rrbe · rrbe · May 22, 2026 · May 22, 2026
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -7,6 +7,12 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Changed
+- Removed the 4-column outer margin that cat mode and TUI body rows
+  shared, plus the additional 2-column inset on cat-mode table rows.
+  Content now starts at column 0. The gutter originally mirrored `glow`;
+  with TUI as the default it cost 4 cols for no remaining visual gain.
+
 ## [0.5.0] - 2026-05-21
 
 ### Changed

diff --git a/docs/LINK_PICKER_DESIGN.md b/docs/LINK_PICKER_DESIGN.md
@@ -79,3 +79,16 @@ They are complementary. A realistic plan could be:
 2. Revisit **C** later if the inline-hint flow feels worth the rendering complexity.
 
 Either way, the status-bar `take(9)` overlay should be retired once a replacement lands.
+
+---
+
+## Update — 2026-05-22: `MARGIN_WIDTH` gutter no longer exists
+
+The constraint phrased as "must not shift the body layout's column
+alignment for heading images (`MARGIN_WIDTH` gutter)" referenced the
+4-column outer margin that cat mode and TUI body rows used to share.
+That gutter was removed (along with the `MARGIN_WIDTH` constant) now
+that TUI is the default mode. The underlying constraint still holds —
+label/prefix spans added by any future link picker must not shift the
+column where heading images land — but the alignment column is now `0`
+(or `30` when ToC is open), not `4` / `34`.
diff --git a/docs/TUI_MODE_DEBUG_LOG.md b/docs/TUI_MODE_DEBUG_LOG.md
@@ -195,3 +195,18 @@ Residual items from Rounds 1-3. Test on both Ghostty and iTerm2:
   hypotheses tested.
 - Keep `make check` green at each round; manual-only behavior fixes
   still need snapshot validation that cat mode is unaffected.
+
+---
+
+## Update — 2026-05-22: `MARGIN_WIDTH` is gone
+
+This log references `MARGIN_WIDTH` in the H3 bug analysis ("No
+`MARGIN_WIDTH` prefix on TUI body RLines", "column aligns with image
+column (`MARGIN_WIDTH = 4`)"). That constant — along with the 4-space
+outer margin that mirrored `glow` — has been removed now that TUI is the
+default mode. Body rows in both cat and TUI start at column 0; heading
+images are placed at column 0 (or column 30 when the ToC panel is open).
+
+The H3 fix described in the original log is unaffected in spirit: heading
+images still need to be placed at the same column where the text would
+have rendered. The number is just `0`/`30` now instead of `4`/`34`.
diff --git a/docs/TUI_MODE_PLAN.md b/docs/TUI_MODE_PLAN.md
@@ -3299,3 +3299,30 @@ git commit -m "chore: bump version to 0.4.0"
 - **Placeholders:** No TBD/TODO in code. Where a task body mentions "refined in Phase N", the referenced task implements it.
 - **Type consistency:** `Style` fields (`fg/bg/bold/italic/underline/strikethrough/dim`) introduced in Task 1.1 are used consistently through `cat.rs` (Task 1.8) and `viewport.rs`/`search.rs`. `HeadingImage` moved to `render.rs` in Task 1.1 and re-referenced in `tui/kitty.rs` (Task 3.2) via path `crate::render::HeadingImage`. Kitty protocol APIs in Task 3.1 (`transmit/place/delete_placement/delete_all_for_client`) are the ones called by `ImageLifecycle` in Task 3.2.
 - **Known manual gates:** Task 1.9 requires human audit of snapshot diffs; Task 8.1 is the Ghostty/iTerm2 QA pass. Both are called out explicitly.
+
+---
+
+## Update — 2026-05-22: Outer margin removed
+
+The original plan reserved a 4-column outer margin (`MARGIN` = `"    "`,
+`MARGIN_WIDTH` = `4`) on every cat-mode line and on every TUI body row,
+mirroring `glow`'s gutter. With TUI now the default mode (post-v0.5.0), the
+gutter cost a fixed 4 columns of horizontal real estate for no remaining
+visual win, so it has been removed entirely.
+
+What changed vs. the snippets in this plan:
+
+- `src/style.rs` — `MARGIN` and `MARGIN_WIDTH` constants deleted.
+- `src/cat.rs` — every `{MARGIN}` prefix dropped from `write_line` /
+  `emit_code_block` / `write_paragraph`; `prefix_visual_width` drops the
+  `MARGIN_WIDTH` term (only quote bars contribute); `wrap_and_write` no
+  longer subtracts margin from `term_width`.
+- `src/tui/mod.rs` — the per-row leading-space span is gone; the heading
+  image `col_offset` collapses to `0` when ToC is closed and `30` when it
+  is open.
+- `src/tui/viewport.rs` — `wrap_all` no longer reserves 4 cols.
+
+Snapshot fixtures under `fixtures/expected/*.ansi` were regenerated. The
+visible diff is exactly: leading `"    "` removed from each rendered line,
+and wrap points shift later (because each line now has 4 more usable
+columns). All `make check` gates remain green.
diff --git a/fixtures/expected/emoji-test.ansi b/fixtures/expected/emoji-test.ansi
@@ -1,35 +1,35 @@
-    <IMG>
+<IMG>
 
-    <IMG>
+<IMG>
 
-    这是一份专门用于验证标题图片渲染的测试文档。
+这是一份专门用于验证标题图片渲染的测试文档。
 
-    <IMG>
+<IMG>
 
-      • 单个 emoji: 😀 😎 ✨ 🚀
-      • 中英混排: Hello 世界 🌍
-      • 符号混排: ✅ Done · ⚠ Warning · ❌ Failed
-      • 常见 emoji 变体: ☀️ ❤️ ⭐️
+  • 单个 emoji: 😀 😎 ✨ 🚀
+  • 中英混排: Hello 世界 🌍
+  • 符号混排: ✅ Done · ⚠ Warning · ❌ Failed
+  • 常见 emoji 变体: ☀️ ❤️ ⭐️
 
-    <IMG>
+<IMG>
 
-    正文仍然由终端自身字体渲染，所以这里主要用来对比标题和正文的表现差异。
+正文仍然由终端自身字体渲染，所以这里主要用来对比标题和正文的表现差异。
 
-    [38;5;240m│  [3;38;5;250m引用块里也放几个字符：💡 🛠 📦[0m
+[38;5;240m│  [3;38;5;250m引用块里也放几个字符：💡 🛠 📦[0m
 
-    <IMG>
+<IMG>
 
-      [1mCase[0m              [2m  │  [0m[1mExample[0m            
-      [2m──────────────────[0m[2m  ┼  [0m[2m───────────────────[0m
-      Single emoji      [2m  │  [0m😀                 
-      Mixed text        [2m  │  [0m修正版 ✨ version 2
-      Symbol-like       [2m  │  [0m✅ ⚠ ❌            
-      Variation selector[2m  │  [0m☀️ ❤️                
+[1mCase[0m              [2m  │  [0m[1mExample[0m            
+[2m──────────────────[0m[2m  ┼  [0m[2m───────────────────[0m
+Single emoji      [2m  │  [0m😀                 
+Mixed text        [2m  │  [0m修正版 ✨ version 2
+Symbol-like       [2m  │  [0m✅ ⚠ ❌            
+Variation selector[2m  │  [0m☀️ ❤️                
 
-    <IMG>
+<IMG>
 
-    这一行用于观察复杂 ZWJ emoji 的边界表现：👨‍👩‍👧‍👦 👩🏽‍💻 🧑‍🚀
+这一行用于观察复杂 ZWJ emoji 的边界表现：👨‍👩‍👧‍👦 👩🏽‍💻 🧑‍🚀
 
-    <IMG>
+<IMG>
 
-    如果修复生效，H1-H3 里的大部分单 emoji 和常见符号不应再显示成缺字框。
+如果修复生效，H1-H3 里的大部分单 emoji 和常见符号不应再显示成缺字框。
diff --git a/fixtures/expected/full-syntax-zh.ansi b/fixtures/expected/full-syntax-zh.ansi
@@ -1,70 +1,70 @@
-    <IMG>
+<IMG>
 
-    <IMG>
+<IMG>
 
-    <IMG>
+<IMG>
 
-    <IMG>
+<IMG>
 
-    [1m这是六级标题 h6[0m
+[1m这是六级标题 h6[0m
 
-    <IMG>
+<IMG>
 
-    [3m这段文字将显示为斜体[23m
-    [3m这也是斜体[23m
+[3m这段文字将显示为斜体[23m
+[3m这也是斜体[23m
 
-    [1m这段文字将显示为粗体[0m
-    [1m这也是粗体[0m
+[1m这段文字将显示为粗体[0m
+[1m这也是粗体[0m
 
-    [3m你 [23m[1m[3m可以[0m[3m 组合使用它们[23m
+[3m你 [23m[1m[3m可以[0m[3m 组合使用它们[23m
 
-    <IMG>
+<IMG>
 
-    <IMG>
+<IMG>
 
-      • 项目 1
-      • 项目 2
-      • 项目 2a
-      • 项目 2b
-        • 项目 3a
-        • 项目 3b
+  • 项目 1
+  • 项目 2
+  • 项目 2a
+  • 项目 2b
+    • 项目 3a
+    • 项目 3b
 
-    <IMG>
+<IMG>
 
-      1. 项目 1
-      2. 项目 2
-      3. 项目 3
-        1. 项目 3a
-        2. 项目 3b
+  1. 项目 1
+  2. 项目 2
+  3. 项目 3
+    1. 项目 3a
+    2. 项目 3b
 
-    <IMG>
+<IMG>
 
-    [2m[🖼 这是替代文本。](/image/Markdown-mark.svg)[0m
+[2m[🖼 这是替代文本。](/image/Markdown-mark.svg)[0m
 
-    <IMG>
+<IMG>
 
-    你可能正在使用 [36m[4mMarkdown 实时预览[24m[0m [38;5;245m(https://markdownlivepreview.com/)[0m。
+你可能正在使用 [36m[4mMarkdown 实时预览[24m[0m [38;5;245m(https://markdownlivepreview.com/)[0m。
 
-    <IMG>
+<IMG>
 
-    [38;5;240m│  [3;38;5;250mMarkdown 是一种轻量级标记语言，使用纯文本格式语法，由 John Gruber 和[0m
-    [38;5;240m│  [3;38;5;250mAaron Swartz 于 2004 年创建。[0m
-    [38;5;240m│  [38;5;240m│  [3;38;5;250mMarkdown 常用于编写 readme[0m
-    [38;5;240m│  [38;5;240m│  [3;38;5;250m文件、在线论坛中的消息格式化，以及使用纯文本编辑器创建富文本。[0m
+[38;5;240m│  [3;38;5;250mMarkdown 是一种轻量级标记语言，使用纯文本格式语法，由 John Gruber 和 Aaron[0m
+[38;5;240m│  [3;38;5;250mSwartz 于 2004 年创建。[0m
+[38;5;240m│  [38;5;240m│  [3;38;5;250mMarkdown 常用于编写 readme[0m
+[38;5;240m│  [38;5;240m│  [3;38;5;250m文件、在线论坛中的消息格式化，以及使用纯文本编辑器创建富文本。[0m
 
-    <IMG>
+<IMG>
 
-      [1m左对齐列[0m[2m  │  [0m[1m居中对齐列[0m
-      [2m────────[0m[2m  ┼  [0m[2m──────────[0m
-      左侧 foo[2m  │  [0m右侧 foo  
-      左侧 bar[2m  │  [0m右侧 bar  
-      左侧 baz[2m  │  [0m右侧 baz  
+[1m左对齐列[0m[2m  │  [0m[1m居中对齐列[0m
+[2m────────[0m[2m  ┼  [0m[2m──────────[0m
+左侧 foo[2m  │  [0m右侧 foo  
+左侧 bar[2m  │  [0m右侧 bar  
+左侧 baz[2m  │  [0m右侧 baz  
 
-    <IMG>
+<IMG>
 
-    [48;5;236m[38;5;213m let message = '你好，世界'; [0m
-    [48;5;236m[38;5;213m alert(message);             [0m
+[48;5;236m[38;5;213m let message = '你好，世界'; [0m
+[48;5;236m[38;5;213m alert(message);             [0m
 
-    <IMG>
+<IMG>
 
-    这个网站使用了 [38;5;213m[48;5;236m markedjs/marked [0m。
+这个网站使用了 [38;5;213m[48;5;236m markedjs/marked [0m。
diff --git a/fixtures/expected/full-syntax.ansi b/fixtures/expected/full-syntax.ansi
@@ -1,71 +1,71 @@
-    <IMG>
+<IMG>
 
-    <IMG>
+<IMG>
 
-    <IMG>
+<IMG>
 
-    <IMG>
+<IMG>
 
-    [1mThis is a Heading h6[0m
+[1mThis is a Heading h6[0m
 
-    <IMG>
+<IMG>
 
-    [3mThis text will be italic[23m
-    [3mThis will also be italic[23m
+[3mThis text will be italic[23m
+[3mThis will also be italic[23m
 
-    [1mThis text will be bold[0m
-    [1mThis will also be bold[0m
+[1mThis text will be bold[0m
+[1mThis will also be bold[0m
 
-    [3mYou [23m[1m[3mcan[0m[3m combine them[23m
+[3mYou [23m[1m[3mcan[0m[3m combine them[23m
 
-    <IMG>
+<IMG>
 
-    <IMG>
+<IMG>
 
-      • Item 1
-      • Item 2
-      • Item 2a
-      • Item 2b
-        • Item 3a
-        • Item 3b
+  • Item 1
+  • Item 2
+  • Item 2a
+  • Item 2b
+    • Item 3a
+    • Item 3b
 
-    <IMG>
+<IMG>
 
-      1. Item 1
-      2. Item 2
-      3. Item 3
-        1. Item 3a
-        2. Item 3b
+  1. Item 1
+  2. Item 2
+  3. Item 3
+    1. Item 3a
+    2. Item 3b
 
-    <IMG>
+<IMG>
 
-    [2m[🖼 This is an alt text.](/image/Markdown-mark.svg)[0m
+[2m[🖼 This is an alt text.](/image/Markdown-mark.svg)[0m
 
-    <IMG>
+<IMG>
 
-    You may be using [36m[4mMarkdown Live Preview[24m[0m [38;5;245m(https://markdownlivepreview.com/)[0m.
+You may be using [36m[4mMarkdown Live Preview[24m[0m [38;5;245m(https://markdownlivepreview.com/)[0m.
 
-    <IMG>
+<IMG>
 
-    [38;5;240m│  [3;38;5;250mMarkdown is a lightweight markup language with plain-text-formatting[0m
-    [38;5;240m│  [3;38;5;250msyntax, created in 2004 by John Gruber with Aaron Swartz.[0m
-    [38;5;240m│  [38;5;240m│  [3;38;5;250mMarkdown is often used to format readme files, for writing messages[0m
-    [38;5;240m│  [38;5;240m│  [3;38;5;250min online discussion forums, and to create rich text using a plain[0m
-    [38;5;240m│  [38;5;240m│  [3;38;5;250mtext editor.[0m
+[38;5;240m│  [3;38;5;250mMarkdown is a lightweight markup language with plain-text-formatting syntax,[0m
+[38;5;240m│  [3;38;5;250mcreated in 2004 by John Gruber with Aaron Swartz.[0m
+[38;5;240m│  [38;5;240m│  [3;38;5;250mMarkdown is often used to format readme files, for writing messages in[0m
+[38;5;240m│  [38;5;240m│  [3;38;5;250monline discussion forums, and to create rich text using a plain text[0m
+[38;5;240m│  [38;5;240m│  [3;38;5;250meditor.[0m
 
-    <IMG>
+<IMG>
 
-      [1mLeft columns[0m[2m  │  [0m[1mRight columns[0m
-      [2m────────────[0m[2m  ┼  [0m[2m─────────────[0m
-      left foo    [2m  │  [0mright foo    
-      left bar    [2m  │  [0mright bar    
-      left baz    [2m  │  [0mright baz    
+[1mLeft columns[0m[2m  │  [0m[1mRight columns[0m
+[2m────────────[0m[2m  ┼  [0m[2m─────────────[0m
+left foo    [2m  │  [0mright foo    
+left bar    [2m  │  [0mright bar    
+left baz    [2m  │  [0mright baz    
 
-    <IMG>
+<IMG>
 
-    [48;5;236m[38;5;213m let message = 'Hello world'; [0m
-    [48;5;236m[38;5;213m alert(message);              [0m
+[48;5;236m[38;5;213m let message = 'Hello world'; [0m
+[48;5;236m[38;5;213m alert(message);              [0m
 
-    <IMG>
+<IMG>
 
-    This web site is using [38;5;213m[48;5;236m markedjs/marked [0m.
+This web site is using [38;5;213m[48;5;236m markedjs/marked [0m.