diff --git a/CHANGELOG.md b/CHANGELOG.md
index b752911..9f69d1a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -13,7 +13,12 @@ All notable changes to **Rich Markdown Diff** will be documented in this file.
 - **Quick Edit**: Fixed a bug where the Quick Edit overlay loaded incorrect source text when editing documents that contain frontmatter metadata.
 - **Obsidian Tags**: Expanded the tag parser to support Japanese, Chinese, and other multi-byte characters.
 - **Marp Support**: Fixed slide transition animations and restored accurate dark/light theme styling in the webview.
-- **Stability & Rendering**: Resolved layout and event-handling bugs, including table scroll wrapping, code block placeholder collisions, and duplicate event listeners.
+- **Stability & Rendering**:
+  - Fixed horizontal scroll clipping of line highlights on code blocks and tables.
+  - Resolved visual alignment and active highlight issues for embedded code blocks and task list checkboxes.
+  - Fixed potential memory leaks in clipboard comparisons and child process hangs in Git Blame.
+- **Compare Commands**: Fixed a bug where comparing a file with itself opened a blank diff panel.
+
 
 ## [1.3.1] - 2026-05-24
 
diff --git a/fixtures/expected/comprehensive.html b/fixtures/expected/comprehensive.html
index b0e5e17..fd681be 100644
--- a/fixtures/expected/comprehensive.html
+++ b/fixtures/expected/comprehensive.html
@@ -25,14 +25,14 @@ <h3 data-line="28" data-line-end="29">Task List</h3>
 <li class="task-list-item" data-line="31" data-line-end="32"><input class="task-list-item-checkbox" checked disabled type="checkbox" /> Task 2</li>
 <ins class="diffins diff-block"><li data-all-inserted="true" class="task-list-item" data-line="32" data-line-end="34"><input class="task-list-item-checkbox" checked disabled type="checkbox" /> Task 3</li></ins></ul>
 <h2 data-line="34" data-line-end="35">Code Blocks</h2>
-<pre><code data-line="36" data-line-end="46" class="language-javascript"><span class="hljs-keyword">function</span> <span class="hljs-title function_">greet</span>(<span class="hljs-params">name</span>) {<span class="hljs-comment"><ins class="diffins">// Updated comment in v2</ins></span>
+<div class="code-block-wrapper"><pre><code data-line="36" data-line-end="46" class="language-javascript"><span class="hljs-keyword">function</span> <span class="hljs-title function_">greet</span>(<span class="hljs-params">name</span>) {<span class="hljs-comment"><ins class="diffins">// Updated comment in v2</ins></span>
   <span class="hljs-variable language_">console</span>.<span class="hljs-title function_">log</span>(<span class="hljs-string">`Hello, <span class="hljs-subst">${name}</span>!<ins class="diffins">&nbsp;Welcome!`</ins></span><ins class="diffins">);
 }
 
 </ins><span class="hljs-keyword"><ins class="diffins">function</ins></span><ins class="diffins">&nbsp;</ins><span class="hljs-title function_"><ins class="diffins">farewell</ins></span><ins class="diffins">(</ins><span class="hljs-params"><ins class="diffins">name</ins></span><ins class="diffins">) {
   </ins><span class="hljs-variable language_"><ins class="diffins">console</ins></span><ins class="diffins">.</ins><span class="hljs-title function_"><ins class="diffins">log</ins></span><ins class="diffins">(</ins><span class="hljs-string"><ins class="diffins">`Goodbye, </ins><span class="hljs-subst"><ins class="diffins">${name}</ins></span><ins class="diffins">!</ins>`</span>);
 }
-</code></pre><del class="diffdel diff-block"><h2 >Tables</h2></del><del class="diffmod diff-block"><table data-line="39" data-line-end="44">
+</code></pre></div><del class="diffdel diff-block"><h2 >Tables</h2></del><del class="diffmod diff-block"><table data-line="39" data-line-end="44">
 <thead>
 <tr data-line="39" data-line-end="40">
 <th data-line="39" data-line-end="40">Feature</th>
@@ -53,8 +53,7 @@ <h2 data-line="34" data-line-end="35">Code Blocks</h2>
 <td data-line="43" data-line-end="44">✅</td>
 </tr>
 </tbody>
-</table></del>
-<h2 data-line="47" data-line-end="48">Links and Images</h2>
+</table></del><h2 data-line="47" data-line-end="48">Links and Images</h2>
 <p data-line="49" data-line-end="51"><a href="https://github.com">Visit GitHub</a><a href="https://marketplace.visualstudio.com"><ins class="diffins">Visit VS Code Marketplace</ins></a></p>
 <h2 data-line="52" data-line-end="53">Blockquotes</h2>
 <blockquote data-line="54" data-line-end="57">
diff --git a/src/extension.ts b/src/extension.ts
index f950005..4cfb93f 100644
--- a/src/extension.ts
+++ b/src/extension.ts
@@ -935,6 +935,14 @@ async function createAndBindDiffPanel(
     getDiffPanelOptions(context),
   );
 
+  context.subscriptions.push(panel);
+  panel.onDidDispose(() => {
+    const idx = context.subscriptions.indexOf(panel);
+    if (idx > -1) {
+      context.subscriptions.splice(idx, 1);
+    }
+  });
+
   await bindDiffPanel(panel, context, resolveState);
   return panel;
 }
@@ -1170,10 +1178,12 @@ export function activate(context: vscode.ExtensionContext) {
       // Helper to track active panel for shortcuts
       attachPanelTracking(panel);
 
+      context.subscriptions.push(panel);
+
       panel.webview.html = webviewContent;
 
       // Handle Double Click
-      panel.webview.onDidReceiveMessage((message) => {
+      const messageDisposable = panel.webview.onDidReceiveMessage((message) => {
         if (message.command === "openSource") {
           const side = message.side;
           const line = message.line;
@@ -1198,6 +1208,14 @@ export function activate(context: vscode.ExtensionContext) {
           }
         }
       });
+
+      panel.onDidDispose(() => {
+        messageDisposable.dispose();
+        const idx = context.subscriptions.indexOf(panel);
+        if (idx > -1) {
+          context.subscriptions.splice(idx, 1);
+        }
+      });
     },
   );
 
@@ -1373,6 +1391,7 @@ export function activate(context: vscode.ExtensionContext) {
           vscode.window.showInformationMessage(
             l10n.t("You are comparing the same file."),
           );
+          return;
         }
 
         void showTwoFilesDiff(selectedForCompareUri, targetUri, context);
diff --git a/src/gitBlameResolver.ts b/src/gitBlameResolver.ts
index 6425189..f390212 100644
--- a/src/gitBlameResolver.ts
+++ b/src/gitBlameResolver.ts
@@ -67,6 +67,8 @@ export async function resolveBlameInfo(
     // \t<line_content>
     const child = child_process.spawn("git", ["blame", "--porcelain", fileName], { cwd });
 
+    child.stderr?.resume();
+
     const rl = readline.createInterface({
       input: child.stdout,
       crlfDelay: Infinity,
diff --git a/src/markdown/renderer.ts b/src/markdown/renderer.ts
index 0fef07a..220f581 100644
--- a/src/markdown/renderer.ts
+++ b/src/markdown/renderer.ts
@@ -99,7 +99,11 @@ function configureRules(md: MarkdownIt) {
       return `<div class="mermaid"${attrs} data-original-content="${escapedContent}">\n${escapedContent}\n</div>`;
     }
 
-    return defaultFence(tokens, idx, options, env, self);
+    // Wrap code blocks in a container div so that the ::after gutter marker
+    // (positioned at left: -16px) is not clipped by <pre>'s overflow-x: auto,
+    // which creates a scroll container that clips absolutely-positioned children.
+    const rendered = defaultFence(tokens, idx, options, env, self);
+    return `<div class="code-block-wrapper">${rendered}</div>`;
   };
 
   // Image Resolver Support
diff --git a/src/markdown/structuralDiff.ts b/src/markdown/structuralDiff.ts
index 58e7865..8cf8e09 100644
--- a/src/markdown/structuralDiff.ts
+++ b/src/markdown/structuralDiff.ts
@@ -960,6 +960,20 @@ export function replaceBalancedTags(
       }
     }
 
+    if (options.tokenizeCodeBlocks !== false && html.startsWith('<div class="code-block-wrapper">', i)) {
+      const start = i;
+      const end = findClosing(html, i, "div");
+      if (end > -1) {
+        const content = html.substring(start, end);
+        const token = createToken(content, "CODEBLOCK", tokens);
+        result += token;
+        i = end;
+        continue;
+      }
+    }
+
+    // Fallback: also tokenize bare <pre> elements (e.g. from Marp or other renderers
+    // that do not use the code-block-wrapper div).
     if (options.tokenizeCodeBlocks !== false && html.startsWith("<pre", i)) {
       const start = i;
       const end = findClosing(html, i, "pre");
@@ -1053,8 +1067,8 @@ export function replaceBalancedTags(
       }
     }
 
-    // Tables (already covered by listRegex, but keeping for compatibility if listRegex doesn't match for some reason)
-    if (html.startsWith("<table", i)) {
+    // Tables (fallback when list/table container tokenization is disabled)
+    if (options.tokenizeListContainers === false && html.startsWith("<table", i)) {
       const start = i;
       const end = findClosing(html, i, "table");
       if (end > -1) {
@@ -1400,57 +1414,89 @@ export function refineBlockDiffs(
 
   // NOTE: We cannot use a simple adjacency regex (del<pre></pre>del ins<pre></pre>ins) because
   // other diff elements (e.g. a deleted section) may sit between the del-pre and ins-pre blocks.
-  // Instead, collect all del-wrapped and ins-wrapped <pre> blocks globally, pair them by index,
+  // Instead, collect all del-wrapped and ins-wrapped code blocks globally, pair them by index,
   // re-diff each pair, and substitute back via placeholder tokens.
+  //
+  // Code blocks may appear as:
+  //   A) <del><div class="code-block-wrapper"><pre ...>...</pre></div></del>  (standard renderer)
+  //   B) <del><pre ...>...</pre></del>                                        (bare, e.g. Marp)
   {
-    const delPreRegex =
-      /<del([^>]*)>\s*<pre([^>]*)>([\s\S]*?)<\/pre>\s*<\/del>/gi;
-    const insPreRegex =
-      /<ins([^>]*)>\s*<pre([^>]*)>([\s\S]*?)<\/pre>\s*<\/ins>/gi;
-
     interface PreBlock {
       full: string;
+      wrapperAttrs: string; // div attrs (empty string for bare <pre>)
       preAttrs: string;
       inner: string;
+      isWrapped: boolean;   // true → code-block-wrapper present
     }
-    const delBlocks: PreBlock[] = [];
-    const insBlocks: PreBlock[] = [];
+    const delWrappedBlocks: PreBlock[] = [];
+    const insWrappedBlocks: PreBlock[] = [];
+    const delBareBlocks: PreBlock[] = [];
+    const insBareBlocks: PreBlock[] = [];
+
+    // Pattern A: del/ins wrapping the code-block-wrapper div
+    const delWrappedRegex =
+      /<del([^>]*)>\s*<div class="code-block-wrapper"([^>]*)>\s*<pre([^>]*)>([\s\S]*?)<\/pre>\s*<\/div>\s*<\/del>/gi;
+    const insWrappedRegex =
+      /<ins([^>]*)>\s*<div class="code-block-wrapper"([^>]*)>\s*<pre([^>]*)>([\s\S]*?)<\/pre>\s*<\/div>\s*<\/ins>/gi;
 
     let m: RegExpExecArray | null;
+    while ((m = delWrappedRegex.exec(resultHtml)) !== null) {
+      delWrappedBlocks.push({ full: m[0], wrapperAttrs: m[2], preAttrs: m[3], inner: m[4], isWrapped: true });
+    }
+    while ((m = insWrappedRegex.exec(resultHtml)) !== null) {
+      insWrappedBlocks.push({ full: m[0], wrapperAttrs: m[2], preAttrs: m[3], inner: m[4], isWrapped: true });
+    }
+
+    // Pattern B: del/ins wrapping a bare <pre> (fallback for Marp etc.)
+    const delPreRegex =
+      /<del([^>]*)>\s*<pre([^>]*)>([\s\S]*?)<\/pre>\s*<\/del>/gi;
+    const insPreRegex =
+      /<ins([^>]*)>\s*<pre([^>]*)>([\s\S]*?)<\/pre>\s*<\/ins>/gi;
+
     while ((m = delPreRegex.exec(resultHtml)) !== null) {
-      delBlocks.push({
-        full: m[0],
-        preAttrs: m[2],
-        inner: m[3],
-      });
+      delBareBlocks.push({ full: m[0], wrapperAttrs: "", preAttrs: m[2], inner: m[3], isWrapped: false });
     }
     while ((m = insPreRegex.exec(resultHtml)) !== null) {
-      insBlocks.push({
-        full: m[0],
-        preAttrs: m[2],
-        inner: m[3],
+      insBareBlocks.push({ full: m[0], wrapperAttrs: "", preAttrs: m[2], inner: m[3], isWrapped: false });
+    }
+
+    const diffedPairs: Array<{
+      delFull: string;
+      insFull: string;
+      diffed: string;
+    }> = [];
+
+    const pairWrappedCount = Math.min(delWrappedBlocks.length, insWrappedBlocks.length);
+    for (let i = 0; i < pairWrappedCount; i++) {
+      const innerDiff = diffCodeBlocks(
+        delWrappedBlocks[i].inner,
+        insWrappedBlocks[i].inner,
+      );
+      const diffedPre = `<pre${insWrappedBlocks[i].preAttrs}>${innerDiff}</pre>`;
+      const diffed = `<div class="code-block-wrapper"${insWrappedBlocks[i].wrapperAttrs}>${diffedPre}</div>`;
+      diffedPairs.push({
+        delFull: delWrappedBlocks[i].full,
+        insFull: insWrappedBlocks[i].full,
+        diffed,
+      });
+    }
+
+    const pairBareCount = Math.min(delBareBlocks.length, insBareBlocks.length);
+    for (let i = 0; i < pairBareCount; i++) {
+      const innerDiff = diffCodeBlocks(
+        delBareBlocks[i].inner,
+        insBareBlocks[i].inner,
+      );
+      const diffedPre = `<pre${insBareBlocks[i].preAttrs}>${innerDiff}</pre>`;
+      diffedPairs.push({
+        delFull: delBareBlocks[i].full,
+        insFull: insBareBlocks[i].full,
+        diffed: diffedPre,
       });
     }
 
-    const pairCount = Math.min(delBlocks.length, insBlocks.length);
+    const pairCount = diffedPairs.length;
     if (pairCount > 0) {
-      const diffedPairs: Array<{
-        delFull: string;
-        insFull: string;
-        diffed: string;
-      }> = [];
-      for (let i = 0; i < pairCount; i++) {
-        // Diff ONLY the inner content of the pre block
-        const innerDiff = diffCodeBlocks(
-          delBlocks[i].inner,
-          insBlocks[i].inner,
-        );
-        diffedPairs.push({
-          delFull: delBlocks[i].full,
-          insFull: insBlocks[i].full,
-          diffed: `<pre${insBlocks[i].preAttrs}>${innerDiff}</pre>`,
-        });
-      }
 
       const uniqueRunId = Math.random().toString(36).slice(2, 10);
       for (let i = 0; i < diffedPairs.length; i++) {
@@ -1771,10 +1817,15 @@ export function normalizeMathBlockDiffs(html: string): string {
 }
 
 export function cleanupCheckboxArtifacts(html: string): string {
-  return html.replace(
-    /(<input[^>]+class="task-list-item-checkbox"[^>]*>)(\s*)(?=(?:<p\b|<div\b|<ins[^>]*>\s*\[))/gi,
+  let result = html.replace(
+    /(<input[^>]+class="task-list-item-checkbox"[^>]*>)(\s*)(?=(?:<p\b|<div\b|<del[^>]*>\s*\[))/gi,
     '<del class="diffdel">$1</del>$2',
   );
+  result = result.replace(
+    /(<input[^>]+class="task-list-item-checkbox"[^>]*>)(\s*)(?=(?:<p\b|<div\b|<ins[^>]*>\s*\[))/gi,
+    '<ins class="diffins">$1</ins>$2',
+  );
+  return result;
 }
 
 export function stripDataLineAttributes(html: string): string {
@@ -2213,42 +2264,38 @@ export function verifyDiffIntegrity(
     return true; // Nothing to check
   }
 
-  const diffWordsSet = new Set(getWords(diffText));
+  const diffWordsMap = new Map<string, number>();
+  for (const word of getWords(diffText)) {
+    diffWordsMap.set(word, (diffWordsMap.get(word) || 0) + 1);
+  }
 
-  // Sample a subset of words to check to avoid performance issues on huge documents
-  // but ensure we check enough to detect truncation.
-  const sampleSize = Math.min(newWords.length, 200);
-  const step = Math.max(1, Math.floor(newWords.length / sampleSize));
+  const newWordsMap = new Map<string, number>();
+  for (const word of newWords) {
+    newWordsMap.set(word, (newWordsMap.get(word) || 0) + 1);
+  }
 
   let missingCount = 0;
-  let checkedCount = 0;
-  for (let i = 0; i < newWords.length; i += step) {
-    const word = newWords[i];
-    checkedCount++;
-    if (!diffWordsSet.has(word)) {
-      missingCount++;
+  let totalChecked = 0;
+  const missingWords: string[] = [];
+
+  for (const [word, newCount] of newWordsMap.entries()) {
+    const diffCount = diffWordsMap.get(word) || 0;
+    if (diffCount < newCount) {
+      missingCount += (newCount - diffCount);
+      if (missingWords.length < 10) {
+        missingWords.push(word);
+      }
     }
+    totalChecked += newCount;
   }
 
-  // Allow a very small margin of error (e.g. 1.0%) for edge cases where htmldiff
-  // might legitimately combine or slightly transform words (e.g. case changes, punctuation).
-  const failureThreshold = 0.01; // 1.0% margin of error
-  const missingRatio = checkedCount > 0 ? missingCount / checkedCount : 0;
+  const failureThreshold = 0.02; // 2.0% margin of error
+  const missingRatio = totalChecked > 0 ? missingCount / totalChecked : 0;
   const isBroken = missingRatio > failureThreshold;
 
   if (isBroken) {
-    const missingWords = [];
-    for (let i = 0; i < newWords.length; i += step) {
-      const word = newWords[i];
-      if (!diffWordsSet.has(word)) {
-        missingWords.push(word);
-        if (missingWords.length >= 10) {
-          break;
-        }
-      }
-    }
     console.warn(
-      `Integrity check failed: missing ${missingCount}/${checkedCount} words (${(missingRatio * 100).toFixed(1)}%). Missing: ${missingWords.join(", ")}`,
+      `Integrity check failed: missing ${missingCount}/${totalChecked} words (${(missingRatio * 100).toFixed(1)}%). Missing: ${missingWords.join(", ")}`,
     );
     return false;
   }
diff --git a/src/markdown/webviewTemplate.ts b/src/markdown/webviewTemplate.ts
index ee5113c..c4b97f7 100644
--- a/src/markdown/webviewTemplate.ts
+++ b/src/markdown/webviewTemplate.ts
@@ -450,6 +450,8 @@ export function getWebviewContent(
         dl,
         blockquote,
         pre,
+        .code-block-wrapper,
+        .table-block-wrapper,
         .table-scroll,
         hr,
         .markdown-alert,
@@ -512,6 +514,17 @@ export function getWebviewContent(
           padding: 0;
           border-radius: 0;
         }
+        /* Wrapper around <pre> code blocks to avoid the gutter marker being clipped
+           by pre's overflow-x: auto scroll container. The wrapper stays overflow:
+           visible so the ::after gutter bar can appear in the left gutter padding. */
+        .code-block-wrapper {
+            position: relative;
+            overflow: visible;
+            margin-bottom: var(--markdown-block-spacing);
+        }
+        .code-block-wrapper pre {
+            margin-bottom: 0;
+        }
         pre {
             background-color: var(--vscode-textCodeBlock-background, var(--markdown-raised-background));
             padding: 8px 10px;
@@ -690,6 +703,11 @@ export function getWebviewContent(
         p > img:only-child {
           display: block;
         }
+        .table-block-wrapper {
+            position: relative;
+            overflow: visible;
+            margin-bottom: var(--markdown-block-spacing);
+        }
         .table-scroll {
           width: 100%;
           max-width: 100%;
@@ -834,6 +852,7 @@ export function getWebviewContent(
         ins:has(.footnote-item), del:has(.footnote-item),
         ins:has(li), del:has(li),
         ins:has(pre), del:has(pre),
+        ins:has(.code-block-wrapper), del:has(.code-block-wrapper),
         ins:has(table), del:has(table),
         ins:has(h1), del:has(h1),
         ins:has(h2), del:has(h2),
@@ -862,7 +881,7 @@ export function getWebviewContent(
 
 
         /* Container Borders for Block Diffs (Alerts, Code, Mermaid) */
-        :is(.markdown-alert, .mermaid, pre):is(:has(ins), :has(del), :parent(ins), :parent(del), .diffins, .diffdel) {
+        :is(.markdown-alert, .mermaid, pre, .code-block-wrapper):is(:has(ins), :has(del), :parent(ins), :parent(del), .diffins, .diffdel) {
             position: relative;
         }
 
@@ -955,8 +974,8 @@ export function getWebviewContent(
 
 
 
-        ins:has(> h1, > h2, > h3, > h4, > h5, > h6, > p, > img, > table, > .table-scroll, > ul, > ol, > dl, > li, > blockquote, > div, > pre, > hr, > section, > details, > summary, > figure),
-        del:has(> h1, > h2, > h3, > h4, > h5, > h6, > p, > img, > table, > .table-scroll, > ul, > ol, > dl, > li, > blockquote, > div, > pre, > hr, > section, > details, > summary, > figure) {
+        ins:has(> h1, > h2, > h3, > h4, > h5, > h6, > p, > img, > table, > .table-block-wrapper, > .table-scroll, > ul, > ol, > dl, > li, > blockquote, > div, > pre, > hr, > section, > details, > summary, > figure),
+        del:has(> h1, > h2, > h3, > h4, > h5, > h6, > p, > img, > table, > .table-block-wrapper, > .table-scroll, > ul, > ol, > dl, > li, > blockquote, > div, > pre, > hr, > section, > details, > summary, > figure) {
             display: block;
           width: fit-content;
           max-width: 100%;
@@ -1344,14 +1363,14 @@ export function getWebviewContent(
         }
 
         /* Specific High Visibility for Complex Blocks (Code/Mermaid/Math) */
-        pre.selected-change,
+        :is(pre, .code-block-wrapper).selected-change,
         .mermaid.selected-change, 
         .katex-block.selected-change {
             overflow: visible !important;
             display: block; 
         }
 
-        pre.selected-change.selected-ins,
+        :is(pre, .code-block-wrapper).selected-change.selected-ins,
         .mermaid.selected-change.selected-ins,
         .katex-block.selected-change.selected-ins {
           background-color: rgba(34, 197, 94, 0.25) !important;
@@ -1359,7 +1378,7 @@ export function getWebviewContent(
           box-shadow: 0 0 0 2px rgba(34, 197, 94, 0.8) !important;
         }
 
-        pre.selected-change.selected-del,
+        :is(pre, .code-block-wrapper).selected-change.selected-del,
         .mermaid.selected-change.selected-del,
         .katex-block.selected-change.selected-del {
           background-color: rgba(248, 113, 113, 0.2) !important;
@@ -1367,7 +1386,7 @@ export function getWebviewContent(
           box-shadow: 0 0 0 2px rgba(239, 68, 68, 0.8) !important;
         }
 
-        pre.selected-change.selected-mod,
+        :is(pre, .code-block-wrapper).selected-change.selected-mod,
         .mermaid.selected-change.selected-mod,
         .katex-block.selected-change.selected-mod {
           background-color: rgba(59, 130, 246, 0.08) !important;
@@ -1375,6 +1394,10 @@ export function getWebviewContent(
           box-shadow: 0 0 0 2px rgba(59, 130, 246, 0.3) !important;
         }
 
+        .code-block-wrapper.selected-change pre {
+            background-color: transparent !important;
+        }
+
         /* Image Focus Style (same as Mermaid) */
         .selected-change img {
           border: 1px solid rgba(255, 165, 0, 0.9) !important;
@@ -2730,13 +2753,13 @@ export function getWebviewContent(
                 const getComplexContainer = (el) => {
                   // Case 1: The change is inside a complex visual block like Mermaid or KaTeX.
                   // Table and stable code-block diffs stay granular so the ruler and selection can stay local.
-                  const ancestor = el.closest('.mermaid') || el.closest('.katex-block') || el.closest('svg');
+                  const ancestor = el.closest('.mermaid') || el.closest('.katex-block') || el.closest('svg') || el.closest('.code-block-wrapper');
                     if (ancestor) return ancestor;
 
                   // Case 2: The change wraps a complex visual block (e.g. a new code block or diagram added)
                   // We prefer the child container for highlighting as it's the visual element.
                     if (el.querySelector) {
-                     let child = el.querySelector('pre') || el.querySelector('.mermaid') || el.querySelector('.katex-block');
+                     let child = el.querySelector('.code-block-wrapper') || el.querySelector('pre') || el.querySelector('.mermaid') || el.querySelector('.katex-block');
                          if (!child) {
                              // Only treat SVG as complex if it's NOT an alert icon
                              const svg = el.querySelector('svg');
diff --git a/src/markdownDiff.ts b/src/markdownDiff.ts
index f499f05..47b3f93 100644
--- a/src/markdownDiff.ts
+++ b/src/markdownDiff.ts
@@ -55,18 +55,18 @@ function wrapTablesForScrolling(html: string): string {
   return html.replace(
     tableRegex,
     (match, tagType, tagAttrs, offset, fullString) => {
-      // Check if this match is already wrapped in a div.table-scroll
+      // Check if this match is already wrapped in a div.table-scroll/table-block-wrapper
       const preceding = fullString.slice(0, offset).trim();
       const following = fullString.slice(offset + match.length).trim();
 
-      const isPrecededByScrollDiv = /<div\b[^>]*\bclass=["'][^"']*\btable-scroll\b[^"']*["'][^>]*>\s*$/i.test(preceding);
-      const isFollowedByCloseDiv = /^\s*<\/div>/i.test(following);
+      const isPrecededByScrollDiv = /<div\b[^>]*\bclass=["'][^"']*\b(table-scroll|table-block-wrapper)\b[^"']*["'][^>]*>\s*(?:<div\b[^>]*\bclass=["'][^"']*\btable-scroll\b[^"']*["'][^>]*>\s*)?$/i.test(preceding);
+      const isFollowedByCloseDiv = /^\s*<\/div>\s*(?:<\/div>)?/i.test(following);
 
       if (isPrecededByScrollDiv && isFollowedByCloseDiv) {
         return match;
       }
 
-      return `<div class="table-scroll">${match}</div>`;
+      return `<div class="table-block-wrapper"><div class="table-scroll">${match}</div></div>`;
     }
   );
 }
diff --git a/src/test/runTest.ts b/src/test/runTest.ts
index 00723f8..c6c3369 100644
--- a/src/test/runTest.ts
+++ b/src/test/runTest.ts
@@ -66,12 +66,14 @@ async function main() {
       "index",
     );
     const runtimeRoot = path.join(
-      os.tmpdir(),
-      `rich-markdown-diff-host-${Date.now()}`,
+      extensionDevelopmentPath,
+      ".vscode-test",
+      "user-data-dir",
     );
     const userDataDir = path.join(runtimeRoot, "user-data");
     const extensionsDir = path.join(runtimeRoot, "extensions");
 
+    await fs.rm(runtimeRoot, { recursive: true, force: true });
     await fs.mkdir(userDataDir, { recursive: true });
     await fs.mkdir(extensionsDir, { recursive: true });
 
diff --git a/src/test/unit/edgeCases.test.ts b/src/test/unit/edgeCases.test.ts
index 7a99899..2b7c0d1 100644
--- a/src/test/unit/edgeCases.test.ts
+++ b/src/test/unit/edgeCases.test.ts
@@ -31,7 +31,12 @@ describe("MarkdownDiffProvider - Edge Cases", () => {
     // It should be wrapped in a single del with diff-block class
     assert.ok(diff.includes("diff-block"), "Should have diff-block class for code block deletion");
     assert.ok(diff.includes("<pre"), "Should contain the pre tag");
-    assert.ok(diff.match(/<del[^>]*class="[^"]*diff-block[^"]*"[^>]*>\s*<pre/im), "del tag should wrap pre tag");
+    // The del tag wraps the code-block-wrapper div which contains pre
+    assert.ok(
+      diff.match(/<del[^>]*class="[^"]*diff-block[^"]*"[^>]*>\s*<div class="code-block-wrapper"[^>]*>\s*<pre/im) ||
+      diff.match(/<del[^>]*class="[^"]*diff-block[^"]*"[^>]*>\s*<pre/im),
+      "del tag should wrap code block (via code-block-wrapper div or directly)",
+    );
   });
 
   it("should highlight added horizontal rules with diff-block", () => {
@@ -147,7 +152,7 @@ describe("MarkdownDiffProvider - Edge Cases", () => {
     // 2. Table inside del should wrap the del container, not the table inside it
     const delInput = `<del class="diffdel diff-block">${table}</del>`;
     const delOutput = provider.getWebviewContent(delInput, "", "", "", "");
-    assert.ok(delOutput.includes(`<div class="table-scroll"><del class="diffdel diff-block">${table}</del></div>`), "Should wrap outer del rather than nesting block-in-inline");
+    assert.ok(delOutput.includes(`<div class="table-block-wrapper"><div class="table-scroll"><del class="diffdel diff-block">${table}</del></div></div>`), "Should wrap outer del rather than nesting block-in-inline");
   });
 
   it("BUG-03: should not double-wrap tables even if table-scroll div has attributes and trailing whitespace/newlines", () => {
diff --git a/src/test/unit/markdownDiff.test.ts b/src/test/unit/markdownDiff.test.ts
index abf63e3..3066a6c 100644
--- a/src/test/unit/markdownDiff.test.ts
+++ b/src/test/unit/markdownDiff.test.ts
@@ -852,7 +852,7 @@ describe("MarkdownDiffProvider", () => {
     );
     assert.ok(
       webviewContent.includes(
-        "const ancestor = el.closest('.mermaid') || el.closest('.katex-block') || el.closest('svg');",
+        "const ancestor = el.closest('.mermaid') || el.closest('.katex-block') || el.closest('svg') || el.closest('.code-block-wrapper');",
       ),
       "Complex visual blocks like Mermaid and KaTeX should still be promoted to their rendered container while stable code blocks stay granular",
     );
@@ -992,15 +992,15 @@ describe("MarkdownDiffProvider", () => {
     );
     assert.ok(
       webviewContent.includes(
-        "const ancestor = el.closest('.mermaid') || el.closest('.katex-block') || el.closest('svg');",
+        "const ancestor = el.closest('.mermaid') || el.closest('.katex-block') || el.closest('svg') || el.closest('.code-block-wrapper');",
       ),
-      "Stable code blocks with inner line diffs should stay granular instead of being promoted through closest('pre')",
+      "Stable code blocks with inner line diffs should be promoted to .code-block-wrapper as a stable anchor",
     );
     assert.ok(
       webviewContent.includes(
-        "let child = el.querySelector('pre') || el.querySelector('.mermaid') || el.querySelector('.katex-block');",
+        "let child = el.querySelector('.code-block-wrapper') || el.querySelector('pre') || el.querySelector('.mermaid') || el.querySelector('.katex-block');",
       ),
-      "Wrapped code-block insertions should resolve to the pre container for active highlighting",
+      "Wrapped code-block insertions should resolve to the .code-block-wrapper container for active highlighting",
     );
     assert.ok(
       webviewContent.includes(".selected-change.selected-ins {") &&
@@ -1010,7 +1010,7 @@ describe("MarkdownDiffProvider", () => {
       "Inserted active changes should use green selection styling instead of the old yellow overlay",
     );
     assert.ok(
-      webviewContent.includes("pre.selected-change.selected-ins,") &&
+      webviewContent.includes(":is(pre, .code-block-wrapper).selected-change.selected-ins,") &&
         webviewContent.includes("border: 1px solid #22c55e !important;") &&
         webviewContent.includes(
           "box-shadow: 0 0 0 2px rgba(34, 197, 94, 0.8) !important;",
@@ -1052,10 +1052,10 @@ describe("MarkdownDiffProvider", () => {
       "heading-prefix class should prevent number prefixes from wrapping",
     );
     assert.ok(
-      /ins:has\(> h1, > h2, > h3, > h4, > h5, > h6, > p, > img, > table, > \.table-scroll, > ul, > ol, > dl, > li, > blockquote, > div, > pre, > hr, > section, > details, > summary, > figure\),[\s\S]*del:has\(> h1, > h2, > h3, > h4, > h5, > h6, > p, > img, > table, > \.table-scroll, > ul, > ol, > dl, > li, > blockquote, > div, > pre, > hr, > section, > details, > summary, > figure\) \{[\s\S]*display: block;[\s\S]*width: fit-content;/m.test(
+      /ins:has\(> h1, > h2, > h3, > h4, > h5, > h6, > p, > img, > table, > \.table-block-wrapper, > \.table-scroll, > ul, > ol, > dl, > li, > blockquote, > div, > pre, > hr, > section, > details, > summary, > figure\),[\s\S]*del:has\(> h1, > h2, > h3, > h4, > h5, > h6, > p, > img, > table, > \.table-block-wrapper, > \.table-scroll, > ul, > ol, > dl, > li, > blockquote, > div, > pre, > hr, > section, > details, > summary, > figure\) \{[\s\S]*display: block;[\s\S]*width: fit-content;/m.test(
         webviewContent,
       ),
-      "Modified headings should be set as block elements so the background color spans the full pane width",
+      "Modified headings should be set as block elements so the background color spans the full width",
     );
   });
 
@@ -1175,7 +1175,7 @@ describe("MarkdownDiffProvider", () => {
     );
 
     assert.ok(
-      /<div class="table-scroll">\s*<table>/m.test(webviewContent),
+      /<div class="table-block-wrapper"><div class="table-scroll">\s*<table>/m.test(webviewContent),
       "Tables should be wrapped in a dedicated scroll container so wide tables scroll locally instead of stretching the pane",
     );
     assert.ok(
diff --git a/src/test/visual/__screenshots__/vrt.test.js-snapshots/comprehensive-v1-v2-split-light-chromium-linux.png b/src/test/visual/__screenshots__/vrt.test.js-snapshots/comprehensive-v1-v2-split-light-chromium-linux.png
index ad929a6..fd09c34 100644
Binary files a/src/test/visual/__screenshots__/vrt.test.js-snapshots/comprehensive-v1-v2-split-light-chromium-linux.png and b/src/test/visual/__screenshots__/vrt.test.js-snapshots/comprehensive-v1-v2-split-light-chromium-linux.png differ
diff --git a/src/test/visual/__screenshots__/vrt.test.js-snapshots/marp-v1-v2-split-dark-chromium-linux.png b/src/test/visual/__screenshots__/vrt.test.js-snapshots/marp-v1-v2-split-dark-chromium-linux.png
index 6c104ac..b5fe25c 100644
Binary files a/src/test/visual/__screenshots__/vrt.test.js-snapshots/marp-v1-v2-split-dark-chromium-linux.png and b/src/test/visual/__screenshots__/vrt.test.js-snapshots/marp-v1-v2-split-dark-chromium-linux.png differ