TIL about ambiguous width unicode characters. Turns out some locales render these chars as double width. I'm attempting to work out a solution.

Seems like maybe there are some universal half-width characters that can be used.

https://www.unicode.org/reports/tr11/

Weird. Same issue with NL-locale @ firefox, while terminal is ok. So it is not confined to East-Asian locales if that is what you think.

Unfortunately even if you pick nominally-equal-width glyphs, on the web you can still get screwed over by font substitution/fallback done by the browser.