; }
      to { top: 1px; }
    }
  </style>

  <script>
    'use strict';

    idl_test(
      ['css-animations'],
      ['html', 'dom', 'cssom'],
      idl_array => {
        try {
          window.keyframes = document.styleSheets[0].cssRules[0];
        } catch (e) {
          // Surfaced in idlharness.js's test_object below.
        }

        idl_array.add_objects({
          AnimationEvent: ['new AnimationEvent("animationstart")'],
          CSSKeyframesRule: ['keyframes'],
          CSSKeyframeRule: [