app.js Overview The file serves as the main controller for the Markdown Previewer application. It manages user interactions, updates the live preview, handles toolbar actions, saves data to Local Storage, synchronizes scrolling, exports content, and applies syntax highlighting. This file connects the user interface with the Markdown parser, ensuring that changes made in the editor are instantly reflected in the preview panel. What I Added: Live Markdown rendering with real-time updates, Debounced rendering to improve performance while typing Scroll synchronization between editor and preview panels Local, Storage support for automatic save and restore Toolbar buttons for common Markdown formatting Copy HTML functionality using the Clipboard API Markdown file download functionality Clear editor and storage reset feature, Basic syntax highlighting for code blocks, Error handling for rendering and storage operations, Application initialization and startup logic. What I Learned: While building app.js, I gained practical experience with modern JavaScript and browser APIs. I learned how to manipulate the DOM, listen for user events, and update page content dynamically. I also explored Local Storage for data persistence, the Clipboard API for copying content, and the Blob API for generating downloadable files. Additionally, I learned performance optimization techniques such as debouncing, implemented scroll synchronization, worked with regular expressions for syntax highlighting, and improved application reliability through error handling and modular JavaScript design. Key Concepts Practiced DOM Manipulation, Event HandlingES6 Modules, Arrow Functions, Local Storage API, Clipboard APIBlob APIError Handling (try/catch)Debouncing, Regular Expressions, Syntax Highlighting, Scroll Synchronization, Dynamic Rendering, Modular JavaScript Architecture User Interface.