Doesn't work on 3.6.10 on Linux. You should be able to move all 4 sliders and have the shadow go in different ways. Only one works for me. I did get another one working with some fiddling, but it works way better in the Chromium browser.
The left hand drag buttons are inverted (When you grip one and drag right, it slides left). And my curiousity involving what the []wtf control is supposed to do is overwhelming.
Normally you're only allowed to move one slider at a time, because shadows only point one way. []wtf lets you create multiple shadows in more directions.
Needs a mothereffing repeating background image or pattern.
One trick I use for circle-style gradient backgrounds is to have three sides of your gradient all end in the same color (you can use an inner shadow atop your gradient in PS for this) and then to pin the image to top/bottom/center with CSS attachment and positioning. Finally, set the page's background color to the same color as the end of your gradient.
