Using other elements, like <strong>continue anyway</strong>, inside the button element can give a button a bit of style.

<html>
<body>
<h3>Warning</h3>
<p>This site contains humor that may cause uncontrollable laughter.</p>
<button><strong>continue anyway</strong></button>
</body>
</html>]]>

Make sure to pick <strong>continue anyway</strong>.