.toc-sidebar {
    position: sticky;
    top: 100px;       /* 跟 header 不要重疊 */
    max-width: 160px;
    padding: 20px;
    border-left: 3px solid #eee;
    font-size: 16px;
    line-height: 1.6;
    height: fit-content;
}

.toc-sidebar ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.toc-sidebar li {
    margin-bottom: 12px;
}

.toc-sidebar a {
    text-decoration: none;
    color: #333;
}

.toc-sidebar a:hover {
    color: #007AFF;
}

.toc-sidebar a.active {
    font-weight: bold;
    color: #007AFF;
}

.article-layout {
    display: flex;
    gap: 40px;
}

.article-content {
    flex: 1;
    max-width: 780px;
}

/* *********************************** */