Stackable box without support

This is a remix of https://www.thingiverse.com/thing:647425.

I printed the thing and found a few things that could be improved.

1. Less material, shorter printing time
I could spare much material and time by reducing the wall thickness and placing ribs instead, not compromising the strength and the stiffness.
That made my model weighing about 45g, with about 3-4 hours of printing time with the layer height of 0.25 mm.

2. Wider ledge
I also found that the ledge of the previous model was too narrow, or chamfered to make stacking unstable.

3. 3D-printing friendly design
The previous design does not have fillets at some edges, which is likely to cause warping. I put fillets properly and printed with ABS without any warping.

How the boxes stack: https://youtu.be/w4mE3RXgPW8


The characteristic dimensions of the small box are as the following:
-Length: 120 mm
-Width: 90 mm
-Height: 50 mm.

The characteristic dimensions of the large box are as the following:
-Leng