The app header should be displayed globally across all pages. It provides a familiar and persistent way for users to navigate. The app header should be hidden if a modal is open.

The content of the app header should remain consistent across all pages. On unauthenticated pages (e.g., login), a version with only the logo may be used.

If the page has scrollable content, the app header should remain fixed and visible at the top of the screen.

Navigation items should display a visible hover state. If a nav item opens a menu or tooltip, the nav item should remain in an active state.