feat: add CSS bundle optimization demo using reusable animation tokens

[Pr241singh]

Related Issue

Closes #1116

Description

This PR adds a demonstration showcasing how reusable CSS variables and centralized animation tokens can help reduce repetitive declarations and improve maintainability in a growing CSS framework.

Following the repository contribution guidelines, this submission does not modify any framework source files and is implemented entirely within the submissions/ directory.

Added Files

submissions/examples/css-bundle-optimization-demo/
├── demo.html
├── style.css
└── README.md

Features

Token-Based Architecture Demo

• Centralized transition duration tokens
• Shared easing curve variables
• Reusable design tokens
• Consistent component behavior

Comparison Showcase

• Before optimization example
• After optimization example
• Demonstration of reduced duplication

Interactive Components

• Button component
• Card component
• Badge component
• Modal preview component

Benefits Demonstrated

• Reduced CSS repetition
• Easier maintenance
• Improved consistency
• Better scalability
• Preparation for future SCSS mixin adoption

Testing

• Verified demo renders correctly in browser
• Verified responsive layout behavior
• Verified token-based transitions work consistently across components
• Verified self-contained implementation with no external dependencies

Checklist

• Added files only inside submissions/examples/
• Included demo.html
• Included style.css
• Included README.md
• Followed repository contribution guidelines
• No modifications to core/
• No modifications to components/
• No modifications to existing framework source files

[github-actions]

✅ Submission Validation Passed!

Great job! All required files are present.

📁 Folder: submissions/examples/css-bundle-optimization-demo

Files found:

• ✅ demo.html
• ✅ style.css
• ✅ README.md

🚀 Next Steps:

• The maintainer will review your PR
• Respond to any feedback if requested
• Once approved, your contribution will be merged!

Thank you for contributing to EaseMotion CSS! 🎉