Simplest thing is to have light and dark mode themes, use whatever the user has set for their system settings, and also have a toggle to switch between light and dark. You may like dark mode for most things you browse but then would prefer something in light mode.
The problem with this is that you now have 2x the UX testing to make sure everything is useable and looks aesthetically pleasing. Probably OK for a large website, but as a solo entrepreneur, that ends up adding a lot of overhead.
