Hello Codeforces
I couldn't find a suitable dark theme for AtCoder, except for one called Solarized Dark by magurofly, which was predominantly blue rather than truly dark. To align it more with my preferences, I decided to tweak the script's source code by adjusting some color variables.
Here's a preview :
Here's the link to the GitHub repo: Link
The repository includes a brief installation guide to assist you in setting up the theme