This tests interactivity and event handlers on use elements. It also tests
that the SVGElementInstance.correspondingElement property and the
CSSStyleDeclaration.setProperty() method defined in
DOM Level 2 Style. By testing different ways of setting the fill on a rectangle
it verifies that the result is consistent, and that CSS properly overrides
the specified values.
You should at first see a pyramid of four pink rects. Click each of the pink rects once.
If the useragent doesn't support CSS, this test does not apply.
The test has passed if when clicking each of the rects the clicked rect turns blue - note that only the clicked rect must turn blue, if any other rect turns blue too then the test has failed.
The reference image shows the final state, what the result should be after all rects have been clicked.