chromium/third_party/blink/web_tests/external/wpt/css/CSS2/positioning/position-relative-nested-001.xht

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
    <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="position-relative-nested-001-ref.xht" />

        <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>