I need a straightforward, responsive website that showcases every title in my library and reflects availability changes the moment they happen. No login or membership system is required; visitors simply browse the catalogue. Your main task is to connect the front-end to an external database or API so that new, removed, or updated books appear instantly without a page refresh. All code must be cleanly separated—one HTML file, one CSS file, and one JavaScript file—so I can maintain each layer independently. Deliverables • index.html, styles.css, and app.js as distinct files • Real-time sync with my existing external database (you can suggest the most practical method: REST, WebSocket, Firebase, etc.) • Clear inline comments so I can tweak or expand the code later • Responsive layout that works smoothly on desktop, tablet, and phone I may request a few minor tweaks once I see it live, but overall I’m looking for quick, high-quality turnaround on this single-page dynamic catalogue.