<!DOCTYPE html>
<link rel="help" href="https://wicg.github.io/layout-instability/" />
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="resources/util.js"></script>
<div id="multicol" style="position:relative; columns:40; width:500px; column-gap:0;">
  <div style="height:4000px; background:black;"></div>
</div>
<script>

promise_test(async () => {
  const watcher = new ScoreWatcher;
  await waitForAnimationFrames(2);

  multicol.style.top = '100px';
  const expectedScore = computeExpectedScore(500 * (100 + 100), 100);

  await watcher.promise;
  assert_equals(watcher.score, expectedScore);
}, 'Move balanced multicol container');

</script>