[Flam]

I removed the image completely now courtesy of another commenter. Anyhow, wouldn't base64 be cheating? ;)

[nnnnni]

Nope, it makes it self-contained, therefore more pure!

...or at least that's the way I look at it.

[hnriot]

well, technically you're using javascript, so it's already cheating. Obviously, you have to use it, but it does break the claim of using only html/css

[Flam]

The javascript was added much later by popular demand to make the time accurate. Remove it and it remains functional.