title: Full width header
body: <p>I'm trying to make my header full width but I don't know why it doesn't work, the high is perfect but I don't know what's wrong with the width,
  I would appreciate it if you can help me, this is what I have tried:</p>
  
  <pre><code>#header {
    width:100%;
   -webkit-background-size: contain;
    -moz-background-size: contain;
    -o-background-size: contain;
    background-size: contain;
    padding-bottom: 9%;
    background-repeat: no-repeat;}
  </code></pre>
  
  <p>Thank you.</p>