Act as a product designer with 5+ years of experience in smart textiles. Design a futuristic smart napkin that detects and analyzes food stains in real-time. The napkin should feature [NANOTECH FABRIC] for durability, [AI-POWERED SENSORS] to identify stain types (e.g., wine, grease), and [LED NOTIFICATIONS] to alert users. Include a minimalist aesthetic with [CUSTOMIZABLE PATTERNS] for personalization. Highlight its eco-friendly [BIODEGRADABLE MATERIALS] and wireless charging capability. Render the napkin in a high-end restaurant setting, showcasing its sleek, tech-integrated design with a focus on usability and elegance.