How to make an object with curvy edges

Question

I'm just starting to learn Blender, and I want to model an smartphone, but I'm stuck because I need to recreate this curvy part:

This is what I have so far:

Can you tell me what technique to use here to make it curvy?

Answer 1

Create an edge loop:

Scale it down:

Bevel:

Answer 2

I suppose it's also worth pointing out, that if the 'Shape' setting of a superellipse bevel is set below 0.25, the curvature becomes concave:

(Left: 0.5, Right: 0.17)