Oooh I think I figured it out myself. Setting "font-size: (...)" in CSS but in the line for "html{" seems to control it. Okay!!!
Glad u figured it out! If the problem comes back though, feel free to reach out to me, I'll take a look at the code and try to figure out what's causing the issue.
My god these thumbnails look like shit. These are iframes ok they look better irl