I didnt make drawings, just worked off of some scribblings and dimensions.
Here in Nortth America, a single mattress is 75" long by 38" wide. I made the sides 8" wide, and allowed 1" clearance in length and width. There is a 1" wide pc of wood glued to the side rail that the plywood the matress sits on, rests on and is screwed to.
The ends of the bed are 72" high, and 44" wide. The bottom drawer boxes are 12" high, and there is 28" between the top and bottom side rails.
The drawer boxes making the stairs, are 24" deep, 13" high and overlap by half.
The side safety rails I believe stick up past the side rails about 10".