title: left and top properties are not animated
body: <p>In the animation below the transform is animated correctly, but the left and top properties are not. Why is this?</p>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-css lang-css prettyprint-override"><code>.element-animation {
    background-color: yellow;
    width: 30px;
    height: 30px;
    animation: animationFrames ease 2s;
    animation-iteration-count: infinite;
  }
  @keyframes animationFrames {
    0% {
      left: 0px;
      top: 0px;
      opacity: 1;
      transform: rotate(0deg) scaleX(1) scaleY(1) skewX(0deg) skewY(0deg);
    }
    25% {
      left: 0px;
      top: -90px;
    }
    75% {
      left: 200px;
      top: -90px;
    }
    100% {
      left: 200px;
      top: 0px;
      opacity: 1;
      transform: rotate(0deg) scaleX(2) scaleY(2) skewX(45deg) skewY(45deg);
    }
  }</code></pre>
  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;div class="element-animation"&gt;&lt;/div&gt;</code></pre>
  </div>
  </div>
  </p>