:root{color-scheme:light;font-family:Segoe UI,ui-sans-serif,system-ui,-apple-system,Roboto,sans-serif;line-height:1.5;--gold: #f5a623;--gold-dark: #d4901a;--green: #4caf50;--green-dark: #388e3c;--bg: #fdf6ee;--card: #fff;--text: #2d2013;--text-muted: #7a6b58;--border: #e8ddd0;--accent: #6c5ce7;--accent-light: #a29bfe;--room-floor: #d4a574;--room-wall: #f0e6d3;--room-ceiling: #f5ece0;--shadow: 0 2px 12px rgba(0,0,0,.08)}*{box-sizing:border-box;margin:0;padding:0}html,body,#root{min-height:100vh;background:var(--bg);color:var(--text)}body{font-size:15px}button{font-family:inherit;cursor:pointer;border:none;outline:none;transition:all .15s ease}button:active{transform:scale(.96)}.app{max-width:520px;margin:0 auto;padding:0 0 80px;min-height:100vh}.header{display:flex;align-items:center;justify-content:space-between;padding:16px 20px;background:var(--card);border-bottom:1px solid var(--border);position:sticky;top:0;z-index:20}.header h1{font-size:1.15rem;font-weight:700;color:var(--text)}.coin-badge{display:flex;align-items:center;gap:6px;background:linear-gradient(135deg,#fef3c7,#fde68a);padding:6px 14px;border-radius:20px;font-weight:700;font-size:.95rem;color:#92400e;box-shadow:0 1px 4px #f5a6234d}.coin-icon{font-size:1.1rem}.bottom-nav{position:fixed;bottom:0;left:50%;transform:translate(-50%);width:100%;max-width:520px;display:flex;background:var(--card);border-top:1px solid var(--border);z-index:20;padding-bottom:env(safe-area-inset-bottom,0)}.nav-btn{flex:1;display:flex;flex-direction:column;align-items:center;gap:2px;padding:10px 0 8px;background:transparent;color:var(--text-muted);font-size:.7rem;font-weight:600;letter-spacing:.02em;text-transform:uppercase}.nav-btn .nav-icon{font-size:1.35rem}.nav-btn.active{color:var(--accent)}.page{padding:16px 20px;animation:fadeIn .2s ease}@keyframes fadeIn{0%{opacity:0;transform:translateY(6px)}to{opacity:1;transform:translateY(0)}}.room-container{perspective:800px;margin-bottom:20px}.room{position:relative;width:100%;height:320px;border-radius:16px;overflow:hidden;box-shadow:var(--shadow);border:2px solid var(--border)}.room-wall{position:absolute;top:0;right:0;bottom:0;left:0;background:linear-gradient(180deg,var(--room-ceiling) 0%,var(--room-wall) 30%,var(--room-wall) 65%,var(--room-floor) 65%,var(--room-floor) 100%)}.room-floor-line{position:absolute;left:0;right:0;top:65%;height:2px;background:#c4956a}.room-item{position:absolute;font-size:2.2rem;filter:drop-shadow(0 2px 3px rgba(0,0,0,.15));transition:all .3s ease;animation:placeItem .35s cubic-bezier(.34,1.56,.64,1);cursor:pointer}@keyframes placeItem{0%{transform:scale(0) rotate(-20deg);opacity:0}to{transform:scale(1) rotate(0);opacity:1}}.room-empty{position:absolute;top:0;right:0;bottom:0;left:0;display:flex;align-items:center;justify-content:center;color:var(--text-muted);font-size:.9rem;text-align:center;padding:40px;pointer-events:none}.section-title{font-size:1rem;font-weight:700;margin-bottom:12px;color:var(--text)}.challenge-card{background:var(--card);border:1px solid var(--border);border-radius:14px;padding:18px;margin-bottom:12px;box-shadow:var(--shadow)}.challenge-header{display:flex;align-items:center;justify-content:space-between;margin-bottom:8px}.challenge-name{font-weight:700;font-size:.95rem}.challenge-reward{display:flex;align-items:center;gap:4px;font-weight:700;font-size:.85rem;color:var(--gold-dark)}.challenge-question{font-size:.9rem;color:var(--text-muted);margin-bottom:14px;line-height:1.5}.options-grid{display:grid;grid-template-columns:1fr 1fr;gap:8px}.option-btn{padding:10px 12px;border-radius:10px;font-size:.85rem;font-weight:600;background:var(--bg);border:2px solid var(--border);color:var(--text);transition:all .15s ease}.option-btn:hover{border-color:var(--accent-light);background:#f0edff}.option-btn.correct{border-color:var(--green);background:#e8f5e9;color:var(--green-dark)}.option-btn.wrong{border-color:#e57373;background:#ffebee;color:#c62828}.option-btn:disabled{cursor:default;opacity:.7}.challenge-result{margin-top:12px;padding:10px 14px;border-radius:10px;font-weight:700;font-size:.85rem;text-align:center}.challenge-result.correct{background:#e8f5e9;color:var(--green-dark)}.challenge-result.wrong{background:#ffebee;color:#c62828}.challenge-meta{display:flex;gap:8px;margin-bottom:10px}.tag{display:inline-block;font-size:.65rem;font-weight:700;letter-spacing:.06em;text-transform:uppercase;padding:3px 8px;border-radius:6px}.tag-math{background:#e3f2fd;color:#1565c0}.tag-science{background:#e8f5e9;color:#2e7d32}.tag-language{background:#fce4ec;color:#c62828}.tag-logic{background:#f3e5f5;color:#7b1fa2}.tag-geography{background:#fff3e0;color:#e65100}.shop-grid{display:grid;grid-template-columns:1fr 1fr;gap:12px}.shop-item{background:var(--card);border:2px solid var(--border);border-radius:14px;padding:16px 12px;text-align:center;cursor:pointer;transition:all .15s ease;box-shadow:var(--shadow)}.shop-item:hover{border-color:var(--accent-light);transform:translateY(-2px)}.shop-item.owned{border-color:var(--green);background:#f1f8f1}.shop-item.cant-afford{opacity:.5}.shop-item-emoji{font-size:2.4rem;margin-bottom:6px;display:block}.shop-item-name{font-weight:700;font-size:.82rem;margin-bottom:4px}.shop-item-price{font-size:.78rem;color:var(--gold-dark);font-weight:700}.shop-item-owned-badge{font-size:.7rem;color:var(--green-dark);font-weight:700}.inventory-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:10px}.inventory-item{background:var(--card);border:2px solid var(--border);border-radius:12px;padding:14px 8px;text-align:center;cursor:pointer;transition:all .15s ease}.inventory-item.placed{border-color:var(--accent);background:#f0edff}.inventory-item:hover{border-color:var(--accent-light)}.inventory-item-emoji{font-size:1.8rem;margin-bottom:4px;display:block}.inventory-item-name{font-size:.72rem;font-weight:600;color:var(--text-muted)}.toast-container{position:fixed;top:70px;left:50%;transform:translate(-50%);z-index:100;display:flex;flex-direction:column;gap:8px;pointer-events:none}.toast{padding:10px 20px;border-radius:12px;font-weight:700;font-size:.85rem;animation:toastIn .3s ease,toastOut .3s ease 1.5s forwards;white-space:nowrap;box-shadow:0 4px 16px #0000001f}.toast-earn{background:linear-gradient(135deg,#fef3c7,#fde68a);color:#92400e}.toast-spend{background:linear-gradient(135deg,#e8f5e9,#c8e6c9);color:#2e7d32}.toast-info{background:linear-gradient(135deg,#e3f2fd,#bbdefb);color:#1565c0}@keyframes toastIn{0%{opacity:0;transform:translateY(-10px)}to{opacity:1;transform:translateY(0)}}@keyframes toastOut{0%{opacity:1}to{opacity:0;transform:translateY(-10px)}}.category-filter{display:flex;gap:6px;margin-bottom:14px;overflow-x:auto;padding-bottom:4px}.cat-btn{padding:6px 14px;border-radius:20px;font-size:.75rem;font-weight:700;background:var(--card);border:2px solid var(--border);color:var(--text-muted);white-space:nowrap}.cat-btn.active{border-color:var(--accent);color:var(--accent);background:#f0edff}.complete-banner{background:linear-gradient(135deg,#a29bfe,#6c5ce7);color:#fff;text-align:center;padding:24px 20px;border-radius:16px;margin-bottom:16px}.complete-banner h2{font-size:1.1rem;margin-bottom:4px}.complete-banner p{font-size:.85rem;opacity:.9}.reset-btn{margin-top:12px;padding:10px 24px;border-radius:10px;background:#fff3;color:#fff;font-weight:700;font-size:.85rem;-webkit-backdrop-filter:blur(4px);backdrop-filter:blur(4px)}.reset-btn:hover{background:#ffffff4d}