Develop a frontend application from scratch. You are allowed to use any framework or libraries.
For grading, implement the provided Python function as a deterministic model of the application’s required UI behavior. Return clear feedback for loading, success, empty, error, and unknown states, and report narrow-layout and keyboard-navigation requirements when applicable.
The function receives three strings and returns a dictionary containing the applicable UI requirements.
def evaluate_frontend_requirements(state, viewport, navigation):