title: css unset not working in chrome, fine in firefox
body: <p>I'm working on a responsive layout with the following css:</p>
  
  <pre><code>#page_container {
      max-width: 960px;
      width: 100%;
      margin: 0 auto;
      position: relative;
      padding: 0;
  }
  #header {
      position: relative;
      top: -10px;
      padding:0;
      height: 190px;
  }
  #logo_image {
      position: absolute;
      left: 250px;
      top: -10px;
  }
  @media only screen and (max-width: 960px) {
  #logo_image {
      position: relative;
      margin: 0 auto;     
      max-height: 150px;
      top:0px;
      left: unset;
  }
  </code></pre>
  
  <p>The idea is that below 960 px in width the logo image should be smaller and centered. This is working fine in firefox, but in chrome the "left: unset;" is not being processed and the image is appearing far to the left of center. </p>
  
  <p>I am not aware of any compatibility issues with unset and in fact use it elsewhere on the page without problems. Am I missing something obvious here?</p>