css/css-multicol/broken-column-rule-1.html

<!DOCTYPE HTML>
<title>CSS Test: breaking of column rule</title>
<meta charset="utf-8">
<link rel="author" title="L. David Baron" href="https://dbaron.org/">
<link rel="help" href="https://drafts.csswg.org/css-multicol/#column-gaps-and-rules">
<link rel="match" href="broken-column-rule-1-ref.html">
<style>

.outer {
  height: 100px;
  column-fill: auto;
  width: 550px;
  column-count: 4;
  column-gap: 50px;
  /* leaves 100px for each column */
}

.inner {
  column-count: 2;
  column-rule: 2px solid blue;
  height: 250px;
}

.fill {
  height: 500px; /* work around https://bugzilla.mozilla.org/show_bug.cgi?id=1374479#c4 */
}

</style>

<div class="outer">
  <div class="inner">
    <div class="fill"></div>
  </div>
</div>