values when defining 'font-size' property refer to the computed font size of the parent element." />

  <style type="text/css">* { margin: 0; padding: 0 }<![CDATA[
  div {font-family: Ahem; font-size: 32px;}

  p {margin: 10px 30px;}

  #test {font-size: 16px;}
  #control, #test {font-size: 2.5ex;} 

  #control2 {font-family: Ahem; font-size: 64px;} 
  ]]></style>

 </head>

 <body>

  <p>The 3 black squares below should have the same width and the same height.</p>

  <div>
   <p id="con