1<html>
2<head>
3<style>
4  body {
5    background: white;
6    display: -webkit-flex;
7    -webkit-justify-content: center;
8    -webkit-align-items: center;
9    -webkit-flex-direction: column;
10  }
11  video {
12    width: 640px;
13    height: 480px;
14    border: 1px solid #e2e2e2;
15    box-shadow: 0 1px 1px rgba(0,0,0,0.2);
16  }
17</style>
18</head>
19<body>
20  <video id="video" autoplay></video>
21  <p>
22    <button id="start">Start</button>
23    <button id="cancel">Cancel</button>
24    <button id="startFromBackgroundPage">Start from background page</button>
25  </p>
26  <script src="app.js"></script>
27</body>
28</html>
29