mozilla-release/layout/reftests/outline/outline-and-3d-transform-2-ref.html

<!DOCTYPE HTML>
<title>Testcase for outline around 3-D transform</title>
<style>

html, body { margin: 0; padding: 0; border: none }

div {
  width: 100px;
  height: 100px;
}

body > div {
  margin-top: 200px;
  margin-left: 200px;
  transform-style: flat;
}

body > div > div {
  transform: rotateX(30deg);
  transform-origin: 50% 50%;
  transform-style: preserve-3d;
  border: 5px solid green;
  margin: -5px;
}

body > div > div > div {
  transform: rotateX(30deg);
  width: 50px; margin-left: 20px; margin-top: -5px;
  transform-origin: 50% 50%;
  transform-style: preserve-3d;
  border: 5px solid blue;
}

</style>

<div><div><div></div></div></div>