Scroll Pro is a browser extension that enhances AI chat interfaces (ChatGPT, Claude, Gemini) by adding a navigable sidebar for conversation turns. It enables users to copy, export (to Markdown, PDF, text, JSON), and navigate chats via a table of contents. The extension operates entirely client-side using React 19.2.0, TypeScript, and Vite, with UI rendered in a Shadow DOM for isolation. Key features include platform-specific DOM parsing, keyboard shortcuts, context menus, and persistent state via browser storage. The architecture centers around a content script entry point that mounts a React app, provider abstractions for each chat platform, and reusable utilities for markdown conversion, scrolling, and file downloads.