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

        body {
            font-family: 'Microsoft YaHei', '微软雅黑', Arial, sans-serif;
            background: linear-gradient(135deg, #1e3c72 0%, #2a5298 100%);
            min-height: 100vh;
            padding: 20px;
        }

        .container {
            max-width: 1400px;
            margin: 0 auto;
            background: white;
            border-radius: 20px;
            box-shadow: 0 20px 60px rgba(0,0,0,0.3);
            overflow: hidden;
        }

        .header {
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            color: white;
            padding: 40px;
            text-align: center;
        }

        .header h1 {
            font-size: 2.5em;
            margin-bottom: 10px;
        }

        .header p {
            font-size: 1.2em;
            opacity: 0.9;
        }

        .content {
            padding: 40px;
        }

        .intro-box {
            background: #f8f9fa;
            border-left: 5px solid #667eea;
            padding: 25px;
            margin-bottom: 40px;
            border-radius: 5px;
        }

        .intro-box h3 {
            color: #667eea;
            margin-bottom: 15px;
            font-size: 1.5em;
        }

        .intro-box p {
            line-height: 1.8;
            color: #555;
            margin-bottom: 10px;
        }

        .monochord-visual {
            background: #2c3e50;
            border-radius: 15px;
            padding: 40px;
            margin-bottom: 40px;
            position: relative;
        }

        .string-container {
            position: relative;
            height: 150px;
            margin: 20px 0;
        }

        .string-base {
            position: absolute;
            top: 50%;
            left: 50px;
            right: 50px;
            height: 4px;
            background: linear-gradient(90deg, #888 0%, #ddd 50%, #888 100%);
            border-radius: 2px;
            box-shadow: 0 2px 5px rgba(0,0,0,0.3);
        }

        .string-marker {
            position: absolute;
            top: 50%;
            width: 10px;
            height: 40px;
            background: #e74c3c;
            transform: translateY(-50%);
            border-radius: 5px;
            transition: left 0.5s ease;
            box-shadow: 0 2px 10px rgba(231, 76, 60, 0.5);
        }

        .vibrating-section {
            position: absolute;
            top: 50%;
            height: 4px;
            background: #3498db;
            transform: translateY(-50%);
            transition: all 0.5s ease;
            box-shadow: 0 0 20px rgba(52, 152, 219, 0.8);
        }

        .string-labels {
            position: absolute;
            width: 100%;
            top: 100px;
            display: flex;
            justify-content: space-between;
            padding: 0 45px;
            color: white;
            font-size: 0.9em;
        }

        .experiments-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
            gap: 25px;
            margin-bottom: 40px;
        }

        .experiment-card {
            background: white;
            border: 2px solid #e0e0e0;
            border-radius: 15px;
            padding: 25px;
            transition: all 0.3s;
            cursor: pointer;
        }

        .experiment-card:hover {
            transform: translateY(-5px);
            box-shadow: 0 10px 30px rgba(0,0,0,0.15);
            border-color: #667eea;
        }

        .experiment-card.active {
            border-color: #667eea;
            background: linear-gradient(135deg, #f5f7fa 0%, #e8ebf5 100%);
            box-shadow: 0 5px 20px rgba(102, 126, 234, 0.3);
        }

        .experiment-header {
            display: flex;
            align-items: center;
            justify-content: space-between;
            margin-bottom: 15px;
        }

        .experiment-number {
            background: #667eea;
            color: white;
            width: 40px;
            height: 40px;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            font-weight: bold;
            font-size: 1.2em;
        }

        .experiment-card.active .experiment-number {
            background: #764ba2;
            animation: pulse 1s infinite;
        }

        @keyframes pulse {
            0%, 100% { transform: scale(1); }
            50% { transform: scale(1.1); }
        }

        .experiment-title {
            flex: 1;
            margin-left: 15px;
        }

        .experiment-title h4 {
            color: #333;
            font-size: 1.3em;
            margin-bottom: 5px;
        }

        .experiment-title .subtitle {
            color: #666;
            font-size: 0.9em;
        }

        .ratio-display {
            background: #f8f9fa;
            padding: 15px;
            border-radius: 10px;
            margin-bottom: 15px;
        }

        .ratio-row {
            display: flex;
            justify-content: space-between;
            margin-bottom: 8px;
            font-size: 0.95em;
        }

        .ratio-row:last-child {
            margin-bottom: 0;
        }

        .ratio-label {
            color: #666;
            font-weight: 500;
        }

        .ratio-value {
            color: #333;
            font-weight: bold;
            font-family: 'Courier New', monospace;
        }

        .description {
            color: #555;
            line-height: 1.6;
            margin-bottom: 15px;
            padding: 12px;
            background: #fafbfc;
            border-radius: 8px;
            border-left: 3px solid #667eea;
        }

        .play-button {
            width: 100%;
            padding: 15px;
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            color: white;
            border: none;
            border-radius: 10px;
            font-size: 1.1em;
            font-weight: bold;
            cursor: pointer;
            transition: all 0.3s;
            box-shadow: 0 4px 10px rgba(102, 126, 234, 0.4);
        }

        .play-button:hover {
            transform: scale(1.05);
            box-shadow: 0 6px 15px rgba(102, 126, 234, 0.6);
        }

        .play-button.playing {
            background: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
        }

        .harmony-info {
            background: linear-gradient(135deg, #ffeaa7 0%, #fdcb6e 100%);
            padding: 30px;
            border-radius: 15px;
            margin-top: 40px;
        }

        .harmony-info h3 {
            color: #2d3436;
            margin-bottom: 15px;
            font-size: 1.5em;
        }

        .harmony-info p {
            color: #2d3436;
            line-height: 1.8;
            margin-bottom: 10px;
        }

        .key-insight {
            background: white;
            padding: 20px;
            border-radius: 10px;
            margin-top: 20px;
            border-left: 5px solid #e17055;
        }

        .key-insight strong {
            color: #e17055;
            font-size: 1.1em;
        }

        .frequency-chart {
            background: white;
            padding: 25px;
            border-radius: 15px;
            margin-top: 30px;
            border: 2px solid #e0e0e0;
        }

        .frequency-chart h3 {
            color: #333;
            margin-bottom: 20px;
            text-align: center;
        }

        .freq-bar-container {
            margin-bottom: 20px;
        }

        .freq-bar-label {
            display: flex;
            justify-content: space-between;
            margin-bottom: 5px;
            font-size: 0.9em;
        }

        .freq-bar {
            height: 30px;
            background: linear-gradient(90deg, #667eea 0%, #764ba2 100%);
            border-radius: 5px;
            transition: width 0.5s ease;
            display: flex;
            align-items: center;
            padding-left: 10px;
            color: white;
            font-weight: bold;
        }
    
.native-audio-fallback{display:block;width:100%;max-width:420px;margin:12px auto;}