testing/web-platform/tests/css/css-transforms/transform-inherit-origin-001.html


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<!DOCTYPE html>
<html>
  <head>
    <title>CSS Test (Transforms): "transform-origin: inherit" and em</title>
    <link rel="author" title="Aryeh Gregor" href="mailto:ayg@aryeh.name">
    <link rel="help" href="http://www.w3.org/TR/css-transforms-1/#transform-origin-property">
    <meta name="assert" content='The &apos;transform-origin&apos;
    property&apos;s computed value (which is what&apos;s inherited if
    &apos;inherit&apos; is specified) is defined as "For &lt;length&gt; the
    absolute value, otherwise a percentage."  In this test, a parent element
    has a transform-origin of &apos;5em 10em&apos; with a font-size of 10px, and
    the child has "transform-origin: inherit".  Since the relative length of
    5em is converted to an absolute length before inheritance, the
    transform-origin should be at the bottom of the child, 50px 100px.  The
    180deg rotation should thus effectively move the child down 100px.  An
    implementation that incorrectly inherited the transform-origin value before
    converting to an absolute length would treat it as 100px 200px, since the
    child has a font-size of 20px, so it would effectively translate the child
    100px right and 300px down.'>
    <link rel="match" href="transform-inherit-origin-ref.html">
    <style>
      body {
        font-size: 10px;
        transform-origin: 5em 10em;
      }
      div {
        height: 100px;
        width: 100px;
        font-size: 20px;
        transform: rotate(180deg);
        transform-origin: inherit;
        background: blue;
      }
    </style>
  </head>
  <body>
    <div></div>
  </body>
</html>