/* ===================================
   现代化 Blog 前台样式
   精致、专业、避免框架感
   =================================== */

/* ========== 全局变量 ========== */
:root {
    /* 颜色系统 - 使用现代化的渐变色 */
    --primary: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --primary-solid: #667eea;
    --secondary: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
    --accent: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);

    /* 中性色 */
    --dark: #1a1a2e;
    --text-primary: #2d2d3a;
    --text-secondary: #6b7280;
    --text-light: #9ca3af;

    /* 背景色 */
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-card: #ffffff;

    /* 边框和分隔 */
    --border-color: #e5e7eb;
    --border-radius: 16px;
    --border-radius-sm: 8px;

    /* 阴影系统 */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-md: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-lg: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    --shadow-xl: 0 25px 50px -12px rgba(0, 0, 0, 0.25);

    /* 动画 */
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-fast: all 0.15s ease;

    /* 字体 */
    --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-display: 'Playfair Display', serif;

    /* 间距 */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
}

/* ========== 基础重置 ========== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: var(--font-primary);
    font-size: 16px;
    line-height: 1.7;
    color: var(--text-primary);
    background: var(--bg-secondary);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

::selection {
    background: var(--primary-solid);
    color: white;
}

/* ========== 容器 ========== */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

/* ========== 导航栏 ========== */
.site-header {
    background: var(--bg-card);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 1000;
    backdrop-filter: blur(10px);
    background: rgba(255, 255, 255, 0.9);
    box-shadow: var(--shadow-sm);
}

.navbar {
    padding: var(--spacing-md) 0;
}

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

.logo {
    text-decoration: none;
    position: relative;
}

.logo-text {
    font-size: 1.5rem;
    font-weight: 700;
    background: var(--primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    letter-spacing: -0.5px;
}

.nav-menu {
    display: flex;
    gap: var(--spacing-lg);
    align-items: center;
}

.nav-link {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    font-size: 0.95rem;
    transition: var(--transition);
    position: relative;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary);
    transition: var(--transition);
}

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

.nav-link:hover::after {
    width: 100%;
}

.mobile-menu-toggle {
    display: none;
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--text-primary);
}

/* ========== 主内容区 ========== */
.main-content {
    min-height: calc(100vh - 300px);
    padding: var(--spacing-xl) 0;
}

/* ========== 文章卡片 ========== */
.posts-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
    gap: var(--spacing-lg);
    margin-top: var(--spacing-lg);
}

.post-card {
    background: var(--bg-card);
    border-radius: var(--border-radius);
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: var(--transition);
    display: flex;
    flex-direction: column;
    border: 1px solid var(--border-color);
}

.post-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.post-card-image {
    width: 100%;
    height: 200px;
    background: var(--primary);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 3rem;
    font-weight: 700;
}

.post-card-content {
    padding: var(--spacing-md);
    flex: 1;
    display: flex;
    flex-direction: column;
}

.post-meta {
    display: flex;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-sm);
    flex-wrap: wrap;
}

.post-category {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    background: var(--accent);
    color: white;
    border-radius: 20px;
    font-size: 0.75rem;
    font-weight: 600;
    text-decoration: none;
    transition: var(--transition);
}

.post-category:hover {
    transform: scale(1.05);
}

.post-date {
    display: flex;
    align-items: center;
    gap: 0.25rem;
    color: var(--text-light);
    font-size: 0.875rem;
}

.post-card-title {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
    line-height: 1.4;
}

.post-card-title a {
    color: var(--text-primary);
    text-decoration: none;
    transition: var(--transition);
}

.post-card-title a:hover {
    background: var(--primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.post-excerpt {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-md);
    font-size: 0.95rem;
    line-height: 1.6;
    flex: 1;
}

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

.post-author {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--text-secondary);
    font-size: 0.875rem;
}

.post-views {
    color: var(--text-light);
    font-size: 0.875rem;
    display: flex;
    align-items: center;
    gap: 0.25rem;
}

/* ========== 文章详情页 ========== */
.post-detail {
    max-width: 800px;
    margin: 0 auto;
    background: var(--bg-card);
    border-radius: var(--border-radius);
    padding: var(--spacing-xl);
    box-shadow: var(--shadow-md);
}

.post-header {
    text-align: center;
    margin-bottom: var(--spacing-xl);
    padding-bottom: var(--spacing-lg);
    border-bottom: 2px solid var(--border-color);
}

.post-title {
    font-family: var(--font-display);
    font-size: 2.5rem;
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: var(--spacing-md);
    color: var(--dark);
}

.post-meta-detail {
    display: flex;
    justify-content: center;
    gap: var(--spacing-lg);
    flex-wrap: wrap;
    color: var(--text-secondary);
    font-size: 0.95rem;
}

.post-meta-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.post-tags {
    display: flex;
    gap: var(--spacing-sm);
    justify-content: center;
    flex-wrap: wrap;
    margin-top: var(--spacing-md);
}

.tag-badge {
    display: inline-block;
    padding: 0.4rem 0.9rem;
    background: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
    color: white;
    border-radius: 20px;
    font-size: 0.85rem;
    text-decoration: none;
    transition: var(--transition);
    font-weight: 500;
}

.tag-badge:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow);
}

.post-content {
    font-size: 1.1rem;
    line-height: 1.8;
    color: var(--text-primary);
}

.post-content h1,
.post-content h2,
.post-content h3 {
    margin-top: var(--spacing-lg);
    margin-bottom: var(--spacing-md);
    color: var(--dark);
    font-weight: 700;
}

.post-content h2 {
    font-size: 1.8rem;
}

.post-content h3 {
    font-size: 1.4rem;
}

.post-content p {
    margin-bottom: var(--spacing-md);
}

.post-content a {
    color: var(--primary-solid);
    text-decoration: none;
    border-bottom: 1px solid var(--primary-solid);
    transition: var(--transition);
}

.post-content a:hover {
    opacity: 0.8;
}

.post-content img {
    max-width: 100%;
    border-radius: var(--border-radius-sm);
    margin: var(--spacing-md) 0;
}

.post-content code {
    background: var(--bg-secondary);
    padding: 0.2rem 0.4rem;
    border-radius: 4px;
    font-size: 0.9em;
    font-family: 'Consolas', 'Monaco', monospace;
}

.post-content pre {
    background: var(--dark);
    color: #f8f8f2;
    padding: var(--spacing-md);
    border-radius: var(--border-radius-sm);
    overflow-x: auto;
    margin: var(--spacing-md) 0;
}

.post-content pre code {
    background: none;
    padding: 0;
    color: inherit;
}

/* ========== 分页 ========== */
.pagination {
    display: flex;
    justify-content: center;
    gap: var(--spacing-sm);
    margin-top: var(--spacing-xl);
}

.pagination a,
.pagination span {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 40px;
    height: 40px;
    padding: 0 var(--spacing-sm);
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius-sm);
    text-decoration: none;
    color: var(--text-primary);
    font-weight: 500;
    transition: var(--transition);
}

.pagination a:hover {
    background: var(--primary);
    color: white;
    border-color: transparent;
    transform: translateY(-2px);
}

.pagination .active {
    background: var(--primary);
    color: white;
    border-color: transparent;
}

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

/* ========== 页脚 ========== */
.site-footer {
    background: var(--dark);
    color: white;
    padding: var(--spacing-xl) 0 var(--spacing-lg);
    margin-top: var(--spacing-xl);
}

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

.footer-section h3,
.footer-section h4 {
    margin-bottom: var(--spacing-md);
    font-weight: 600;
}

.footer-section p {
    color: rgba(255, 255, 255, 0.7);
    line-height: 1.6;
}

.footer-section ul {
    list-style: none;
}

.footer-section ul li {
    margin-bottom: var(--spacing-sm);
}

.footer-section a {
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    transition: var(--transition);
}

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

.footer-bottom {
    text-align: center;
    padding-top: var(--spacing-lg);
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    color: rgba(255, 255, 255, 0.5);
}

/* ========== 响应式设计 ========== */
@media (max-width: 768px) {
    .nav-menu {
        display: none;
    }

    .mobile-menu-toggle {
        display: block;
    }

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

    .post-title {
        font-size: 2rem;
    }

    .post-content {
        font-size: 1rem;
    }
}

/* ========== 页面标题 ========== */
.page-header {
    text-align: center;
    margin-bottom: var(--spacing-xl);
    padding: var(--spacing-xl) 0;
}

.page-title {
    font-family: var(--font-display);
    font-size: 3rem;
    font-weight: 700;
    background: var(--primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: var(--spacing-sm);
}

.page-description {
    color: var(--text-secondary);
    font-size: 1.1rem;
}

/* ========== 搜索 ========== */
.search-form {
    max-width: 600px;
    margin: 0 auto var(--spacing-xl);
}

.search-input-group {
    display: flex;
    gap: var(--spacing-sm);
}

.search-input {
    flex: 1;
    padding: var(--spacing-sm) var(--spacing-md);
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius-sm);
    font-size: 1rem;
    transition: var(--transition);
}

.search-input:focus {
    outline: none;
    border-color: var(--primary-solid);
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

.search-button {
    padding: var(--spacing-sm) var(--spacing-lg);
    background: var(--primary);
    color: white;
    border: none;
    border-radius: var(--border-radius-sm);
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
}

.search-button:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

/* ========== 空状态 ========== */
.empty-state {
    text-align: center;
    padding: var(--spacing-xl);
    color: var(--text-secondary);
}

.empty-state i {
    font-size: 4rem;
    margin-bottom: var(--spacing-md);
    opacity: 0.3;
}

/* ========== Social Links ========== */
.social-links {
    display: flex;
    gap: var(--spacing-sm);
    margin-top: var(--spacing-md);
    flex-wrap: wrap;
}

.social-links a {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    color: white;
    font-size: 1.2rem;
    transition: var(--transition);
    text-decoration: none;
}

.social-links a:hover {
    background: rgba(255, 255, 255, 0.2);
    transform: translateY(-3px);
}