<!DOCTYPE html>

<html>
<head>
  <style type="text/css" media="screen">
    .common {
      position: absolute;
      top: 50px;
      left: 20px;
      height: 100px;
      width: 200px;
    }
    .indicator {
      background-color: green;
    }
    iframe {
      border: none;
    }
  </style>
</head>
<body>
  <!-- You should see a green rectangle -->
  <div class="indicator common"></div>
  <iframe class="common" src="resources/paint-iframe-background-iframe.html"></iframe>
</body>
</html>