That's crazy! The large lag between clicking and the UI updating is slightly annoying, but that's just me nitpicking at something other than the cool technical feat.
yeah, i expected it to be instant to be honest, given it's just markup and there's no "thinking"
It's 1.23MB of CSS & HTML - this is meant to be a stress test of the limits, lag is expected for the next several years of average-at-the-time computers!
I'm curious how it performs on a 10x10 or 16x16 grid
Or until someone packages your madness as a popular library and browsers are forced to optimize it.