Site graphic improvements

A few notes on the graphic language of the site:

- if I had to choose between a light and dark mode for reading text, I would choose light mode. Or give users the option to switch between both
- for longer blocks of copy, I would strongly suggest using a serif font (eg. Times New Roman is a common Serif font). Serifs help our eyes track between words, and make for a better reading experience. (not necessarily needed for header / section text, of course)