## Task
You're building an interactive card that can change its appearance based on user actions. Users can change the background color of the card, resize it, and toggle a "highlighted" state for additional styling.
1. **Change Inline Styles**: When the button is clicked:
   - Change the background color of the `<div>` with ID `card` to `"lightblue"`;
   - Set the width of the card to `"300px"`;
   - Add a `2px solid #333` border around the card.
2. **Toggle a Highlight Class**: When the button is clicked:
   - Add or remove the `highlight` class on the `<div>` with ID `card`.
3. **Add a Dark Theme Class**: When the button is clicked:
   - Add or remove the `dark-theme` class on the `<body>`, which should switch the page's theme.

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- Use `style.backgroundColor` to change the background color of the `<div>` with ID `card` to `"lightblue"`;
- Use `style.width` to set the width of the card to `"300px"`;
- Use `style.border` to add a `2px solid #333` border around the card;
- Use `classList.toggle()` to add or remove the `highlight` class on the `<div>` with ID `card`;
- Use `classList.toggle()` to add or remove the `dark-theme` class on the `<body>`, which should switch the page's theme.

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This course provides an in-depth exploration of key JavaScript principles, focusing on classes, DOM manipulation, event handling, and asynchronous programming. You'll learn to create dynamic and interactive elements, manage user interactions, and handle asynchronous operations. Through a blend of theory and hands-on challenges, this course helps you build practical JavaScript skills for real-world applications.

Learn the fundamentals of JavaScript classes, from class declarations to defining methods that enhance functionality. Discover how to use parameter objects effectively, manage private properties, and control access with getters and setters. Master static properties and static methods and unlock the power of class inheritance using "extends" and "super()" to build scalable and reusable code.

Master DOM manipulation to create dynamic, interactive web applications. Navigate and modify the DOM's structure, dynamically update content, and implement best practices for security and performance. Differentiate between properties and attributes to optimize your code.

Unlock the interactivity of your web applications by mastering JavaScript events. Understand event propagation, control event behavior, and implement efficient event handling for user interactions. Optimize performance with advanced techniques like event delegation.

This section covers the essentials of asynchronous JavaScript, including callbacks, Promises, and async/await. You’ll learn to fetch data from APIs, integrate third-party libraries, and handle multiple requests efficiently, building skills for creating data-driven applications.

Advanced JavaScript Mastery

Challenge: Modifying Element Styles

Task