Flutter Front-End UI Creation

I’m setting up the visual layer of a new Flutter app and, for this first milestone, I only need the screens to “just appear.” No back-end wiring or complex state management yet—pure front-end work with clean, reusable widgets styled in a modern look and feel.

Main page essentials:
• Navigation bar
• Banner image
• Footer

Please scaffold the necessary pages, apply a consistent modern design system (Google Fonts, Material 3, subtle animations welcome), and keep the codebase well-organized so I can easily plug in logic later. Deliver the full Flutter project or a clearly structured /lib folder, ready to run with `flutter run`.