/* 侧边栏目录容器样式 */
#custom-toc {
    background: #f9f9f9;
    border: 1px solid #e1e1e1;
    border-radius: 8px;
    padding: 10px 0 10px 0;
    margin-bottom: 20px;
    font-family: "Segoe UI", "Microsoft YaHei", sans-serif;
    box-shadow: 0 1px 3px rgba(0,0,0,0.05);
    max-height: 80vh;
    overflow-y: auto;
}

/* 目录标题 */
#custom-toc .toc-title {
    font-size: 16px;
    font-weight: bold;
    padding: 0 0 8px 15px;
    border-bottom: 1px solid #e1e1e1;
    margin-bottom: 8px;
    color: #333;
}

/* 目录树基础样式 */
#custom-toc ul {
    list-style: none;
    margin: 0;
    padding: 0;
}

#custom-toc li {
    margin: 0;
    padding: 0;
    line-height: 1.6;
    position: relative;
}

/* 目录链接样式（包含折叠图标和文本） */
#custom-toc .toc-item {
    display: block;
    padding: 5px 10px 5px 20px;
    text-decoration: none;
    color: #2c3e50;
    font-size: 13px;
    transition: all 0.2s;
    border-left: 2px solid transparent;
    cursor: pointer;
}

/* 可折叠的父级项增加箭头图标 */
#custom-toc .toc-parent > .toc-item {
    padding-left: 5px;  /* 为图标腾出空间 */
}

/* 折叠图标样式 */
#custom-toc .toggle-icon {
    display: inline-block;
    width: 18px;
    text-align: center;
    font-size: 12px;
    margin-right: 4px;
    font-family: monospace;
    user-select: none;
}

/* 不同层级缩进（通过li的类实现） */
#custom-toc .toc-level-2 > .toc-item {
    padding-left: 20px;
    font-weight: 500;
}
#custom-toc .toc-level-3 > .toc-item {
    padding-left: 35px;
    font-size: 12.5px;
}
#custom-toc .toc-level-4 > .toc-item {
    padding-left: 50px;
    font-size: 12px;
    color: #5d6d7e;
}
/* 更深层级可以继续增加 */

/* 鼠标悬浮效果 */
#custom-toc .toc-item:hover {
    background-color: #eaf2f8;
    border-left-color: #2d6a4f;
    color: #1b4d3e;
}

/* 当前阅读章节高亮 */
#custom-toc .toc-current > .toc-item {
    background-color: #e8f5e9;
    border-left-color: #2d6a4f;
    color: #2d6a4f;
    font-weight: 500;
}

/* 折叠状态：子列表隐藏 */
#custom-toc .toc-collapsed > ul {
    display: none;
}