* {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: 'Exo 2', 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
        }
        
        body {
            background: linear-gradient(135deg, #0c1226, #1a2a6c, #2c3e50);
            color: #fff;
            min-height: 100vh;
            overflow-x: hidden;
            position: relative;
            background-attachment: fixed;
        }
        
        body::before {
            content: "";
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background: 
                radial-gradient(circle at 10% 20%, rgba(46, 204, 113, 0.08) 0%, transparent 15%),
                radial-gradient(circle at 90% 70%, rgba(52, 152, 219, 0.08) 0%, transparent 15%),
                radial-gradient(circle at 30% 60%, rgba(155, 89, 182, 0.08) 0%, transparent 15%),
                radial-gradient(circle at 70% 30%, rgba(231, 76, 60, 0.08) 0%, transparent 15%);
            z-index: -1;
        }
        
        .particles {
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            z-index: -1;
            overflow: hidden;
        }
        
        .particle {
            position: absolute;
            border-radius: 50%;
            background: rgba(255, 255, 255, 0.1);
            animation: float 15s infinite linear;
        }
        
        @keyframes float {
            0% { transform: translateY(0) translateX(0) rotate(0deg); }
            100% { transform: translateY(-100vh) translateX(100px) rotate(360deg); }
        }
        
        .container {
            max-width: 1400px;
            margin: 0 auto;
            padding: 20px;
            position: relative;
            z-index: 2;
        }
        
        header {
            text-align: center;
            padding: 30px 0;
            position: relative;
            margin-bottom: 20px;
        }
        
        .logo {
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 15px;
            margin-bottom: 15px;
            position: relative;
        }
        
        .logo i {
            font-size: 3.5rem;
            color: #2ecc71;
            text-shadow: 0 0 20px rgba(46, 204, 113, 0.7);
            animation: pulse 3s infinite alternate;
        }
        
        @keyframes pulse {
            0% { text-shadow: 0 0 10px rgba(46, 204, 113, 0.5); }
            100% { text-shadow: 0 0 30px rgba(46, 204, 113, 0.9), 0 0 60px rgba(46, 204, 113, 0.6); }
        }
        
        h1 {
            font-size: 3.8rem;
            font-family: 'Orbitron', sans-serif;
            background: linear-gradient(to right, #2ecc71, #3498db, #9b59b6);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            text-shadow: 0 2px 15px rgba(0,0,0,0.3);
            letter-spacing: 2px;
            margin-bottom: 10px;
            position: relative;
            display: inline-block;
        }
        
        h1::after {
            content: "";
            position: absolute;
            bottom: -10px;
            left: 0;
            width: 100%;
            height: 4px;
            background: linear-gradient(to right, #2ecc71, #3498db, #9b59b6);
            border-radius: 2px;
        }
        
        .subtitle {
            font-size: 1.3rem;
            color: #ecf0f1;
            max-width: 800px;
            margin: 20px auto 0;
            line-height: 1.7;
            background: rgba(0, 0, 0, 0.3);
            padding: 15px 25px;
            border-radius: 15px;
            border-left: 4px solid #3498db;
            backdrop-filter: blur(5px);
            text-shadow: 0 1px 2px rgba(0,0,0,0.5);
        }
        
        .game-controls {
            display: flex;
            justify-content: center;
            gap: 20px;
            margin: 30px 0;
            flex-wrap: wrap;
        }
        
        .mode-selector {
            background: rgba(25, 35, 65, 0.8);
            border-radius: 15px;
            padding: 20px;
            backdrop-filter: blur(10px);
            border: 1px solid rgba(255, 255, 255, 0.15);
        }
        
        .mode-buttons {
            display: flex;
            gap: 15px;
            flex-wrap: wrap;
            justify-content: center;
        }
        
        .mode-btn {
            background: linear-gradient(135deg, #3498db, #2c3e50);
            color: white;
            border: none;
            padding: 12px 24px;
            border-radius: 25px;
            cursor: pointer;
            transition: all 0.3s ease;
            font-size: 1rem;
            display: flex;
            align-items: center;
            gap: 8px;
            font-family: 'Orbitron', sans-serif;
        }
        
        .mode-btn.active {
            background: linear-gradient(135deg, #2ecc71, #27ae60);
            transform: scale(1.05);
            box-shadow: 0 5px 15px rgba(46, 204, 113, 0.4);
        }
        
        .mode-btn:hover {
            transform: translateY(-3px) scale(1.05);
            box-shadow: 0 8px 20px rgba(0, 0, 0, 0.3);
        }
        
        .settings-panel {
            background: rgba(25, 35, 65, 0.8);
            border-radius: 15px;
            padding: 20px;
            backdrop-filter: blur(10px);
            border: 1px solid rgba(255, 255, 255, 0.15);
            display: flex;
            align-items: center;
            gap: 20px;
            flex-wrap: wrap;
        }
        
        .setting-group {
            display: flex;
            align-items: center;
            gap: 10px;
        }
        
        .setting-group label {
            font-size: 1rem;
            color: #ecf0f1;
        }
        
        .setting-group input, .setting-group select {
            background: rgba(0, 0, 0, 0.3);
            border: 1px solid rgba(255, 255, 255, 0.2);
            border-radius: 8px;
            padding: 8px 12px;
            color: #fff;
            font-size: 1rem;
            width: 100px;
        }
        
        .reset-score-btn {
            background: linear-gradient(135deg, #e74c3c, #c0392b);
            color: white;
            border: none;
            padding: 8px 16px;
            border-radius: 20px;
            cursor: pointer;
            transition: all 0.3s ease;
            font-size: 0.9rem;
            display: flex;
            align-items: center;
            gap: 5px;
        }
        
        .reset-score-btn:hover {
            transform: translateY(-2px);
            box-shadow: 0 5px 15px rgba(231, 76, 60, 0.4);
        }
        
        .game-area {
            display: flex;
            flex-wrap: wrap;
            gap: 30px;
            margin: 40px 0;
        }
        
        .elements-panel {
            flex: 1;
            min-width: 350px;
            background: rgba(25, 35, 65, 0.7);
            border-radius: 20px;
            padding: 25px;
            box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3), 0 0 20px rgba(52, 152, 219, 0.2);
            backdrop-filter: blur(10px);
            border: 1px solid rgba(255, 255, 255, 0.15);
        }
        
        .panel-title {
            font-size: 1.8rem;
            margin-bottom: 25px;
            color: #3498db;
            display: flex;
            align-items: center;
            gap: 10px;
            font-family: 'Orbitron', sans-serif;
            letter-spacing: 1px;
        }
        
        .elements-container {
            display: grid;
            grid-template-columns: repeat(auto-fill, minmax(85px, 1fr));
            gap: 12px;
        }
        
        .element {
            background: linear-gradient(135deg, #3498db, #2c3e50);
            height: 85px;
            border-radius: 12px;
            display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: center;
            cursor: pointer;
            transition: all 0.3s ease;
            box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
            position: relative;
            overflow: hidden;
            border: 2px solid rgba(255, 255, 255, 0.1);
        }
        
        .element:hover {
            transform: translateY(-5px) scale(1.08);
            box-shadow: 0 8px 20px rgba(0, 0, 0, 0.4);
            border-color: rgba(255, 255, 255, 0.3);
        }
        
        .element.selected {
            border-color: #f1c40f;
            box-shadow: 0 0 20px rgba(241, 196, 15, 0.6);
            transform: scale(1.1);
        }
        
        .element-symbol {
            font-size: 2rem;
            font-weight: bold;
            z-index: 1;
            font-family: 'Orbitron', sans-serif;
            text-shadow: 0 0 8px rgba(255,255,255,0.5);
        }
        
        .element-name {
            font-size: 0.8rem;
            margin-top: 4px;
            z-index: 1;
            color: #ecf0f1;
        }
        
        .element-number {
            position: absolute;
            top: 4px;
            left: 6px;
            font-size: 0.65rem;
            z-index: 1;
            color: rgba(255, 255, 255, 0.7);
        }
        
        .reaction-area {
            flex: 2;
            min-width: 450px;
            background: rgba(25, 35, 65, 0.7);
            border-radius: 20px;
            padding: 30px;
            box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3), 0 0 20px rgba(231, 76, 60, 0.2);
            backdrop-filter: blur(10px);
            border: 1px solid rgba(255, 255, 255, 0.15);
            display: flex;
            flex-direction: column;
        }
        
        .beaker-container {
            position: relative;
            display: flex;
            justify-content: center;
            margin-bottom: 30px;
        }
        
        .beaker {
            width: 220px;
            height: 280px;
            background: rgba(255, 255, 255, 0.08);
            border-radius: 0 0 35px 35px;
            position: relative;
            border: 3px solid rgba(255, 255, 255, 0.25);
            overflow: hidden;
            box-shadow: inset 0 -15px 25px rgba(0, 0, 0, 0.3), 0 8px 16px rgba(0, 0, 0, 0.3);
        }
        
        .liquid {
            position: absolute;
            bottom: 0;
            left: 0;
            width: 100%;
            height: 0;
            border-radius: 0 0 32px 32px;
            transition: height 0.8s ease;
        }
        
        .elements-in-beaker {
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            display: flex;
            justify-content: center;
            align-items: flex-end;
            padding-bottom: 15px;
            gap: 12px;
            flex-wrap: wrap;
        }
        
        .element-in-beaker {
            width: 50px;
            height: 50px;
            background: linear-gradient(135deg, #e74c3c, #c0392b);
            border-radius: 10px;
            display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: center;
            cursor: pointer;
            box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
            transition: all 0.3s ease;
            border: 2px solid rgba(255, 255, 255, 0.2);
        }
        
        .element-in-beaker:hover {
            transform: scale(1.15) rotate(5deg);
            box-shadow: 0 6px 16px rgba(0, 0, 0, 0.4);
        }
        
        .equation-area {
            background: rgba(155, 89, 182, 0.2);
            border-radius: 15px;
            padding: 25px;
            margin-bottom: 20px;
            border-left: 4px solid #9b59b6;
        }
        
        .equation-display {
            font-size: 1.8rem;
            font-family: 'Courier New', monospace;
            color: #ecf0f1;
            margin-bottom: 20px;
            text-align: center;
            line-height: 1.6;
        }
        
        .coefficient-input {
            display: inline-block;
            width: 40px;
            height: 30px;
            background: rgba(0, 0, 0, 0.3);
            border: 2px solid #3498db;
            border-radius: 5px;
            text-align: center;
            color: #fff;
            font-size: 1.2rem;
            margin: 0 5px;
        }
        
        .coefficient-input:focus {
            outline: none;
            border-color: #2ecc71;
            box-shadow: 0 0 10px rgba(46, 204, 113, 0.3);
        }
        
        .periodic-challenge-area {
            display: grid;
            grid-template-columns: repeat(auto-fill, minmax(60px, 1fr));
            gap: 8px;
            margin: 20px 0;
        }
        
        .period-slot {
            width: 60px;
            height: 60px;
            border: 2px dashed rgba(255, 255, 255, 0.3);
            border-radius: 8px;
            display: flex;
            align-items: center;
            justify-content: center;
            position: relative;
            transition: all 0.3s ease;
            cursor: pointer;
        }
        
        .period-slot.filled {
            border-style: solid;
            border-color: #2ecc71;
        }
        
        .period-slot:hover {
            border-color: #3498db;
            background: rgba(52, 152, 219, 0.1);
        }
        
        .mini-element {
            width: 50px;
            height: 50px;
            border-radius: 6px;
            display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: center;
            font-size: 0.8rem;
            cursor: pointer;
            transition: all 0.3s ease;
        }
        
        .mini-element:hover {
            transform: scale(1.1);
        }
        
        .chemical-match-area {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 30px;
            margin: 20px 0;
        }
        
        .match-column {
            background: rgba(0, 0, 0, 0.2);
            border-radius: 15px;
            padding: 20px;
        }
        
        .match-item {
            background: rgba(52, 152, 219, 0.3);
            border: 2px solid transparent;
            border-radius: 10px;
            padding: 15px;
            margin: 10px 0;
            cursor: pointer;
            transition: all 0.3s ease;
            text-align: center;
        }
        
        .match-item:hover {
            border-color: #3498db;
            transform: translateY(-2px);
        }
        
        .match-item.selected {
            border-color: #f1c40f;
            background: rgba(241, 196, 15, 0.3);
        }
        
        .match-item.correct {
            border-color: #2ecc71;
            background: rgba(46, 204, 113, 0.3);
        }
        
        .match-item.incorrect {
            border-color: #e74c3c;
            background: rgba(231, 76, 60, 0.3);
        }
        
        .controls {
            display: flex;
            justify-content: center;
            gap: 20px;
            margin-top: auto;
            flex-wrap: wrap;
        }
        
        button {
            background: linear-gradient(to right, #2ecc71, #3498db);
            color: white;
            border: none;
            padding: 14px 32px;
            font-size: 1.2rem;
            border-radius: 40px;
            cursor: pointer;
            transition: all 0.3s ease;
            box-shadow: 0 5px 15px rgba(0, 0, 0, 0.3);
            display: flex;
            align-items: center;
            gap: 10px;
            font-family: 'Orbitron', sans-serif;
            letter-spacing: 1px;
            position: relative;
            overflow: hidden;
        }
        
        button::before {
            content: "";
            position: absolute;
            top: 0;
            left: -100%;
            width: 100%;
            height: 100%;
            background: linear-gradient(90deg, transparent, rgba(255,255,255,0.3), transparent);
            transition: 0.5s;
        }
        
        button:hover {
            transform: translateY(-3px) scale(1.05);
            box-shadow: 0 8px 20px rgba(0, 0, 0, 0.4);
        }
        
        button:hover::before {
            left: 100%;
        }
        
        button:disabled {
            background: linear-gradient(to right, #7f8c8d, #95a5a6);
            cursor: not-allowed;
            transform: none;
            box-shadow: none;
        }
        
        .reaction-result {
            background: rgba(25, 35, 65, 0.7);
            border-radius: 20px;
            padding: 30px;
            box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3), 0 0 20px rgba(155, 89, 182, 0.2);
            backdrop-filter: blur(10px);
            border: 1px solid rgba(255, 255, 255, 0.15);
            margin-top: 30px;
            min-height: 200px;
        }
        
        .result-content {
            display: none;
            animation: fadeIn 0.8s ease;
        }
        
        @keyframes fadeIn {
            from { opacity: 0; transform: translateY(20px); }
            to { opacity: 1; transform: translateY(0); }
        }
        
        .compound-name {
            font-size: 2.2rem;
            color: #2ecc71;
            margin-bottom: 15px;
            font-family: 'Orbitron', sans-serif;
        }
        
        .compound-formula {
            font-size: 1.8rem;
            font-family: 'Courier New', monospace;
            background: rgba(0, 0, 0, 0.3);
            padding: 10px 20px;
            border-radius: 10px;
            display: inline-block;
            margin-bottom: 20px;
            border: 2px solid #3498db;
            box-shadow: 0 0 15px rgba(52, 152, 219, 0.3);
        }
        
        .compound-info {
            line-height: 1.7;
            margin-bottom: 20px;
            font-size: 1.05rem;
        }
        
        .element-detail-modal {
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background: rgba(0, 0, 0, 0.8);
            display: none;
            justify-content: center;
            align-items: center;
            z-index: 1000;
        }
        
        .modal-content {
            background: rgba(25, 35, 65, 0.95);
            border-radius: 20px;
            padding: 40px;
            max-width: 600px;
            width: 90%;
            max-height: 80vh;
            overflow-y: auto;
            border: 2px solid rgba(255, 255, 255, 0.2);
            backdrop-filter: blur(15px);
            position: relative;
        }
        
        .modal-close {
            position: absolute;
            top: 15px;
            right: 20px;
            background: none;
            border: none;
            color: #ecf0f1;
            font-size: 1.5rem;
            cursor: pointer;
            padding: 5px;
        }
        
        .achievement {
            background: linear-gradient(135deg, #f1c40f, #f39c12);
            color: #2c3e50;
            padding: 15px 25px;
            border-radius: 15px;
            margin: 15px 0;
            display: flex;
            align-items: center;
            gap: 15px;
            font-weight: bold;
            animation: achievementPop 0.6s ease;
        }
        
        @keyframes achievementPop {
            0% { transform: scale(0) rotate(180deg); opacity: 0; }
            50% { transform: scale(1.1) rotate(5deg); }
            100% { transform: scale(1) rotate(0deg); opacity: 1; }
        }
        
        .score-board {
            display: flex;
            justify-content: space-between;
            background: rgba(25, 35, 65, 0.7);
            border-radius: 15px;
            padding: 20px 30px;
            margin-top: 30px;
            box-shadow: 0 8px 25px rgba(0, 0, 0, 0.3);
            backdrop-filter: blur(5px);
            border: 1px solid rgba(255, 255, 255, 0.15);
            flex-wrap: wrap;
            gap: 20px;
        }
        
        .score-item {
            text-align: center;
            flex: 1;
            min-width: 120px;
        }
        
        .score-value {
            font-size: 2.5rem;
            font-weight: bold;
            color: #f1c40f;
            line-height: 1;
            font-family: 'Orbitron', sans-serif;
            text-shadow: 0 0 10px rgba(241, 196, 15, 0.5);
        }
        
        .score-label {
            font-size: 1rem;
            color: #bdc3c7;
            margin-top: 5px;
        }
        
        .timer {
            background: rgba(231, 76, 60, 0.2);
            border: 2px solid #e74c3c;
            border-radius: 10px;
            padding: 10px 20px;
            font-size: 1.3rem;
            font-family: 'Orbitron', sans-serif;
            color: #e74c3c;
            text-align: center;
        }
        
        .progress-bar {
            width: 100%;
            height: 8px;
            background: rgba(0, 0, 0, 0.3);
            border-radius: 4px;
            overflow: hidden;
            margin: 20px 0;
        }
        
        .progress-fill {
            height: 100%;
            background: linear-gradient(to right, #2ecc71, #3498db);
            border-radius: 4px;
            transition: width 0.3s ease;
            width: 0%;
        }
        
        .game-level {
            background: rgba(155, 89, 182, 0.3);
            border-radius: 10px;
            padding: 10px 20px;
            text-align: center;
            margin: 10px 0;
            font-family: 'Orbitron', sans-serif;
        }
        
        @media (max-width: 768px) {
            .game-area {
                flex-direction: column;
            }
            
            h1 {
                font-size: 2.5rem;
            }
            
            .mode-buttons {
                flex-direction: column;
                align-items: center;
            }
            
            .game-controls {
                flex-direction: column;
                align-items: center;
            }
            
            .chemical-match-area {
                grid-template-columns: 1fr;
            }
        }