cddr
+                do (setf (gethash role roles) hex)))
+        (warn "Unknown preset: ~S" preset-name))))
+
+(define-preset :default
+  :dark  (:primary "#FFD700" :secondary "#B8860B" :accent "#FFA500"
+          :error "#FF4444" :warning "#FF8800" :success "#44BB44" :info "#4488FF"
+          :text "#FFFFFF" :text-muted "#888888"
+          :background "#1A1A2E" :background-panel "#16213E" :background-element "#0F3460"
+          :border "#334155" :border-active "#FFD700"
+          :diff-added "#164B16" :diff-removed "#4B1616" :diff-context "#1A1A2E"
+          :markdown-heading "#FFD700" :markdown-code "#334155"
+          :markdown-link "#4488FF" :markdown-quote "#888888"
+          :syntax-keyword "#FF79C6" :syntax-function "#50FA7B"
+          :syntax-string "#F1FA8C" :syntax-number "#BD93F9"
+          :syntax-comment "#6272A4" :syntax-type "#8BE9FD")
+  :light (:primary "#B8860B" :secondary "#8B6914" :accent "#FF8C00"
+          :error "#CC0000" :warning "#CC6600" :success "#228B22" :info "#0055CC"
+          :text "#1A1A2E" :text-muted "#888888"
+          :background "#F8F9FA" :background-panel "#FFFFFF" :background-element "#E9ECEF"
+          :border "#DEE2E6" :border-active "#B8860B"
+          :diff-added "#DFD" :diff-removed "#FDD" :diff-context "#F8F9FA"
+          :markdown-heading "#B8860B" :markdown-code "#E9ECEF"
+          :markdown-link "#0055CC" :markdown-quote "#888888"
+          :syntax-keyword "#D63384" :syntax-function "#198754"
+          :syntax-string "#FFC107" :syntax-number "#6F42C1"
+          :syntax-comment "#6C757D" :syntax-type "#0DCAF0"))
+
+(define-preset :nord
+  :dark  (:primary "#88C0D0" :secondary "#81A1C1" :accent "#5E81AC"
+          :error "#BF616A" :warning "#D08770" :success "#A3BE8C" :info "#B48EAD"
+          :text "#ECEFF4" :text-muted "#616E88"
+          :background "#2E3440" :background-panel "#3B4252" :background-element "#434C5E"
+          :border "#4C566A" :border-active "#88C0D0"
+          :diff-added "#164B16" :diff-removed "#4B1616" :diff-context "#2E3440"
+          :markdown-heading "#88C0D0" :markdown-code "#3B4252"
+          :markdown-link "#81A1C1" :markdown-quote "#616E88"
+          :syntax-keyword "#81A1C1" :syntax-function "#A3BE8C"
+          :syntax-string "#EBCB8B" :syntax-number "#B48EAD"
+          :syntax-comment "#616E88" :syntax-type "#88C0D0")
+  :light (:primary "#5E81AC" :secondary "#81A1C1" :accent "#88C0D0"
+          :error "#BF616A" :warning "#D08770" :success "#A3BE8C" :info "#B48EAD"
+          :text "#2E3440" :text-muted "#8F9BB3"
+          :background "#ECEFF4" :background-panel "#FFFFFF" :background-element "#E5E9F0"
+          :border "#D8DEE9" :border-active "#5E81AC"
+          :diff-added "#DFD" :diff-removed "#FDD" :diff-context "#ECEFF4"
+          :markdown-heading "#5E81AC" :markdown-code "#E5E9F0"
+          :markdown-link "#81A1C1" :markdown-quote "#8F9BB3"
+          :syntax-keyword "#81A1C1" :syntax-function "#A3BE8C"
+          :syntax-string "#D08770" :syntax-number "#B48EAD"
+          :syntax-comment "#8F9BB3" :syntax-type "#88C0D0"))