chromium/third_party/blink/web_tests/external/wpt/css/css-conditional/container-queries/container-for-cue.html

<!doctype html>
<html class="reftest-wait">
<head>
  <title>CSS Container Queries Test: Container for pseudo elements</title>
  <link rel="help" href="https://drafts.csswg.org/css-conditional-5/#container-queries">
  <link rel="match" href="container-for-cue-ref.html">
  <script src="/common/reftest-wait.js"></script>
  <style>
    video {
      container-type: size;
      width: 200px;
      height: 200px;
    }
    @container (width = 200px) {
      video::cue { background-color: green }
      video::cue(b) { color: lime }
    }
  </style>
</head>
<body>
  <video autoplay onplaying="this.onplaying = null; this.pause(); takeScreenshot();">
    <source src="/media/white.mp4" type="video/mp4">
    <source src="/media/white.webm" type="video/webm">
    <track default src="support/test.vtt">
  </video>
</body>
</html>