<!DOCTYPE html>
<link rel="help" href="https://drafts.csswg.org/css-gaps-1/#outset">
<link rel="author" title="Sam Davis Omekara Jr." href="mailto:samomekarajr@microsoft.com">
<style>
  .grid-container {
    display: grid;
    grid-gap: 10px;
    grid-template-columns: 100px 100px 100px;
    height: 320px;

    column-rule-color: blue;
    column-rule-style: solid;
    column-rule-width: 5px;
  }

  .item {
    background: gray;
    opacity: 0.5;
  }

  .row-gap {
    position: absolute;
    width: 320px;
 