Polished Login Page – Better UX, Accessibility, and Code Cleanup

[ShraddhaBhujbal11]

This update gives the Login page a small but meaningful makeover.

• Now shows a friendly error message if you try to log in without filling in both fields (instead of silently logging to the console).
• Inputs have proper labels behind the scenes, so screen readers and accessibility tools understand them.
• Cleaned up some repeated Tailwind classes by grouping them into a single variable – easier to maintain.
• Fixed a rogue "p-15" class (Tailwind was confused too) and replaced it with a consistent padding value.
• Swapped out the tag for a React Router so navigating to Register doesn’t reload the entire app.

End result: a login page that’s just as good under the hood as it looks on the outside.