Fonts - I don't fully understand the various CSS font elements so while the site does what I want on Safari, it's not loading my fonts with Firefox even on my own Mac. I suspect things are even worse under Android or Windows.

Markdown vs Restructured Text - Maybe I need more control and need to integrate some CSS/HTML to add things I can't get. Like a to do list with checkboxes. (Yes, there's markdown-checklists, another thing to figure out)