<html><head>
<title>:root pseudo-class</title>
<style type="text/css">html { background-color : red }
*:root { background-color: lime }</style>
<link rel="author" title="Daniel Glazman" href="http://glazman.org/">
<link rel="help" href="https://www.w3.org/TR/css3-selectors/#selectors"> <!-- bogus link to make sure it gets found -->
<meta name="flags" content="">
</head>
<body>
<p>The background of the document should be green</p>
</body></html>