<!--
     Any copyright is dedicated to the Public Domain.
     http://creativecommons.org/licenses/publicdomain/
-->
<!DOCTYPE html>
<html>
<head>
<style>
.unit { display:inline-block; width:100px; height:1px; background:blue; }
</style>
</head>
<body style="margin:0; width:300px; line-height:100px;">
  <span class="unit"></span><span class="unit"
  ></span><span class="unit"></span><span style="background:lime"><span class="unit"
  ></span></span>
</body>
</html>