refactor: separate HTML, CSS, and JS files (#600)

[biswajit760]

Description

This PR restructures the project to follow standard web development practices by separating HTML, CSS, and JavaScript files. Previously, all styling and scripts were embedded directly within HTML files, which made maintenance and scalability difficult.

Changes Made:

• Moved inline CSS from HTML files to separate .css files for better readability and maintainability.

• Moved inline JavaScript from HTML files to separate .js files for modularity and cleaner code structure.

• Updated HTML files to correctly link the new CSS and JS files.

• Ensured that all pages maintain their original functionality and styling after the separation.

#600 Issue No

Benefits:

• Improved code readability and organization.

• Easier maintenance and future enhancements.

• Better adherence to web development best practices.

Testing:

• Verified that all pages render correctly.

• Tested all JavaScript functionalities to ensure no breakage.

• Checked responsiveness and styling consistency across different pages.

Type of change

• Bug fix
• New feature
• Improvement
• Documentation update

How Has This Been Tested?

Explain how you tested your changes.

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my code
• I have commented my code where necessary
• I have added tests that prove my fix is effective or that my feature works
• I have made corresponding changes to the documentation

[github-actions]

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