App Interface Guideline: Navigation — Modal Escape. Keywords: modal dismiss close affordance. Platform: iOS/Android/React Native. Description: Modals/sheets must have clear close actions. Do: Provide close button and swipe-down where platform expects. Don't: Trapping users in modal with no obvious exit. Good Example: <Modal><Button title="Close" onPress={onClose} /></Modal>. Bad Example: <Modal><View>{children}</View></Modal>. Severity: High.