css/css-values/lh-unit-002.html

<!DOCTYPE html>
<meta charset="utf-8">
<title>CSS Values and Units Test: using lh in font-size</title>
<link rel="author" title="Florian Rivoal" href="https://florian.rivoal.net/">
<link rel="help" href="https://drafts.csswg.org/css-values-4/#font-relative-lengths">
<link rel="match" href="../reference/ref-filled-green-100px-square.xht">
<meta name="assert" content="The lh unit resolves against the parent when used in the font-size property.">
<style>
div {
  width: 100px;
  height: 100px;
  background: red;
  line-height: 50px;
}
aside {
  background: green;
  height: 1em;
  line-height: 42px; /* number doesn't matter, as long as it's neither 50 nor 100*/
  font-size: 2lh;
}

</style>

<p>Test passes if there is a filled green square and <strong>no red</strong>.</p>

<div><aside>&nbsp;</aside></div>