Here are some examples of style sheet rules that can be used to make the dark mod forum a bit more readable.
How to use this
Put the rules below in a file named UserContent.css in your profile:
- Windows: %APPDATA%\Mozilla\Firefox\Profiles\userContent.css
- Linux: /home/USERNAME/.mozilla/firefox/PROFILENAME.default/chrome/userContent.css
In all cases replace the bold part with your actual data.
See also: How do I find my Firefox profile
You can download a full file from here.