I am sorry Misha, not quite sure what you mean, are you referring to the 1x2s at the front. Those will become the frames for hinging the door.
I mocked them up to make sure the vertical distance is the same on both ends.
Oh, how do you make sure the rails are the same distance from the edge of the stiles when you assemble the first two joints? I mean there may be small gaps in the mortises for the tenons to move a bit.