<!DOCTYPE html>
<!--
 | For inline non-replaced elements, the height of the content area should be
 | based on the font.
 |   https://www.w3.org/TR/CSS21/visudet.html#inline-non-replaced
 -->
<html>
<head>
  <style>
    body {
      margin: 0px;
      font-family: Roboto;
      font-size: 16px;
    }
  </style>
</head>
<body>
<div style="width:20px; line-height:30px; background:#2196F3;">
  <span style="background:#1565C0;">xx xx</span>
</div>
</body>
</html>