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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Microsoft YaHei", sans-serif;
    line-height: 1.6;
    color: #1a365d;
    background-color: #fff;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

a {
    text-decoration: none;
    color: inherit;
    transition: color 0.3s ease;
}

/* 导航栏 */
.header {
    background-color: #1a365d;
    padding: 15px 0;
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

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

.nav-brand .logo {
    font-size: 24px;
    font-weight: bold;
    color: #fff;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 30px;
}

.nav-link {
    color: rgba(255, 255, 255, 0.9);
    font-size: 16px;
    padding: 8px 0;
    position: relative;
}

.nav-link:hover,
.nav-link.active {
    color: #fff;
}

.nav-link.active::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 2px;
    background-color: #ff6b35;
}

/* Hero 区域 */
.hero {
    background: linear-gradient(135deg, #1a365d 0%, #2c5282 100%);
    padding: 100px 0;
    text-align: center;
    color: #fff;
}

.hero-title {
    font-size: 48px;
    font-weight: bold;
    margin-bottom: 15px;
}

.hero-subtitle {
    font-size: 20px;
    margin-bottom: 30px;
    opacity: 0.9;
}

/* 按钮样式 */
.btn {
    display: inline-block;
    padding: 12px 30px;
    border-radius: 6px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    border: none;
}

.btn-primary {
    background-color: #ff6b35;
    color: #fff;
}

.btn-primary:hover {
    background-color: #e55a2b;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(255, 107, 53, 0.4);
}

.btn-outline {
    background-color: transparent;
    border: 2px solid #1a365d;
    color: #1a365d;
}

.btn-outline:hover {
    background-color: #1a365d;
    color: #fff;
}

/* 通用区块样式 */
.section {
    padding: 80px 0;
}

.section-title {
    font-size: 32px;
    text-align: center;
    margin-bottom: 50px;
    color: #1a365d;
}

/* 精选文章 */
.featured-articles {
    background-color: #f7fafc;
}

.articles-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 30px;
}

.article-card {
    background: #fff;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.article-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 8px 30px rgba(0, 0, 0, 0.12);
}

.article-image {
    width: 100%;
    height: 250px;
    object-fit: cover;
}

.article-content {
    padding: 25px;
}

.article-category {
    display: inline-block;
    background-color: #ebf8ff;
    color: #2c5282;
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 12px;
    font-weight: 600;
    margin-bottom: 12px;
}

.article-title {
    font-size: 20px;
    margin-bottom: 12px;
    color: #1a365d;
}

.article-excerpt {
    color: #4a5568;
    font-size: 14px;
    line-height: 1.7;
    margin-bottom: 15px;
}

.article-link {
    color: #ff6b35;
    font-weight: 600;
    font-size: 14px;
}

.article-link:hover {
    color: #e55a2b;
}

/* 分类区域 */
.categories {
    background-color: #fff;
}

.categories-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 20px;
}

.category-card {
    background: #fff;
    border: 2px solid #e2e8f0;
    border-radius: 12px;
    padding: 30px 20px;
    text-align: center;
    transition: all 0.3s ease;
}

.category-card:hover {
    border-color: #ff6b35;
    transform: translateY(-5px);
    box-shadow: 0 8px 20px rgba(255, 107, 53, 0.15);
}

.category-icon {
    font-size: 48px;
    margin-bottom: 15px;
}

.category-title {
    font-size: 18px;
    color: #1a365d;
    margin-bottom: 8px;
}

.category-count {
    color: #718096;
    font-size: 14px;
}

/* 最新文章列表 */
.latest-articles {
    background-color: #f7fafc;
}

.articles-list {
    max-width: 800px;
    margin: 0 auto 40px;
}

.article-list-item {
    background: #fff;
    border-radius: 8px;
    margin-bottom: 15px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
    transition: transform 0.3s ease;
}

.article-list-item:hover {
    transform: translateX(5px);
}

.article-list-link {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 25px;
}

.article-list-title {
    font-size: 18px;
    color: #1a365d;
    margin-bottom: 8px;
}

.article-list-meta {
    color: #718096;
    font-size: 14px;
}

.article-list-arrow {
    color: #ff6b35;
    font-size: 20px;
    transition: transform 0.3s ease;
}

.article-list-item:hover .article-list-arrow {
    transform: translateX(5px);
}

.text-center {
    text-align: center;
}

/* 页脚 */
.footer {
    background-color: #1a365d;
    color: rgba(255, 255, 255, 0.9);
    padding: 60px 0 30px;
}

.footer-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 40px;
    margin-bottom: 40px;
}

.footer-title {
    font-size: 24px;
    margin-bottom: 15px;
    color: #fff;
}

.footer-description {
    line-height: 1.8;
    opacity: 0.9;
}

.footer-subtitle {
    font-size: 18px;
    margin-bottom: 20px;
    color: #fff;
}

.footer-links {
    list-style: none;
}

.footer-links li {
    margin-bottom: 12px;
}

.footer-links a:hover {
    color: #ff6b35;
}

.social-links {
    display: flex;
    gap: 15px;
}

.social-link {
    display: inline-block;
    padding: 8px 16px;
    background-color: rgba(255, 255, 255, 0.1);
    border-radius: 6px;
    transition: all 0.3s ease;
}

.social-link:hover {
    background-color: #ff6b35;
    color: #fff;
}

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding-top: 30px;
    text-align: center;
    opacity: 0.8;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .hero-title {
        font-size: 32px;
    }

    .hero-subtitle {
        font-size: 16px;
    }

    .nav-menu {
        gap: 15px;
    }

    .nav-link {
        font-size: 14px;
    }

    .section-title {
        font-size: 26px;
    }

    .articles-grid {
        grid-template-columns: 1fr;
    }

    .categories-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 480px) {
    .categories-grid {
        grid-template-columns: 1fr;
    }
}