Since it's possible to set dark/light mode in Strapi via user -> profile -> experience -> Interface mode, it would be nice to have a third option that I believe should be selected by default, which is "system".
This means, whatever your system theme/mode is in, whether it's dark or light, Strapi will automatically use this as well.
I am personally using https://github.com/pacocoursey/next-themes for my own Next.js project, but I'm not sure what package is suitable for Strapi.