A Bedroom with A Clear Roof

I have a bedroom. I just want to build a special one someday when I have a house of my own. First of all, I want it to be large enough. I can’t figure the exact size, though. Just, large enough. Then, I want the bedroom to have a clear roof. How is it possible? A thick, weatherproof glass should be put above the bed. There should be another layer above it, which can be controlled mechanically, to cover the room from sunray when it’s a hot midday. Look, I simply want to see stars at night before I sleep.