title: 100% height dependent on height of brother element
body: <p>I need the element <em>cnt-right</em> to be height 100% of its sibling. </p>
  
  <p>It doesn't have a parent element, only siblings.</p>
  
  <p>Is it possible to accomplish this with CSS? Or do I have to use javascript?</p>
  
  <p>I have this estructure: <a href="https://jsfiddle.net/h7s590az/259/" rel="nofollow noreferrer">jsFiddle</a>
  <a href="https://i.stack.imgur.com/XgjR1.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/XgjR1.png" alt="enter image description here"></a></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>.column {
    display: block;
    min-height: 50px;
    background-color: #ccc;  
    text-align: center;
    float: left;
  }
  
  .decktop-12 {
    width: 100%;
  }
  
  .decktop-8 {
    width: 66%;
  }
  
  .decktop-4 {
    width: 33%;
  }
  
  .cnt {
    background-color: #995595;
  }
  
  .cnt-right {
    background-color: #559959;
  }</code></pre>
  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;div class="mobile-12 decktop-12 cnt-top column"&gt;
    Content top
  &lt;/div&gt;
  &lt;div class="mobile-12 decktop-8 cnt column"&gt;
    Content - main
    &lt;br /&gt; &lt;br /&gt;
    Content - main
    &lt;br /&gt; &lt;br /&gt;
    Content - main
    &lt;br /&gt; &lt;br /&gt;
    Content - main
    &lt;br /&gt; &lt;br /&gt;
    Content - main
  &lt;/div&gt;
  &lt;div class="mobile-12 decktop-4 cnt-right column"&gt;
    Content - right
  &lt;/div&gt;
  &lt;div class="mobile-12 decktop-12 cnt-bottom column"&gt;
    Content bottom
  &lt;/div&gt;</code></pre>
  </div>
  </div>
  </p>