title: Grid area won't move into grid rows with percentage values
body: <p>I can get the div to move to the correct column but not the correct row.</p>
  
  <p>This will display the blue rectangle in the correct column, but for whatever reason it isn't moving in to the row I need it to. Thank you all for your help.</p>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-css lang-css prettyprint-override"><code>body {
    display: grid;
    grid-template-columns: 1fr 1fr 1fr;
    grid-template-rows: 10% 80% 10%;
  }
  
  #navigation {
    grid-column: 2/2;
    grid-row: 2/2;
    height: 400px;
    width: 100%;
    background-color: blue;
  }</code></pre>
  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;div id="navigation"&gt;&lt;/div&gt;
  &lt;div id="menunBar"&gt;&lt;/div&gt;
  &lt;div id="mainContent"&gt;&lt;/div&gt;</code></pre>
  </div>
  </div>
  </p>