css/css-grid/grid-model/grid-inline-multicol-001.html

<!DOCTYPE html>
<meta charset="utf-8">
<title>CSS Grid Layout Test: 'column-*' properties from inline grid container does not apply to grid items</title>
<link rel="author" title="Manuel Rego Casasnovas" href="mailto:rego@igalia.com">
<link rel="help" href="http://www.w3.org/TR/css-grid-1/#grid-containers" title="3.1 Establishing Grid Containers">
<link rel="help" href="http://www.w3.org/TR/css3-multicol/#the-number-and-width-of-columns" title="3. The number and width of columns">
<link rel="match" href="../../reference/ref-filled-green-100px-square.xht">
<meta name="assert" content="This test checks that 'column-*' properties in the Multicol module are ignored in grid items when applied to an inline grid container.">
<style>
  #reference-overlapped-red {
    position: absolute;
    background-color: red;
    width: 100px;
    height: 100px;
    z-index: -1;
  }

  .test-overlapping-green {
    background-color: green;
    width: 100px;
    height: 50px;
  }

  .inline-grid {
    display: inline-grid;
    column-width: 50px;
  }
</style>
<p>Test passes if there is a filled green square and <strong>no red</strong>.</p>

<div id="reference-overlapped-red"></div>

<div class="inline-grid">
  <div class="test-overlapping-green"></div>
  <div class="test-overlapping-green"></div>
</div>