<!DOCTYPE html>
<html>
  <head>
    <title>CSS Reftest Reference</title>
    <link rel="author" title="Matt Woodrow" href="mailto:mwoodrow@mozilla.com">
    <link rel="author" title="Aryeh Gregor" href="mailto:ayg@aryeh.name">
    <style>
      #container {
        position: relative;
        height: 300px;
        width: 300px;
        margin: 50px 100px;
        border: 2px solid blue;
      }
      #parent {
        margin: 10px;
        width: 280px;
        height: 280px;
        background-color: #844BCA;
      }
    </style>
  </head>
  <body>
    <div id="container">
      <div id="parent"></div>
    </div>
  </body>
</html>