css/css-animations/animation-fill-mode-001-manual.html

<!DOCTYPE html>
<meta charset="utf-8">
<title>CSS Animations Test: animation-fill-mode - none</title>
<link rel="author" title="Intel" href="http://www.intel.com">
<link rel="reviewer" title="Zhiqiang Zhang" href="mailto:zhiqiang.zhang@intel.com"> <!-- 2015-05-07 -->
<link rel="help" href="https://drafts.csswg.org/css-animations-1/#animation-name">
<link rel="help" href="https://drafts.csswg.org/css-animations-1/#animation-duration">
<link rel="help" href="https://drafts.csswg.org/css-animations-1/#animation-fill-mode">
<meta name="flags" content="animated">
<meta name="assert" content="When animation-fill-mode is set to none,
                             animation has no effect when it is applied but not executing.">
<style>
  div {
    animation-name: sample;
    animation-duration: 5s;
    animation-fill-mode: none;

    background-color: blue;
    height: 100px;
    width: 100px;
    position: relative;
  }
  @keyframes sample {
    from {
      background-color: yellow;
    }
    to {
      background-color: green;
    }
  }
</style>
<body>
  <p>
    Test passes if there is a filled color square with 'Filler Text',
    whose color gradually changes in the order: YELLOW to GREEN.
    After the animation is finished, the color goes back to BLUE.
  </p>
  <div>Filler Text</div>
</body>