title: 'Position: bottom' not working on relatively positioned button element
body: <p><em>Goal</em>: Get the <code>button</code> element fixed to the bottom of the <code>main</code> element. I tried positioning it's container with relative positioning so it sticks to the bottom:</p>
  
  <pre><code>/* POSITIONING NOT WORKING. I WANT THIS DIV FIXED TO BOTTOM OF PARENT */
  .wrapper:nth-child( 4 ) {
    background-color: #bbb;
    position: relative;
    bottom: 0;
  }
  </code></pre>
  
  <p>This isn't moving the <code>.wrapper</code> div at all. Ideas?</p>
  
  <p><div class="snippet" data-lang="js" data-hide="true" data-console="true" data-babel="false">
  <div class="snippet-code snippet-currently-hidden">
  <pre class="snippet-code-css lang-css prettyprint-override"><code>@import url( "https://necolas.github.io/normalize.css/latest/normalize.css" );
  * {
    box-sizing: border-box;
  }
  main {
    background-color: #eee;
  }
  main, input {
    padding: 2%;
  }
  main input {
    width: 100%;
    margin: 5% 0;
    border: 0;
  }
  .clr-fix::after {
    content: "";
    display: block;
    clear: both;
  }
  .wrapper {
    width: 23%;
    margin: 1%;
    padding: 2%;
    background-color: #ddd;
    float: left;
  }
  
  /* POSITIONING NOT WORKING. I WANT THIS DIV FIXED TO BOTTOM OF PARENT */
  .wrapper:nth-child( 4 ) {
    background-color: #bbb;
    position: relative;
    bottom: 0;
  }</code></pre>
  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;main class="clr-fix"&gt;
  
    &lt;div class="wrapper"&gt;
      &lt;input type="text" value="position:bottom"&gt;
      &lt;input type="text"&gt;
      &lt;input type="text"&gt;
      &lt;input type="text"&gt;
    &lt;/div&gt;
  
    &lt;div class="wrapper"&gt;
      &lt;input type="text"&gt;
      &lt;input type="text" value="Isn't working"&gt;
      &lt;input type="text"&gt;
      &lt;input type="text"&gt;
    &lt;/div&gt;
  
    &lt;div class="wrapper"&gt;
      &lt;input type="text"&gt;
      &lt;input type="text"&gt;
      &lt;input type="text" value="On 'A button'"&gt;
      &lt;input type="text"&gt;
    &lt;/div&gt;
  
    &lt;div class="wrapper"&gt;
      &lt;button&gt;A button&lt;/button&gt;
    &lt;/div&gt;
  
  &lt;/main&gt;</code></pre>
  </div>
  </div>
  </p>