chromium/third_party/blink/web_tests/external/wpt/css/selectors/featureless-002.html

<!doctype html>
<meta charset="utf-8">
<title>Compound selectors only match if all simples do</title>
<link rel="help" href="https://drafts.csswg.org/selectors-4/#featureless">
<link rel="match" href="/css/reference/ref-filled-green-100px-square-only.html">
<p>Test passes if there is a filled green square.</p>
<div class=host>
    <template shadowrootmode="open">
      <style>
        div {
          width: 100px;
          height: 25px;
        }
        .red { background-color: red; }
        .green { background-color: green; }

        /* Make sure a compound selector can match it */
        :host:host .t1 {
          background-color: green;
        }
        /* Make sure various compounds *can't* match it */
        div:host > .t2 {
          background-color: red;
        }
        :host.host > .t3 {
          background-color: red;
        }
        *:host > .t4 {
          background-color: red;
        }
      </style>
      <div class="red t1"></div>
      <div class="green t2"></div>
      <div class="green t3"></div>
      <div class="green t4"></div>
      <slot></slot>
    </template>
    <section></section>
</div>