title: GWT CssResource and using @media to support both large and small screens
body: <p>I'm using GWT's ClientBundle and CssResource to pull in my css definitions.</p>
  
  <p>I'd like to set viewports depending upon screen size. Do you know how to achieve this within CssResource?</p>
  
  <p>My failed attempt... for ease of testing I've used background shades instead. But for all devices the background is green.</p>
  
  <pre><code>body {background-color:green;}
  
  @media only screen and (max-width:480px) {
  body {background-color:red;}
  }
  </code></pre>
  
  <p>GWT [v2.5] Compiler kicks out a warning:
  [WARN] Line x column 12: encountered "screen". Was expecting one of: "{" ","</p>
  
  <p>Just a warning but in this case it's not to be ignored.</p>