doc: update stylesheet to match the frontpage
- Changed colors to match frontpage as close as possible.
- Links are slightly more horizontally padded as compared before to accomodate for the hover effect.
- Slightly reduced the scroll indication height (the fade-out) on the TOC.
- The main content is now offset using margin instead of the previous border hack.
- Remove
a:visited
style, I couldn't find a satisfying color as the link style is already pretty bright.
Note: This doesn't cover syntax-highlighted code boxes. The main page uses dark boxes and another highlighting system. Not sure yet what to do here. Open for suggestions.
cc: @nodejs/documentation @nodejs/website @chrisdickinson