feat: improve button UI in light mode

[nazneen-p1]

Summary

This PR improves the Light Mode UI of the DevCard page by enhancing visual consistency, spacing, and overall user experience. The changes focus on refining the layout and styling to make the interface cleaner and more modern without affecting functionality.

Closes #78

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Type of Change

• Bug fix
• New feature
• Refactor (no functional change)
• UI / Design change
• Tests only
• Documentation
• Infrastructure / DevOps
• Security

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What Changed

• Improved layout spacing and alignment in app.css
• Enhanced card container styling for better visual hierarchy
• Updated background colors for a cleaner Light Mode experience
• Added subtle hover effects to improve user interaction

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How to Test

1. Run the project locally using pnpm dev
2. Open the DevCard page in the browser
3. Verify improved spacing, layout consistency, and visual appearance in Light Mode

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Checklist

• My code follows the project's coding style (pnpm -r run lint passes).
• TypeScript compiles without errors (pnpm -r run typecheck).
• I have added or updated tests for the changes I made.
• All tests pass locally (pnpm -r run test).
• I have updated documentation where necessary.
• No new console.log or debug statements left in the code.
• Breaking changes are documented in this PR description.

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Screenshots / Recordings

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After:

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Additional Context

This PR focuses on incremental UI improvements for the DevCard page. Further UI enhancements (buttons, navbar, forms) will be addressed in separate PRs to keep changes modular and easy to review.