/* 全局样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Arial', sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #f4f4f4;
}

/* 头部样式 */
header {
    background-color: #35424a;
    color: white;
    padding: 20px 0;
    text-align: center;
    border-bottom: #e8491d 3px solid;
}

header h1 {
    margin-bottom: 10px;
}

nav ul {
    list-style: none;
    padding: 0;
}

nav ul li {
    display: inline;
    margin: 0 15px;
}

nav ul li a {
    color: white;
    text-decoration: none;
    font-size: 18px;
}

nav ul li a:hover {
    color: #e8491d;
    font-weight: bold;
}

/* 主要内容样式 */
main {
    max-width: 1000px;
    margin: 20px auto;
    padding: 20px;
    background-color: white;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
}

section {
    margin-bottom: 30px;
    padding: 20px;
    background-color: #f9f9f9;
    border-radius: 5px;
}

section h2 {
    color: #35424a;
    margin-bottom: 15px;
    border-bottom: 2px solid #e8491d;
    padding-bottom: 5px;
}

section p {
    margin-bottom: 10px;
    line-height: 1.8;
}

section ul {
    margin-left: 20px;
    margin-bottom: 10px;
}

section ul li {
    margin-bottom: 5px;
}

/* 页脚样式 */
footer {
    background-color: #35424a;
    color: white;
    text-align: center;
    padding: 15px 0;
    margin-top: 20px;
    border-top: #e8491d 3px solid;
    position: relative;
    bottom: 0;
    width: 100%;
}

/* 思维导图样式 */
.mind-map-container {
    position: relative;
    padding: 40px 20px;
    background-color: #fff;
    border-radius: 8px;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
    min-height: 500px;
}

/* 节点样式 */
.node {
    background-color: #35424a;
    color: white;
    padding: 15px 20px;
    border-radius: 5px;
    margin: 10px;
    display: inline-block;
    font-weight: bold;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.2);
    position: relative;
}

/* 中心节点 */
.node.main {
    background-color: #e8491d;
    font-size: 24px;
    padding: 20px 30px;
}

/* 中心主题 */
.mind-map-center {
    text-align: center;
    margin-bottom: 60px;
}

/* 第一级分支 */
.mind-map-level-1 {
    display: flex;
    justify-content: space-around;
    flex-wrap: wrap;
}

.branch {
    text-align: center;
    position: relative;
    flex: 1;
    min-width: 200px;
}

/* 第二级分支 */
.mind-map-level-2 {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    margin-top: 20px;
}

.mind-map-level-2 .node {
    background-color: #4a6fa5;
    font-size: 14px;
    padding: 10px 15px;
}

/* 分支连接线（使用伪元素创建） */
.branch::before {
    content: '';
    position: absolute;
    top: -30px;
    left: 50%;
    width: 2px;
    height: 30px;
    background-color: #333;
    transform: translateX(-50%);
}

.mind-map-level-2::before {
    content: '';
    position: absolute;
    top: 60px;
    left: 50%;
    width: 100px;
    height: 2px;
    background-color: #333;
    transform: translateX(-50%);
}

.mind-map-level-2 .node::before {
    content: '';
    position: absolute;
    top: -20px;
    left: 50%;
    width: 2px;
    height: 20px;
    background-color: #333;
    transform: translateX(-50%);
}

/* 思维导图说明部分 */
.mind-map-description {
    margin-top: 40px;
    padding: 20px;
    background-color: #fff;
    border-radius: 8px;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
}

.mind-map-description h3 {
    color: #35424a;
    margin-bottom: 15px;
    border-bottom: 2px solid #e8491d;
    padding-bottom: 5px;
}

.mind-map-description ul {
    margin-left: 20px;
}

.mind-map-description li {
    margin-bottom: 10px;
    line-height: 1.6;
}

/* 表格样式 */
.table-container {
    overflow-x: auto;
    margin-top: 20px;
}

.mind-map-table {
    width: 100%;
    border-collapse: collapse;
    background-color: white;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
    border-radius: 5px;
    overflow: hidden;
}

.mind-map-table th,
.mind-map-table td {
    padding: 15px;
    text-align: center;
    border: 1px solid #ddd;
    vertical-align: middle;
}

.mind-map-table th {
    background-color: #35424a;
    color: white;
    font-weight: bold;
}

.mind-map-table tr:nth-child(even) {
    background-color: #f9f9f9;
}

.mind-map-table tr:hover {
    background-color: #f1f1f1;
}

.mind-map-table td {
    font-size: 14px;
}

/* 响应式设计 */
@media (max-width: 768px) {
    nav ul li {
        display: block;
        margin: 10px 0;
    }

    main {
        padding: 10px;
    }

    section {
        padding: 15px;
    }

    /* 响应式思维导图 */
    .mind-map-level-1 {
        flex-direction: column;
        align-items: center;
    }

    .branch {
        margin-bottom: 40px;
        width: 100%;
    }

    .branch::before {
        left: 50%;
        top: -40px;
        height: 40px;
    }

    .mind-map-level-2 {
        flex-direction: column;
        align-items: center;
    }

    .mind-map-level-2::before {
        display: none;
    }
}