
  </head>

  <body>
    <section class="preview">
      <div class="grid">
        <div class="item">
          <div class="subitem"></div>
        </div>
      </div>
    </section>

    <textarea class="playable playable-css" style="height: 350px">
.grid {
  display: grid;
  grid-template-columns: repeat(9, 1fr);
  grid-template-rows: repeat(4, minmax(100px, auto));
}

.item {
  display: grid;
  grid-column: 2 / 7;
  grid-row: 2 / 4;
  grid-template-columns: subgrid;
  grid-template-rows: repeat(3, 80px)