I go even further on the minimal UI personally lol. Black box over the date/time is an edit and the theme I have is animated so it has rain partiles falling down. But I like as much of my screen as possible to be the content and want the browser out of the way. I'm hoping they don't entirely break my current setup. It's technically Floorp but that's Firefox based so we'll see.

Edit: Figured I should clarify. When I say minimal I mean like how MUCH of the UI I have. Like tabs and search bar in the same row. I don't mean like minimalism. I'm clearly more maximalist in my themeing than you lol.

I was hoping for screenshot sharing, lol. Yours look ~~similar~~ familiar, I wouldn't be surprised if we shared in the past whenever we had this topic before.

Mine evolves from time to time. Sometimes I learn something new from new screenshots and incorporate that. One such recent "implementation" is the Bookmarks Toolbar. I created a top level directory named "Favorites" and put all quick access bookmarks in there and moved the toolbar to the same level of tabs, to save me an entire extra line of bar. My current Firefox looks like this:

I'm on KDE, the titlebar is disabled for all windows (I'm an auto tiler person). BTW I'm not sure how to get rid off the rounded corners of the window, but that is not Firefox specific.