Gather some inspiration from other dark modes: screenshots of pages or elements of other websites that work well, articles about best practices, etc.
Review all parts of the app in dark mode: does it look good? A common complaint is that the dark mode is too light
Suggestion Ivan: use slate instead of zinc for dark mode (but keep zinc for light mode)
Keep the hierarchy in mind: elements closer to the user (like popups) should still be lighter than elements farther away (currently some popups have a darker background).
slate
instead ofzinc
for dark mode (but keep zinc for light mode)