<!DOCTYPE html>
<title>fieldset containing block</title>
<link rel=match href=fieldset-containing-block-ref.html>
<style>
p { margin: 0; height: 100px }
fieldset { position: relative; border: none; padding: 0; margin: 0; }
legend { padding: 0; width: 100px; height: 50px; background: lime; }
div { position: absolute; top: 0; width: 100px; height: 50px; background: lime; }
.behind { height:100px; top: 108px; background: red; }
</style>
<p>There should be no red.</p>
<div class="behind"></div>
<fieldset><legend></legend><div></div></fieldset>