DiscussionTools topic containers have inconsistent font sizes when browser default font size is changed. The normal page text, headings, and section edit links respect the browser default font size (they don't use the exact value, but they scale relative to it, mostly by using CSS em units). The topic metadata and the subscribe buttons do not respect it, instead always using 14px font size.
We haven't noticed this before, because with default browser settings, Vector page text also uses a 14px font. (And we did it this way because the button is technically inside the heading, and using a relative size would require tediously adjusting it for every skin's different heading sizes. This should be easier to fix after T314714: Metadata and buttons should be inserted after a heading, not inside of it.)
Screenshot provided by @Jonesey95 (reported at https://en.wikipedia.org/wiki/Wikipedia_talk:Talk_pages_project#c-Jonesey95-20221213185200-Matma_Rex-20221213155800) – looks like 14px or 15px font size:
To reproduce, go to your browser settings, search for "font size", and change the value. The default is "medium" or "16px".
- Chrome etc.:
(taken at https://en.wikipedia.org/wiki/Wikipedia:Village_pump_(technical)?dtenable=1#Quarry_of_my_page_moves_that_renames_a_page_with_a_certain_suffix, but any page will behave the same)