css/css-transforms/perspective-zero-3.html

<!DOCTYPE html>
<meta charset=UTF-8>
<title>CSS Test: perspective(0)</title>
<link rel="author" title="L. David Baron" href="https://dbaron.org/">
<link rel="author" title="Google" href="http://www.google.com/">
<link rel="help" href="https://drafts.csswg.org/css-transforms-2/#perspective-property">
<link rel="help" href="https://github.com/w3c/csswg-drafts/issues/413">
<meta name="assert" content="perspective: 0 should be clamped to 1px">
<link rel="match" href="reference/green.html">
<style>
#outer {
  width: 100px;
  height: 100px;
  background: red;
  perspective: 0;
  perspective-origin: top left;
}
#inner {
  width: 50px;
  height: 50px;
  background: green;
  /* perspective: 0 should be treated as perspective(1px), which should
   * cause this box to be much larger. */
  transform: translateZ(0.5px);
}
</style>
<p>Pass if there is NO red below:</p>
<div id="outer"><div id="inner"></div></div>