/* ==========================================================
   ARTICLE TABLE OF CONTENTS
========================================================== */

.article-toc {
    background: var(--color-surface);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-lg);
    overflow: hidden;
    margin-bottom: 24px;
}

.article-toc__toggle {
    width: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 16px 20px;
    background: none;
    border: none;
    cursor: pointer;
    font-size: 15px;
    font-weight: 700;
    color: var(--text-primary);
    text-align: left;
}
.article-toc__toggle:hover { background: var(--color-background); }

.article-toc__chevron {
    transition: transform var(--transition-normal);
    flex-shrink: 0;
}
.article-toc__toggle[aria-expanded="false"] .article-toc__chevron {
    transform: rotate(-90deg);
}

.article-toc__list {
    list-style: none;
    margin: 0;
    padding: 0 20px 16px;
    display: flex;
    flex-direction: column;
    gap: 2px;
    counter-reset: toc;
}
.article-toc__toggle[aria-expanded="false"] + .article-toc__list {
    display: none;
}

.article-toc__item { position: relative; }

.article-toc__link {
    display: block;
    padding: 6px 12px 6px 0;
    color: var(--text-secondary);
    font-size: 14px;
    line-height: 1.5;
    text-decoration: none;
    border-radius: var(--radius-sm);
    transition: color var(--transition-fast), background var(--transition-fast);
}
.article-toc__link:hover {
    color: var(--link);
    background: var(--badge-info-bg);
    padding-left: 8px;
}
.article-toc__link.is-active {
    color: var(--link);
    font-weight: 600;
}

/* Sub-list (H3) */
.article-toc__sublist {
    list-style: none;
    margin: 0;
    padding: 0 0 0 16px;
}
.article-toc__sublist .article-toc__link {
    font-size: 13px;
    color: var(--text-muted);
}

/* Sticky sidebar */
.single-article-sidebar .article-toc {
    position: sticky;
    top: 24px;
    max-height: calc(100vh - 48px);
    overflow-y: auto;
}

@media (max-width: 900px) {
    .single-article-sidebar .article-toc {
        position: static;
        max-height: none;
    }
}