.mne {
    --mne-primary: #8b5cf6;
    --mne-primary-rgb: 139, 92, 246;
    --mne-secondary: #d946ef;
    --mne-accent: #f59e0b;
    --mne-bg-card: rgba(255, 255, 255, 0.8);
    --mne-border-card: rgba(139, 92, 246, 0.2);
    --mne-text-main: #1e293b;
    --mne-text-muted: #64748b;
    --mne-glass-bg: rgba(255, 255, 255, 0.5);
    --mne-glass-border: rgba(139, 92, 246, 0.1);
    --mne-piano-bg: #18181b;

    max-width: 1000px;
    margin: 2rem auto;
    background: var(--mne-bg-card);
    backdrop-filter: blur(16px);
    border: 1px solid var(--mne-border-card);
    border-radius: 2rem;
    padding: 2.5rem;
    color: var(--mne-text-main);
    display: flex;
    flex-direction: column;
    gap: 2.5rem;
  }

  .theme-dark .mne {
    --mne-bg-card: rgba(15, 23, 42, 0.8);
    --mne-border-card: rgba(139, 92, 246, 0.3);
    --mne-text-main: #f8fafc;
    --mne-text-muted: #94a3b8;
    --mne-glass-bg: rgba(30, 41, 59, 0.5);
    --mne-glass-border: rgba(255, 255, 255, 0.1);
  }

  .mne__header {
    text-align: center;
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
  }

  #mne-note-display {
    font-size: 2.5rem;
    font-weight: 950;
    background: linear-gradient(135deg, var(--mne-primary), var(--mne-secondary));
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    margin: 0;
    letter-spacing: -1px;
  }

  .mne__piano-container {
    overflow-x: auto;
    padding: 1rem 0;
    display: flex;
    justify-content: center;
  }

  .mne__piano {
    display: flex;
    position: relative;
    background: var(--mne-piano-bg);
    padding: 0.75rem;
    border-radius: 1rem;
    user-select: none;
  }

  .mne__key {
    cursor: pointer;
    transition: all 0.15s cubic-bezier(0.4, 0, 0.2, 1);
    display: flex;
    align-items: flex-end;
    justify-content: center;
    padding-bottom: 1rem;
    font-size: 0.7rem;
    font-weight: 800;
    text-transform: uppercase;
  }

  .mne__key--white {
    width: 44px;
    height: 180px;
    background: linear-gradient(to bottom, #fff 0%, #f1f5f9 100%);
    border: 1px solid #e2e8f0;
    border-radius: 0 0 6px 6px;
    margin: 0 1px;
    z-index: 1;
    color: #94a3b8;
  }

  .mne__key--black {
    width: 32px;
    height: 110px;
    background: linear-gradient(to bottom, #334155 0%, #0f172a 100%);
    border: 1px solid #000;
    border-radius: 0 0 4px 4px;
    margin-left: -16px;
    margin-right: -16px;
    z-index: 2;
    color: #475569;
  }

  .mne__key:hover {
    transform: translateY(4px);
    filter: brightness(0.95);
  }

  .mne__key--white.active {
    background: var(--mne-primary);
    color: white;
    border-color: var(--mne-primary);
  }

  .mne__key--black.active {
    background: var(--mne-secondary);
    color: white;
    border-color: var(--mne-secondary);
  }

  .mne__octave-group {
    display: flex;
    position: relative;
  }

  .mne__info-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1.5rem;
  }

  .mne__info-card {
    background: var(--mne-glass-bg);
    border: 1px solid var(--mne-glass-border);
    border-radius: 1.5rem;
    padding: 1.75rem;
    display: flex;
    flex-direction: column;
    gap: 1.25rem;
    transition: transform 0.2s;
  }

  .mne__info-card:hover {
    transform: translateY(-5px);
  }

  .mne__card-title {
    font-size: 0.75rem;
    font-weight: 900;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--mne-primary);
    border-bottom: 1px solid var(--mne-glass-border);
    padding-bottom: 0.5rem;
  }

  .mne__system-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
  }

  .mne__system-label {
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--mne-text-muted);
  }

  .mne__system-value {
    font-weight: 800;
    font-size: 1.15rem;
    color: var(--mne-text-main);
  }

  .mne__val-highlight {
    color: var(--mne-primary);
  }

  .mne__octave-selector {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 1rem;
    flex-wrap: wrap;
  }

  .mne__octave-label {
    font-size: 0.8rem;
    font-weight: 800;
    text-transform: uppercase;
    color: var(--mne-text-muted);
  }

  .mne__octave-buttons {
    display: flex;
    gap: 0.35rem;
    background: var(--mne-glass-bg);
    padding: 0.4rem;
    border-radius: 0.75rem;
    border: 1px solid var(--mne-glass-border);
  }

  .mne__octave-btn {
    background: transparent;
    border: none;
    color: var(--mne-text-muted);
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 0.5rem;
    cursor: pointer;
    font-weight: 800;
    transition: all 0.2s;
  }

  .mne__octave-btn:hover {
    background: rgba(var(--mne-primary-rgb), 0.1);
    color: var(--mne-primary);
  }

  .mne__octave-btn.active {
    background: var(--mne-primary);
    color: white;
  }

  .mne__actions {
    display: flex;
    gap: 1rem;
    margin-top: 0.5rem;
  }

  .mne__btn {
    flex: 1;
    padding: 0.85rem;
    border-radius: 1rem;
    border: none;
    font-weight: 800;
    font-size: 0.9rem;
    cursor: pointer;
    transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  }

  .mne__btn--play {
    background: linear-gradient(135deg, var(--mne-primary), var(--mne-secondary));
    color: white;
  }

  .mne__btn--copy {
    background: var(--mne-glass-bg);
    color: var(--mne-text-main);
    border: 1px solid var(--mne-glass-border);
  }

  .mne__btn:hover {
    transform: translateY(-3px) scale(1.02);
    filter: brightness(1.1);
  }

  .mne__frequency-display {
    display: flex;
    align-items: baseline;
    gap: 0.5rem;
  }

  .mne__freq-val {
    font-size: 3.5rem;
    font-weight: 950;
    letter-spacing: -2px;
    color: var(--mne-primary);
  }

  .mne__hz-unit {
    font-size: 1.25rem;
    font-weight: 800;
    color: var(--mne-text-muted);
  }

  .mne__visualizer-container {
    width: 100%;
    height: 80px;
    background: rgba(0, 0, 0, 0.05);
    border-radius: 1rem;
    overflow: hidden;
    display: flex;
    align-items: center;
    border: 1px solid var(--mne-glass-border);
  }

  .theme-dark .mne__visualizer-container {
    background: rgba(255, 255, 255, 0.05);
  }

  #mne-visualizer {
    width: 100%;
    height: 100%;
  }

  @media (max-width: 768px) {
    .mne {
      padding: 1.5rem;
      margin: 1rem;
      border-radius: 1.5rem;
    }

    #mne-note-display {
      font-size: 1.75rem;
    }

    .mne__key--white {
      width: 36px;
      height: 140px;
    }

    .mne__key--black {
      width: 24px;
      height: 90px;
      margin-left: -12px;
      margin-right: -12px;
    }

    .mne__freq-val {
      font-size: 2.5rem;
    }
  }

  @media (max-width: 600px) {
    .mne {
      padding: 1rem;
      margin: 0;
      border-radius: 1rem;
      gap: 1.5rem;
    }

    #mne-note-display {
      font-size: 1.4rem;
      letter-spacing: -0.5px;
    }

    .mne__octave-selector {
      flex-direction: column;
      gap: 0.6rem;
    }

    .mne__octave-label {
      font-size: 0.7rem;
    }

    .mne__octave-buttons {
      flex-wrap: wrap;
      justify-content: center;
      gap: 0.25rem;
    }

    .mne__octave-btn {
      width: 28px;
      height: 28px;
      font-size: 0.8rem;
    }

    .mne__piano-container {
      padding: 0.5rem 0;
    }

    .mne__piano {
      padding: 0.5rem;
    }

    .mne__key--white {
      width: 22px;
      height: 110px;
      padding-bottom: 0.5rem;
      font-size: 0.55rem;
    }

    .mne__key--black {
      width: 14px;
      height: 68px;
      margin-left: -7px;
      margin-right: -7px;
      font-size: 0.45rem;
      padding-bottom: 0.35rem;
    }

    .mne__info-grid {
      grid-template-columns: 1fr;
      gap: 1rem;
    }

    .mne__info-card {
      padding: 1.25rem;
      gap: 1rem;
      border-radius: 1rem;
    }

    .mne__info-card:hover {
      transform: none;
    }

    .mne__system-label {
      font-size: 0.8rem;
    }

    .mne__system-value {
      font-size: 1rem;
    }

    .mne__freq-val {
      font-size: 2rem;
      letter-spacing: -1px;
    }

    .mne__hz-unit {
      font-size: 1rem;
    }

    .mne__btn {
      padding: 0.75rem;
      font-size: 0.85rem;
    }

    .mne__visualizer-container {
      height: 60px;
    }
  }