<root>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
 <style type="text/css">
 root, html, body {
  display: block;
  margin: 0; padding: 0;
 }
 #the-root {
  padding: 30px 0;
 }
 #the-html {
  background-color: green;
  height: 100px;
 }
 </style>
</head>
<body>
<div id="the-root">
 <div id="the-html"></div>
</div>
</body>
</html>
</root>