hello client,
Let me introduce myself, Oscar Halawa, thank you for the competition.
I know that you prefer designs that have a Japandi-modern feel. In my design proposal, I interpreted it with slightly dark earth colors to provide a light-dark area that draws focus to the vanity and toilet, this will suit your black window color concept
The focal points are the washbasin and toilet, so the unique material emphasis is on these places. I have also provided a pdf file for further information.
I hope you like it!