Many of them are now automatically generated by autoprefixer, while
others are unnecessary based on .browserslistrc, and some were just
wrong (the linear-gradient based checkerboard pattern in lightbox has
been broken in Firefox for a while).
Signed-off-by: Anders Kaseorg <anders@zulipchat.com>
Apparently, the 30px width we allocated to the bullets was
insufficient with the larger font size there.
Edit by tabbott: better to just increase it to 32px everywhere.
`code-section` is a feature of the markdown system, therefore the
associated CSS should be in the `markdown.scss` file. I also refactored
to use SCSS nesting.
Anders Kaseorg
Rishi Gupta
Alexandra Ciobica