chromium/third_party/blink/web_tests/fast/spatial-navigation/snav-more-aligned-at-top.html

<!doctype html>
<style>
  #more-aligned {background: green; padding: 100px;}
  #less-aligned {background: red; padding: 99px;}
</style>

<span id="less-aligned" class="more" tabindex="0">x</span><span id="more-aligned" class="more" tabindex="0">x</span>

<script src="../../resources/testharness.js"></script>
<script src="../../resources/testharnessreport.js"></script>
<script src="resources/snav-testharness.js"></script>
<script>
  snav.assertFocusMoves([["Down", "more-aligned"]]);
</script>

<p><em>Manual test instruction: Ensure SpatNav goes to the, projection wise,
"more aligned" element first, even though it comes second in DOM order.</em></p>

<p>When two rects are on the same distance from current focus F, SpatNav
should prioritize the rect that can absorb most of F's projection.</p>

<p>When looking for the closest "insider" (here, focusables inside the
document), SpatNav projects the document's edge onto each candidate.</p>