css/css-pseudo/highlight-cascade/highlight-cascade-008.html

<!DOCTYPE html>
<title>Custom property values from the originating element</title>
<link rel="author" title="Stephen Chenney" href="mailto:schenney@chromium.org">
<link rel="help" href="https://drafts.csswg.org/css-pseudo-4/#highlight-cascade">
<link rel="match" href="highlight-cascade-008-ref.html">
<meta name="assert" value="This test verifies that custom properties from the originating element are used to resolve var() on highlight pseudos.">
<meta name="fuzzy" content="0-255;0-10">
<script src="../support/selections.js"></script>
<style>
  :root {
    --background-color: green;
    --decoration-color: yellow;
  }
  :root::selection {
    --background-color: cyan;
    --decoration-color: magenta;
  }
  div::selection {
    background-color: var(--background-color, red);
    text-decoration-line: underline;
    text-decoration-style: line;
    text-decoration-color: var(--decoration-color, red);
  }
  span {
    --background-color: purple;
  }
  span::selection {
    --background-color: blue;
    background-color: var(--background-color, red);
  }
</style>
<div style="width: 300px">PASS if background-color is green when selected, <span>except this which is blue</span>, and underline is yellow.</div>
<script>
  selectNodeContents(document.querySelector("div"));
</script>