* {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
        }
        
        body {
            display: flex;
            flex-direction: column;
            min-height: 100vh;
            background: linear-gradient(135deg, #f5f8ff 0%, #e6f0ff 100%);
            color: #333;
            padding: 0 15px;
        }
        
        header {
            background: linear-gradient(135deg, #1e5799, #207cca);
            color: white;
            text-align: center;
            padding: 1.3rem 0;
            border-radius: 0 0 15px 15px;
            margin: 0 15px;
            box-shadow: 0 4px 15px rgba(0,0,0,0.15);
        }
        
        h1 {
            font-size: 2.1rem;
            margin-bottom: 0.3rem;
            font-weight: 600;
        }
        
        .subtitle {
            font-size: 1.05rem;
            opacity: 0.92;
            max-width: 500px;
            margin: 0 auto;
        }
        
        .app-container {
            display: flex;
            flex-direction: column;
            max-width: 1000px;
            margin: 1.5rem auto;
            width: 100%;
            gap: 1.3rem;
        }
        
        .teaching-info {
            background: white;
            padding: 1.3rem;
            border-radius: 12px;
            box-shadow: 0 3px 12px rgba(0,0,0,0.08);
            margin-bottom: 8px;
        }
        
        .teaching-info h2 {
            color: #1e5799;
            margin-bottom: 12px;
            display: flex;
            align-items: center;
            gap: 10px;
            font-size: 1.4rem;
        }
        
        .teaching-info p {
            line-height: 1.65;
            color: #444;
            margin-bottom: 8px;
            font-size: 1.05rem;
        }
        
        .teaching-info .highlight {
            background: #e8f0fd;
            padding: 10px 15px;
            border-radius: 8px;
            border-left: 4px solid #207cca;
        }
        
        .content-wrapper {
            display: flex;
            gap: 1.5rem;
        }
        
        .control-panel {
            flex: 1;
            background: white;
            padding: 1.3rem;
            border-radius: 12px;
            box-shadow: 0 3px 12px rgba(0,0,0,0.08);
            display: flex;
            flex-direction: column;
            gap: 1.8rem;
            min-width: 260px;
        }
        
        .control-header {
            margin-bottom: 1rem;
            color: #1e5799;
            font-size: 1.35rem;
            display: flex;
            align-items: center;
            gap: 10px;
        }
        
        .control-group {
            margin-bottom: 0;
        }
        
        .control-label {
            display: block;
            margin-bottom: 12px;
            font-weight: 600;
            color: #555;
            font-size: 1.1rem;
            display: flex;
            align-items: center;
            gap: 8px;
        }
        
        .slider-container {
            display: flex;
            align-items: center;
            gap: 15px;
            margin-top: 5px;
        }
        
        .slider {
            flex: 1;
            -webkit-appearance: none;
            height: 10px;
            border-radius: 5px;
            background: linear-gradient(to right, #1a4780, #207cca);
            outline: none;
        }
        
        .slider::-webkit-slider-thumb {
            -webkit-appearance: none;
            width: 28px;
            height: 28px;
            border-radius: 50%;
            background: #fff;
            cursor: pointer;
            border: 3px solid #207cca;
            box-shadow: 0 2px 6px rgba(0,0,0,0.2);
            transition: all 0.2s ease;
        }
        
        .slider::-webkit-slider-thumb:hover {
            transform: scale(1.15);
            background: #e6f0ff;
        }
        
        .value-display {
            width: 65px;
            padding: 10px 12px;
            font-size: 1.25rem;
            text-align: center;
            border: 2px solid #e4ebf5;
            border-radius: 8px;
            font-weight: 700;
            color: #1a4780;
            background: #f8faff;
            box-shadow: inset 0 2px 4px rgba(0,0,0,0.05);
        }
        
        .demo-area {
            flex: 1.8;
            display: flex;
            flex-direction: column;
            align-items: center;
            gap: 1rem;
        }
        
        .canvas-container {
            width: 100%;
            height: 350px;
            display: flex;
            justify-content: center;
            align-items: center;
            background: white;
            border-radius: 12px;
            box-shadow: 0 3px 12px rgba(0,0,0,0.08);
            padding: 15px;
        }
        
        canvas {
            max-width: 340px;
            max-height: 340px;
        }
        
        .fraction-display {
            font-size: 4.5rem;
            font-weight: 800;
            color: #1a4780;
            display: flex;
            align-items: center;
            height: 95px;
            text-shadow: 2px 2px 4px rgba(0,0,0,0.1);
            transition: all 0.3s ease;
        }
        
        .fraction-display span {
            font-size: 3.2rem;
            margin: 0 10px;
            color: #207cca;
        }
        
        .value-indicators {
            display: flex;
            justify-content: space-around;
            width: 100%;
            margin-top: 5px;
            gap: 10px;
        }
        
        .indicator-card {
            flex: 1;
            text-align: center;
            background: #207cca;
            color: white;
            padding: 15px 0;
            border-radius: 10px;
            box-shadow: 0 4px 8px rgba(0,0,0,0.15);
        }
        
        .indicator-card .title {
            font-size: 1.1rem;
            font-weight: 600;
            margin-bottom: 8px;
        }
        
        .indicator-card .value {
            font-size: 2.5rem;
            font-weight: 700;
        }
        
        footer {
            background: linear-gradient(135deg, #1e5799, #1a4780);
            color: white;
            text-align: center;
            padding: 1.3rem 0;
            font-size: 1rem;
            border-radius: 15px 15px 0 0;
            margin: 0 15px;
            margin-top: auto;
        }
        
        .copyright {
            opacity: 0.9;
            margin-top: 0.5rem;
            font-size: 0.95rem;
        }
        
        @media (max-width: 768px) {
            .content-wrapper {
                flex-direction: column;
            }
            
            .app-container {
                margin: 1rem auto;
            }
            
            h1 {
                font-size: 1.8rem;
            }
            
            .subtitle {
                font-size: 0.95rem;
                padding: 0 10px;
            }
            
            .fraction-display {
                font-size: 3.5rem;
            }
            
            .canvas-container {
                height: 300px;
            }
            
            .value-display {
                width: 60px;
                font-size: 1.15rem;
                padding: 8px 10px;
            }
            
            .value-indicators {
                flex-direction: column;
            }
            
            .control-panel {
                gap: 1.2rem;
            }
            
            .fraction-display span {
                font-size: 2.5rem;
            }
        }
        
        /* 动画效果 */
        @keyframes fractionPulse {
            0% { transform: scale(1); }
            50% { transform: scale(1.05); }
            100% { transform: scale(1); }
        }
        
        .fraction-update {
            animation: fractionPulse 0.4s ease;
        }