Thanks for this! I'm using it as-is right now, but I'll probably fiddle around with the colors and or font sizes at some point.

Edit: Here's a screenshot of what I ended up with. I tweaked the font sizes, added a bit of code to make the content/space taken up by the actual fic a bit narrower.

Still a bit unhappy at the colors that appear when I hover over the navigation and greeting tabs and I when you hover over the fandom name it's going with the AO3 default of maroon background + white text but I can't figure out what parts of the code to change. Oh well.