/* 全局样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #3498db;
    --primary-dark: #2980b9;
    --secondary-color: #2c3e50;
    --text-color: #333;
    --text-light: #666;
    --border-color: #ddd;
    --bg-color: #f8f9fa;
    --card-bg: #ffffff;
    --success-color: #27ae60;
    --danger-color: #e74c3c;
    --warning-color: #f39c12;
    --shadow: 0 2px 8px rgba(0,0,0,0.1);
    --shadow-hover: 0 4px 16px rgba(0,0,0,0.15);
}

body {
    font-family: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    color: var(--text-color);
    background-color: var(--bg-color);
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

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

/* 头部导航 */
.header {
    background: var(--card-bg);
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 100;
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 0;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.nav {
    display: flex;
    gap: 2rem;
}

.nav-link {
    color: var(--text-color);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s;
    position: relative;
}

.nav-link:hover,
.nav-link.active {
    color: var(--primary-color);
}

.nav-link.active::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 100%;
    height: 2px;
    background: var(--primary-color);
}

/* 主内容区 */
.main {
    flex: 1;
    padding: 2rem 0;
}

/* 筛选区域 */
.filter-section {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 1rem;
    margin-bottom: 2rem;
    flex-wrap: wrap;
}

.filter-buttons {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.filter-btn {
    padding: 0.5rem 1rem;
    border: 1px solid var(--border-color);
    background: var(--card-bg);
    border-radius: 20px;
    cursor: pointer;
    transition: all 0.3s;
    font-size: 0.9rem;
}

.filter-btn:hover {
    background: var(--bg-color);
}

.filter-btn.active {
    background: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

.search-box {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    background: var(--card-bg);
    padding: 0.5rem 1rem;
    border-radius: 20px;
    border: 1px solid var(--border-color);
    min-width: 250px;
}

.search-box i {
    color: var(--text-light);
}

.search-box input {
    border: none;
    outline: none;
    background: transparent;
    flex: 1;
    font-size: 0.9rem;
}

/* 文章网格 */
.posts-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.post-card {
    background: var(--card-bg);
    border-radius: 12px;
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: all 0.3s;
    cursor: pointer;
    display: flex;
    flex-direction: column;
}

.post-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-hover);
}

.post-cover {
    width: 100%;
    height: 200px;
    object-fit: cover;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
}

.post-content {
    padding: 1.5rem;
    flex: 1;
    display: flex;
    flex-direction: column;
}

.post-meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
    font-size: 0.85rem;
    color: var(--text-light);
}

.post-category {
    background: var(--primary-color);
    color: white;
    padding: 0.25rem 0.75rem;
    border-radius: 12px;
    font-size: 0.8rem;
}

.post-views {
    display: flex;
    align-items: center;
    gap: 0.3rem;
}

.post-title {
    font-size: 1.3rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--secondary-color);
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.post-summary {
    color: var(--text-light);
    font-size: 0.95rem;
    line-height: 1.6;
    margin-bottom: 1rem;
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
    flex: 1;
}

.post-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: 1rem;
    border-top: 1px solid var(--border-color);
}

.post-author {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--text-light);
    font-size: 0.9rem;
}

.post-date {
    color: var(--text-light);
    font-size: 0.85rem;
}

.post-tags {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
    margin-top: 0.5rem;
}

.tag {
    background: var(--bg-color);
    padding: 0.2rem 0.6rem;
    border-radius: 10px;
    font-size: 0.8rem;
    color: var(--text-light);
}

/* 加载状态 */
.loading {
    text-align: center;
    padding: 3rem;
    color: var(--text-light);
    font-size: 1.2rem;
}

.loading i {
    margin-right: 0.5rem;
}

/* 空状态 */
.empty-state {
    text-align: center;
    padding: 4rem 2rem;
    color: var(--text-light);
}

.empty-state i {
    font-size: 4rem;
    margin-bottom: 1rem;
    color: var(--border-color);
}

.empty-state p {
    font-size: 1.2rem;
    margin-bottom: 1.5rem;
}

/* 分页 */
.pagination {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 1rem;
    margin: 2rem 0;
}

.pagination-btn {
    padding: 0.75rem 1.5rem;
    border: 1px solid var(--border-color);
    background: var(--card-bg);
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.pagination-btn:hover:not(:disabled) {
    background: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

.pagination-btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.page-info {
    font-weight: 500;
    color: var(--text-color);
}

/* 按钮样式 */
.btn {
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    font-size: 1rem;
    transition: all 0.3s;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    text-decoration: none;
}

.btn-primary {
    background: var(--primary-color);
    color: white;
}

.btn-primary:hover {
    background: var(--primary-dark);
}

.btn-success {
    background: var(--success-color);
    color: white;
}

.btn-danger {
    background: var(--danger-color);
    color: white;
}

.btn-secondary {
    background: var(--border-color);
    color: var(--text-color);
}

/* 页脚 */
.footer {
    background: var(--secondary-color);
    color: white;
    text-align: center;
    padding: 2rem 0;
    margin-top: auto;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .header-content {
        flex-direction: column;
        gap: 1rem;
    }

    .filter-section {
        flex-direction: column;
        align-items: stretch;
    }

    .search-box {
        min-width: 100%;
    }

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

    .nav {
        gap: 1rem;
    }
}