<!DOCTYPE html>
<!-- TODO: Add more relative font size tests when needed. -->
<html>
<head>
  <style>
    body {
      font-family: Roboto;
      font-size: 20px;
    }

    span {
      font-size: 2em;
    }
  </style>
</head>
<body>
  Hello, <span> Cobalt! </span>
</body>
</html>