## Purpose
Define stable requirements for frontend-motion-system.

## Requirements

### Requirement: Navigation transitions SHALL use a maintainable baseline motion system
The frontend SHALL provide route and panel transition effects using a baseline motion mechanism suitable for long-term maintenance.

#### Scenario: Route transition feedback
- **WHEN** a user navigates between report modules
- **THEN** the shell SHALL provide consistent transition feedback
- **THEN** transitions SHALL NOT block route completion or data loading

### Requirement: Motion behavior SHALL support reduced-motion accessibility
The motion system SHALL respect reduced-motion user preferences.

#### Scenario: Reduced-motion preference
- **WHEN** user agent indicates reduced motion preference
- **THEN** non-essential animations SHALL be minimized or disabled
- **THEN** primary interactions SHALL remain fully usable

### Requirement: Motion effects SHALL preserve functional correctness
Animation implementation SHALL NOT alter data correctness, query timing semantics, or interaction outcomes.

#### Scenario: Interactive action during motion
- **WHEN** users perform filtering, refresh, or drill-down actions during transitions
- **THEN** resulting API calls and state updates SHALL remain functionally equivalent to non-animated execution
