How can I change the display size of H2 sub-headings in my blog posts?

I am trying to change my sub heading size in only my blog posts. I want sub heading to be H2 for SEO reasons but I’d like them to appear as H3 or maybe H4. I am not sure where in my code or how to ask the body of the article to display H2 as H3 or H4.

I was able to find out where to change the article title and notices my default is for the title to display H1 as H2, I want to do something similar for sub-headings in my blog

Hi @propervelo ,

Would you mind to share your Store URL website? with password if its unpublish. Thanks!

there is no plug published, however. Hopefully that might be enough to
help figure out how to modify the h2 for just the one section. I couldn’t
quite figure out the coding for it and was going to screw everything up too
much if i kept trying.

Thank you,
-Brad