There are two different ways to configure the Light/Dark mode appearance of your Cyfrin Ecosystem.
Drop Down
Click on the drop down menu in the top right of the navigation bar.
Select the Light/Dark mode toggle to configure your preferred UI
Settings Page
If you're already in your settings page, or if you just like extra clicks:
Click on the drop down menu in the top right of the navigation bar.
Click Settings
Select Appearance on the left side navigation bar
Configure Light/Dark mode or tell Cyfrin to follow your system configuration!