.toc-block {
    --toc-accent: #2563eb;
    --toc-bg: #f8fafc;
    --toc-border: #e2e8f0;
    background: var(--toc-bg);
    border: 1px solid var(--toc-border);
    border-left: 4px solid var(--toc-accent);
    border-radius: 0.5rem;
    padding: 1.25rem 1.5rem;
    font-size: 0.9375rem;
    margin-bottom: 1.5rem;
}
.toc-block__title { margin: 0 0 0.75rem; font-weight: 700; font-size: 1em; color: #0f172a; }
.toc-block__toggle { display: flex; align-items: center; justify-content: space-between; width: 100%; background: none; border: none; cursor: pointer; padding: 0; margin: 0 0 0.75rem; font: inherit; color: inherit; }
.toc-block__toggle .toc-block__title { margin: 0; pointer-events: none; }
.toc-block__arrow { display: inline-block; width: 0.5rem; height: 0.5rem; border-right: 2px solid var(--toc-accent); border-bottom: 2px solid var(--toc-accent); transform: rotate(45deg); transition: transform 0.2s; flex-shrink: 0; }
.toc-block__toggle[aria-expanded="false"] .toc-block__arrow { transform: rotate(-45deg); }
.toc-block__list { margin: 0; padding: 0; list-style: none; display: flex; flex-direction: column; gap: 0.3rem; }
.toc-block__list li { margin: 0; padding-block: 0.1em; }
.toc-block__list a { color: var(--toc-accent); text-decoration: none; display: inline-flex; gap: 0.3em; }
.toc-block__list a:hover { text-decoration: underline; }
.toc-block__list a.toc-block__link--active { font-weight: bold; }
.toc-block__num { color: #94a3b8; font-size: 0.9em; min-width: 1.5em; }
.toc-block__empty { color: #94a3b8; font-style: italic; font-size: 0.875em; margin: 0; }
@media (prefers-color-scheme: dark) {
    .toc-block { --toc-bg: #1e293b; --toc-border: #334155; --toc-accent: #60a5fa; color: #cbd5e1; }
    .toc-block__title { color: #f1f5f9; }
}