Hello There!
Hope you are doing good!
Unfortunately, the theme doesn’t have font size options so as you said, here is the custom CSS to change the font size.
Please use the below CSS to change the font size for h1, h2, h3, and body
.h1, h1 { font-size:24px; } /* all h1 tags */
.h2, h2 { font-size:24px; } /* all h2 tags */
.h3, h3 { font-size:24px; } /* all h3 tags */
.body { font-size:24px; } /* body tags */
However, it will not change the font size if any child node uses its own font-size rule, in this case, you have to add selector as “h2 > a”
Hope this helps!
Have a great weekend ahead!
Regards,
Team ProDesigns