CSS 3D cube infinite rotation

HTML

<!-- 
Inspired by
http://www.paulrhayes.com/experiments/cube-3d/
 -->
<div id="cube-wrapper">
    <div id="cube">
        <div class="face one">
            x
        </div>
        <div class="face two">
            ∫
        </div>
        <div class="face three">
            +
        </div>
        <div class="face four">
                     
            -
        </div>
        <div class="face five">
          ^0^  ∞
        </div>
        <div class="face six">
            %
        </div>
    </div>
</div>

CSS

@-webkit-keyframes rotating {
    from {
      -webkit-transform: rotateX(-10deg) rotateY(20deg); }

    to {
      -webkit-transform: rotateX(-10deg) rotateY(380deg); }
}
#cube-wrapper {
  -webkit-perspective: 800;
  -moz-perspective: 800px;
  -o-perspective: 800;
  -webkit-perspective-origin: 50% 200px;
  -moz-perspective-origin: 50% 200px;
  -o-perspective-origin: 50% 200px;
  margin-top: 30px;
  margin-bottom: 100px;
 }

#cube-wrapper{
    margin-top: 100px;    
}  

#cube-wrapper #cube {
    height: 200px;
    width: 200px;
    -webkit-transform: rotateX(-10deg) rotateY(20deg);
    -moz-transform: rotateX(-10deg) rotateY(20deg);
    -o-transform: rotateX(-10deg) rotateY(20deg);
    transform: rotateX(-10deg) rotateY(20deg);
    -webkit-animation: rotating 5s linear infinite;
    position: relative;
    margin: 0 auto;
    -webkit-transition: -webkit-transform 1s ease;
    -moz-transition: -moz-transform 1s ease;
    -o-transition: -o-transform 1s ease;
    transition: transform 1s ease;
    -webkit-transform-style: preserve-3d;
    -moz-transform-style: preserve-3d;
    -o-transform-style: preserve-3d;
    transform-style: preserve-3d; }

    #cube-wrapper #cube .face {
      width: 200px;
      height: 200px; }

    #cube-wrapper #cube .one {
      -moz-transform: rotateX(90deg) translateZ(100px);
      -o-transform: rotateX(90deg) translateZ(100px);
      -webkit-transform: rotateX(90deg) translateZ(100px);
      transform: rotateX(90deg) translateZ(100px); }

    #cube-wrapper #cube .two {
      -webkit-transform: translateZ(100px);
      -moz-transform: translateZ(100px);
      -o-transform: translateZ(100px);
      transform: translateZ(100px); }

    #cube-wrapper #cube .three {
      -webkit-transform: rotateY(90deg) translateZ(100px);
      -moz-transform: rotateY(90deg) translateZ(100px);
      -o-transform: rotateY(90deg) translateZ(100px);
      transform: rotateY(90deg) translateZ(100px); }

    #cube-wrapper #cube .four {
     ...