[GreenCity - Admin Section] Refactoring Admin Section Files in GreenCity

[Maryna-511750]

Description of a Change request:
Perform a comprehensive refactoring of the files related to the GreenCity Admin Panel. This includes improving the structure and readability of the CSS files, ensuring consistency in styling, and removing any redundant or unused styles. Additionally, verify that the HTML and JavaScript files in the admin panel adhere to best practices for maintainability and scalability.

Reason for Change:
The current CSS files in the GreenCity Admin Panel may contain redundant, inconsistent, or outdated code, making them difficult to maintain and extend. This can slow down future development and potentially introduce styling bugs. Refactoring will improve code quality, reduce technical debt, and streamline future enhancements or fixes.

Acceptance Criteria

• CSS files are refactored to ensure clarity, consistency, and adherence to a modular structure.
• Unused styles are removed, and redundant definitions are merged or eliminated.
• HTML files are reviewed and adjusted to follow semantic best practices, where applicable.
• JavaScript files are checked to ensure they interact with the refactored CSS appropriately.

Epic link
Epic #910 [Epic] (#910)