Styles, and Light & Dark modes: There are multiple style options which allow you to view the site in either and light or dark mode. There is also a "Pro" style which has some UI features often appreciated by power users (such as a sticky secondary navbar on desktop, and Alerts and Conversations accessible directly in the bottom mobile navbar on mobile). You can set your style in your
Account Preferences or at the bottom left of the page, below the "About us" section.