<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html>
<head>
<title>CSS Test: Vertical centering with negative and positive top positioning</title>
<link rel="author" title="Microsoft" href="http://www.microsoft.com/">
<link rel="help" href="http://www.w3.org/TR/CSS21/visuren.html#positioning-scheme">
<link rel="match" href="reference/position-relative-nested-001-ref.htm">
<meta name="flags" content="">
<meta name="assert" content="Equal 50% positive and negative positioning can vertically center objects.">
<style type="text/css">
#outer
{
background: green repeat-x center url('support/red_box.png');
/* red_box.png is a 100px by 100px red square */
height: 300px;
width: 200px;
}
#inner
{
background-color: red;
height: 100px;
position: relative;
top: 50%
}
#inner-most
{
background-color: green;
height: 150px;
/* 150px == top-half of red_box.png's height + #inner's height */
position: relative;
top: -50%;
/* 50% is 50% of the height of #inner-most's containing block
which is #inner */
/* to move the top of the #inner-most box from pixel 150
on the y-axis of #outer to pixel 100 on the y-axis of #outer */
}
</style>
</head>
<body>
<p>Test passes if there is <strong>no red</strong>.</p>
<div id="outer">
<div id="inner">
<div id="inner-most"></div>
</div>
</div>
</body>
</html>