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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
    line-height: 1.6;
    color: #333;
    background: #f5f5f5;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 15px;
}

/* 头部导航 */
header {
    background: #fff;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px 0;
}

.logo {
    font-size: 24px;
    font-weight: bold;
    color: #e63946;
    text-decoration: none;
    transition: color 0.3s;
}

.logo:hover {
    color: #c1121f;
}

nav {
    display: flex;
    gap: 20px;
}

nav a {
    color: #333;
    text-decoration: none;
    font-size: 16px;
    transition: color 0.3s;
    padding: 5px 10px;
}

nav a:hover {
    color: #e63946;
}

/* Hero区域 */
.hero {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 60px 0;
    text-align: center;
    margin-bottom: 40px;
}

.hero h1 {
    font-size: 36px;
    margin-bottom: 20px;
    font-weight: bold;
}

.hero p {
    font-size: 18px;
    opacity: 0.9;
    max-width: 800px;
    margin: 0 auto;
    line-height: 1.8;
}

/* 关键词分类区域 */
.keywords-section {
    margin: 40px 0;
}

.section-title {
    font-size: 28px;
    font-weight: bold;
    margin-bottom: 30px;
    text-align: center;
    color: #333;
}

.keyword-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 25px;
    margin-bottom: 40px;
}

.keyword-card {
    background: white;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 4px 12px rgba(0,0,0,0.1);
    transition: transform 0.3s, box-shadow 0.3s;
    text-decoration: none;
    color: inherit;
    display: block;
}

.keyword-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 20px rgba(0,0,0,0.15);
}

.keyword-image {
    width: 100%;
    height: 200px;
    object-fit: cover;
    display: block;
}

.keyword-content {
    padding: 20px;
}

.keyword-title {
    font-size: 20px;
    font-weight: bold;
    margin-bottom: 10px;
    color: #333;
}

.keyword-desc {
    color: #666;
    font-size: 14px;
    line-height: 1.6;
}

/* 内页链接区域 */
.internal-links {
    background: white;
    padding: 40px 20px;
    border-radius: 12px;
    margin: 40px 0;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}

.internal-links h2 {
    font-size: 24px;
    margin-bottom: 25px;
    text-align: center;
    color: #333;
}

.link-list {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 15px;
    list-style: none;
}

.link-list a {
    color: #667eea;
    text-decoration: none;
    padding: 10px;
    border-radius: 6px;
    transition: background 0.3s;
    display: block;
    text-align: center;
}

.link-list a:hover {
    background: #f0f0f0;
}

/* 关于内容区域 */
.about-content {
    background: white;
    padding: 30px;
    border-radius: 12px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}

.about-content p {
    margin-bottom: 15px;
    line-height: 1.8;
    color: #555;
}

.about-content p:last-child {
    margin-bottom: 0;
}

/* 底部 */
footer {
    background: #2d3748;
    color: white;
    padding: 40px 0 20px;
    margin-top: 60px;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
    margin-bottom: 30px;
}

.footer-section h3 {
    margin-bottom: 15px;
    font-size: 18px;
    color: white;
}

.footer-section a {
    color: #cbd5e0;
    text-decoration: none;
    display: block;
    margin-bottom: 8px;
    transition: color 0.3s;
}

.footer-section a:hover {
    color: white;
}

.footer-bottom {
    text-align: center;
    padding-top: 20px;
    border-top: 1px solid #4a5568;
    color: #cbd5e0;
    font-size: 14px;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .hero h1 {
        font-size: 28px;
    }
    
    .hero p {
        font-size: 16px;
        padding: 0 15px;
    }
    
    nav {
        display: none;
    }
    
    .keyword-grid {
        grid-template-columns: 1fr;
    }
    
    .section-title {
        font-size: 24px;
    }
    
    .link-list {
        grid-template-columns: 1fr;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
    }
}

/* 加载优化 */
img {
    loading: lazy;
}

/* 平滑滚动 */
html {
    scroll-behavior: smooth;
}