How to change font in opencart 2.3?

Question

opencart

Good evening!

I encountered such a problem when working in the techstore template, I changed the font sizes of stylesheet.css, after several manipulations the result was not very good, I wanted to fix everything back, but nothing happened.
I tried to re-upload css files (allstyles, flipclock, fonts, jquery-ui, jquery.mmenu, stylesheet, even the default stylesheet) nothing changes.

Now, can someone please tell me which css file needs to be replaced or in which file, which line should be changed so that the font size is corrected?