/* Chart hierarchy — HIG: semibold titles, medium metadata */
    .charts-slot > details.ds-chart-stack-section > summary {
      font-size: var(--ds-text-headline);
      font-weight: var(--ds-weight-semibold);
      letter-spacing: -0.01em;
      color: var(--ds-text);
    }
    .charts-slot > details.ds-chart-stack-section > summary .ds-summary-total {
      font-size: var(--ds-text-body);
      font-weight: var(--ds-weight-medium);
      color: var(--ds-text-secondary);
    }
    /* Top-level History metrics (Assets / Liabilities / RE) — collapsible, closed by default */
    .ds-chart-stack-section--metric {
      display: flex;
      flex-direction: column;
      gap: var(--ds-chart-row-gap);
      padding-top: 0;
    }
    .ds-chart-stack-section--metric > .ds-chart-stack-section-hero .ds-chart-item--hero {
      margin-bottom: 0;
    }
    .ds-chart-stack-section--metric[open] {
      gap: var(--ds-chart-row-gap);
    }
    .ds-chart-stack-section-body--details {
      display: flex;
      flex-direction: column;
      gap: 0;
      padding-top: 0;
    }
    .ds-chart-stack-section-body--details > details.ds-chart-stack-section:first-child {
      margin-top: 0;
    }
    .ds-chart-stack-section-body > details.ds-chart-stack-section:not(.ds-chart-stack-section--nested) > summary {
      font-size: var(--ds-text-body);
      font-weight: var(--ds-weight-semibold);
      color: var(--ds-text-secondary);
    }
    .ds-chart-stack-section-body > details.ds-chart-stack-section:not(.ds-chart-stack-section--nested) > summary .ds-summary-total {
      font-size: var(--ds-text-caption);
      font-weight: var(--ds-weight-medium);
    }
    details.ds-chart-stack-section--nested > summary {
      font-size: var(--ds-text-chart-bucket);
      font-weight: var(--ds-weight-medium);
      color: var(--ds-text-secondary);
    }
    details.ds-chart-stack-section--nested > summary .ds-summary-total {
      font-size: var(--ds-text-caption);
      font-weight: var(--ds-weight-medium);
    }
    details.ds-chart-stack-section {
      padding-top: 0;
    }
    details.ds-chart-stack-section > summary {
      cursor: pointer;
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: var(--ds-space-3);
      list-style: none;
    }
    details.ds-chart-stack-section > summary::-webkit-details-marker { display: none; }
    details.ds-chart-stack-section[open] > summary .ds-chevron { transform: rotate(90deg); }
    details.ds-chart-stack-section .ds-chart-stack-section--nested {
      margin-left: var(--ds-space-3);
      padding-top: 0;
    }

    .ds-chart-stack-section-label {
      display: inline-flex;
      align-items: baseline;
      gap: 0.35rem;
      font-size: inherit;
      font-weight: inherit;
      color: inherit;
    }
    .ds-chart-stack-section-body {
      display: flex;
      flex-direction: column;
      gap: var(--ds-chart-row-gap);
      padding-top: 0;
    }
    details.ds-chart-stack-section[open] > .ds-chart-stack-section-body {
      padding-top: var(--ds-chart-row-gap);
    }