fix: improve responsiveness for <=480px screens

[sujalkurkute]

Description

Improved frontend responsiveness for screens <=480px by refining layout behavior and spacing for mobile devices.

Changes made

• Improved mobile responsiveness for the app layout
• Fixed button wrapping and spacing issues
• Prevented horizontal overflow on smaller screens
• Improved footer responsiveness
• Improved panel and tab responsiveness for mobile devices
• Enhanced usability on narrow-width screens

Related Issue

Fixes #217

Type of change

• Bug fix
• New feature / enhancement
• Documentation update
• Test addition
• Refactor

Checklist

• I have read CONTRIBUTING.md
• My branch is up to date with main
• I have run pytest -v and all tests pass
• I have not introduced duplicate issues or features
• My PR title follows the format: feat/fix/docs/test: short description
• I have added tests for new features (Level 2 and 3 issues)
• No hardcoded secrets or API keys in my code
• This PR is linked to a GSSoC 2026 issue

Added responsive improvements for <=480px screens.

Test evidence

Frontend responsiveness tested manually at:
- 480px
- 375px
- 320px

Screenshot