<!DOCTYPE html>
<title>Tests that anchor names are correctly tree-scoped even with style sheet sharing</title>
<link rel="help" href="https://drafts.csswg.org/css-anchor-1/#target-anchor-element">
<link rel="author" href="mailto:xiaochengh@chromium.org">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>

<style>
body {
  margin: 0;
}

.host {
  width: 100px;
  height: 100px;
}

#host2 {
  margin-left: 200px;
}
</style>

<div class="host" id="host1"></div>
<div class="host" id="host2"></div>

<script>
document.querySelectorAll('.host').forEach(host => {
  let shadow = host.attachShadow({mode: 'open'});
  shadow.innerHTML = `
    <style>
      div { width: 100px; height: 100px; }
      #anchor { anchor-name: --a; background: orange; }
      #target {
        position: fixed;
        background: lime;
        left: anchor(--a left);
        top: anchor(--a bottom);
      }
    </style>
    <div id=anchor>anchor</div>
    <div id=target>target</div>
  `;
});

test(() => {
  const target1 = host1.shadowRoot.getElementById('target');
  assert_equals(target1.offsetLeft, 0);
  assert_equals(target1.offsetTop, 100);

  const target2 = host2.shadowRoot.getElementById('target');
  assert_equals(target2.offsetLeft, 200);
  assert_equals(target2.offsetTop, 200);
}, 'Anchor names in different tree scopes should not be confused');
</script>
