diff --git a/index.html b/index.html
index 06bec27..109edb1 100644
--- a/index.html
+++ b/index.html
@@ -1,14 +1,88 @@
 <!DOCTYPE html>
-<html lang="en">
+<html lang="en" data-theme="light">
 <head>
   <meta charset="UTF-8">
   <title>Deploy Test</title>
-  <style>body{background:#0d0d0d;color:#e0e0e0;font-family:system-ui;display:flex;flex-direction:column;align-items:center;justify-content:center;min-height:100vh;gap:1rem;}code{color:#7c9ef5;}</style>
+  <style>
+    :root[data-theme="light"] {
+      --bg: #f5f5f5;
+      --fg: #111111;
+      --card: #ffffff;
+      --border: #ddd;
+      --accent: #4a6ef5;
+      --btn-bg: #111;
+      --btn-fg: #fff;
+      --btn-hover: #333;
+    }
+    :root[data-theme="dark"] {
+      --bg: #0d0d0d;
+      --fg: #e0e0e0;
+      --card: #161616;
+      --border: #2a2a2a;
+      --accent: #7c9ef5;
+      --btn-bg: #2a2a2a;
+      --btn-fg: #e0e0e0;
+      --btn-hover: #3a3a3a;
+    }
+    *, *::before, *::after { box-sizing: border-box; }
+    body {
+      background: var(--bg);
+      color: var(--fg);
+      font-family: system-ui, sans-serif;
+      display: flex;
+      flex-direction: column;
+      align-items: center;
+      justify-content: center;
+      min-height: 100vh;
+      gap: 1rem;
+      transition: background .2s, color .2s;
+      margin: 0;
+      padding: 1rem;
+    }
+    h1 { margin: 0; }
+    p { max-width: 520px; text-align: center; line-height: 1.6; }
+    code { color: var(--accent); }
+    #theme-toggle {
+      position: fixed;
+      top: 1rem;
+      right: 1rem;
+      background: var(--btn-bg);
+      color: var(--btn-fg);
+      border: 1px solid var(--border);
+      border-radius: 8px;
+      padding: .45rem .85rem;
+      font-size: .85rem;
+      cursor: pointer;
+      font-family: inherit;
+      transition: background .15s;
+    }
+    #theme-toggle:hover { background: var(--btn-hover); }
+  </style>
 </head>
 <body>
+  <button id="theme-toggle">🌙 Dark mode</button>
   <h1>Deploy verified</h1>
   <p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.</p>
   <p>Committed by OpenClaw at <code>2026-03-13 10:11:00 UTC</code></p>
+  <script>
+    (function() {
+      var root = document.documentElement;
+      var btn = document.getElementById('theme-toggle');
+      // Load saved preference; default to light
+      var saved = localStorage.getItem('theme') || 'light';
+      setTheme(saved);
+
+      btn.addEventListener('click', function() {
+        setTheme(root.getAttribute('data-theme') === 'light' ? 'dark' : 'light');
+      });
+
+      function setTheme(t) {
+        root.setAttribute('data-theme', t);
+        localStorage.setItem('theme', t);
+        btn.textContent = t === 'light' ? '🌙 Dark mode' : '☀️ Light mode';
+      }
+    })();
+  </script>
 <script src="https://dev.bl.pixeldev.eu/feedback-tool/widget.js" data-repo="pixeldev/test"></script>
 </body>
 </html>
