css/css-scoping/host-is-006.html

<!doctype html>
<meta charset="utf-8">
<title>:host and :is, descendant</title>
<link rel="author" title="Emilio Cobos Álvarez" href="mailto:emilio@crisal.io">
<link rel="author" title="Mozilla" href="https://mozilla.org">
<link rel="help" href="https://drafts.csswg.org/selectors/#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>
  <template shadowrootmode=open>
    <style>
    #foo {
      width: 100px;
      height: 100px;
      background: red;
    }
    :host, :root {
      #foo {
        background: green;
      }
    }
    </style>
    <div id=foo></div>
  </template>
</div>