-template-rows: 100px 150px 50% 1fr;
  }
</style>

<div class="template-rows-based">
  <div>A</div>
  <div>B</div>
  <div>C</div>
  <div>D</div>
</div>



<style>
  .named-grid-rows {
    display: grid;
    grid-template-rows: [row-1-start] 100px [row-1-end row-2-start] 100px [row-2-end];
  }
</style>

<div class="named-grid-rows">
  <div>A</div>
  <div>B</div>
</div>



<style>
  .template-areas {
    display: grid;
    grid-template:
      [header-row-start] "header header header" 100px [header-row-end]
 