ConstReadonlyARENA: 10Combat arena and training grounds - 경기장
ReadonlyBACKGROUND: 0Background scenes and effects - 배경
ReadonlyDEBUG: 80Debug and performance overlays - 디버그
ReadonlyEFFECTS: 30Visual effects and particles - 효과
ReadonlyHUD: 40HUD elements (health bars, timers) - HUD
ReadonlyMOBILE_CONTROLS: 50Mobile touch controls - 모바일제어
ReadonlyMODAL: 60Modal dialogs and overlays - 모달
ReadonlyPLAYERS: 20Player characters and enemies - 플레이어
ReadonlyTOOLTIP: 70Tooltips and hints - 툴팁
Z-index hierarchy for layering UI elements
Ensures consistent stacking order across all screens