<html xmlns="http://www.w3.org/1999/xhtml">
 <head>
  <title>CSS Absolute Positioning: Collapsible Margins</title>
  <style type="text/css">
   /* Set Up Conditions */
   * { margin: 0; padding: 0; border: 0; position: static; float: none; top: auto; left: auto; right: auto; bottom: auto; display: block; }
   head { display: none; } body { padding: 1em; }
   /* Test */
   .margin { margin-bottom: 2em; }
   .abs { position: absolute; background: green; z-index: 1; height: 1em; width: 10em; }
   .flow { background: red; height: 1em; width: 10em; }
  </style>
 </head>
 <body>

  <div class="margin">This page should have a single green block 2em below this paragraph and no red. </div>
  <div class="abs"/> <div class="flow"/>

 </body>
</html>
