Dark Theme along with High Contrast needs new voting buttons (and possibly other style changes)

[floydpink]

Steps to reproduce this issue

1. Enable "Dark Theme"
2. Enable "High contrast"
3. Notice how the voting buttons are "invisible" now

Expected result

• The voting buttons should still be visible/usable
• The page background should be dark (?)

Actual result

• Voting buttons are not seen because of their color being the same as page background color
• Page background is not dark

Notes and screenshots

Not sure if this is just my machine/browser/other-addons

[PxlBuzzard]

Duplicate of #97