title: responsive background image not resizing
body: <p>My college asked me to code a site for a project but make it responsive. The image i'm using for the header background is not resizing.
  This is the code for the HTML</p>
  
  <pre><code> &lt;div id="headerbackground"&gt;&lt;/div&gt;
  </code></pre>
  
  <p>And for the style i've put </p>
  
  <pre><code>#headerbackground {
  background-image: url('../images/header.png');
  background-size: contain;
  max-width:100%;
  max-height: 100%;
  }
  </code></pre>
  
  <p>I've followed a few tutorials but no luck </p>