feat: Add dark mode for login and register pages

[Tarun-Upadhyay-616]

Description

This PR implements a dark mode feature for the Login and Register pages. This provides a better user experience, especially in low-light environments, and improves visual accessibility. The styles have been updated to support both light and dark themes based on user preference or a toggle (if applicable).

Fixes #292

Type of Change

• Bug fix
• New feature
• Documentation update
• Code refactoring
• Other

Testing

How has this been tested?

• Manual testing
• Added/updated tests
• Tested on multiple browsers/devices

Test Details:

• Manually tested the dark mode functionality on both the /login and /register routes.
• Verified that all UI elements (input fields, labels, buttons, links, and error messages) are styled correctly and have proper contrast in both light and dark modes.
• Confirmed that switching modes works as expected.
• Tested on Chrome and Firefox to ensure cross-browser compatibility.

Checklist

• Code follows project style guidelines
• Self-reviewed my code
• Updated documentation if needed
• No new warnings or errors
• Tested changes locally

Hacktoberfest (if applicable)

• This is a meaningful contribution (not spam/low-effort)
• I have read the contribution guidelines

[vercel]

@Tarun-Upadhyay-616 is attempting to deploy a commit to the Harsh Dev's projects Team on Vercel.

A member of the Team first needs to authorize it.

[Harshdev625]

Change color combo not looking appealing in dark mode

[Tarun-Upadhyay-616]

Thanks for the feedback, @Harshdev625. Could you let me know which specific color combinations you'd like me to change? Or do you have any suggestions for a better palette?

[Harshdev625]

@Tarun-Upadhyay-616 See how we implemented other pages and get better idea from pinterest