Dark for me. The flow colors carry the whole chart and they read brighter against it. Did you check how the thin low-value flows hold up in light mode? That’s usually where sankeys fall apart.
The contact page is usually the last page anyone designs.
We made it one of the best
Recent client work: a contact section UI design for a company with offices across cities. Globe in the back, every location up front, and small interactions that make the whole web design feel alive.