/* 全局样式 */
body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.7;
    margin: 0;
    padding: 0;
    background-color: #f9f8f7; /* 暖灰色背景 */
    color: #333;
}

.header,
.footer {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
}

/* 头部样式 */
header {
    background-color: #3a6073; /* 深灰蓝色 */
    color: #fff;
    padding: 15px 0;
    border-bottom: 3px solid #a1c181; /* 柔和绿边框 */
}

.header {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 2.7em;
    font-weight: bold;
    color: #fff;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.4);
}

.nav a {
    color: #fff;
    text-decoration: none;
    padding: 14px 22px;
    border-radius: 10px;
    background-color: rgba(255, 255, 255, 0.15);
    transition: background-color 0.3s ease;
}

.nav a:hover {
    background-color: rgba(255, 255, 255, 0.35);
}

/* 主要内容样式 */
.main {
    max-width: 1200px;
    margin: 30px auto;
    display: flex;
    padding: 20px;
}

.content {
    flex: 3;
    padding-right: 30px;
}

.item {
    background-color: #fff;
    padding: 40px;
    border-radius: 15px;
    box-shadow: 0 6px 12px rgba(0, 0, 0, 0.12);
    transition: transform 0.3s ease;
}

.item:hover {
    transform: translateY(-7px);
}

.item h1 {
    color: #2e5f2d; /* 深绿色 */
    border-bottom: 3px solid #a1c181; /* 柔和绿 */
    padding-bottom: 18px;
    margin-bottom: 35px;
    font-size: 2.5em;
}

.item section {
    margin-bottom: 35px;
}

/* 侧边栏样式 */
.sidebar {
    flex: 1;
    background-color: #fff;
    padding: 40px;
    border-radius: 15px;
    box-shadow: 0 6px 12px rgba(0, 0, 0, 0.12);
}

.title {
    color: #3a6073; /* 深灰蓝色 */
    border-bottom: 3px solid #a1c181; /* 柔和绿 */
    padding-bottom: 18px;
    margin-bottom: 25px;
    font-size: 2em;
}

.related {
    list-style: none;
    padding: 0;
}

.related li {
    padding: 12px 0;
    border-bottom: 1px dashed #ccc;
}

.related li:last-child {
    border-bottom: none;
}

.related a {
    color: #556b2f; /* 深橄榄绿 */
    text-decoration: none;
    transition: color 0.3s ease;
}

.related a:hover {
    color: #2e5f2d; /* 深绿色 */
}

/* 页脚样式 */
footer {
    background-color: #556b2f; /* 深橄榄绿 */
    color: #fff;
    text-align: center;
    padding: 20px 0;
    border-top: 3px solid #a1c181; /* 柔和绿 */
}

.copyright {
    font-size: 1.1em;
}

/* 特殊元素样式 */
mark {
    background-color: #ffdb58; /* 金色 */
    padding: 4px 10px;
    border-radius: 7px;
    font-weight: bold;
    color: #333;
}

/* 表格样式 */
table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 25px;
}

th,
td {
    border: 1px solid #ddd;
    padding: 15px;
    text-align: left;
}

th {
    background-color: #f5f5dc; /* 米色 */
    color: #556b2f; /* 深橄榄绿 */
    font-weight: bold;
}

/* 列表样式 */
ul,
ol {
    margin-top: 20px;
    margin-bottom: 20px;
}

ul li {
    list-style-type: square;
    margin-left: 30px;
    padding: 10px 0;
}

/* 链接样式 */
a {
    color: #3a6073; /* 深灰蓝色 */
    text-decoration: none;
    transition: color 0.3s ease;
}

a:hover {
    color: #2e5f2d; /* 深绿色 */
}

/* 细节样式 */
details {
    margin-bottom: 25px;
    border: 1px solid #ddd;
    border-radius: 10px;
    padding: 20px;
    background-color: #f9f9f9;
}

summary {
    font-weight: bold;
    cursor: pointer;
    padding: 10px;
    border-radius: 8px;
    background-color: #e9e9e9;
    transition: background-color 0.3s ease;
}

summary:hover {
    background-color: #d5d5d5;
}