text: <!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: Margin collapsing - elements that collapse margins have to effect on positions of other elements that also have margins that are collapsing</title>
          <link rel="author" title="Microsoft" href="http://www.microsoft.com/" />
          <link rel="reviewer" title="Gérard Talbot" href="http://www.gtalbot.org/BrowserBugsSection/css21testsuite/" /> <!-- 2012-08-15 -->
          <link rel="help" href="http://www.w3.org/TR/CSS21/box.html#collapsing-margins" />
  		<link rel="match" href="margin-collapse-002-ref.xht" />
  
          <meta name="flags" content="ahem image" />
          <meta name="assert" content="Positions of elements that have been collapsed through (empty elements) have no effect on positions of other elements whose margins are being collapsed." />
          <link rel="stylesheet" type="text/css" href="/fonts/ahem.css" />
          <style type="text/css">
              div
              {
                  font: 20px/1em Ahem;
                  width: 5em;
              }
              div div
              {
                  height: 1em;
              }
              #div1
              {
                  background: url('support/margin-collapse-2em-space.png') left -1em;
                  border-top: 1em solid green;
              }
              #div2
              {
                  background: red;
              }
              #div3
              {
                  background: red;
                  height: 0;
                  margin-top: 2em;
                  margin-bottom: 2em;
              }
              #div4
              {
                  background: green;
                  margin-top: 2em;
              }
          </style>
      </head>
      <body>
          <p>Test passes if there is <strong>no red</strong>.</p>
          <div id="div1">
              <div id="div2">
                  <div id="div3"></div>
                  <div id="div4"></div>
              </div>
          </div>
      </body>
  </html>