xDifference=0-15;totalPixels=0-80" />
  <meta name="assert" content="A rotateY transform with perspective
  should result in a trapezoid."/>
  <style type="text/css"><![CDATA[
div {
  height: 150px;
  width: 150px;
}
.background {
  background-color: green;
  height: 200px;
  width: 200px;
}
.container {
  position: absolute;
  top: 20px;
  left: 0;
  perspective: 500px;
}
.transformed {
  background-color: green;
  transform: rotateY(50deg);
}
.stair {
  background-color: red;
  position: absolute;
}
#one 