position-visibility-no-overflow.html

<!DOCTYPE html>
<meta charset="utf-8">
<title>CSS Anchor Positioning Test: position-visibility: no-overflow</title>
<link rel="help" href="https://drafts.csswg.org/css-anchor-position-1/#position-visibility">
<link rel="match" href="position-visibility-no-overflow-ref.html">
<style>
  #scroll-container {
    position: relative;
    overflow: hidden scroll;
    width: 400px;
    height: 100px;
  }

  .anchor {
    width: 100px;
    height: 100px;
    background: orange;
    display: inline-block;
  }

  .target {
    position: absolute;
    position-visibility: no-overflow;
    position-area: block-end;
    width: 100px;
    height: 100px;
    background: red;
    top: 0;
    left: 0;
  }
</style>

<div id="scroll-container">
  <!-- #target1 should not be visible because it overflows the containing block. -->
  <div class="anchor" style="anchor-name: --a1;">anchor1</div>
  <div id="target1" class="target" style="position-anchor: --a1;">target1</div>
</div>

chromium/third_party/blink/web_tests/external/wpt/css/css-anchor-position/position-visibility-no-overflow.html