<html xmlns="http://www.w3.org/1999/xhtml">
 <head>
  <title>run-in and the line box model</title>
  <style type="text/css">
   .r { color: white; display: run-in; }
   .b { backgound: green; line-height: 0; }
   span { color: white; }
  </style>
 </head>
 <body>
  <p>There should be a green line below.</p>
  <div class="r">This li</div>
  <div class="b"><span>ne should be green.</span></div>
 </body>
</html>