Seems like you're asking for UI components (page, panel, button) that you can just use? This isn't the problem Next is trying to solve. You might be better off

Seems like you're asking for UI components (page, panel, button) that you can just use? This isn't the problem Next is trying to solve. You might be better off with something like MaterialUI, Ant, Bootstrap, of any of the many other batteries-included UI frameworks. Or I guess Web Components were supposed to solve this problem, too, but I think they missed their window.