<!DOCTYPE html>
<title>Tests scrolling with anchor in fixed-positioned scroller</title>
<link rel="help" href="https://drafts.csswg.org/css-anchor-position-1/#scroll">
<link rel="author" href="mailto:[email protected]">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="support/test-common.js"></script>
<style>
body {
margin: 0;
height: 200vh;
}
#scroller {
position: fixed;
width: 200px;
height: 200px;
overflow-y: scroll;
}
#anchor {
position: absolute;
width: 100px;
height: 100px;
top: 200px;
background: orange;
anchor-name: --a;
}
#target {
position: fixed;
width: 100px;
height: 100px;
bottom: anchor(top);
position-anchor: --a;
background: lime;
}
</style>
<div id=scroller>
<div id=anchor></div>
</div>
<div id=target></div>
<script>
promise_test(async () => {
await waitUntilNextAnimationFrame();
assert_equals(target.getBoundingClientRect().top, 100);
document.documentElement.scrollTop = 100;
await waitUntilNextAnimationFrame();
assert_equals(target.getBoundingClientRect().top, 100);
}, 'Target should not scroll with viewport when anchor is in fixed-positioned scroller');
</script>
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