<html>
<head>
<style type="text/css">
#mostImportant {color:red; background:yellow;}
</style>
</head>
<body>
<h1>This is important!</h1>
<ul id="mostImportant">
<li>item 1</li>
<li>item 2</li>
<li>item 3</li>
</ul>
<p>This is a paragraph.</p>
<p>...</p>
</body>
</html>