Prevent sub and sup from affecting line-height.
Set touch-action on .items to prevent browser navigation.
Move font-family specific CSS to the appropriate file.
Update primary font-family for UI to be even more
compatible with various operating systems.
Make .entry-content font-weight variable depending
on font-family used.
- Use CSS variables instead of inherence
- Rename default theme to "Light - Serif"
- Rename Black theme to "Dark - Serif"
- Rename "Sans-Serif" theme to "Light - Sans Serif"
- Add "System" theme that use system preferences: Dark or Light
- Add Serif and Sans-Serif variants for each color theme
