This is a perfect combo of my two favorite ideas for that space under the stairs leading to the basement. A reading nook AND book storage and shelves . assuming that there is enough space for this there.
stairs rail make a picture rail hand rail steel modern staircase original vision limited. Custom built cooler with LED lighting for the wine cellar under stairs. Ample shelf e under a modern staircase.
shelves not all the way to the floor save space. A blind inside frame of window leaves room for the desk while not crowding the room with curtains, and the pendant light is a nice touch. Home office + guest room inspiration