In general, the bathroom design under the stairs has an uneven position because there are high and low sections. Therefore we need special methods and techniques to design this type of bathroom so that it feels comfortable. Moreover, you want to have a new bathroom, but with a small space.
The space under the stairs that is not parallel is nothing to worry about, you can design it in such a way that the bathroom on the lower floor remains unique, or in other words, it has good aesthetic value. On uneven areas, you can place storage racks for toiletries and toiletries.
Well, here you can see some bathroom designs under the stairs that you might want to have.
7 Amazing Under-Stair Bathroom Designs For New Bathrooms