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

body {
    font-family: Georgia, 'Times New Roman', serif;
    background: linear-gradient(135deg, #1a1a2e 0%, #16213e 50%, #0f3460 100%);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
}

.container {
    background: #fffef7;
    border-radius: 16px;
    padding: 40px 40px 36px;
    text-align: center;
    box-shadow: 0 24px 64px rgba(0, 0, 0, 0.5);
    max-width: 1100px;
    width: 100%;
}

h1 {
    font-size: 2rem;
    color: #1a1a2e;
    letter-spacing: 0.02em;
    margin-bottom: 6px;
}

.subtitle {
    color: #718096;
    font-size: 0.95rem;
    margin-bottom: 24px;
    font-style: italic;
}

.scale-name {
    font-size: 1.6rem;
    font-weight: bold;
    color: #2b4c7e;
    margin-bottom: 16px;
    min-height: 2.2rem;
    letter-spacing: 0.03em;
}

.notation-container {
    background: #fefefe;
    border: 1px solid #e2e8f0;
    border-radius: 10px;
    padding: 8px 4px;
    margin-bottom: 28px;
    overflow: hidden;
    min-height: 160px;
}

.notation-container svg {
    display: block;
    max-width: 100%;
    height: auto;
}

.btn {
    background: linear-gradient(135deg, #2b4c7e, #567ba8);
    color: #fff;
    border: none;
    padding: 14px 36px;
    font-size: 1rem;
    font-family: Georgia, serif;
    border-radius: 50px;
    cursor: pointer;
    letter-spacing: 0.04em;
    transition: transform 0.15s ease, box-shadow 0.15s ease;
    box-shadow: 0 4px 14px rgba(43, 76, 126, 0.35);
}

.btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 22px rgba(43, 76, 126, 0.5);
}

.btn:active {
    transform: translateY(0);
    box-shadow: 0 2px 8px rgba(43, 76, 126, 0.3);
}

.octave-selector {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    margin-top: 20px;
}

.octave-label {
    color: #718096;
    font-size: 0.9rem;
    font-style: italic;
    margin-right: 4px;
}

.oct-btn {
    background: transparent;
    color: #2b4c7e;
    border: 2px solid #2b4c7e;
    width: 44px;
    height: 44px;
    font-size: 1rem;
    font-family: Georgia, serif;
    font-weight: bold;
    border-radius: 50%;
    cursor: pointer;
    transition: all 0.15s ease;
}

.oct-btn:hover {
    background: rgba(43, 76, 126, 0.1);
}

.oct-btn.active {
    background: linear-gradient(135deg, #2b4c7e, #567ba8);
    color: #fff;
    border-color: transparent;
    box-shadow: 0 4px 14px rgba(43, 76, 126, 0.35);
}

@media (max-width: 520px) {
    .container {
        padding: 28px 16px 24px;
    }
    h1 {
        font-size: 1.5rem;
    }
    .scale-name {
        font-size: 1.25rem;
    }
}