<title>Reference, bug 643781</title>
<style>
html { background: white; }
body {
   padding: 1px;
   background: blue;
   width: 100px;
   font-size: 0px; /* remove the effect of the strut ascent and descent */
}
div {
   background: aqua;
   height: 33px;
}
</style>
<body>
<div></div>
</body>