<html>
<head>
<style>
h1.visible {visibility:visible}
h1.hidden {visibility:hidden}
</style>
</head>
<body>
<h1 class="visible">This is a visible heading</h1>
<h1 class="hidden">This is an invisible heading</h1>
<p>Notice that the invisible heading still takes up space.</p>
</body>
</html>