diff --git a/index.html b/index.html
index e9ed4dc..21fdb5b 100644
--- a/index.html
+++ b/index.html
@@ -85,6 +85,13 @@ body {
 .search-box input::placeholder { color: var(--text-tertiary); }
 .search-box input:focus { border-color: var(--color-primary); box-shadow: 0 0 0 2px var(--color-primary-bg); background: var(--bg-container); }
 .search-box .search-icon { position: absolute; left: 10px; top: 50%; transform: translateY(-50%); color: var(--text-tertiary); font-size: 15px; pointer-events: none; }
+.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; padding: 0;
+}
+.header-bar .theme-btn:hover { background: var(--bg-elevated); }
 
 .chip-bar {
   display: none; padding: 10px 16px 0; background: var(--bg-container);
@@ -269,6 +276,7 @@ body {
       <span class="search-icon">&#x1F50D;</span>
       <input type="text" id="searchInput" placeholder="搜索文档..." autocomplete="off">
     </div>
+    <button class="theme-btn" id="themeBtn"></button>
   </div>
 </header>
 
@@ -297,9 +305,10 @@ var themeLabel = '';
 function setTheme(t) {
   htmlEl.setAttribute('data-theme', t);
   localStorage.setItem('wiki-theme', t);
-  themeLabel = t === 'dark' ? '☀️  切换浅色模式' : '🌙  切换深色模式';
-  document.getElementById('drawerThemeBtn').textContent = themeLabel;
-  document.querySelectorAll('.sidebar .theme-toggle-btn').forEach(function(b) { b.textContent = themeLabel; });
+  var label = t === 'dark' ? '☀️' : '🌙';
+  document.getElementById('themeBtn').textContent = label;
+  document.getElementById('drawerThemeBtn').textContent = label + '  切换' + (t === 'dark' ? '浅色' : '深色') + '模式';
+  document.querySelectorAll('.sidebar .theme-toggle-btn').forEach(function(b) { b.textContent = label + '  切换' + (t === 'dark' ? '浅色' : '深色') + '模式'; });
 }
 
 var saved = localStorage.getItem('wiki-theme');