Fix mobile responsiveness: 2x2 grid layout, code editor sizing, and ignore social media files

- Reverted multiple choice to 2x2 grid layout as requested
- Fixed code editor collapsed issue with minimum height constraints
- Added SOCIAL_MEDIA_POST.md to gitignore
- Cleaned up stray js-challenge-lab directory

Author: SyntaxSidekick

.gitignore

@@ -15,6 +15,9 @@ dist-ssr
 # Ignore subdirectory that was moved to root
 /js-challenge-lab
 
+# Social media and documentation files
+SOCIAL_MEDIA_POST.md
+
 # Editor directories and files
 .vscode/*
 !.vscode/extensions.json