Need help with fixing CSS on my wiki

[brisk fulcrum]

a recent update to miraheze broke all the css stuff on my wiki, and i have no clue how to fix it. both me and a friend have tried, to basically no success, so i'm making a post in case anyone who knows what they're doing more than we do is willing to help
( for context, the wiki hosts a comic )

there's quite a few extensions which use CSS, but these are the main ones;

the wiki uses a template to get a dark theme on nearly every page since i never actually figured out how to change the default skin's colours, and there's a darker version;
https://termsofservice.wikitide.org/wiki/Template:Dark / https://termsofservice.wikitide.org/wiki/Template:Darker
(Template:Dark is probably better off as a skin just applied to pages by default rather than a template, but Template:Darker is only used on a few pages)

there's also this image carousel that's supposed to be on the main page, featuring the 30 main characters;
https://termsofservice.wikitide.org/wiki/Template:ContestantCarousel30
and there's a template to make table borders invisible, leaving only the text, used on every character page;
https://termsofservice.wikitide.org/wiki/Template:Invisitable

editing on the wiki isn't open to the public, because once the comic releases, i don't want random people editing it, but you're free to post your miraheze username to recieve editing permissions so figuring out a fix for these is easier. any help is appreciated

for comparison, here's a screenshot of what the main page used to look like, and what it looks like now that it's broken

[frigid furnace]

Your not the only one experiencing this issue
Our group is trying to fix the templates when miraheze also updated

Although, not as severe as what your going through

[mossy cove]

PeepoSadRain

[exotic salmon]

@haughty sentinel

[haughty sentinel]

Template:Dark and Template:Darker:
Dark should probably just go in common.css
the h1 rule in Darker is missing a close bracket at the end, itll work if u fix that
still looking at the other ones

carousel: tbh just put it in common.css
Invisitable: its mad that the hexcodes are #0000 and not #000, fix that and itll fix

[brisk fulcrum]

tried changing the hexcodes to three-digit numbers, that just causes it to make the entire table black without making it invisible

and i don't have enough knowledge on css to even attempt fixing the other templates

[haughty sentinel]

hm, try transparent?

[brisk fulcrum]

doesn't seem to work