[raphlinus]

Any time, friend. Your basic move is to set the lang metadata accurately and choose a font that does have these style differences implemented in the loca table.

Best of luck and feel free to reach out if you have more specific questions.

[qingcharles]

So I went to check on the font that I'd chosen for my European/Latin/Cyrillic body text, and I guess I got very lucky with my pick:

https://github.com/googlefonts/literata

I'm already strict with marking the html pages with the correct lang and culture tags etc, but I'll be double-checking everything now. Thank you again for educating me :)