✨ don't forget, frequency units like Hz and kHz are valid dimensions in CSS! 
be careful, as browser support for the <frequency> data type is a little spotty 
you know, in retrospect, i fear i have done some Harm on the Internet today by not putting the punchline in the original Tweet
any time i find a completely unused spec like this i feel like i've wandered down a dead-end corridor in the backrooms
drafts.csswg.org/css-values/#frequency