.container {
    max-width: 900px;
    width: 100%;
    margin: 0 auto;
    padding: 20px;
    background: var(--window-gradient);
    border-radius: 20px;
    border: 1px solid var(--outline-color);
    backdrop-filter: blur(10px);
    box-shadow: 0 20px 40px rgba(0,0,0,0.3);
    margin-top: 80px;
}

h1 {
    text-align: center;
    margin-bottom: 30px;
    font-size: 2.5em;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.3);
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

.elevens-bar {
    display: grid;
    grid-template-columns: repeat(21, 1fr);
    gap: 1px;
    margin-bottom: 20px;
    height: 60px;
}

.ninths-multiples-grid {
    display: grid;
    grid-template-columns: repeat(13, 1fr);
    gap: 1px;
    margin-bottom: 20px;
    height: 260px;
}

.piano-grid {
    display: grid;
    grid-template-columns: repeat(9, 1fr);
    gap: 4px;
    margin-bottom: 30px;
    aspect-ratio: 1;
}

.key {
    border: 2px solid var(--outline-color);
    border-radius: 12px;
    font-size: 0.9em;
    font-weight: bold;
    cursor: pointer;
    transition: all 0.1s ease;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    user-select: none;
    box-shadow: 0 3px 6px rgba(0,0,0,0.2);
    position: relative;
    min-height: 60px;
    background: var(--tertiary-color);
    color: var(--on-tertiary);
}

.key.elevens {
    background: var(--accent-gradient);
    border-color: var(--accent-color);
    color: var(--on-accent);
    font-size: 0.8em;
}

.key.ninths {
    color: var(--on-tertiary);
    font-size: 1.0em;
}

.key.inactive {
    background: var(--outline-color) !important;
    color: var(--on-tertiary) !important;
    opacity: 0.5;
    cursor: not-allowed;
    border-color: var(--outline-color);
}

.key:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 10px rgba(0,0,0,0.3);
    border-color: var(--primary-color);
}

.key.elevens:hover {
    border-color: var(--accent-color);
}

.key:active, .key.active {
    transform: translateY(0);
    box-shadow: 0 2px 4px rgba(0,0,0,0.3);
    border-color: var(--primary-color);
    border-width: 3px;
}

.key.center {
    border-color: var(--accent-color);
    border-width: 3px;
    box-shadow: 0 0 15px rgba(16, 185, 129, 0.5);
}

.ratio {
    font-size: 0.8em;
    opacity: 0.9;
    font-weight: normal;
}

.interval {
    font-size: 0.7em;
    opacity: 0.9;
}

.note-name {
    font-size: 0.8em;
    font-weight: bold;
}

.frequency {
    font-size: 0.6em;
    opacity: 0.7;
    margin-top: 2px;
}

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

.control-group {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 5px;
}

.control-group label {
    font-size: 0.9em;
    opacity: 0.9;
    color: var(--text-color);
}

input[type="range"] {
    width: 120px;
    background: var(--tertiary-color);
    accent-color: var(--accent-color);
}

select {
    background: var(--secondary-color);
    color: var(--on-secondary);
    border: 1px solid var(--outline-color);
    border-radius: 6px;
    padding: 8px 12px;
}

.instructions {
    background: var(--window-color);
    border: 1px solid var(--outline-color);
    border-radius: 15px;
    padding: 20px;
    margin-top: 20px;
    text-align: center;
    line-height: 1.6;
    backdrop-filter: blur(10px);
}

.instructions h3 {
    color: var(--primary-color);
    margin-bottom: 15px;
}

.note-info {
    background: var(--secondary-color);
    color: var(--on-secondary);
    border: 1px solid var(--outline-color);
    border-radius: 10px;
    padding: 15px;
    margin-bottom: 20px;
    text-align: center;
    font-size: 1.1em;
}

.legend {
    display: flex;
    justify-content: center;
    gap: 30px;
    margin-bottom: 20px;
    font-size: 0.9em;
}

.legend-item {
    display: flex;
    align-items: center;
    gap: 8px;
}

.legend-dot {
    width: 12px;
    height: 12px;
    border-radius: 50%;
}

.legend-dot.center {
    background: var(--accent-color);
}

.legend-dot.elevens {
    background: var(--accent-color);
}