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

body {
    font-family: 'Inter', 'Segoe UI', system-ui, -apple-system, sans-serif;
    min-height: 100vh;
    background: linear-gradient(135deg, #1a1a2e 0%, #16213e 50%, #0f3460 100%);
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 20px;
}

.container {
    width: 100%;
    max-width: 450px;
}

.card {
    background: rgba(255, 255, 255, 0.05);
    backdrop-filter: blur(20px);
    border-radius: 24px;
    padding: 40px;
    border: 1px solid rgba(255, 255, 255, 0.1);
    box-shadow: 0 25px 50px rgba(0, 0, 0, 0.3);
}

h1 {
    color: #fff;
    font-size: 28px;
    font-weight: 700;
    text-align: center;
    margin-bottom: 8px;
    background: linear-gradient(135deg, #00d9ff, #00ff88);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.subtitle {
    color: rgba(255, 255, 255, 0.5);
    text-align: center;
    margin-bottom: 30px;
    font-size: 14px;
}

.metronome-display {
    display: flex;
    flex-direction: column;
    align-items: center;
    margin-bottom: 30px;
}

.bpm-display {
    text-align: center;
    margin-bottom: 20px;
}

#bpm-value {
    font-size: 80px;
    font-weight: 700;
    color: #fff;
    font-family: 'Consolas', monospace;
    line-height: 1;
    background: linear-gradient(135deg, #00d9ff, #00ff88);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.bpm-label {
    display: block;
    color: rgba(255, 255, 255, 0.5);
    font-size: 14px;
    text-transform: uppercase;
    letter-spacing: 2px;
    margin-top: 5px;
}

.beat-indicator {
    display: flex;
    gap: 15px;
}

.beat-dot {
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.1);
    transition: all 0.1s ease;
}

.beat-dot.active {
    background: linear-gradient(135deg, #00d9ff, #00ff88);
    box-shadow: 0 0 20px rgba(0, 217, 255, 0.6);
    transform: scale(1.3);
}

.beat-dot.accent {
    background: #ff4757;
    box-shadow: 0 0 20px rgba(255, 71, 87, 0.6);
}

.tempo-slider {
    margin-bottom: 25px;
}

.tempo-slider input[type="range"] {
    width: 100%;
    height: 8px;
    -webkit-appearance: none;
    appearance: none;
    border-radius: 4px;
    background: rgba(255, 255, 255, 0.1);
    outline: none;
    cursor: pointer;
}

.tempo-slider input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 24px;
    height: 24px;
    border-radius: 50%;
    background: linear-gradient(135deg, #00d9ff, #00ff88);
    cursor: pointer;
    box-shadow: 0 2px 15px rgba(0, 217, 255, 0.5);
    transition: transform 0.2s ease;
}

.tempo-slider input[type="range"]::-webkit-slider-thumb:hover {
    transform: scale(1.2);
}

.tempo-marks {
    display: flex;
    justify-content: space-between;
    margin-top: 8px;
    padding: 0 5px;
}

.tempo-marks span {
    color: rgba(255, 255, 255, 0.3);
    font-size: 10px;
    text-transform: uppercase;
}

.controls {
    display: flex;
    justify-content: center;
    gap: 20px;
    margin-bottom: 30px;
}

.tap-btn {
    width: 90px;
    height: 90px;
    border-radius: 50%;
    border: 3px solid rgba(255, 255, 255, 0.2);
    background: transparent;
    color: #fff;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
}

.tap-btn:hover {
    border-color: #00d9ff;
    background: rgba(0, 217, 255, 0.1);
}

.tap-btn:active {
    transform: scale(0.95);
    background: rgba(0, 217, 255, 0.2);
}

.play-btn {
    width: 90px;
    height: 90px;
    border-radius: 50%;
    border: none;
    background: linear-gradient(135deg, #00d9ff, #00ff88);
    color: #1a1a2e;
    font-size: 24px;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 10px 30px rgba(0, 217, 255, 0.3);
}

.play-btn:hover {
    transform: scale(1.05);
    box-shadow: 0 15px 40px rgba(0, 217, 255, 0.4);
}

.play-btn.playing {
    background: linear-gradient(135deg, #ff4757, #ff6b81);
    box-shadow: 0 10px 30px rgba(255, 71, 87, 0.3);
}

.settings {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.setting-group label {
    display: block;
    color: rgba(255, 255, 255, 0.6);
    font-size: 12px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-bottom: 10px;
}

.beat-buttons,
.sound-buttons {
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
}

.beat-btn,
.sound-btn {
    padding: 10px 18px;
    border: 2px solid rgba(255, 255, 255, 0.15);
    border-radius: 20px;
    background: transparent;
    color: rgba(255, 255, 255, 0.7);
    font-size: 13px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.beat-btn:hover,
.sound-btn:hover {
    background: rgba(0, 217, 255, 0.15);
    border-color: #00d9ff;
    color: #00d9ff;
}

.beat-btn.active,
.sound-btn.active {
    background: linear-gradient(135deg, #00d9ff, #00ff88);
    border-color: transparent;
    color: #1a1a2e;
    font-weight: 600;
}

.volume-control {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.volume-control label {
    color: rgba(255, 255, 255, 0.6);
    font-size: 12px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.volume-control input[type="range"] {
    width: 100%;
    height: 6px;
    -webkit-appearance: none;
    appearance: none;
    border-radius: 3px;
    background: rgba(255, 255, 255, 0.1);
    outline: none;
    cursor: pointer;
}

.volume-control input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 18px;
    height: 18px;
    border-radius: 50%;
    background: #fff;
    cursor: pointer;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.3);
}

.footer {
    text-align: center;
    margin-top: 30px;
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.footer a {
    color: rgba(255, 255, 255, 0.5);
    text-decoration: none;
    font-size: 14px;
    transition: color 0.3s ease;
}

.footer a:hover {
    color: #00d9ff;
}

.copyright {
    color: rgba(255, 255, 255, 0.3);
    font-size: 12px;
}

@media (max-width: 480px) {
    .card {
        padding: 25px;
    }
    
    #bpm-value {
        font-size: 60px;
    }
    
    .play-btn,
    .tap-btn {
        width: 80px;
        height: 80px;
        font-size: 14px;
    }
    
    .play-btn {
        font-size: 22px;
    }
}