Trouble Blending Surfaces

New to Rhino and having trouble getting the sides and bottom of this box to smoothly blend. I’ve tried blending, fillets, curve network, and cage edits with limited success. I’m trying to maintain the angles of the sides and the top curve as it is tangent to another piece. Any suggestions? I’ve been at it for hours. Thanks!

RecessTest.3dm (322.7 KB)

If smoothness wins over precision of the radius, then loft with the Loose option (And History, in my example - you can scale/move/edit the curves to change the surfaces) is a good way to go.

RecessTest_PG.3dm (82.6 KB)

Thank you Pascal. Greatly appreciated!