The staircase, shelves, loft, and bathroom are a gorgeous concept! I love how much space is available in the living area, and the shelves on the stairs are an awesome detail. It creates a closet-landing spot. I'd like to change the materials used for the walls/counters to give it a better aesthetic, possibly move the mini-fridge, and turn the bathroom door into a pocket door. But, otherwise this is a fantastic layout. Well done!!
The stairs don't incorporate storage and anything you think you're going to store down there will be a pain to reach and you won't really use. That's valuable lost space. Also, I don't care for the bathroom opening up so close to the kitchen... Don't shit where you eat is an expression for a reason.