css/CSS2/positioning/absolute-non-replaced-width-003.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: Absolutely positioned non-replaced elements with 'margin-left' and 'margin-right' set to 'auto'</title>
        <link rel="author" title="Microsoft" href="http://www.microsoft.com/" />
        <link rel="reviewer" title="Gérard Talbot" href="http://www.gtalbot.org/BrowserBugsSection/css21testsuite/" /> <!-- 2012-08-31 -->
        <link rel="help" href="http://www.w3.org/TR/CSS21/visudet.html#abs-non-replaced-width" />
		<link rel="match" href="absolute-non-replaced-width-003-ref.xht" />

        <meta name="flags" content="ahem" />
        <meta name="assert" content="When 'left', 'width' and 'right' are not 'auto', set 'margin-left' and 'margin-right' to equal values." />
        <link rel="stylesheet" type="text/css" href="/fonts/ahem.css" />
        <style type="text/css">
            #containingblock
            {
                border: solid black;
                height: 200px;
                position: relative;
                width: 400px;
            }
            div div
            {
                /*
                  left				:  100px
                +
                  margin-left		:  solve
                +
                  border-left-width :    0px
                +
                  padding-left		:    0px
                +
                  width				:  100px
                +
                  padding-right		:    0px
                +
                  border-right-width:    0px
                +
                  margin-right		:  solve
                +
                  right				: -200px
                =============================
          width of containing block :  400px

                */

                background: red;
                color: blue;
                font: 100px/1em Ahem;
                left: 100px;
                margin-left: auto; /* value is solved to 200px */
                margin-right: auto; /* value is solved to 200px */
                position: absolute;
                right: -200px;
                width: 100px;
            }
        </style>
    </head>
    <body>
        <p>Test passes if a filled blue square is in the <strong>upper-right corner</strong> of an hollow black rectangle and if there is <strong>no red</strong>.</p>
        <div id="containingblock">
            <div>X</div>
        </div>
    </body>
</html>