embed demo video in landing page

index.html

@@ -17,8 +17,10 @@
   <div class="container">
     <div class="main-card">
       <div class="app-preview">
-        <div class="preview-image">
-          <div class="camera-feed">👋 → 🤖💃</div>
+        <div class="preview-image" style="padding: 0; background: #000; border-radius: 15px; overflow: hidden;">
+          <video autoplay loop muted playsinline style="width: 100%; border-radius: 15px;">
+            <source src="demo.mp4" type="video/mp4">
+          </video>
         </div>
       </div>
       <div class="app-details">