<!DOCTYPE html>
<html>
<head>
    <style>
        div { width: 100px; height: 200px; }
    </style>
</head>
<body>
<p>Grids can act as containing blocks for positioned content.</p>
<div style="width: 100px; height: 200px; background-color: green;"></div>
</body>
</html>