css/css-values/ch-unit-017.html

<!DOCTYPE html>
<meta charset="utf-8">
<title>CSS Values and Units Test: support for the ch 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/ch-unit-016-ref.html">
<meta name="assert" content="In vertical upright writing modes, the ch unit is equal to the vertical advance of the zero glyph.">
<style>
@font-face {
  font-family: ChTestShortZero;
  src: url(resources/ChTestShortZero.woff);
}
div {
  height: 10px;
  background-color: blue;
  margin-top: 10px;
}
.test {
  writing-mode: vertical-rl;
  text-orientation: upright;
  width: 5ch;
}
.ref {
  width: 100px;
}
</style>
<p>The test passes if there are two blue rectangles of equal length.</p>
<!-- ChTestShortZero has a '0' glyph whose vertical advance is a quarter
     of the units per em, so ch units in vertical upright writing modes
     should compute to 0.25em, resulting in the div being 100px width. -->
<div class="test" style="font: 80px ChTestShortZero;"></div>
<div class="ref"></div>