Not to undercut the open source nature of this, but what makes this "beautiful"? From a design standpoint, it's basic tailwind. Neutral grey tailwind at that, using Lucide icons. There's nothing wrong with these, but it'd be more apt to say that the design is unopinionated. It's the default choice when design intent is the afterthought and a focus is on functionality.

Again, not trying to undercut - looks like a solid agent interface, it just struck me as strange that beautiful was the adjective chosen when design seems to not be the objective here.