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

body {
    font-family: 'Times New Roman', serif;
    line-height: 1.8;
    color: #2c3e50;
    background-color: #f9f9f9;
}

/* 头部导航样式 */
header {
    background: #34495e;
    color: white;
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

.nav-menu {
    list-style: none;
    display: flex;
    justify-content: center;
    gap: 1.5rem;
    flex-wrap: wrap;
}

.nav-menu li a {
    color: white;
    text-decoration: none;
    font-size: 0.9rem;
    font-weight: normal;
    transition: color 0.3s ease;
    padding: 0.5rem 1rem;
    border-radius: 4px;
}

.nav-menu li a:hover {
    color: #3498db;
    background: rgba(255,255,255,0.1);
}

.nav-menu li a.active {
    color: #3498db;
    background: rgba(255,255,255,0.2);
    font-weight: bold;
}

/* 下拉菜单样式 */
.nav-menu .dropdown {
    position: relative;
}

.nav-menu .dropdown:hover {
    background: rgba(255,255,255,0.1);
    border-radius: 4px;
}

.dropdown-content {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    background-color: #34495e;
    min-width: 180px;
    box-shadow: 0 8px 16px rgba(0,0,0,0.2);
    z-index: 1001;
    border-radius: 0 0 4px 4px;
}

.dropdown-content li {
    display: block;
}

.dropdown-content li a {
    color: white;
    padding: 0.7rem 1rem;
    text-decoration: none;
    display: block;
    text-align: left;
    font-size: 0.85rem;
    border-radius: 0;
}

.dropdown-content li a:hover {
    background-color: rgba(255,255,255,0.2);
    color: #3498db;
}

.dropdown:hover .dropdown-content {
    display: block;
}

/* 主要内容样式 */
main {
    max-width: 900px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

/* 通用章节样式 */
section {
    background: white;
    padding: 3rem 4rem;
    margin: 2rem 0;
    border-radius: 2px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.08);
}

/* 封面页样式 */
.cover-page {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    background: linear-gradient(135deg, #34495e 0%, #2c3e50 100%);
    color: white;
    margin: 0;
    padding: 2rem;
}

.cover-content {
    max-width: 600px;
}

.cover-prefix {
    font-size: 1.2rem;
    margin-bottom: 0.5rem;
    font-weight: normal;
    opacity: 0.9;
}

.cover-name {
    font-size: 4rem;
    margin-bottom: 1rem;
    font-weight: bold;
    letter-spacing: 2px;
}

.cover-image {
    width: 180px;
    height: 240px;
    border-radius: 2px;
    border: 3px solid white;
    margin-bottom: 2rem;
    object-fit: cover;
    box-shadow: 0 4px 12px rgba(0,0,0,0.2);
}

.cover-title {
    font-size: 2rem;
    margin-bottom: 1rem;
    font-weight: normal;
}

.cover-subtitle {
    font-size: 1.2rem;
    margin-bottom: 3rem;
    color: #bdc3c7;
    font-style: italic;
}

.contact-info {
    font-size: 1rem;
    line-height: 2;
}

.contact-info p {
    margin: 0.5rem 0;
}

/* 目录样式 */
.toc-section {
    background: #f8f9fa;
    border-left: 4px solid #3498db;
}

.table-of-contents {
    margin-top: 2rem;
}

.table-of-contents ol {
    list-style-type: decimal;
    padding-left: 2rem;
}

.table-of-contents li {
    margin-bottom: 1rem;
}

.table-of-contents ul {
    list-style-type: disc;
    padding-left: 2rem;
    margin-top: 0.5rem;
}

.table-of-contents ul li {
    margin-bottom: 0.5rem;
}

.table-of-contents ul li a {
    font-size: 1rem;
}

.table-of-contents a {
    color: #2c3e50;
    text-decoration: none;
    font-size: 1.1rem;
    transition: color 0.3s ease;
}

.table-of-contents a:hover {
    color: #3498db;
    text-decoration: underline;
}

/* 内容章节样式 */
.content-section {
    background: white;
}

.content-section h2 {
    color: #34495e;
    margin-bottom: 2rem;
    font-size: 2.5rem;
    font-weight: bold;
    padding-bottom: 0.5rem;
    border-bottom: 2px solid #3498db;
}

.content {
    font-size: 1.1rem;
}

.content p {
    margin-bottom: 1.5rem;
    text-align: justify;
}

/* 无序列表 */
.content ul {
    margin-bottom: 1.2rem;
    padding-left: 1.8rem;
}

.content ul li {
    margin-bottom: 0.6rem;
}

/* 有序列表（重点：缩进 + 首行缩进） */
.content ol {
    margin-bottom: 1.2rem;
    padding-left: 2.2rem;   /* 整体缩进 */
}

.content ol li {
    margin-bottom: 0.8rem;
    text-indent: 2em;       /* 首行缩进：论文风格 */
}

/* 页脚样式 */
footer {
    background: #34495e;
    color: white;
    text-align: center;
    padding: 2rem 0;
    margin-top: 3rem;
    font-size: 0.9rem;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .nav-menu {
        gap: 0.5rem;
    }
    
    .nav-menu li a {
        font-size: 0.8rem;
        padding: 0.3rem 0.8rem;
    }
    
    section {
        padding: 2rem 1.5rem;
        margin: 1rem 0;
    }
    
    .cover-name {
        font-size: 2.5rem;
    }
    
    .cover-title {
        font-size: 1.5rem;
    }
    
    .cover-subtitle {
        font-size: 1rem;
    }
    
    .content-section h2 {
        font-size: 1.8rem;
    }
    
    .content {
        font-size: 1rem;
    }
    
    .table-of-contents ol {
        padding-left: 1.5rem;
    }
    
    .table-of-contents a {
        font-size: 1rem;
    }
}

/* 打印样式 */
@media print {
    header {
        display: none;
    }
    
    section {
        box-shadow: none;
        margin: 0;
        padding: 0;
    }
    
    .cover-page {
        min-height: 50vh;
    }
    
    footer {
        display: none;
    }
}