Bold Font Throughout Site

Hi there,

I tried to edit code to make my Pages appear BOLD on the homepage of my site (font-weight: bold) — however I did something that turned all fonts, basically everywhere, BOLD — which I do not want. Does anyone know what I can do to reverse this? I’m unsure where in the theme Editor this is coded/controlled.

Here is my site:
https://www.diana-irvine.com

You’ll see what I mean

Thanks!