*{box-sizing:border-box}:root{font-family:Segoe UI,Tahoma,Geneva,Verdana,sans-serif;color:#f5f7fa;background:#0f172a}html,body,#root{margin:0;width:100%;height:100%}.app-shell{width:100%;height:100%;display:grid;grid-template-rows:auto 1fr;background:linear-gradient(135deg,#111827,#0b1220)}.topbar{position:relative;z-index:10;display:flex;gap:16px;flex-wrap:wrap;justify-content:space-between;align-items:center;padding:12px 16px;border-bottom:1px solid rgba(255,255,255,.15);background:#0f172aeb;-webkit-backdrop-filter:blur(4px);backdrop-filter:blur(4px)}.topbar h1{margin:0;font-size:1.1rem}.topbar p{margin:4px 0 0;font-size:.85rem;color:#cbd5e1}.scene-switcher{display:flex;gap:8px;flex-wrap:wrap}.scene-switcher button{border:1px solid rgba(255,255,255,.25);background:#1f2937;color:#e5e7eb;padding:8px 10px;border-radius:8px;font-size:.8rem;cursor:pointer}.scene-switcher button.active{background:#2563eb;border-color:#60a5fa;color:#fff}.scene-container{min-height:0}.scene-container>*{width:100%;height:100%}