css/css-anchor-position/anchor-scroll-chained-001.html

<!DOCTYPE html>
<title>Tests scroll adjustments of element anchored to another anchored element</title>
<link rel="author" href="mailto:wangxianzhu@chromium.org">
<link rel="help" href="https://drafts.csswg.org/css-anchor-1/">
<link rel="match" href="reference/anchor-scroll-chained-001-ref.html">
<style>
body {
  margin: 0;
}

div {
  width: 100px;
  height: 100px;
}

#scroller {
  overflow: scroll;
}

#anchor {
  anchor-name: --a1;
  height: 20px;
  background: orange;
}

#anchored1 {
  position: absolute;
  position-anchor: --a1;
  left: anchor(--a1 left);
  top: anchor(--a1 bottom);
  background: green;
  anchor-name: --a2;
}

#anchored2 {
  position: absolute;
  position-anchor: --a2;
  left: anchor(--a2 left);
  top: anchor(--a2 bottom);
  background: lime;
}

</style>

<div id="scroller">
  <div style="height: 230px"></div>
  <div id="anchor"></div>
  <div style="height: 230px"></div>
</div>
<div id="anchored1"></div>
<div id="anchored2"></div>

<script>
scroller.scrollTop = 200;
</script>