Added usercss (#12) version
Fix white header with the new header (#14) - @Internet-Anon

Changelog:

Fix #11
Moved several important parts of legacy css to scss.
Please create an issue if this created any missing styles or other bugs.

Fixed Queue page having items with white background and unreadable text - Thanks @William1Gray

Fixed Store button in header always having white background
Fixed header on small devices (hamburger menu and search bar)
Fixed white outline on arrows used on various collections (e.g. the manga chapter selector)

Fixed un-themed carousel arrows on watch page.

Fix missing theme on the info tooltip on the premium comparison page
Move login theme over to scss

Theme store page
Clean up the icons used on the browser bar

Fixed theming of the orange info-box ("view the [season] lineup)
Moved theming of various info-boxes to scss
Split chrome and Firefox builds: This fixes the various custom icons not displaying on Firefox, probably most noticible on the queue page.

Remove accidental youtube.com required permission.

Changed to using sass, with the old style being included as the legacy styles.
Redid how the theme is applied, which should fix the issue where the theme wouldn't always apply on Firefox.
These were both based originally based on how the Dark-youtube-plugin did it, but almost all the code involved has since been modified at least somewhat.

Touched up and converted several pages to SASS, including:
the footer
the free trial page
the header
the portrait grid, used on various pages, including history and the show page
the premium comparison page
the queue page
the sidebar, used on various pages, including history
the tabs, used on various pages, including anime, and history

Darken notification box to make it more readable - @tholinka
Fix theme in inbox - @tholinka
Fix theme on vrv button - @tholinka

Themed Availability Information Box (fixes #5). - @link07
Themed Background (to fix login page showing a bit of white). - @link07

Themed trial box on player page.
Themed the redeem guest pass page.
First Firefox release.