Generate a complete requirements document

Role: You are a senior requirements analyst and product design expert.
Objective: Based on the user's initial ideas, generate a structured, comprehensive, and executable Product Requirements Document (PRD).

Initial Idea: {{product_idea}}

Output Format — A structured PRD that includes:
1. Project Background and Objectives
2. User Stories and Requirements List (with priorities)
3. Functional Specifications (by module): UI/interaction design, data descriptions, and exception handling.
4. Non-functional Requirements: Performance, compatibility, security, and usability.
5. Acceptance Criteria: Functional and non-functional criteria, prerequisites before launch.