Something random that popped in my head at work (because it is so boring where I work)...

How is the Death Star structured?
If you think of a building or (space)ship, all of the floors or decks are generally horizontally parallel. And every time we have had the Death Star (either of them) on film, it has the appearance of all decks/floors being horizontally parallel, from the bottom of the sphere to the top.
There's no indication that the levels are curved (like the space station in Space Odyssey 2001), or any sign of the lifts changing directions (like in Star Trek)... but we do know that there are towers on the surface (like the Emperor's tower and gun stations), which are clearly sitting on the surface like buildings on the surface of a planet.
As such, those constructs on the surface are not parallel to all of the decks/floors/levels inside the Death Star... if all of the internal levels are parallel (stacked on top of each other like in an office building). So how do people get into the surface buildings, if the rest of the structure is layered like a regular building?
When ships fly into the Death Star to land in one of the hangers (Vader's shuttle, Millennium Falcon, Emperor's shuttle) they all fly into the side of the Death Star, as if the levels are parallel to the equator... and not like an onion, which would be better for gravity, and make more sense for the "buildings" that stick out of the surface of the Death Star.

Too much thought about something fictional?
Or has this already been explained from an official source, like in one of those reference or cut-away books?