Enhanced login & Sign-in UI/UX Sheet

[ChandanGowdaKS]

Problem:

• Login and Sign up buttons overlap;
• The login page and sign-up UI/UX can be improved according to dark mode and light mode.

Before:

After solving the issue:

• Improved light/dark toggle button with Hover.
• nice UI/UX for Sign-in and login page.

[github-actions]

Thanks for creating a PR for your Issue! ☺️

Kindly Star the repo ⭐ We'll review Your PR as soon as possible.
In the meantime, please double-check the file changes and ensure that all commits are accurate.

If there are any unresolved review comments, feel free to resolve them. 🙌🏼

[ChandanGowdaKS]

Fixed responsiveness for mobile devices.

@AKing-283 I'd like to ask you to check and merge both changes.