Hover is a great experience on desktop, but it annoyingly requires having a separate solution for mobile. Right now 60+% of the traffic on the site is from mobile devices, so figuring out something (hopefully simple and very lightweight) that works for both mobile and desktop is the goal.

Your suggestion is noted, though!

Along these lines, I've always liked the system Randall uses for What If: https://what-if.xkcd.com/

Agreed. I've pinched his popup implementation for my homepage and expanded it a little so that there's both a footnotes section with anchor links at the bottom for non-JS use and search engines, as well as the popup panels. E.g. https://www.buttercookie.de/The%20Burkiss%20Way/Transcripts/...

Oh thanks, I really like this variant. It needs a name: click-to-hover, perhaps?