Use top toggles for related content (e.g., "Details" vs. "Reviews"). Use bottom navigation for completely different parts of the app (e.g., "Home" vs. "Settings"). Never mix the two.
When you toggle to a new screen using a top menu, what happens when the user presses the device's "Back" button?
Toggling between screens via the top is about , not just navigation. It tells the user: "You are not leaving the page; you are just looking at a different angle of it."
.screen.active display: block;