Cam-Lift Hinges
A cam-lift hinge raises the door while it swings and lets it drop back down when it closes.
One height
A standard butt stays at one height the whole way. Hung low enough to seal, the door drags. Hung high enough to clear, the closed door leaves a gap at the floor.
The cam
The knuckle is a cam. As the door opens, that cam lifts the door just enough for the bottom to clear carpet or a threshold. Up while the door is moving, down when it is shut, so the bottom can seal.
The close
On the way back down the cam, the weight of the door draws it toward closed. Use a cam-lift hinge where the door has to pass over the floor condition and still sit tight when shut.