Dark Mode with option for the user

Hi, I was looking at the dark mode implemantation of the twenty twentyone theme. It looked like a nice jumping of point for a dark mode that users can activate themselves. I would only like the Kadence version of it, so styling options and of cource your wonderfull implementation of the other features. If nessacery it could also be included in the pro addon. My clients would like a nice solution, the hacky version i now use is not really compatible. Many thanks and would love to hear from the community!