* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: #333;
    background: #f8fafc;
}

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

/* 头部导航 */
.header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 15px 0;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

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

.nav-brand h1 a {
    color: white;
    text-decoration: none;
    font-size: 24px;
    font-weight: 600;
}
}

.nav-link:hover,
.nav-link.active {
    opacity: 0.8;
}

.nav-actions {
    display: flex;
    gap: 15px;
}

.btn-primary,
.btn-secondary {
    padding: 8px 20px;
    border-radius: 20px;
    text-decoration: none;
    font-weight: 500;
    transition: all 0.3s ease;
}

.btn-primary {
    background: rgba(255, 255, 255, 0.2);
    color: white;
}

.btn-primary:hover {
    background: rgba(255, 255, 255, 0.3);
}

.btn-secondary {
    color: white;
    border: 1px solid rgba(255, 255, 255, 0.3);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.1);
}

/* 主要内容 */
.main {
    padding: 40px 0;
    min-height: calc(100vh - 200px);
}

.page-header {
    text-align: center;
    margin-bottom: 40px;
}

.page-header h1 {
    font-size: 36px;
    font-weight: 700;
    color: #1e293b;
    margin-bottom: 10px;
}

.page-header p {
    color: #64748b;
    font-size: 18px;
}

.content-grid {
    display: grid;
    grid-template-columns: 1fr 300px;
    gap: 40px;
}

/* 资讯网格 */
.news-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 25px;
    margin-bottom: 40px;
}

.news-card {
    background: white;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.news-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.15);
}

.news-image {
    height: 200px;
    overflow: hidden;
    position: relative;
}

.news-image a {
    display: block;
    width: 100%;
    height: 100%;
}

.news-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.3s ease;
}

.news-card:hover .news-image img {
    transform: scale(1.05);
}

.image-placeholder {
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, #8b5cf6 0%, #7c3aed 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 48px;
}

.featured-badge {
    position: absolute;
    top: 15px;
    right: 15px;
    background: #f59e0b;
    color: white;
    padding: 4px 12px;
    border-radius: 12px;
    font-size: 12px;
    font-weight: 500;
}

.news-content {
    padding: 20px;
}

.news-title {
    margin-bottom: 10px;
}

.news-title a {
    color: #1e293b;
    text-decoration: none;
    font-size: 18px;
    font-weight: 600;
    line-height: 1.4;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.news-title a:hover {
    color: #8b5cf6;
}

.news-summary {
    color: #64748b;
    font-size: 14px;
    line-height: 1.6;
    margin-bottom: 15px;
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.news-meta {
    display: flex;
    gap: 15px;
    margin-bottom: 10px;
    font-size: 12px;
    color: #94a3b8;
}

.news-stats {
    display: flex;
    gap: 15px;
    font-size: 12px;
    color: #94a3b8;
}

/* 分页 */
.pagination {
    display: flex;
    justify-content: center;
    gap: 10px;
    margin-top: 40px;
}

.page-btn {
    padding: 10px 16px;
    background: white;
    color: #64748b;
    text-decoration: none;
    border-radius: 8px;
    border: 1px solid #e2e8f0;
    transition: all 0.3s ease;
}

.page-btn:hover {
    background: #f8fafc;
    border-color: #cbd5e1;
}

.page-btn.active {
    background: #8b5cf6;
    color: white;
    border-color: #8b5cf6;
}

/* 侧边栏 */
.sidebar {
    display: flex;
    flex-direction: column;
    gap: 30px;
}

.sidebar-section {
    background: white;
    border-radius: 12px;
    padding: 25px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
}

.sidebar-section h3 {
    margin: 0 0 20px 0;
    font-size: 18px;
    font-weight: 600;
    color: #374151;
    border-bottom: 2px solid #8b5cf6;
    padding-bottom: 8px;
}

.featured-list {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.featured-item {
    display: flex;
    gap: 12px;
    padding: 12px;
    border-radius: 8px;
    text-decoration: none;
    color: inherit;
    transition: background 0.3s ease;
}

.featured-item:hover {
    background: #f8fafc;
}

.featured-image {
    width: 60px;
    height: 40px;
    border-radius: 6px;
    overflow: hidden;
    flex-shrink: 0;
}

.featured-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.featured-image .image-placeholder {
    font-size: 16px;
    background: #f3f4f6;
    color: #9ca3af;
}

.featured-info {
    flex: 1;
    min-width: 0;
}

.featured-info h4 {
    margin: 0 0 5px 0;
    font-size: 14px;
    font-weight: 500;
    color: #374151;
    line-height: 1.4;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.featured-meta {
    display: flex;
    gap: 10px;
    font-size: 12px;
    color: #64748b;
}

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

.course-link {
    display: flex;
    align-items: center;
    gap: 15px;
    padding: 20px;
    background: #f8fafc;
    border-radius: 8px;
    text-decoration: none;
    color: inherit;
    transition: all 0.3s ease;
}

.course-link:hover {
    background: #f1f5f9;
    transform: translateY(-2px);
}

.course-icon {
    font-size: 32px;
}

.course-text h4 {
    margin: 0 0 5px 0;
    color: #374151;
    font-size: 16px;
    font-weight: 600;
}

.course-text p {
    margin: 0;
    color: #64748b;
    font-size: 14px;
}

/* 空状态 */
.empty-state {
    text-align: center;
    padding: 80px 20px;
    background: white;
    border-radius: 12px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
}

.empty-icon {
    font-size: 64px;
    margin-bottom: 20px;
}

.empty-state h3 {
    color: #374151;
    font-size: 24px;
    margin-bottom: 10px;
}

.empty-state p {
    color: #64748b;
    margin-bottom: 30px;
}

/* 底部 */
.footer {
    background: #1e293b;
    color: white;
    text-align: center;
    padding: 20px 0;
    margin-top: 50px;
}

/* 响应式设计 */
@media (max-width: 1024px) {
    .content-grid {
        grid-template-columns: 1fr;
        gap: 30px;
    }
    
    .sidebar {
        order: -1;
    }
}

@media (max-width: 768px) {
    .header .container {
        flex-direction: column;
        gap: 15px;
    }
    
    .nav-menu {
        gap: 20px;
    }
    
    .page-header h1 {
        font-size: 28px;
    }
    
    .page-header p {
        font-size: 16px;
    }
    
    .news-grid {
        grid-template-columns: 1fr;
        gap: 20px;
    }
    
    .news-content {
        padding: 15px;
    }
    
    .sidebar-section {
        padding: 20px;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 15px;
    }
    
    .news-image {
        height: 150px;
    }
    
    .news-title a {
        font-size: 16px;
    }
    
    .news-summary {
        font-size: 13px;
    }
    
    .pagination {
        flex-wrap: wrap;
    }
    
    .page-btn {
        padding: 8px 12px;
        font-size: 14px;
    }
}