Implemented sticky navbar for persistent visibility during scroll

[jency1]

Closes #365

Changes

• Made the navbar sticky for improved user experience on scroll.
• Updated the styles for better responsiveness across devices.

Flags

• Ensure that sticky behavior works well across different screen sizes.
• Double-check if the navbar overlaps any content on scroll in specific cases.

Screenshots or Video

With Sticky Navbar

Without Sticky Navbar

Related Issues

• Issue Make Navbar Sticky for Persistent Visibility During Scroll #365
• Pull Request Implemented sticky navbar for persistent visibility during scroll #366

Author Checklist

• Ensure you provide a DCO sign-off for your commits using the --signoff option of git commit.
• Vital features and changes captured in unit and/or integration tests
• Commits messages follow AP format
• Extend the documentation, if necessary
• Merging to main from fork:branchname

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