erence/200-200-green.html"
  />

  <style type="text/css">

      html, body { margin: 0px; padding: 0px; }

      html { background: white; overflow: hidden; }
      #outer { position: relative; background: green; }

      #outer { width: attr(data-test px, 200px); height: 200px; }

  </style>

</head>
<body>

  <div id="outer" data-test="300px"></div>

</body>
</html>
