css/css-animations/animation-timing-function-007-manual.html

<!DOCTYPE html>
<meta charset="utf-8">
<title>CSS Animations Test: animation-timing-function - step-start</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">
<link rel="help" href="https://drafts.csswg.org/css-animations-1/#animation-timing-function">
<meta name="flags" content="animated">
<meta name="assert" content="When animation-timing-function is set to step-start,
                             animation will play the end effect at the start of the interval.">
<style>
  div {
    height: 100px;
    width: 100px;
    position: absolute;
  }

  #test-step-start {
    animation-name: sample;
    animation-duration: 10s;
    animation-fill-mode: forwards;
    animation-timing-function: step-start;

    background-color: blue;
  }

  #ref-no-animation {
    background-color: red;
    left: 150px;
  }

  @keyframes sample {
    from {
      left: 0px;
    }
    to {
      left: 150px;
    }
  }
</style>
<body>
  <p>
    Test passes if there is a filled blue square with 'Filler Text',
    which stays right, and if there is NO red.
  </p>
  <div id="ref-no-animation"></div>
  <div id="test-step-start">Filler Text</div>
</body>