diff --git a/docs/superpowers/specs/2026-05-29-toolbar-breadcrumb-design.md b/docs/superpowers/specs/2026-05-29-toolbar-breadcrumb-design.md
new file mode 100644
index 0000000..e4bffbb
--- /dev/null
+++ b/docs/superpowers/specs/2026-05-29-toolbar-breadcrumb-design.md
@@ -0,0 +1,103 @@
+# Toolbar Breadcrumb Design
+
+## Goal
+
+Replace the static toolbar title with a breadcrumb that reflects the current document location.
+
+Target format:
+
+`Docs / 目录1 / 目录2 / 文件标题`
+
+The final segment uses the current file title instead of the raw file name.
+
+## Scope
+
+In scope:
+
+- Update the toolbar breadcrumb display in the reading view.
+- Derive breadcrumb segments from the current markdown file path.
+- Use the resolved markdown title for the last segment.
+- Keep the breadcrumb display-only for now.
+
+Out of scope:
+
+- Clicking breadcrumb segments to navigate.
+- Renaming directory segments with custom labels.
+- Changing sidebar navigation behavior.
+
+## Data Source
+
+The client already has the data needed for breadcrumb rendering:
+
+- `currentFile` tracks the selected markdown file path.
+- `navTree` contains file metadata, including titles extracted from markdown.
+- `initialContent` and `defaultFile` cover first-load rendering.
+
+No server-side schema changes are required for this feature.
+
+## Behavior
+
+### First load
+
+- If the page loads with an initial document, render the breadcrumb immediately.
+- If the page loads at `/` and auto-selects a homepage, render the breadcrumb for that file.
+
+### On file change
+
+- When a new markdown file finishes loading, refresh the toolbar breadcrumb.
+- Keep the final segment synced with the rendered file title.
+
+### Segment rules
+
+- Always start with `Docs`.
+- For files in the root directory, show `Docs / 文件标题`.
+- For nested files, show each directory name in order, followed by the file title.
+- If a file has no H1 title, fall back to the file name without extension.
+
+### Failure behavior
+
+- If a hash points to a file that fails to load, do not replace the breadcrumb with a broken path.
+- Keep the most recent valid breadcrumb until a valid file is rendered.
+
+## Implementation Plan
+
+### Template
+
+Replace the single static toolbar title node with a breadcrumb container that the client can fully control.
+
+### Client logic
+
+Add two small helpers in `public/app.js`:
+
+- A title index builder that maps file paths to their resolved display titles from `navTree`.
+- A breadcrumb renderer that splits `currentFile` into directory segments and appends the resolved file title as the last segment.
+
+Call the breadcrumb renderer in both places that establish visible content:
+
+- Initial content hydration
+- Successful `loadFile()` completion
+
+### Styling
+
+Keep the existing toolbar visual style, but allow breadcrumb segments to wrap the available width more gracefully:
+
+- Directory segments may truncate first.
+- The final file-title segment should remain most visible.
+- Mobile layout should continue to fit within the existing toolbar structure.
+
+## Testing
+
+Verify these cases:
+
+- Root path auto-loads a homepage and shows `Docs / 文件标题`
+- Root-level markdown file selection
+- Nested markdown file selection
+- Direct refresh on a deep hash URL
+- Markdown file without an H1 title
+- Narrow viewport layout does not break the toolbar
+
+## Review Notes
+
+- Breadcrumb remains display-only by design.
+- Directory labels come from real folder names, not markdown metadata.
+- This change is intentionally client-side only to keep the diff narrow.
diff --git a/public/app.js b/public/app.js
index 8d61fd7..8f5263e 100644
--- a/public/app.js
+++ b/public/app.js
@@ -13,6 +13,7 @@
   const btnToggleSidebar = document.getElementById('btnToggleSidebar');
   const btnToggleTheme = document.getElementById('btnToggleTheme');
   const themeSelect = document.getElementById('themeSelect');
+  const toolbarBreadcrumb = document.getElementById('toolbarBreadcrumb');
   const contentBody = document.getElementById('contentBody');
   const emptyState = document.getElementById('emptyState');
   const markdownContent = document.getElementById('markdownContent');
@@ -23,11 +24,13 @@
   const tocPanel = document.getElementById('tocPanel');
   const loadingBar = document.getElementById('loadingBar');
   const sidebar = document.getElementById('sidebar');
+  const app = document.getElementById('app');
   const mobileNavBtn = document.getElementById('mobileNavBtn');
   const themeStylesheet = document.getElementById('themeStylesheet');
   const themeHighlightStylesheet = document.getElementById('themeHighlightStylesheet');
 
   let currentFile = null;
+  const titleByPath = buildTitleIndex(navTree);
   const fallbackTheme = themes[0] || {
     id: 'default',
     label: 'Default',
@@ -115,10 +118,12 @@
   function setSidebarVisible(visible) {
     if (visible) {
       sidebar.classList.remove('collapsed');
+      app.classList.remove('sidebar-collapsed');
       localStorage.setItem('webook-sidebar', 'visible');
       btnToggleSidebar.textContent = '☰';
     } else {
       sidebar.classList.add('collapsed');
+      app.classList.add('sidebar-collapsed');
       localStorage.setItem('webook-sidebar', 'hidden');
       btnToggleSidebar.textContent = '☷';
     }
@@ -197,6 +202,63 @@
     return div.innerHTML;
   }
 
+  function buildTitleIndex(items, index = {}) {
+    if (!Array.isArray(items)) return index;
+
+    items.forEach((item) => {
+      if (item.type === 'file') {
+        const title = item.meta && item.meta.title
+          ? item.meta.title
+          : item.name.replace(/\.(md|markdown)$/i, '');
+        index[item.path] = title;
+        return;
+      }
+
+      if (item.type === 'dir' && Array.isArray(item.children)) {
+        buildTitleIndex(item.children, index);
+      }
+    });
+
+    return index;
+  }
+
+  function getFileDisplayTitle(filePath, preferredTitle) {
+    if (preferredTitle) return preferredTitle;
+    if (titleByPath[filePath]) return titleByPath[filePath];
+    if (!filePath) return '';
+    const fileName = filePath.split('/').pop() || filePath;
+    return fileName.replace(/\.(md|markdown)$/i, '');
+  }
+
+  function renderToolbarBreadcrumb(filePath, preferredTitle) {
+    if (!toolbarBreadcrumb) return;
+
+    const segments = ['<span class="toolbar-kicker">Docs</span>'];
+    const parts = typeof filePath === 'string' && filePath
+      ? filePath.split('/').filter(Boolean)
+      : [];
+
+    if (!parts.length) {
+      toolbarBreadcrumb.innerHTML = segments.join('');
+      return;
+    }
+
+    const directoryParts = parts.slice(0, -1);
+    const fileTitle = getFileDisplayTitle(filePath, preferredTitle);
+
+    directoryParts.forEach((part) => {
+      segments.push('<span class="toolbar-divider">/</span>');
+      segments.push(`<span class="toolbar-segment">${escapeHtml(part)}</span>`);
+    });
+
+    if (fileTitle) {
+      segments.push('<span class="toolbar-divider">/</span>');
+      segments.push(`<span class="toolbar-segment is-current">${escapeHtml(fileTitle)}</span>`);
+    }
+
+    toolbarBreadcrumb.innerHTML = segments.join('');
+  }
+
   // Render nav
   sidebarNav.innerHTML = renderNavTree(navTree);
 
@@ -308,7 +370,6 @@
   async function loadFile(filePath) {
     if (currentFile === filePath) return;
 
-    currentFile = filePath;
     showLoading();
 
     try {
@@ -325,11 +386,14 @@
       emptyState.style.display = 'none';
       markdownContent.style.display = '';
 
+      currentFile = filePath;
       articleTitle.textContent = data.title;
       articleBody.innerHTML = data.html;
+      enhanceCodeBlocks();
       buildTOC();
 
       renderArticleMeta(data.meta);
+      renderToolbarBreadcrumb(filePath, data.title);
 
       // Scroll to top
       contentBody.scrollTop = 0;
@@ -379,6 +443,77 @@
     // For now, server-side rendering handles highlighting.
   }
 
+  function enhanceCodeBlocks() {
+    const blocks = articleBody.querySelectorAll('pre.hljs');
+    blocks.forEach((block) => {
+      if (block.parentElement && block.parentElement.classList.contains('code-block-shell')) return;
+
+      const shell = document.createElement('div');
+      shell.className = 'code-block-shell';
+      block.parentNode.insertBefore(shell, block);
+      shell.appendChild(block);
+
+      const button = document.createElement('button');
+      button.type = 'button';
+      button.className = 'code-copy-btn';
+      button.textContent = '复制';
+      button.setAttribute('aria-label', '复制代码');
+      shell.appendChild(button);
+    });
+  }
+
+  async function writeClipboardText(text) {
+    if (navigator.clipboard && window.isSecureContext) {
+      await navigator.clipboard.writeText(text);
+      return true;
+    }
+
+    const textarea = document.createElement('textarea');
+    textarea.value = text;
+    textarea.setAttribute('readonly', '');
+    textarea.style.position = 'fixed';
+    textarea.style.top = '0';
+    textarea.style.left = '-9999px';
+    document.body.appendChild(textarea);
+    textarea.focus();
+    textarea.select();
+
+    let copied = false;
+    try {
+      copied = document.execCommand('copy');
+    } finally {
+      textarea.remove();
+    }
+
+    if (!copied) {
+      throw new Error('copy command failed');
+    }
+
+    return true;
+  }
+
+  async function copyCodeFromButton(button) {
+    const shell = button.closest('.code-block-shell');
+    const block = shell ? shell.querySelector('pre') : null;
+    const code = block ? block.querySelector('code') : null;
+    if (!code) return;
+
+    const text = code.textContent || '';
+
+    try {
+      await writeClipboardText(text);
+      button.textContent = '已复制';
+    } catch (_) {
+      button.textContent = '复制失败';
+    }
+
+    window.setTimeout(() => {
+      if (button.isConnected) {
+        button.textContent = '复制';
+      }
+    }, 1600);
+  }
+
   function renderArticleMeta(meta) {
     const created = formatDate(meta.created);
     const modified = formatDate(meta.modified);
@@ -442,11 +577,13 @@
     markdownContent.style.display = '';
     articleTitle.textContent = initialContent.title;
     articleBody.innerHTML = initialContent.html;
+    enhanceCodeBlocks();
     buildTOC();
 
     renderArticleMeta(initialContent.meta);
 
     currentFile = defaultFile;
+    renderToolbarBreadcrumb(defaultFile, initialContent.title);
     if (defaultFile && history.replaceState) {
       history.replaceState(null, '', '#' + encodeURIComponent(defaultFile));
     }
@@ -472,6 +609,7 @@
   }
 
   window.addEventListener('hashchange', handleHashChange);
+  handleHashChange();
 
   // === Event Listeners ===
   btnToggleTheme.addEventListener('click', toggleColorMode);
@@ -490,6 +628,14 @@
       scrollToHeading(link.getAttribute('data-target'));
     });
   }
+  if (articleBody) {
+    articleBody.addEventListener('click', function (e) {
+      const button = e.target.closest('.code-copy-btn');
+      if (!button) return;
+      e.preventDefault();
+      copyCodeFromButton(button);
+    });
+  }
 
   // === Keyboard Shortcuts ===
   document.addEventListener('keydown', function (e) {
diff --git a/public/style.css b/public/style.css
index 7df636c..a7f20e2 100644
--- a/public/style.css
+++ b/public/style.css
@@ -14,6 +14,10 @@
   --brand-soft: rgba(58, 111, 247, 0.12);
   --code-bg: #0f172a;
   --code-fg: #e5edf9;
+  --code-toolbar-bg: #f4f7fb;
+  --code-panel-border: rgba(148, 163, 184, 0.24);
+  --code-panel-shadow: 0 18px 40px rgba(148, 163, 184, 0.18);
+  --code-line-number: #94a3b8;
   --shadow-lg: 0 20px 50px rgba(15, 23, 42, 0.08);
   --shadow-md: 0 10px 28px rgba(15, 23, 42, 0.08);
   --shadow-sm: 0 4px 16px rgba(15, 23, 42, 0.06);
@@ -51,6 +55,11 @@ a:hover { color: var(--brand-strong); }
   display: grid;
   grid-template-columns: var(--sidebar-width) minmax(0, 1fr);
   height: 100vh;
+  transition: grid-template-columns var(--transition);
+}
+
+.app.sidebar-collapsed {
+  grid-template-columns: 0 minmax(0, 1fr);
 }
 
 .sidebar {
@@ -63,8 +72,18 @@ a:hover { color: var(--brand-strong); }
   background: var(--bg);
   backdrop-filter: none;
   box-shadow: none;
+  overflow: hidden;
+  transition:
+    margin-left var(--transition),
+    opacity var(--transition),
+    visibility var(--transition);
+}
+.sidebar.collapsed {
+  margin-left: calc(-1 * var(--sidebar-width));
+  opacity: 0;
+  visibility: hidden;
+  pointer-events: none;
 }
-.sidebar.collapsed { margin-left: calc(-1 * var(--sidebar-width)); }
 .sidebar-header { display: grid; gap: 14px; padding-bottom: 14px; }
 .sidebar-brand {
   display: flex; align-items: center; gap: 12px;
@@ -167,14 +186,41 @@ a:hover { color: var(--brand-strong); }
   border-bottom: 0;
   backdrop-filter: none;
 }
-.toolbar-breadcrumb { display: flex; align-items: center; gap: 10px; min-width: 0; }
+.toolbar-breadcrumb {
+  display: flex;
+  align-items: center;
+  gap: 10px;
+  min-width: 0;
+  flex: 1;
+  overflow: hidden;
+}
 .toolbar-kicker {
   display: inline-flex; align-items: center;
   padding: 5px 10px; border-radius: 999px;
   background: var(--brand-soft); color: var(--brand); font-size: 12px; font-weight: 700;
+  flex: 0 0 auto;
+}
+.toolbar-divider,
+.toolbar-segment {
+  color: var(--text-muted);
+  font-size: 14px;
+  flex: 0 1 auto;
+  min-width: 0;
+}
+.toolbar-divider {
+  flex: 0 0 auto;
+}
+.toolbar-segment {
+  white-space: nowrap;
+  overflow: hidden;
+  text-overflow: ellipsis;
+}
+.toolbar-segment.is-current {
+  color: var(--text);
+  font-weight: 600;
+  flex-shrink: 0;
+  max-width: min(42vw, 420px);
 }
-.toolbar-divider, .toolbar-title { color: var(--text-muted); font-size: 14px; }
-.toolbar-title { color: var(--text); font-weight: 600; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
 .toolbar-actions { display: flex; align-items: center; gap: 8px; }
 .theme-select-wrap {
   display: inline-flex;
@@ -295,15 +341,70 @@ a:hover { color: var(--brand-strong); }
   padding: 0.18em 0.42em; border-radius: 8px;
   background: rgba(148, 163, 184, 0.14); color: var(--text);
 }
-.article-body pre {
-  margin: 1.2em 0; padding: 18px 20px;
-  border-radius: 20px; overflow: auto;
-  background: var(--code-bg) !important; color: var(--code-fg);
-  border: 1px solid rgba(148, 163, 184, 0.12);
-  box-shadow: var(--shadow-md);
+.code-block-shell {
+  position: relative;
+  margin: 1.2em 0;
 }
-.article-body pre code {
-  padding: 0; background: transparent; color: inherit; font-size: 0.92rem;
+.article-body .code-block-shell pre {
+  margin: 0;
+  padding: 52px 20px 18px;
+  border-radius: 20px;
+  overflow: auto;
+  color: var(--code-fg);
+  border: 1px solid var(--code-panel-border);
+  box-shadow: var(--code-panel-shadow);
+  background:
+    radial-gradient(circle at 24px 18px, #ff5f57 0 5px, transparent 5.5px),
+    radial-gradient(circle at 44px 18px, #febc2e 0 5px, transparent 5.5px),
+    radial-gradient(circle at 64px 18px, #28c840 0 5px, transparent 5.5px),
+    linear-gradient(180deg, var(--code-toolbar-bg) 0 36px, var(--code-bg) 36px 100%) !important;
+}
+.article-body .code-block-shell pre code {
+  padding: 0;
+  background: transparent;
+  color: inherit;
+  font-size: 0.92rem;
+  line-height: 1.6;
+}
+.code-copy-btn {
+  position: absolute;
+  top: 10px;
+  right: 12px;
+  height: 28px;
+  padding: 0 10px;
+  border: 1px solid var(--code-panel-border);
+  border-radius: 9px;
+  background: rgba(255, 255, 255, 0.78);
+  color: var(--text-muted);
+  font: inherit;
+  font-size: 12px;
+  font-weight: 700;
+  line-height: 1;
+  cursor: pointer;
+  backdrop-filter: blur(10px);
+  opacity: 0;
+  pointer-events: none;
+  transition: opacity var(--transition), color var(--transition), background var(--transition), border-color var(--transition);
+}
+.code-copy-btn:hover {
+  color: var(--text);
+  background: rgba(255, 255, 255, 0.94);
+  border-color: var(--border-strong);
+}
+.code-block-shell:hover .code-copy-btn,
+.code-block-shell:focus-within .code-copy-btn {
+  opacity: 1;
+  pointer-events: auto;
+}
+[data-color-mode="light"] .article-body .code-block-shell pre .hljs-ln-n {
+  color: var(--code-line-number);
+}
+[data-color-mode="dark"] .code-copy-btn {
+  background: rgba(15, 23, 42, 0.78);
+  color: var(--text-muted);
+}
+[data-color-mode="dark"] .code-copy-btn:hover {
+  background: rgba(30, 41, 59, 0.94);
 }
 .article-body table {
   width: 100%; margin: 1.2em 0; border-collapse: collapse;
@@ -404,11 +505,17 @@ a:hover { color: var(--brand-strong); }
   .sidebar {
     position: fixed; inset: 0 auto 0 0; z-index: 220;
     width: min(86vw, 320px); transform: translateX(-100%);
+    visibility: visible;
+    opacity: 1;
     transition: transform 220ms ease;
     box-shadow: var(--shadow-lg);
   }
   .sidebar.mobile-visible { transform: translateX(0); }
-  .sidebar.collapsed { margin-left: 0; }
+  .sidebar.collapsed {
+    margin-left: 0;
+    visibility: visible;
+    opacity: 1;
+  }
   .content-toolbar { padding-left: 18px; }
   .toolbar-breadcrumb { min-width: 0; }
   .theme-select-wrap { max-width: 150px; }
@@ -432,6 +539,10 @@ a:hover { color: var(--brand-strong); }
     width: 92px;
     padding: 0 10px;
   }
+  .code-copy-btn {
+    opacity: 1;
+    pointer-events: auto;
+  }
 }
 
 [data-doc-theme="toc"] .content {
diff --git a/public/themes/default/theme.css b/public/themes/default/theme.css
index 42b795c..862ad7a 100644
--- a/public/themes/default/theme.css
+++ b/public/themes/default/theme.css
@@ -12,8 +12,12 @@ html[data-theme-id="default"][data-color-mode="light"] {
   --brand: #3a6ff7;
   --brand-strong: #2757d6;
   --brand-soft: rgba(58, 111, 247, 0.12);
-  --code-bg: #0f172a;
-  --code-fg: #e5edf9;
+  --code-bg: #fbfdff;
+  --code-fg: #233044;
+  --code-toolbar-bg: #eef3f9;
+  --code-panel-border: rgba(148, 163, 184, 0.28);
+  --code-panel-shadow: 0 20px 44px rgba(148, 163, 184, 0.18);
+  --code-line-number: #9aa9bc;
   --shadow-lg: 0 20px 50px rgba(15, 23, 42, 0.08);
   --shadow-md: 0 10px 28px rgba(15, 23, 42, 0.08);
   --shadow-sm: 0 4px 16px rgba(15, 23, 42, 0.06);
@@ -42,8 +46,12 @@ html[data-theme-id="default"][data-color-mode="dark"] {
   --brand: #7aa2ff;
   --brand-strong: #93b4ff;
   --brand-soft: rgba(122, 162, 255, 0.14);
-  --code-bg: #020617;
+  --code-bg: #142033;
   --code-fg: #dbeafe;
+  --code-toolbar-bg: #1b2a40;
+  --code-panel-border: rgba(148, 163, 184, 0.16);
+  --code-panel-shadow: 0 14px 32px rgba(2, 6, 23, 0.22);
+  --code-line-number: #6f8099;
   --shadow-lg: 0 24px 60px rgba(2, 6, 23, 0.34);
   --shadow-md: 0 14px 32px rgba(2, 6, 23, 0.28);
   --shadow-sm: 0 6px 18px rgba(2, 6, 23, 0.2);
diff --git a/public/themes/paper/theme.css b/public/themes/paper/theme.css
index 9765aba..663abab 100644
--- a/public/themes/paper/theme.css
+++ b/public/themes/paper/theme.css
@@ -12,8 +12,12 @@ html[data-theme-id="paper"][data-color-mode="light"] {
   --brand: #8a5a2b;
   --brand-strong: #6f451d;
   --brand-soft: rgba(138, 90, 43, 0.12);
-  --code-bg: #2b2118;
-  --code-fg: #f8efe3;
+  --code-bg: #fffaf4;
+  --code-fg: #4a3422;
+  --code-toolbar-bg: #f4e8da;
+  --code-panel-border: rgba(138, 90, 43, 0.22);
+  --code-panel-shadow: 0 18px 38px rgba(122, 77, 38, 0.12);
+  --code-line-number: #b09072;
   --shadow-lg: 0 18px 42px rgba(77, 52, 29, 0.1);
   --shadow-md: 0 10px 24px rgba(77, 52, 29, 0.08);
   --shadow-sm: 0 4px 14px rgba(77, 52, 29, 0.06);
@@ -42,8 +46,12 @@ html[data-theme-id="paper"][data-color-mode="dark"] {
   --brand: #d1a16c;
   --brand-strong: #e0b88c;
   --brand-soft: rgba(209, 161, 108, 0.14);
-  --code-bg: #120d09;
+  --code-bg: #2a1f16;
   --code-fg: #f8efe3;
+  --code-toolbar-bg: #3a2b20;
+  --code-panel-border: rgba(205, 173, 141, 0.16);
+  --code-panel-shadow: 0 14px 30px rgba(0, 0, 0, 0.18);
+  --code-line-number: #8f7762;
   --shadow-lg: 0 24px 60px rgba(0, 0, 0, 0.32);
   --shadow-md: 0 14px 30px rgba(0, 0, 0, 0.24);
   --shadow-sm: 0 6px 16px rgba(0, 0, 0, 0.18);
diff --git a/src/server.js b/src/server.js
index f493a07..6e46a51 100644
--- a/src/server.js
+++ b/src/server.js
@@ -103,6 +103,72 @@ function renderPage({ title, nav, docTheme, customThemeHref, themes, initialThem
   });
 }
 
+function normalizeEntryName(name) {
+  return String(name)
+    .replace(/\.(md|markdown)$/i, '')
+    .toLowerCase()
+    .replace(/[\s\-_.]+/g, '');
+}
+
+function selectDefaultFile(nav, rootDir) {
+  const rootFiles = Array.isArray(nav)
+    ? nav.filter((item) => item.type === 'file')
+    : [];
+
+  if (rootFiles.length === 0) {
+    return null;
+  }
+
+  const rootDirName = normalizeEntryName(path.basename(rootDir));
+  const matchers = [
+    (name) => name.includes('index'),
+    (name) => name.includes('首页'),
+    (name) => rootDirName && (name.includes(rootDirName) || rootDirName.includes(name)),
+    (name) => name.includes('readme')
+  ];
+
+  for (const matcher of matchers) {
+    const matched = rootFiles.find((item) => matcher(normalizeEntryName(item.name)));
+    if (matched) {
+      return matched.path;
+    }
+  }
+
+  return rootFiles[0].path;
+}
+
+function buildInitialContent(renderer, rootDir, relativeFilePath) {
+  if (!relativeFilePath) {
+    return null;
+  }
+
+  const fullPath = path.join(rootDir, relativeFilePath);
+  if (!fs.existsSync(fullPath)) {
+    return null;
+  }
+
+  const content = fs.readFileSync(fullPath, 'utf-8');
+  const env = { filePath: relativeFilePath };
+  const html = renderer.render(stripLeadingTitle(content), env);
+  const stats = fs.statSync(fullPath);
+  const match = content.match(/^#\s+(.+)$/m);
+  const fileName = path.basename(relativeFilePath);
+  const pageTitle = match ? match[1].trim() : fileName.replace(/\.(md|markdown)$/i, '');
+  const chineseChars = (content.match(/[\u4e00-\u9fff\u3400-\u4dbf\uf900-\ufaff]/g) || []).length;
+  const englishWords = (content.match(/[a-zA-Z0-9]+/g) || []).length;
+
+  return {
+    title: pageTitle,
+    html,
+    meta: {
+      created: stats.birthtime.toISOString(),
+      modified: stats.mtime.toISOString(),
+      wordCount: chineseChars + englishWords,
+      fileName
+    }
+  };
+}
+
 /**
  * Create and start the webook server
  */
@@ -205,37 +271,8 @@ function createServer(opts) {
   app.get('/', (req, res) => {
     try {
       const nav = scanDirectory(dir);
-      // Try to find a README.md or index.md as default
-      const defaultFiles = ['README.md', 'readme.md', 'index.md', 'INDEX.md'];
-      let initialContent = null;
-      let defaultFile = null;
-
-      for (const df of defaultFiles) {
-        const dfPath = path.join(dir, df);
-        if (fs.existsSync(dfPath)) {
-          defaultFile = df;
-          const content = fs.readFileSync(dfPath, 'utf-8');
-          const env = { filePath: df };
-          const html = renderer.render(stripLeadingTitle(content), env);
-          const stats = fs.statSync(dfPath);
-          const match = content.match(/^#\s+(.+)$/m);
-          const dfTitle = match ? match[1].trim() : df.replace(/\.md$/i, '');
-          const chineseChars = (content.match(/[\u4e00-\u9fff\u3400-\u4dbf\uf900-\ufaff]/g) || []).length;
-          const englishWords = (content.match(/[a-zA-Z0-9]+/g) || []).length;
-
-          initialContent = {
-            title: dfTitle,
-            html,
-            meta: {
-              created: stats.birthtime.toISOString(),
-              modified: stats.mtime.toISOString(),
-              wordCount: chineseChars + englishWords,
-              fileName: df
-            }
-          };
-          break;
-        }
-      }
+      const defaultFile = selectDefaultFile(nav, dir);
+      const initialContent = buildInitialContent(renderer, dir, defaultFile);
 
       res.send(renderPage({
         title,
diff --git a/views/page.html b/views/page.html
index 26009fa..db42869 100644
--- a/views/page.html
+++ b/views/page.html
@@ -28,10 +28,8 @@
     </aside>
     <main class="content">
       <div class="content-toolbar">
-        <div class="toolbar-breadcrumb">
+        <div class="toolbar-breadcrumb" id="toolbarBreadcrumb" aria-label="当前文档路径">
           <span class="toolbar-kicker">Docs</span>
-          <span class="toolbar-divider">/</span>
-          <span class="toolbar-title">{{SITE_TITLE}}</span>
         </div>
         <div class="toolbar-actions">
           <label class="theme-select-wrap" for="themeSelect" title="切换主题包">