<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
 <head>
  <title>background on body should not fill the viewport when root has background</title>
  <style>
   html { background-color:lime; }
   body { background-color:red; height:0; }
  </style>
 </head>
 <body>
  <p>The entire viewport should be green and there should be no red.</p>
 </body>
</html>