* {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }

        body {
            font-family: 'Segoe UI', 'Poppins', system-ui, -apple-system, sans-serif;
            min-height: 100vh;
            background: linear-gradient(135deg, #0a1a1f 0%, #1a2a3a 50%, #0a1a1f 100%);
            color: white;
            overflow-x: hidden;
            display: flex;
            flex-direction: column;
            align-items: center;
            padding: 1rem;
        }

        /* 视频背景 */
        .video-container {
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            z-index: -2;
            overflow: hidden;
        }
        .video-container video {
            position: absolute;
            top: 50%;
            left: 50%;
            min-width: 100%;
            min-height: 100%;
            width: auto;
            height: auto;
            transform: translate(-50%, -50%);
            object-fit: cover;
            opacity: 0.3;
        }
        .overlay {
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background: linear-gradient(135deg, rgba(10,26,31,0.95) 0%, rgba(26,42,58,0.9) 50%, rgba(10,26,31,0.95) 100%);
            z-index: -1;
        }

        /* 头部 */
        .header {
            position: relative;
            z-index: 2;
            width: 100%;
            max-width: 420px;
            display: flex;
            justify-content: space-between;
            align-items: center;
            margin-bottom: 1rem;
        }

        .back-btn {
            padding: 0.6rem 1.2rem;
            background: rgba(255,255,255,0.1);
            border-radius: 20px;
            font-size: 0.9rem;
            color: white;
            text-decoration: none;
            transition: all 0.3s ease;
            border: 1px solid rgba(255,255,255,0.2);
            backdrop-filter: blur(10px);
        }

        .back-btn:hover {
            background: rgba(255,255,255,0.2);
        }

        .title-container {
            text-align: center;
        }

        .title {
            font-size: clamp(1.5rem, 8vw, 2.2rem);
            font-weight: 800;
            background: linear-gradient(135deg, #fff, #ffd89b);
            background-clip: text;
            -webkit-background-clip: text;
            color: transparent;
        }

        .subtitle {
            font-size: 0.8rem;
            color: rgba(255,255,255,0.5);
            letter-spacing: 1px;
        }



        /* 游戏区域 */
        .game-container {
            position: relative;
            z-index: 2;
            width: 100%;
            max-width: 420px;
            aspect-ratio: 1;
            background: rgba(255,255,255,0.05);
            backdrop-filter: blur(20px);
            border-radius: 16px;
            padding: 8px;
            border: 1px solid rgba(255,255,255,0.1);
            box-shadow: 0 8px 32px rgba(0,0,0,0.3);
        }

        .game-grid {
            width: 100%;
            height: 100%;
            display: grid;
            grid-template-columns: repeat(4, 1fr);
            grid-template-rows: repeat(4, 1fr);
            gap: 8px;
        }

        .cell {
            background: rgba(255,255,255,0.08);
            border-radius: 10px;
            display: flex;
            align-items: center;
            justify-content: center;
            position: relative;
            overflow: hidden;
            transition: all 0.15s ease;
        }

        .tile {
            position: absolute;
            width: calc(100% - 4px);
            height: calc(100% - 4px);
            border-radius: 8px;
            display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: center;
            transition: all 0.25s cubic-bezier(0.25, 0.46, 0.45, 0.94);
            opacity: 1;
            transform: scale(1);
        }

        .tile.new {
            animation: pop 0.25s cubic-bezier(0.25, 0.46, 0.45, 0.94);
        }

        .tile.merged {
            animation: merge 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94);
        }

        @keyframes appear {
            from { 
                opacity: 0; 
                transform: scale(0); 
            }
            to { 
                opacity: 1; 
                transform: scale(1); 
            }
        }

        @keyframes pop {
            0% { 
                opacity: 0;
                transform: scale(0); 
            }
            50% { 
                transform: scale(1.15); 
            }
            100% { 
                opacity: 1;
                transform: scale(1); 
            }
        }

        @keyframes merge {
            0% { 
                transform: scale(1); 
            }
            50% { 
                transform: scale(1.25); 
            }
            100% { 
                transform: scale(1); 
            }
        }

        /* 元素样式 */
        .tile-1 { background: linear-gradient(135deg, #e8f5e9, #c8e6c9); color: #2e7d32; }
        .tile-2 { background: linear-gradient(135deg, #e3f2fd, #bbdefb); color: #1565c0; }
        .tile-3 { background: linear-gradient(135deg, #fff3e0, #ffe0b2); color: #e65100; }
        .tile-4 { background: linear-gradient(135deg, #fce4ec, #f8bbd9); color: #c2185b; }
        .tile-5 { background: linear-gradient(135deg, #e8eaf6, #c5cae9); color: #3949ab; }
        .tile-6 { background: linear-gradient(135deg, #e0f2f1, #b2dfdb); color: #00897b; }
        .tile-7 { background: linear-gradient(135deg, #fff8e1, #ffecb3); color: #f57c00; }
        .tile-8 { background: linear-gradient(135deg, #f3e5f5, #e1bee7); color: #7b1fa2; }
        .tile-9 { background: linear-gradient(135deg, #e0f7fa, #b2ebf2); color: #00838f; }
        .tile-10 { background: linear-gradient(135deg, #fbe9e7, #ffccbc); color: #bf360c; }
        .tile-11 { background: linear-gradient(135deg, #f3e5f5, #d1c4e9); color: #5e35b1; }
        .tile-12 { background: linear-gradient(135deg, #ffecb3, #ffd54f); color: #f57c00; box-shadow: 0 0 20px rgba(255, 215, 0, 0.5); }

        .element-symbol {
            font-size: clamp(1.2rem, 6vw, 1.8rem);
            font-weight: 800;
        }

        .element-number {
            font-size: 0.6rem;
            opacity: 0.7;
        }

        /* 控制按钮 */
        .controls {
            position: relative;
            z-index: 2;
            width: 100%;
            max-width: 420px;
            margin-top: 1rem;
            display: flex;
            justify-content: center;
            gap: 1rem;
        }

        .control-btn {
            padding: 0.8rem 2rem;
            background: rgba(255,255,255,0.08);
            backdrop-filter: blur(10px);
            border-radius: 12px;
            border: 1px solid rgba(255,255,255,0.2);
            color: white;
            font-size: 0.9rem;
            font-weight: 600;
            cursor: pointer;
            transition: all 0.3s ease;
        }

        .control-btn:hover {
            background: rgba(255,255,255,0.15);
            transform: translateY(-2px);
        }

        .control-btn:active {
            transform: translateY(0);
        }

        /* 游戏说明 */
        .instructions {
            position: relative;
            z-index: 2;
            width: 100%;
            max-width: 420px;
            margin-top: 1.5rem;
            background: rgba(255,255,255,0.05);
            backdrop-filter: blur(10px);
            border-radius: 12px;
            padding: 1rem;
            border: 1px solid rgba(255,255,255,0.1);
        }

        .instructions h3 {
            font-size: 0.9rem;
            margin-bottom: 0.5rem;
            color: #64ffda;
        }

        .instructions p {
            font-size: 0.8rem;
            color: rgba(255,255,255,0.6);
            line-height: 1.5;
        }

        /* 元素图例 */
        .legend {
            position: relative;
            z-index: 2;
            width: 100%;
            max-width: 420px;
            margin-top: 1rem;
            background: rgba(255,255,255,0.05);
            backdrop-filter: blur(10px);
            border-radius: 12px;
            padding: 1rem;
            border: 1px solid rgba(255,255,255,0.1);
        }

        .legend h3 {
            font-size: 0.9rem;
            margin-bottom: 0.8rem;
            color: #64ffda;
        }

        .legend-grid {
            display: grid;
            grid-template-columns: repeat(6, 1fr);
            gap: 6px;
        }

        .legend-item {
            aspect-ratio: 1;
            border-radius: 6px;
            display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: center;
            font-size: 0.65rem;
        }

        /* 弹窗 */
        .modal-overlay {
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background: rgba(0,0,0,0.8);
            backdrop-filter: blur(10px);
            display: flex;
            align-items: center;
            justify-content: center;
            z-index: 100;
            opacity: 0;
            visibility: hidden;
            transition: all 0.3s ease;
        }

        .modal-overlay.show {
            opacity: 1;
            visibility: visible;
        }

        .modal-content {
            background: rgba(20, 35, 45, 0.95);
            border-radius: 20px;
            padding: 2rem;
            text-align: center;
            max-width: 320px;
            width: 90%;
            border: 1px solid rgba(255,255,255,0.2);
            transform: scale(0.9);
            transition: transform 0.3s ease;
        }

        .modal-overlay.show .modal-content {
            transform: scale(1);
        }

        .modal-title {
            font-size: 1.8rem;
            font-weight: 800;
            margin-bottom: 1rem;
            background: linear-gradient(135deg, #ffd89b, #ffecb3);
            background-clip: text;
            -webkit-background-clip: text;
            color: transparent;
        }

        .modal-text {
            font-size: 0.95rem;
            color: rgba(255,255,255,0.7);
            margin-bottom: 1.5rem;
            line-height: 1.5;
        }

        .modal-score {
            font-size: 1.2rem;
            color: #64ffda;
            margin-bottom: 1.5rem;
        }

        .modal-btn {
            padding: 0.8rem 2.5rem;
            background: linear-gradient(135deg, #0f4c5f, #1b6b85);
            border-radius: 30px;
            font-weight: 600;
            color: white;
            border: none;
            cursor: pointer;
            transition: all 0.3s ease;
        }

        .modal-btn:hover {
            background: linear-gradient(135deg, #1b6b85, #2c8cb0);
            transform: scale(1.05);
        }

        /* 移动端控制提示 */
        .swipe-hint {
            position: relative;
            z-index: 2;
            margin-top: 1rem;
            font-size: 0.75rem;
            color: rgba(255,255,255,0.4);
            text-align: center;
        }

        /* 响应式 */
        @media (max-width: 480px) {
            .game-container {
                padding: 6px;
            }
            
            .game-grid {
                gap: 6px;
            }
            
            .element-symbol {
                font-size: 1.2rem;
            }
        }