Changed header from sticky to fixed positioning and added proper margin offset
(mt-20) to main element to prevent content from being covered. The fixed header
now stays at the top during scroll while content renders below it properly.
- Fixed header: changed from sticky to fixed with left-0 right-0 full width
- Main spacing: added mt-20 margin-top with relative z-10 preserved
- Restored z-index layering for content positioning
Also added Week 3 completion documentation and Week 4 planning files:
- WEEK3-COMPLETION.md: Comprehensive audit of Week 3 implementation
- WEEK3-4-TRANSITION.md: Handoff document with git workflow
- WEEK4-PLAN.md: Full technical roadmap for Week 4 forms & interactions
- PROGRESS-STATUS-WEEK4.txt: Updated cumulative progress tracking
- Updated HANDOFF.md with Week 3 summary and Week 4 readiness
