If it can’t be done within obsidian forum settings, you could in the Brave browser …
- install a bookmarklet
title: jSmall
url:
javascript:(function()%7Bfunction%C2%A0r(o)%C2%A0%7Bif%C2%A0(o.style)%C2%A0%7Bo.style.fontSize%C2%A0%3D%C2%A0’small’%3Bo.style.lineHeight%C2%A0%3D%C2%A0’1.2em’%3B%7Dvar%C2%A0cn%C2%A0%3D%C2%A0o.childNodes%2Ci%3Bfor%C2%A0(i%C2%A0%3D%C2%A00%3B%C2%A0i%C2%A0<%C2%A0cn.length%3B%C2%A0%2B%2Bi)%C2%A0r(cn%5Bi%5D)%3B%7Dr(document.body)%7D)()
If the small in the javascript is not the right size, you can replace it with …
xx-small | x-small | small | medium | large | x-large | xx-large
The bookmarklet will only work within the current tab, so you might be better of installing a …
- Chrome extension (that I believe work in the Brave browser for mac)
such as Zoom Page WE OR Zoom for Google Chrome