<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html>
<head>
<title>Percentage logical width of absolute-positioned replaced elements</title>
<style type="text/css">
.box img {
height: 100%;
right: 0px;
position: absolute;
top: 0px;
width: 100%;
z-index: 0;
}
.box {
background-color: red;
border: solid black 2px;
position: relative;
padding: 5px;
height: 300px;
}
.box * {
position: relative;
text-align: center;
z-index: 1;
}
body { -webkit-writing-mode: vertical-rl }
</style>
<link rel="help" href="http://www.w3.org/TR/CSS21/visudet.html#the-width-property" title="10.2 Content width: the 'width' property - <percentage> value">
</head>
<body>
<div class="box">
<img src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAUAAAAFCAIAAAACDbGyAAAAGXRFWHRTb2Z0d2FyZQBBZG9iZSBJbWFnZVJlYWR5ccllPAAAABVJREFUeNpiZPjPgAyYGBgo4gMEGABPkgEJUvO9mgAAAABJRU5ErkJggg==">
<p>There should be no red on this page</p>
</div>
</body>
</html>