.mb-root {
    --mb-accent: #16a34a;
    --mb-accent-hover: #15803d;
    --mb-sos-bg: #fff1f2;
    --mb-sos-color: #e11d48;
    --mb-sos-border: #fecdd3;
    --mb-sos-hover-bg: #ffe4e6;
    --mb-display-bg: #111827;
    --mb-bulb-off: #1e293b;
    --mb-bulb-border-off: #334155;
    --mb-ticker-color: #4ade80;
    --mb-status-bg: rgba(30, 41, 59, 0.8);
    --mb-status-border: #334155;
    --mb-card-bg: #fff;
    --mb-card-border: #f1f5f9;
    --mb-text-main: #1e293b;
    --mb-text-label: #64748b;
    --mb-text-hint: #94a3b8;
    --mb-field-border: #e2e8f0;
    --mb-field-focus: #16a34a;
    --mb-extras-border: #f1f5f9;
    --mb-toggle-off: #cbd5e1;

    width: 100%;
    max-width: 42rem;
    margin: 0 auto;
  }

  .theme-dark .mb-root {
    --mb-card-bg: #0f172a;
    --mb-card-border: #1e293b;
    --mb-text-main: #e2e8f0;
    --mb-text-label: #94a3b8;
    --mb-text-hint: #475569;
    --mb-field-border: #334155;
    --mb-sos-bg: rgba(225, 29, 72, 0.1);
    --mb-sos-border: rgba(225, 29, 72, 0.2);
    --mb-sos-hover-bg: rgba(225, 29, 72, 0.15);
    --mb-extras-border: #1e293b;
    --mb-toggle-off: #475569;
  }

  .mb-card {
    border-radius: 1.5rem;
    overflow: hidden;
    border: 1px solid var(--mb-card-border);
    box-shadow: 0 20px 40px -12px rgba(0, 0, 0, 0.08);
    background: var(--mb-card-bg);
  }

  .mb-display {
    background: var(--mb-display-bg);
    padding: 2rem;
    position: relative;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    min-height: 220px;
    gap: 1.25rem;
  }

  .mb-bulb {
    width: 6rem;
    height: 6rem;
    border-radius: 50%;
    background: var(--mb-bulb-off);
    border: 4px solid var(--mb-bulb-border-off);
    display: flex;
    align-items: center;
    justify-content: center;
    color: #475569;
    position: relative;
    z-index: 1;
    transition: background 0.05s, border-color 0.05s, box-shadow 0.05s, color 0.05s;
  }

  .mb-ticker-wrap {
    height: 2rem;
    overflow: hidden;
    width: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
  }

  .mb-ticker {
    color: var(--mb-ticker-color);
    font-size: 1.5rem;
    font-weight: 700;
    letter-spacing: 0.2em;
    white-space: nowrap;
  }

  .mb-status-badge {
    position: absolute;
    top: 1rem;
    right: 1rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    background: var(--mb-status-bg);
    border: 1px solid var(--mb-status-border);
    padding: 0.375rem 0.75rem;
    border-radius: 9999px;
    backdrop-filter: blur(4px);
  }

  .mb-status-led {
    width: 0.5rem;
    height: 0.5rem;
    border-radius: 50%;
    background: #64748b;
    transition: background 0.2s;
  }

  .mb-status-text {
    font-size: 0.6875rem;
    font-weight: 700;
    color: #94a3b8;
    letter-spacing: 0.08em;
  }

  .mb-controls {
    padding: 2rem;
    display: flex;
    flex-direction: column;
    gap: 2rem;
  }

  .mb-field-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 0.75rem;
  }

  .mb-field-label {
    font-size: 0.8125rem;
    font-weight: 700;
    color: var(--mb-text-label);
    text-transform: uppercase;
    letter-spacing: 0.05em;
  }

  .mb-char-count {
    font-size: 0.8125rem;
    font-weight: 600;
    color: var(--mb-accent);
  }

  .mb-textarea {
    width: 100%;
    font-size: 1.125rem;
    font-weight: 700;
    color: var(--mb-text-main);
    background: transparent;
    border: none;
    border-bottom: 2px solid var(--mb-field-border);
    outline: none;
    padding: 0.5rem 0;
    resize: none;
    text-transform: uppercase;
    transition: border-color 0.2s;
  }

  .mb-textarea::placeholder {
    color: var(--mb-text-hint);
    text-transform: none;
    font-weight: 400;
  }

  .mb-textarea:focus {
    border-color: var(--mb-field-focus);
  }

  .mb-btn-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 0.75rem;
  }

  .mb-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 1rem 1.25rem;
    border-radius: 0.75rem;
    font-weight: 700;
    font-size: 0.875rem;
    letter-spacing: 0.04em;
    text-transform: uppercase;
    border: none;
    cursor: pointer;
    transition: background 0.15s, transform 0.1s, opacity 0.15s;
  }

  .mb-btn:active {
    transform: scale(0.97);
  }

  .mb-btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
  }

  .mb-btn-transmit {
    background: var(--mb-accent);
    color: #fff;
    box-shadow: 0 4px 14px rgba(22, 163, 74, 0.35);
  }

  .mb-btn-transmit:hover:not(:disabled) {
    background: var(--mb-accent-hover);
  }

  .mb-btn-sos {
    background: var(--mb-sos-bg);
    color: var(--mb-sos-color);
    border: 2px solid var(--mb-sos-border);
  }

  .mb-btn-sos:hover:not(:disabled) {
    background: var(--mb-sos-hover-bg);
  }

  .mb-extras {
    display: flex;
    align-items: center;
    justify-content: center;
    padding-top: 1rem;
    border-top: 1px solid var(--mb-extras-border);
  }

  .mb-toggle-label {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    cursor: pointer;
  }

  .mb-toggle-wrap {
    position: relative;
    display: flex;
    align-items: center;
  }

  .mb-toggle {
    position: absolute;
    opacity: 0;
    width: 0;
    height: 0;
  }

  .mb-toggle-track {
    width: 2.75rem;
    height: 1.5rem;
    background: var(--mb-toggle-off);
    border-radius: 9999px;
    cursor: pointer;
    transition: background 0.2s;
    position: relative;
  }

  .mb-toggle-track::after {
    content: '';
    position: absolute;
    top: 2px;
    left: 2px;
    width: 1.25rem;
    height: 1.25rem;
    border-radius: 50%;
    background: #fff;
    transition: transform 0.2s;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.2);
  }

  .mb-toggle:checked + .mb-toggle-track {
    background: var(--mb-accent);
  }

  .mb-toggle:checked + .mb-toggle-track::after {
    transform: translateX(1.25rem);
  }

  .mb-toggle-text {
    font-size: 0.9375rem;
    font-weight: 500;
    color: var(--mb-text-label);
    transition: color 0.15s;
  }

  .mb-toggle-label:hover .mb-toggle-text {
    color: var(--mb-accent);
  }