title: "background-size: cover" does not cover mobile screen
body: <p>I have a photo background on my site using <code>background-size:cover</code>. It works for the most part but leaves a weird ~30px white space on my Galaxy S3 in portrait mode.</p>
  
  <p>I've attached a screenshot. The 1px teal line is to illustrate the entire screen. Seems like the background stops right after the social media <code>ul</code>s.</p>
  
  <p>I tested this by removing the <code>ul</code> and the background attached it self to the bottom of the tagline text.</p>
  
  <p><img src="https://i.stack.imgur.com/EaCEZ.png" alt="problem screenshot"></p>
  
  <p>Also, here's my CSS pertaining mobile portait view:</p>
  
  <pre><code>@media only screen and (max-width: 480px) {
  
  .logo {
      position: relative;
      background-size:70%;
      -webkit-background-size: 70%;
      -moz-background-size: 70%;
      -o-background-size: 70%;
      margin-top: 30px;
  }   
  
  h1 {
      margin-top: -25px;
      font-size: 21px;
      line-height: 21px;
      margin-bottom: 15px;
  }
  
  h2 {
      font-size: 35px;
      line-height: 35px;
  }
  
  .footer_mobile {
      display: block;
      margin-top: 20px;
      margin-bottom: 0px;
  }
  
  li {
      display: block;
      font-size: 1.3em;
  }
  </code></pre>
  
  <p>This used to not happen, but I guess I accidentally bugged it while trying to solve another issue.</p>