title: animate: zoom background in CSS
body: <p>I want to animate the background image (zoom from 100% to 120%)
  The zoom from 100 to 120 works fine. After it zooms to 120, the image is set automatically to 100 and the same procedure starts again. 
  I want to zoom it back. 
  Like this: from 100 to 120 and than from 120 to 100. How is this possible?</p>
  
  <pre><code>.imageBlub{
      background: url('../Images/blub.jpg');
      background-size: 100% auto;
      animation: animatedBackground 6s linear infinite;
  
  }
  
  @keyframes animatedBackground {
      from { background-size: 100% auto; }
      to {  background-size: 120% auto;}
  }
  </code></pre>