diff --git a/index.html b/index.html
index e7f8eef..25e027a 100644
--- a/index.html
+++ b/index.html
@@ -71,14 +71,13 @@ body {
   display: flex; align-items: center; padding: 0 16px; z-index: 100; gap: 12px;
 }
 [data-theme="dark"] .header-bar { background: rgba(20,20,20,0.95); }
-.header-bar .menu-btn, .header-bar .theme-btn {
-  display: none; width: 36px; height: 36px; border: none; background: none;
-  cursor: pointer; border-radius: var(--radius-sm); align-items: center; justify-content: center;
-  flex-shrink: 0;
+.header-bar .theme-btn {
+  width: 36px; height: 36px; border: none; background: none;
+  cursor: pointer; border-radius: var(--radius-sm);
+  display: flex; align-items: center; justify-content: center;
+  font-size: 16px; color: var(--text-secondary); flex-shrink: 0;
 }
-.header-bar .menu-btn:hover, .header-bar .theme-btn:hover { background: var(--bg-elevated); }
-.header-bar .menu-btn svg { width: 20px; height: 20px; color: var(--text-secondary); }
-.header-bar .theme-btn { font-size: 16px; }
+.header-bar .theme-btn:hover { background: var(--bg-elevated); }
 .header-bar .brand { display: flex; align-items: baseline; gap: 8px; flex-shrink: 0; }
 .header-bar h1 {
   font-size: 15px; font-weight: 700;
@@ -250,26 +249,10 @@ body {
   background: var(--bg-elevated); color: var(--text-tertiary); flex-shrink: 0;
 }
 
-/* ===== Dark mode toggle button (desktop) ===== */
-.theme-toggle {
-  display: none;
-  margin-left: auto;
-  align-items: center;
-  gap: 8px;
-  cursor: pointer;
-}
-.theme-toggle button {
-  width: 36px; height: 36px; border: none; background: none;
-  cursor: pointer; border-radius: var(--radius-sm);
-  display: flex; align-items: center; justify-content: center;
-  font-size: 16px; color: var(--text-secondary);
-}
-.theme-toggle button:hover { background: var(--bg-elevated); }
-
-/* ===== Desktop ===== */
+/* ===== Desktop only ===== */
 @media (min-width: 769px) {
   .chip-bar { display: none !important; }
-  .theme-toggle { display: flex; }
+  .header-bar .menu-btn { display: none; }
 }
 
 /* ===== Mobile ===== */
@@ -290,12 +273,7 @@ body {
   .wiki-section-title { font-size: 16px; }
   .wiki-toc-item { padding: 10px 14px 10px 36px; }
   .wiki-toc-header { padding: 12px 14px; }
-
-  /* Theme toggle in mobile header */
-  .theme-toggle { display: flex !important; margin-left: 0; }
-  .theme-toggle button {
-    width: 32px; height: 32px; font-size: 15px;
-  }
+  .header-bar .theme-btn { width: 32px; height: 32px; font-size: 15px; }
 }
 </style>
 </head>
@@ -313,9 +291,7 @@ body {
     <span class="search-icon">&#x1F50D;</span>
     <input type="text" id="searchInput" placeholder="搜索文档..." autocomplete="off">
   </div>
-  <div class="theme-toggle">
-    <button class="theme-btn" id="themeBtn" title="切换深色/浅色主题"></button>
-  </div>
+  <button class="theme-btn" id="themeBtn" title="切换深色/浅色主题"></button>
 </header>
 
 <!-- Mobile chip filter bar -->