Use a serif font for headings and a sans font for text. For code blocks or anything requiring monospace be sure it clearly defines characters (like profont) suc

Use a serif font for headings and a sans font for text. For code blocks or anything requiring monospace be sure it clearly defines characters (like profont) such as 0. You can go all Sans-Serif or all Serif but it won't be the same as combining the two. Going Sans-Serif for headlines and Serif for text kind of works but you have a narrower range of choices. We use a Serif font for headlines and a Sans-Serif for body text, freeing us up to use the Sans-Serif font exclusively in certain situations for headlines where needed, and the Serif font for bolder statements.