Update demo.html

Author: aimtyaem

demo.html

@@ -23,7 +23,7 @@
     <div class="demo-container">
         <section id="demo-video">
             <h2>QuantumMind AI in Action</h2>
-            <iframe src="demo_video.mp4" allowfullscreen></iframe>
+            <iframe src="https://www.youtube.com/watch?v=w7aL26VlFu4" allowfullscreen></iframe>
 
             <div class="code-highlight">
                 <h3>Core Simulation Logic</h3>
@@ -148,4 +148,4 @@ <h3>Stress Simulation</h3>
   <a href="#license">License</a> | <a href="#privacy">Privacy</a>  
 </footer>  
 </body>
-</html>
+</html>