title: programmatically changing webkit-transformation values in animation rules
body: <p>I have this stylesheet:</p>
  
  <pre><code>        @-webkit-keyframes run {
              0% {
                  -webkit-transform: translate3d(0px, 0px, 0px);
              }            
              100% {
                  -webkit-transform: translate3d(0px, 1620px, 0px);
              }
          }
  </code></pre>
  
  <p>Now, I would like to modify the value of 1620px depending on some parameters. Like this:</p>
  
  <pre><code>        @-webkit-keyframes run {
              0% {
                  -webkit-transform: translate3d(0px, 0px, 0px);
              }            
              100% {
                  -webkit-transform: translate3d(0px, height*i, 0px);
              }
          }
  </code></pre>
  
  <p>I would prefer to be able to use JavaScript and jQuery, though a pure CSS solution would be ok.</p>
  
  <p>This is for an iPhone game that runs in it's mobile Apple Safari browser.</p>