diff --git a/extension/setup.html b/extension/setup.html
new file mode 100644
index 0000000..30b2336
--- /dev/null
+++ b/extension/setup.html
@@ -0,0 +1,113 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+  <meta charset="UTF-8">
+  <meta name="viewport" content="width=device-width, initial-scale=1.0">
+  <title>idfoto — vault setup</title>
+  <link rel="stylesheet" href="styles.css">
+  <style>
+    body {
+      width: auto;
+      max-width: 560px;
+      margin: 40px auto;
+      padding: 0 20px;
+      max-height: none;
+      overflow-y: auto;
+    }
+
+    .step-instructions {
+      background: #161b22;
+      border: 1px solid #30363d;
+      border-radius: 6px;
+      padding: 16px;
+      margin: 12px 0;
+      font-size: 12px;
+      line-height: 1.7;
+    }
+
+    .step-instructions ol {
+      padding-left: 20px;
+    }
+
+    .step-instructions li {
+      margin-bottom: 4px;
+    }
+
+    .step-instructions code {
+      background: #21262d;
+      padding: 1px 5px;
+      border-radius: 3px;
+      font-size: 12px;
+    }
+
+    .image-preview {
+      max-width: 200px;
+      max-height: 150px;
+      border-radius: 4px;
+      border: 1px solid #30363d;
+      margin-top: 8px;
+    }
+
+    .strength-bar {
+      height: 4px;
+      background: #21262d;
+      border-radius: 2px;
+      margin-top: 6px;
+      overflow: hidden;
+    }
+
+    .strength-bar-fill {
+      height: 100%;
+      border-radius: 2px;
+      transition: width 0.2s, background 0.2s;
+    }
+
+    .strength-bar-fill.weak { background: #f85149; width: 25%; }
+    .strength-bar-fill.fair { background: #d29922; width: 50%; }
+    .strength-bar-fill.good { background: #3fb950; width: 75%; }
+    .strength-bar-fill.strong { background: #58a6ff; width: 100%; }
+
+    .success-box {
+      background: #0d1b0e;
+      border: 1px solid #238636;
+      border-radius: 6px;
+      padding: 20px;
+      margin: 16px 0;
+      text-align: center;
+    }
+
+    .success-box h3 {
+      color: #3fb950;
+      margin-bottom: 8px;
+    }
+
+    .config-blob {
+      background: #161b22;
+      border: 1px solid #30363d;
+      border-radius: 4px;
+      padding: 12px;
+      font-size: 11px;
+      word-break: break-all;
+      user-select: all;
+      margin: 12px 0;
+      max-height: 120px;
+      overflow-y: auto;
+    }
+
+    .test-result {
+      display: inline-flex;
+      align-items: center;
+      gap: 6px;
+      margin-top: 8px;
+      font-size: 12px;
+    }
+
+    .test-result.pass { color: #3fb950; }
+    .test-result.fail { color: #f85149; }
+  </style>
+</head>
+<body>
+  <div id="app"></div>
+  <script src="setup.js"></script>
+</body>
+</html>
