:root {
    --primary-color: #667eea;
    --secondary-color: #764ba2;
    --background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --card-bg: #ffffff;
    --text-primary: #2d3748;
    --text-secondary: #718096;
    --border-color: #e2e8f0;
    --error-color: #f56565;
    --shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background: var(--background);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 20px;
}

.container {
    width: 100%;
    max-width: 500px;
}

.player-card {
    background: var(--card-bg);
    border-radius: 20px;
    padding: 40px 30px;
    box-shadow: var(--shadow);
}

h1 {
    color: var(--text-primary);
    text-align: center;
    margin-bottom: 30px;
    font-size: 28px;
    font-weight: 700;
}

.audio-info {
    margin-bottom: 20px;
    text-align: center;
}

.track-title {
    color: var(--text-primary);
    font-size: 18px;
    font-weight: 600;
    margin-bottom: 8px;
}

.track-time {
    color: var(--text-secondary);
    font-size: 14px;
}

.progress-container {
    margin: 20px 0;
}

.progress-bar {
    width: 100%;
    height: 8px;
    -webkit-appearance: none;
    appearance: none;
    background: var(--border-color);
    border-radius: 4px;
    outline: none;
    cursor: pointer;
}

.progress-bar::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 18px;
    height: 18px;
    background: var(--primary-color);
    border-radius: 50%;
    cursor: pointer;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
}

.progress-bar::-moz-range-thumb {
    width: 18px;
    height: 18px;
    background: var(--primary-color);
    border-radius: 50%;
    cursor: pointer;
    border: none;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
}

.controls {
    display: flex;
    justify-content: center;
    gap: 15px;
    margin: 30px 0;
}

.control-btn {
    width: 60px;
    height: 60px;
    border-radius: 50%;
    border: none;
    background: var(--primary-color);
    color: white;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s ease;
    box-shadow: 0 4px 12px rgba(102, 126, 234, 0.4);
}

.control-btn:hover {
    transform: scale(1.05);
    box-shadow: 0 6px 16px rgba(102, 126, 234, 0.6);
}

.control-btn:active {
    transform: scale(0.95);
}

.icon {
    width: 28px;
    height: 28px;
}

.icon-small {
    width: 20px;
    height: 20px;
}

.hidden {
    display: none !important;
}

.volume-control {
    display: flex;
    align-items: center;
    gap: 12px;
    margin: 25px 0;
    padding: 15px;
    background: #f7fafc;
    border-radius: 10px;
}

.volume-control label {
    display: flex;
    align-items: center;
    color: var(--text-primary);
}

.volume-slider {
    flex: 1;
    height: 6px;
    -webkit-appearance: none;
    appearance: none;
    background: var(--border-color);
    border-radius: 3px;
    outline: none;
    cursor: pointer;
}

.volume-slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 16px;
    height: 16px;
    background: var(--primary-color);
    border-radius: 50%;
    cursor: pointer;
}

.volume-slider::-moz-range-thumb {
    width: 16px;
    height: 16px;
    background: var(--primary-color);
    border-radius: 50%;
    cursor: pointer;
    border: none;
}

.volume-value {
    color: var(--text-secondary);
    font-size: 14px;
    min-width: 40px;
    text-align: right;
}

.error-message {
    margin-top: 15px;
    padding: 12px;
    background: #fff5f5;
    border: 1px solid #feb2b2;
    border-radius: 8px;
    color: var(--error-color);
    font-size: 14px;
    text-align: center;
}

@media (max-width: 600px) {
    .player-card {
        padding: 30px 20px;
    }
    
    h1 {
        font-size: 24px;
    }
    
    .control-btn {
        width: 50px;
        height: 50px;
    }
    
    .icon {
        width: 24px;
        height: 24px;
    }
}