.toc {
    position: sticky;
    top: 100px;
    align-self: flex-start;
}

#toc-nav {
    display: flex;
    flex-direction: column;
    gap: 8px;
    margin-top: 12px;
}

#toc-nav a {
    font-size: 14px;
    color: #6b7280;
    text-decoration: none;
    padding: 4px 12px;
    border-left: 2px solid transparent;
    transition: all 0.2s;
}

#toc-nav a:hover {
    color: #111827;
}

/* 当前阅读位置高亮 */
#toc-nav a.active {
    color: #f97316;
    border-left-color: #f97316;
    font-weight: 500;
}

/* h3 子级缩进 */
#toc-nav a.toc-sub {
    padding-left: 24px;
    font-size: 13px;
}