body {
    font-family: "Helvetica Neue", Arial, sans-serif;
    margin: 0;
    padding: 0;
    background: #f5f7fa;
    color: #333;
    line-height: 1.75;
}

/* 头部 */
header {
    background: linear-gradient(135deg, #222, #333);
    color: #fff;
    padding: 35px 20px;
    text-align: center;
    letter-spacing: 0.5px;
}

/* 导航栏 */
nav {
    background: #2f3b52;
    padding: 12px;
    text-align: center;
}
nav a {
    color: #fff;
    margin: 0 15px;
    font-size: 15px;
    text-decoration: none;
    opacity: 0.9;
}
nav a:hover {
    opacity: 1;
    text-decoration: underline;
}

/* 主体内容区域 */
.container {
    max-width: 900px;
    margin: 0 auto;
    padding: 25px;
}

/* 面包屑 */
.breadcrumb {
    font-size: 14px;
    color: #666;
    margin-bottom: 20px;
}
.breadcrumb a {
    color: #666;
    text-decoration: none;
}
.breadcrumb a:hover {
    text-decoration: underline;
}

/* 文章容器 */
article {
    background: #fff;
    padding: 40px;
    margin-bottom: 25px;
    border-radius: 10px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.08);
}

/* 文章标题 */
article h1 {
    margin-top: 0;
    margin-bottom: 20px;
    font-size: 32px;
    letter-spacing: 0.5px;
    color: #222;
    border-bottom: 2px solid #f0f0f0;
    padding-bottom: 15px;
}

/* 文章元信息 */
.article-meta {
    color: #888;
    font-size: 14px;
    margin-bottom: 30px;
    padding-bottom: 20px;
    border-bottom: 1px solid #f0f0f0;
}
.article-meta span {
    margin-right: 20px;
}

/* 目录导航 */
.article-toc {
    background: #f8fafc;
    border: 1px solid #e6edf5;
    border-radius: 8px;
    padding: 22px 24px;
    margin-bottom: 30px;
}
.article-toc h2 {
    margin: 0 0 12px;
    font-size: 20px;
}
.article-toc ol {
    margin: 0;
    padding-left: 22px;
}
.article-toc li {
    margin-bottom: 8px;
}
.article-toc a {
    color: #333;
    text-decoration: none;
}
.article-toc a:hover {
    text-decoration: underline;
}

/* 文章内容 */
.article-content {
    font-size: 16px;
    line-height: 1.8;
}
.article-lead {
    font-size: 17px;
    color: #444;
    background: #fafafa;
    border-left: 4px solid #2f3b52;
    padding: 18px 20px;
    border-radius: 8px;
    margin-bottom: 28px;
}
.article-content h2 {
    scroll-margin-top: 24px;
    margin-top: 35px;
    margin-bottom: 15px;
    font-size: 24px;
    color: #333;
}
.article-content h3 {
    margin-top: 25px;
    margin-bottom: 12px;
    font-size: 20px;
    color: #444;
}
.article-content p {
    margin-bottom: 20px;
    text-align: justify;
}
.article-content ul,
.article-content ol {
    margin-bottom: 20px;
    padding-left: 30px;
}
.article-content li {
    margin-bottom: 10px;
}
.article-content blockquote {
    margin: 25px 0;
    padding: 15px 20px;
    background: #f9f9f9;
    border-left: 4px solid #2f3b52;
    color: #555;
}
.article-content code {
    background: #f5f5f5;
    padding: 2px 6px;
    border-radius: 3px;
    font-family: "Courier New", monospace;
    font-size: 14px;
}
.article-content pre {
    background: #f5f5f5;
    padding: 15px;
    border-radius: 5px;
    overflow-x: auto;
    margin-bottom: 20px;
}
.article-content pre code {
    background: none;
    padding: 0;
}
.article-content img {
    max-width: 100%;
    height: auto;
    display: block;
    margin: 25px auto;
    border-radius: 5px;
}

/* 相关文章 */
.related-articles {
    background: #fff;
    padding: 25px;
    margin-bottom: 25px;
    border-radius: 10px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.08);
}
.related-articles h2 {
    margin-top: 0;
    margin-bottom: 16px;
    font-size: 24px;
}
.related-articles ul {
    list-style: none;
    padding: 0;
    margin: 0;
}
.related-articles li {
    padding: 12px 0;
    border-bottom: 1px solid #f0f0f0;
}
.related-articles li:last-child {
    border-bottom: none;
}
.related-articles a {
    color: #333;
    text-decoration: none;
}
.related-articles a:hover {
    text-decoration: underline;
}

/* 文章导航 */
.article-nav {
    background: #fff;
    padding: 20px;
    border-radius: 10px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.08);
    display: flex;
    justify-content: space-between;
    gap: 15px;
}
.article-nav .nav-item {
    flex: 1;
}
.article-nav .nav-label {
    display: block;
    font-size: 13px;
    color: #888;
    margin-bottom: 8px;
}
.article-nav a {
    color: #333;
    text-decoration: none;
    padding: 10px 20px;
    border: 1px solid #ddd;
    border-radius: 5px;
    background: #fff;
    transition: all 0.2s ease;
    display: inline-block;
}
.article-nav a:hover {
    background: #2f3b52;
    color: #fff;
    border-color: #2f3b52;
}
.article-nav .back {
    text-align: center;
}
.article-nav .next {
    text-align: right;
}

/* 页脚 */
footer {
    text-align: center;
    padding: 25px;
    background: #222;
    color: #fff;
    margin-top: 40px;
    font-size: 14px;
    line-height: 1.6;
}