css/css-animations/animation-keyframes-002-manual.html

<!DOCTYPE html>
<meta charset="utf-8">
<title>CSS Animations Test: @keyframes - negative percentage and higher than 100%</title>
<link rel="author" title="Intel" href="http://www.intel.com">
<link rel="reviewer" title="Zhiqiang Zhang" href="mailto:zhiqiang.zhang@intel.com"> <!-- 2015-05-06 -->
<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/#keyframes">
<meta name="flags" content="animated">
<meta name="assert" content="Check that a keyframe selector specifies negative percentage values
                             or values higher than 100%, the keyframe will be ignored.">
<style>
  div {
    animation-name: sample;
    animation-duration: 10s;

    background-color: blue;
    height: 100px;
    width: 100px;
  }

  @keyframes sample {
    -100% {
      background-color: red;
    }
    0% {
      background-color: blue;
    }
    30% {
      background-color: green;
    }
    65% {
      background-color: yellow;
    }
    100% {
      background-color: blue;
    }
    200% {
      background-color: red;
    }
  }
</style>
<body>
  <p>
    Test passes if there is a filled blue square with 'Filler Text'
    initially on page load, if the color of the square gradully changes
    in order: BLUE to GREEN to YELLOW and back to BLUE in 10 seconds,
    and if there is no red.
  </p>
  <div>Filler Text</div>
</body>