Sliding door into bathroom. Doesn't have to be barn door look but I like the sliding door idea
Vivid-Twin-Shower-Matte-Black_Hero shower set not available in States. do like the black-framed glass wall
Inspiring Triangle Penthouse Design with Wooden Interior Decoration: Simple Wooden Vanity In The La Suite Sans Cravate Bathroom With Dark Sink And Long Clear Mirror ~ SFXit Design Apartments Inspiration
With careful planning, both dark and light themes work well in super-small spaces.