[geelen]

No good reason. I'm going to experiment with toggling the element's style instead of adding a class. But because of the way GIFs are rendered, that's an O(n) task on every frame (so is the CSS style recalculation, of course, but I think the browser's CSS engine will be faster than my JS).

[chadscira]

i'm pretty sure a `opacity = 0`, and an `opacity = 1` in the same run loop should perform fine, but nevertheless very cool!