IMPORTANT: As is the case with most Reddit styles "allow subreddits to show me custom styles" must be disabled. There are various ways of doing this, but the most reliable way to disable them regardless of log-in status is to add this adblock filter: "thumbs.redditmedia.com/*.css" (no quotes).
If you're using Firefox this style requires Firefox 35+.

This is a style I've used personally for a while. Since Firefox just started supporting inversion filters I figured I'd convert it to make it compatible and share. It is RES compatible to the extent that I use it (mainly just never-ending Reddit and in page images/videos), but I can't vouch for other RES features (especially style/layout tweaks). I refuse to style ads so you might run into some funky looking ones if you don't do yourself a favor and use an adblocker. I'm not an active member of the "Reddit Community" so if anything (or any important aspect of RES) is missing, let me know and I'll do my best to fix it.

Update 5/2 - Fixed a few background and link colors, but mostly fixed the left margins in comment sections that kept cutting off RES embedded videos (especially with higher browser zoom).

Update 5/17 - Fixed full-screen videos. Also set sidebar overflow to scroll & added a section to eliminate focus rings for embedded Youtube videos globally. They aren't rendering correctly regardless of styles, but they're worse looking in dark styles (they're also fairly useless).