- Add max-height: 92vh and overflow-y: auto to .setup-card so it scrolls
instead of extending past the screen
- Widen .setup-card to 860px to accommodate 2-column deck grid
- Change .deck-assignment-grid from vertical stack to 2-column grid so
4 player panels fit in 2 rows instead of 4
- Reduce .deck-tab-content max-height to 170px and .deck-precon-list to
140px for tighter panels
- Make gradient bar sticky so it stays visible when scrolling
- Add responsive fallback to single column below 640px