Dark Mode
Overview
To utilize the dark mode feature in your project you must visit the themes settings and go to the Dark Mode section. The first step is to enable it.
As default the theme is set to Light mode but if you need to set a either state as default you can use the Toggle switches to do so.
Widget
There is also a widget you can utilize where more information is located in this document
CSS Stylesheet inplementation
Also there is a specific way of changing colors and rules in css for Dark mode usage and you can find information in this document