example.html

<!DOCTYPE html>
<html>
<head>
  <title>github-renderer test</title>
  <style type="text/css">
  .main { }
  .footer { margin:20px 0 0; }
  .btn { border-radius:2px;padding:6px 10px;background:#ddd; }
  </style>
</head>
<body>
<div class="main">
  <h2>Example</h2>
  <div class="modal-body">
      <h3>Test YouTube video:</h3>
      <iframe width="300" height="200" src="http://www.youtube.com/embed/8oPRJh3eCjA" frameborder="0" allowfullscreen></iframe>
    <h3>Audio tag:</h3>
      <audio controls="controls">
        <source src="http://upload.wikimedia.org/wikipedia/en/4/45/ACDC_-_Back_In_Black-sample.ogg" type="audio/ogg" />
        <source src="http://robtowns.com/music/blind_willie.mp3" type="audio/mp3" />
        Your browser does not support the audio element.
      </audio>
  </div>

  <div class="footer">
    <a href="javascript:window.close();" class="btn">Close</a>
  </div>

</div>
</body>
</html>