@apetresc Dark Mode? I'm pretty sure I remember seeing and annoyedly dismissing that announcement for being so bulky yesterday, before it hit April 1st anywhere in the world.
...or, actually, now that I think about it, it might have been the day before, because I was already quite annoyed at the SE crew not having the foresight to dismiss all the "You can now follow things" popups in the tabs I'd middle-clicked open after I dismissed the first one I saw.