/* 2. 側邊欄 */
.blog-sidebar {
    flex: 0 0 250px;
}
.blog-sidebar h2 {
    margin-bottom: 12px;
    font-size: 1.2em;
    color: #333;
}

/* 重置所有層級的清單樣式 */
.blog-sidebar .sidebar-tree,
.blog-sidebar .sidebar-tree ul {
    list-style: none;
    margin: 0;
    padding: 0;
}

/* 第一層節點間距 */
.blog-sidebar .sidebar-tree > li {
    margin-bottom: 8px;
}

/* 子層節點縮排與間距 */
.blog-sidebar .sidebar-tree ul {
    margin: 4px 0 4px 12px;
}
.blog-sidebar .sidebar-tree ul li {
    margin-bottom: 6px;
}

/* 連結樣式 */
.blog-sidebar .sidebar-tree a {
    display: block;
    padding: 8px 12px;
    color: #333;
    text-decoration: none;
    border-radius: 4px;
    transition: background-color 0.2s, color 0.2s;
}

/* hover 與當前分類強調 */
.blog-sidebar .sidebar-tree a:hover,
.blog-sidebar .sidebar-tree .current-cat > a,
.blog-sidebar .sidebar-tree .current-cat-parent > a {
    background-color: #f5f5f5;
    color: #000;
    font-weight: 500;
}