The fonts for HTML are controlled by the fonts available on the user's computer. So the various fonts may well not work on other people's computers.
The fonts chosen were selected from what notes said are commonly found on computers controlled by Microsoft Windows. If you have equivalent (or similar) fonts that are commonly installed on other platforms, let me know and I'll add them.
Fonts for the PDF output contain characters for many, but not all, of the world's languages. If your language is unsupported, let me know and I'll see if I can find an appropriate set of information.