.readings-external-tooltip {
    position: absolute;
    pointer-events: none;
    z-index: 20;
    opacity: 0;
    visibility: hidden;
    background: rgba(255, 255, 255, 0.96);
    border: 1px solid #ccc;
    border-radius: 4px;
    padding: 6px 8px;
    font-family: monospace;
    font-size: 0.75rem;
    color: #333;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
    max-width: calc(100vw - 16px);
    max-height: calc(100vh - 16px);
    overflow: auto;
  }
  .readings-external-tooltip table { border-collapse: collapse; margin: 0; }
  .readings-external-tooltip th {
    text-align: left; font-weight: 600; color: #111; padding: 0 0 4px 0;
    border-bottom: 1px solid #e0ddd8;
  }
  .readings-external-tooltip td { padding: 2px 0 0 0; vertical-align: middle; }
  .readings-external-tooltip .swatch {
    display: inline-block; width: 10px; height: 10px; margin-right: 8px;
    border: 2px solid; vertical-align: middle; flex-shrink: 0;
  }
  .readings-external-tooltip .row-inner { display: flex; align-items: center; }
  .readings-external-tooltip .row-bold { font-weight: 700; color: #111; }