LR window seat inspiration--but with thick cushion. (Note how backrest plane and then seat plane expand overall width without having to thicken the wall.) Napa Valley House by Steven Harris Architecture (Architect: Eliot Lee)
Staircases take up a lot of space, so why not use them for storage as well. Imagine each step is a box with a hidden drawer in it still allowing for additional storage or home office space beneath the staircase.