<!DOCTYPE html>
<meta charset="utf-8">
<title>CSS Reference</title>
<style>
table { border-spacing: 2px; }
td { border: 1px solid; }
td, div { width: 10px; height: 10px; }
div.opc { opacity: 0.99; }
div.green { background: green; }
div.up { margin-top: -10px; }
div.red { background: red; }
</style>
<body>
<p>Each of the following boxes should have a green or
very-nearly-green square inside of it:</p>
<table><tr>
<td>
<div class="green"></div>
</td>
<td>
<div class="red"></div>
<div class="up opc green"></div>
</td>
<td>
<div class="green"></div>
</td>
<td>
<div class="red"></div>
<div class="up opc green"></div>
</td>
<td>
<div class="green"></div>
</td>
<td>
<div class="red"></div>
<div class="up opc green"></div>
</td>
<td>
<div class="green"></div>
</td>
<td>
<div class="green"></div>
</td>
<td>
<div class="green"></div>
</td>
<td>
<div class="green"></div>
</td>
<td>
<div class="red"></div>
<div class="up opc green"></div>
</td>
<td>
<div class="red"></div>
<div class="up opc green"></div>
</td>
</tr></table>
</body>