body {
    font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
    margin: 0;
    padding: 20px;
    background: linear-gradient(135deg, #f5f7fa 0%, #e4e9f2 100%);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
}

.container {
    width: 100%;
    max-width: 800px;
    margin: 0 auto;
    background-color: white;
    padding: 30px;
    border-radius: 16px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.08);
}

h1 {
    text-align: center;
    color: #2c3e50;
    margin-bottom: 30px;
    font-weight: 600;
    font-size: 2.2em;
}

.controls {
    text-align: center;
    margin-bottom: 30px;
    display: flex;
    gap: 15px;
    justify-content: center;
    flex-wrap: wrap;
}

.control-button {
    background-color: #4CAF50;
    color: white;
    border: none;
    padding: 12px 24px;
    border-radius: 8px;
    cursor: pointer;
    font-size: 16px;
    font-weight: 500;
    transition: all 0.3s ease;
    box-shadow: 0 2px 5px rgba(76,175,80,0.2);
}

.control-button:hover {
    background-color: #45a049;
    transform: translateY(-1px);
    box-shadow: 0 4px 8px rgba(76,175,80,0.3);
}

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

.control-button:disabled {
    background-color: #e0e0e0;
    cursor: not-allowed;
    box-shadow: none;
}

.status {
    margin-top: 15px;
    color: #666;
    font-size: 0.9em;
}

.harmonica-chart {
    margin: 30px auto;
    max-width: 100%;
    overflow-x: auto;
    background: #ffffff;
    border-radius: 12px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.05);
}

table {
    width: 100%;
    border-collapse: separate;
    border-spacing: 0;
    margin: 20px 0;
}

th, td {
    text-align: center;
    padding: 15px;
    border: none;
}

th {
    background-color: #f8f9fa;
    color: #2c3e50;
    font-weight: 600;
    font-size: 0.95em;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

tr:first-child th:first-child {
    border-top-left-radius: 12px;
}

tr:first-child th:last-child {
    border-top-right-radius: 12px;
}

.note-box {
    width: 70px;
    height: 45px;
    margin: 0 auto;
    background-color: #ffffff;
    border: 2px solid #e9ecef;
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 15px;
    font-weight: 500;
    transition: all 0.3s ease;
    color: #495057;
}

.note-box.active {
    border-color: #4CAF50;
    box-shadow: 0 0 15px rgba(76,175,80,0.2);
}

.playback-controls {
    text-align: center;
    margin-top: 30px;
    padding: 20px;
    background-color: #f8f9fa;
    border-radius: 12px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.04);
}

.progress-container {
    margin: 15px 0;
    padding: 5px 0;
    width: 100%;
    position: relative;
}

.seek-slider {
    -webkit-appearance: none;
    -moz-appearance: none;
    appearance: none;
    width: 100%;
    height: 6px;
    border-radius: 6px;
    background: linear-gradient(to right, #4CAF50 0%, #4CAF50 var(--seek-percent, 0%), #e9ecef var(--seek-percent, 0%));
    outline: none;
    margin: 0;
    padding: 0;
}

/* Slider thumb styles */
.seek-slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 18px;
    height: 18px;
    border-radius: 50%;
    background: #4CAF50;
    cursor: pointer;
    transition: all 0.2s ease;
    border: 2px solid #ffffff;
    box-shadow: 0 2px 4px rgba(0,0,0,0.15);
    margin-top: -6px;
}

.seek-slider::-moz-range-thumb {
    width: 18px;
    height: 18px;
    border: 2px solid #ffffff;
    border-radius: 50%;
    background: #4CAF50;
    cursor: pointer;
    transition: all 0.2s ease;
    box-shadow: 0 2px 4px rgba(0,0,0,0.15);
}

/* Hover state */
.seek-slider::-webkit-slider-thumb:hover {
    background: #45a049;
    transform: scale(1.1);
    box-shadow: 0 3px 6px rgba(0,0,0,0.2);
}

.seek-slider::-moz-range-thumb:hover {
    background: #45a049;
    transform: scale(1.1);
    box-shadow: 0 3px 6px rgba(0,0,0,0.2);
}

/* Track styles */
.seek-slider::-webkit-slider-runnable-track {
    width: 100%;
    height: 6px;
    background: transparent;
    border-radius: 6px;
    cursor: pointer;
    border: none;
}

.seek-slider::-moz-range-track {
    width: 100%;
    height: 6px;
    background: transparent;
    border-radius: 6px;
    cursor: pointer;
    border: none;
}

/* Focus styles */
.seek-slider:focus {
    outline: none;
}

.seek-slider:focus::-webkit-slider-thumb {
    box-shadow: 0 0 0 4px rgba(76,175,80,0.2);
}

.seek-slider:focus::-moz-range-thumb {
    box-shadow: 0 0 0 4px rgba(76,175,80,0.2);
}

.time-display {
    font-size: 14px;
    color: #495057;
    margin-left: 12px;
    font-weight: 500;
}