Add responsive styles and accessibility improvements

[Dippp10-ally]

📝 Description

This PR improves the navbar by enhancing its responsiveness, accessibility, and overall user experience across different screen sizes. The changes focus on creating a more consistent navigation layout, improving mobile menu interactions, and ensuring better usability for all users.

🔗 Related Issue

Closes #88

✨ Changes Made

• Improved navbar responsiveness for desktop, tablet, and mobile devices.
• Optimized navigation link alignment and spacing.
• Enhanced mobile menu behavior and interaction.
• Improved hover, focus, and active states for navigation items.
• Added or refined accessibility attributes and keyboard navigation support.
• Updated styling for better visual consistency across the application.

🧪 Testing Performed

• Verified navbar layout on multiple screen sizes.
• Tested mobile menu open/close functionality.
• Checked navigation link accessibility using keyboard navigation.
• Confirmed that existing navigation functionality remains unaffected.

📸 Screenshots

✅ Checklist

• Code follows project guidelines and coding standards.
• Changes have been tested locally.
• Responsive behavior verified on different viewport sizes.
• Accessibility considerations reviewed.
• No existing functionality has been broken.
• Documentation updated if required.

[vercel]

@Dippp10-ally is attempting to deploy a commit to the coderzs' projects Team on Vercel.

A member of the Team first needs to authorize it.

[Dippp10-ally]

@coder-zs-cse ji , do assign labels called as gssoc:approved, level:inetrmediate, type:feature , qualiity:exceptional to above pull request number 89 also.....do merge above pull request number 89 also...

[Dippp10-ally]

@coder-zs-cse ji , below is screenshot prior to making changes.....

[Dippp10-ally]

@coder-zs-cse ji , below are screenshots after making changes....