Fixed: Mobile Navbar

[Tripti-09]

Improvements done against BUG: #114

1. Improved header logo behavior: Logo text changes from "Anime Ecstasy" to "AE" when the search bar is opened.
2. Smooth transition: Added animation effect for logo text change and search bar opening.
3. Clean UI: Search bar and header layout now adapt gracefully for different screen sizes.
4. Code optimization: Structured components with conditional rendering for better readability and maintainability.
5. Added mobile responsiveness: Navigation Links (Home, About Us, Watch-list) are kept below the main navbar, for better readability in small devices.
6. Navbar Color: Changed the background color of Navigation Bar from black to gray-800.

Attaching screenshots of implied changes: