Add comprehensive XML book information display system

[Copilot]

This PR implements a complete XML-based book information display system that demonstrates XML structure, XSL transformation, and modern web presentation techniques.

What was implemented

The solution includes three main components:

1. XML Book Catalog (books.xml)

A well-structured XML file containing comprehensive book information with 6 sample books, including:

• Title, Author, ISBN, Publication Date
• Publisher, Genre, Pages, Language
• Price, Availability Status, Star Ratings
• Detailed descriptions
• XSL stylesheet reference for browser transformation

2. XSL Stylesheet (books.xsl)

A professional XSL transformation stylesheet that converts the XML into beautiful HTML with:

• Responsive grid layout for book cards
• Gradient backgrounds and modern styling
• Interactive hover effects and animations
• Color-coded availability status (In Stock/Limited Stock/Out of Stock)
• Mobile-responsive design
• Book count statistics

3. Interactive HTML Display (xml_books.html)

A comprehensive web interface featuring:

• Three viewing modes: View XML Source, View Formatted Display, View Both
• JavaScript-powered XML parsing and rendering
• Syntax-highlighted XML source code display
• Fallback data for offline viewing
• Responsive design for all screen sizes
• Interactive navigation between different views

4. Integration

• Added as Assignment 3 in the Web Technology Lab Assignments page
• Seamless navigation between existing assignments
• Consistent styling with the existing site design

Key Features

• Complete XML Structure: Demonstrates proper XML syntax with comprehensive book metadata
• XSL Transformation: Shows how XML can be transformed into styled HTML using XSL
• Modern Web Interface: Interactive JavaScript-based display with multiple viewing options
• Responsive Design: Works perfectly on desktop, tablet, and mobile devices
• Educational Value: Perfect for learning XML, XSL, and web development concepts

Screenshots

XML Source View with syntax highlighting:

Formatted book display with modern card layout:

Updated assignments page with new XML assignment:

The implementation provides a complete demonstration of XML technologies while maintaining excellent user experience and visual appeal. The XML file can be accessed directly (books.xml) to see the XSL transformation in action, or through the interactive HTML interface (xml_books.html) for a more comprehensive experience.

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