 The smallest size that can completely cover
  it with a 1:1 ratio is 100px by 100px. So, the
  background image should be scaled to 100px by 100px.
  */
  }
  ]]></style>

 </head>

 <body>

  <p>Test passes if there is a filled green square and <strong>no red</strong>.</p>

  <div id="overlapped-red"></div>

  <div id="overlapping-green"></div>

  </body>
</html>