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

<!DOCTYPE html>
<meta charset="utf-8">
<title>CSS Values and Units Test: support for the ex unit</title>
<link rel="author" title="Cameron McCormack" href="mailto:cam@mcc.id.au">
<link rel="help" href="https://drafts.csswg.org/css-values-3/#font-relative-lengths">
<link rel="match" href="reference/ex-unit-002-ref.html">
<meta name="assert" content="The ex unit equals the x-height of the first available font if it has reliable metrics for the x-height.">
<style>
@font-face {
  font-family: ExTest;
  src: url(resources/ExTest.woff);
}
div {
  height: 10px;
  background-color: blue;
  margin-top: 10px;
}
.test {
  width: 10ex;
}
.ref {
  width: 100px;
}
</style>
<p>The test passes if there are two blue rectangles of equal length.</p>
<!-- ExTest is a font whose OS/2 table's sxHeight field is set to an
     eighth of the font's units per em, so ex units should compute to
     0.125em, resulting in the div being 100px wide. -->
<div class="test" style="font: 80px ExTest;"></div>
<div class="ref"></div>