I ran into the same problem about 20 years ago when implementing hover-based dropdown menus on a website. It was only about 10 lines of JS and a couple global variables but I was the only person who understood it. :-P

(These days I would have included more comments.)

Naturally, there was a fallback to pure CSS menus, because we weren't barbarians.

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dylan604 6 hours ago | parent [-]

what did the JS provide that the CSS solve wasn't the only solve?

	▲	jcranmer 6 hours ago \| parent [-]
		Not OP, but my guess is things like timing delay--20 years ago, CSS animations and transitions weren't a thing yet, especially since 20 years ago also puts us in the era of IE6 being a major browser.