Nice idea and really polished look. Nit: clicking "Create X" to add a new tag seems worse than pressing enter to create one as you have to go off the tag menu

Nice idea and really polished look. Nit: clicking "Create X" to add a new tag seems worse than pressing enter to create one as you have to go off the tag menu and back onto it to create or add another, but it's not necessarily clear that you can press enter to create one.