CSS gradient backgrounds

Tested on

1. Edge has a problem with calc() animations (X-Wing, TIE/ad starfighter).
2. Edge doesn't load the page, when selector has property without calc(), but this property is animated with calc().
3. Edge ignores gradients in animations (Clock tower).
4. Safari doesn't fire animations, if the default value of animation-play-state is paused. So I did a little trick here. Special class in the body element sets property animation-play-state: running to all animations and then javascript removes that class.
5. To get better fade effect in gradient use rgba color stop instead of transparent one.
6. Did you hear about conic-gradients? ;)