position-visibility-anchors-visible-position-fixed.tentative.html

<!DOCTYPE html>
<meta charset="utf-8">
<meta name="assert" content="position-visibility: anchors-visible should work with a fixed-position anchored element." />
<title>CSS Anchor Positioning Test: position-visibility: anchors-visible</title>
<link rel="help" href="https://github.com/w3c/csswg-drafts/issues/7758">
<link rel="match" href="position-visibility-anchors-visible-position-fixed-ref.html">
<style>
  #anchor {
    anchor-name: --a1;
    position: absolute;
    top: 0;
    left: 0;
    width: 100px;
    height: 100px;
    background: orange;
  }

  #target {
    position-anchor: --a1;
    position-visibility: anchors-visible;
    position-area: bottom right;
    width: 100px;
    height: 100px;
    background: red;
    position: fixed;
    top: 0;
    left: 0;
  }

  #spacer {
    height: 200vh;
  }
</style>

<!-- Test passes if #target is not visible, due to #anchor being off-screen. -->
<div id="anchor">anchor</div>
<div id="target">target</div>
<div id="spacer"></div>

<script>
  window.scrollTo(0, 100);
</script>

chromium/third_party/blink/web_tests/external/wpt/css/css-anchor-position/position-visibility-anchors-visible-position-fixed.tentative.html