<!DOCTYPE HTML>
<html>
<head>
  <meta charset="utf-8">
  <title>CSS Reftest Test</title>
  <link rel="author" title="Kyle Zentner" href="mailto:zentner.kyle@gmail.com">
  <style>
  #a {
      background: blue;
      margin: 10px;
      width: 50px;
      height: 50px;
  }
  #b {
      width: 50px;
      height: 40px;
      background: green;
  }
  #b-padding {
      height: 10px;
  }
  </style>
</head>
<body>
  <div id="a">
    <div id="b-padding"></div>
    <div id="b"></div>
  </div>
</body>
</html>