/* ========================================
   Product Vision Theme v2.0 - 产品视界
   现代简约设计，墨绿主色，留白充足
   ======================================== */

:root {
    --primary: #10b981;
    --primary-light: #34d399;
    --primary-dark: #059669;
    --secondary: #1e293b;
    --accent: #f59e0b;
    --background: #ffffff;
    --surface: #f8fafc;
    --surface-hover: #f1f5f9;
    --border: #e2e8f0;
    --border-dark: #cbd5e1;
    --text: #334155;
    --text-secondary: #64748b;
    --text-muted: #94a3b8;
    --shadow-sm: 0 1px 2px rgba(0,0,0,0.05);
    --shadow: 0 4px 6px -1px rgba(0,0,0,0.1);
    --space-xs: 4px;
    --space-sm: 8px;
    --space-md: 16px;
    --space-lg: 24px;
    --space-xl: 32px;
    --space-2xl: 48px;
    --space-3xl: 64px;
    --space-4xl: 80px;
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 16px;
    --radius-full: 9999px;
    --transition: all 0.2s ease;
}

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

html {
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
    font-size: 1rem;
    line-height: 1.7;
    color: var(--text);
    background: var(--background);
}

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

a {
    color: inherit;
    text-decoration: none;
    transition: var(--transition);
}

a:hover {
    color: var(--primary);
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

h1, h2, h3, h4, h5, h6 {
    color: var(--secondary);
    font-weight: 700;
    line-height: 1.3;
}

h1 { font-size: 2rem; }
h2 { font-size: 1.5rem; }
h3 { font-size: 1.25rem; }

.container {
    max-width: 1120px;
    margin: 0 auto;
    padding: 0 var(--space-lg);
}

.header {
    background: rgba(255,255,255,0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 64px;
    gap: var(--space-xl);
}

.site-logo {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    font-size: 1.25rem;
    font-weight: 800;
    color: var(--secondary);
    letter-spacing: -0.02em;
    text-decoration: none;
}

.site-logo:hover {
    color: var(--secondary);
}

.logo-icon {
    width: 36px;
    height: 36px;
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
}

.logo-icon svg {
    width: 20px;
    height: 20px;
    color: white;
}

.site-logo span {
    color: var(--primary);
}

.site-nav {
    display: flex;
    align-items: center;
    gap: var(--space-xs);
    flex: 1;
    justify-content: center;
}

.site-nav a {
    padding: var(--space-sm) var(--space-md);
    font-size: 0.9375rem;
    font-weight: 500;
    color: var(--text-secondary);
    border-radius: var(--radius-full);
    transition: var(--transition);
}

.site-nav a:hover {
    color: var(--primary);
    background: var(--surface);
}

.site-nav a.active {
    color: var(--primary);
    background: rgba(16, 185, 129, 0.1);
}

.nav-search {
    display: flex;
    align-items: center;
}

.nav-search form {
    display: flex;
    align-items: center;
    gap: 0;
}

.nav-search input {
    background: var(--surface);
    padding: 10px 16px;
    font-size: 0.875rem;
    width: 180px;
    outline: none;
    border: 1px solid transparent;
    border-radius: var(--radius-full) 0 0 var(--radius-full);
    transition: var(--transition);
    font-weight: 500;
    color: var(--text);
}

.nav-search input:focus {
    background: var(--background);
    border-color: var(--primary);
    width: 220px;
}

.nav-search input::placeholder {
    color: var(--text-muted);
}

.nav-search button {
    background: var(--primary);
    cursor: pointer;
    padding: 10px 16px;
    border: 1px solid var(--primary);
    border-radius: 0 var(--radius-full) var(--radius-full) 0;
    transition: var(--transition);
}

.nav-search button:hover {
    background: var(--primary-dark);
    border-color: var(--primary-dark);
}

.nav-search button svg {
    display: block;
    width: 16px;
    height: 16px;
    color: white;
}

.menu-toggle {
    display: none;
    background: none;
    cursor: pointer;
    padding: var(--space-sm);
    border: none;
}

.menu-toggle svg {
    display: block;
    width: 24px;
    height: 24px;
    color: var(--secondary);
}

.hero-section {
    padding: var(--space-3xl) 0;
}

.hero-grid {
    display: grid;
    grid-template-columns: 1fr 400px;
    gap: var(--space-2xl);
    align-items: center;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: var(--space-xs);
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    color: white;
    padding: 6px 14px;
    font-size: 0.75rem;
    font-weight: 700;
    border-radius: var(--radius-full);
    margin-bottom: var(--space-lg);
}

.hero-badge svg {
    width: 12px;
    height: 12px;
}

.hero-title {
    font-size: 2.75rem;
    font-weight: 800;
    color: var(--secondary);
    line-height: 1.15;
    margin-bottom: var(--space-lg);
    letter-spacing: -0.03em;
}

.hero-title span {
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-desc {
    font-size: 1.125rem;
    color: var(--text-secondary);
    line-height: 1.8;
    margin-bottom: var(--space-xl);
}

.hero-actions {
    display: flex;
    gap: var(--space-md);
    flex-wrap: nowrap;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-sm);
    padding: 10px 20px;
    font-size: 0.875rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    border: none;
    border-radius: var(--radius-full);
    white-space: nowrap;
    flex-shrink: 0;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    color: white;
    box-shadow: 0 4px 14px rgba(16, 185, 129, 0.4);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(16, 185, 129, 0.5);
    color: white;
}

.btn-outline {
    background: transparent;
    color: var(--primary);
    border: 2px solid var(--primary);
}

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

.hero-featured {
    background: white;
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow);
    border: 1px solid var(--border);
}

.hero-featured-label {
    font-size: 0.6875rem;
    font-weight: 700;
    color: var(--accent);
    text-transform: uppercase;
    letter-spacing: 0.08em;
    margin-bottom: var(--space-sm);
    padding: var(--space-md) var(--space-lg) 0;
}

.hero-featured-thumb {
    width: 100%;
    height: 200px;
    object-fit: cover;
    background: var(--surface);
}

.hero-featured-body {
    padding: var(--space-lg);
}

.hero-featured-title {
    font-size: 1.125rem;
    font-weight: 700;
    color: var(--secondary);
    margin-bottom: var(--space-sm);
    line-height: 1.4;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.hero-featured-title a:hover {
    color: var(--primary);
}

.hero-featured-meta {
    display: flex;
    align-items: center;
    gap: var(--space-md);
    font-size: 0.8125rem;
    color: var(--text-muted);
}

.hero-featured-meta .cate {
    background: var(--primary);
    color: white;
    padding: 4px 10px;
    border-radius: var(--radius-full);
    font-weight: 600;
    font-size: 0.6875rem;
}

.main-content {
    margin-top: 0;
    padding-bottom: var(--space-4xl);
}

.section {
    margin-bottom: var(--space-2xl);
}

.section-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: var(--space-lg);
}

.section-title {
    font-size: 1rem;
    font-weight: 700;
    color: var(--text);
    display: flex;
    align-items: center;
    gap: var(--space-sm);
}

.section-title::before {
    content: '';
    width: 24px;
    height: 3px;
    background: linear-gradient(90deg, var(--primary), var(--primary-light));
    border-radius: 2px;
}

.section-more {
    font-size: 0.8125rem;
    font-weight: 600;
    color: var(--text-muted);
    display: flex;
    align-items: center;
    gap: 4px;
    transition: var(--transition);
}

.section-more:hover {
    color: var(--primary);
}

.section-more svg {
    width: 14px;
    height: 14px;
}

.article-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-lg);
}

.friend-links-grid {
    display: grid;
    grid-template-columns: repeat(6, 1fr);
    gap: var(--space-md);
}

.friend-link-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--space-sm);
    padding: var(--space-lg);
    background: white;
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    transition: var(--transition);
    text-align: center;
}

.friend-link-item:hover {
    border-color: var(--primary);
    transform: translateY(-4px);
    box-shadow: var(--shadow);
}

.friend-link-logo {
    width: 48px;
    height: 48px;
    border-radius: var(--radius-sm);
    object-fit: contain;
}

.friend-link-name {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text);
}

.article-card {
    background: white;
    border-radius: var(--radius-md);
    overflow: hidden;
    border: 1px solid var(--border);
    transition: var(--transition);
    display: block;
}

.article-card:hover {
    border-color: var(--primary-light);
    box-shadow: var(--shadow);
    transform: translateY(-4px);
}

.article-card-thumb-wrapper {
    overflow: hidden;
    background: var(--surface);
    aspect-ratio: 16/10;
}

.article-card-thumb {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.4s ease;
}

.article-card:hover .article-card-thumb {
    transform: scale(1.08);
}

.article-card-body {
    padding: var(--space-lg);
}

.article-card-meta {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    font-size: 0.75rem;
    color: var(--text-muted);
    margin-bottom: var(--space-sm);
    font-weight: 500;
}

.article-card-meta .cate-tag {
    background: rgba(16, 185, 129, 0.1);
    color: var(--primary);
    padding: 4px 10px;
    border-radius: var(--radius-full);
    font-weight: 600;
    font-size: 0.6875rem;
    text-transform: uppercase;
    letter-spacing: 0.03em;
}

.article-card-title {
    font-size: 1rem;
    font-weight: 700;
    color: var(--secondary);
    margin-bottom: var(--space-sm);
    line-height: 1.45;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
    transition: color 0.2s ease;
    letter-spacing: -0.01em;
}

.article-card:hover .article-card-title {
    color: var(--primary);
}

.article-card-desc {
    font-size: 0.875rem;
    color: var(--text-secondary);
    line-height: 1.65;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.sidebar {
    position: sticky;
    top: 88px;
}

.widget {
    background: white;
    border-radius: var(--radius-md);
    padding: var(--space-lg);
    margin-bottom: var(--space-lg);
    border: 1px solid var(--border);
}

.widget-title {
    font-size: 0.8125rem;
    font-weight: 700;
    color: var(--secondary);
    margin-bottom: var(--space-md);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.tag-list {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-sm);
}

.tag-item {
    display: inline-flex;
    align-items: center;
    padding: 6px 14px;
    font-size: 0.8125rem;
    font-weight: 500;
    color: var(--text-secondary);
    background: var(--surface);
    border-radius: var(--radius-full);
    transition: var(--transition);
}

.tag-item:hover {
    background: var(--primary);
    color: white;
}

.cate-list {
    list-style: none;
}

.cate-list li {
    margin-bottom: var(--space-xs);
}

.cate-list a {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--space-sm) var(--space-md);
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text);
    background: var(--surface);
    border-radius: var(--radius-sm);
    transition: var(--transition);
}

.cate-list a:hover {
    background: var(--primary);
    color: white;
}

.cate-list a:hover .count {
    background: rgba(255,255,255,0.2);
    color: white;
}

.cate-list .count {
    font-size: 0.75rem;
    font-weight: 700;
    color: var(--text-muted);
    background: white;
    padding: 2px 8px;
    border-radius: var(--radius-full);
}

.article-cover {
    margin: calc(-1 * var(--space-2xl));
    margin-bottom: var(--space-xl);
    border-radius: var(--radius-lg) var(--radius-lg) 0 0;
    overflow: hidden;
    max-height: 200px;
    position: relative;
}

.article-cover::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 80px;
    background: linear-gradient(to bottom, transparent, white);
    pointer-events: none;
}

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

.article-content {
    background: white;
    border-radius: var(--radius-lg);
    padding: var(--space-2xl);
    border: 1px solid var(--border);
    margin-top: var(--space-2xl);
    margin-bottom: var(--space-xl);
}

.article-content .article-cover + .article-header {
    margin-top: var(--space-xl);
}

.article-header {
    margin-bottom: var(--space-xl);
    padding-bottom: var(--space-lg);
    border-bottom: 1px solid var(--border);
}

.article-header h1 {
    font-size: 1.75rem;
    font-weight: 800;
    color: var(--secondary);
    line-height: 1.35;
    margin-bottom: var(--space-md);
    letter-spacing: -0.01em;
}

.article-meta {
    display: flex;
    align-items: center;
    gap: var(--space-lg);
    font-size: 0.875rem;
    color: var(--text-muted);
    flex-wrap: wrap;
}

.article-meta .cate-link {
    background: var(--primary);
    color: white;
    padding: 6px 14px;
    border-radius: var(--radius-full);
    font-weight: 600;
    font-size: 0.75rem;
}

.article-meta .cate-link:hover {
    background: var(--primary-dark);
    color: white;
}

.article-meta .meta-item {
    display: inline-flex;
    align-items: center;
    gap: 6px;
}

.article-meta .meta-item svg {
    opacity: 0.6;
}

.article-body {
    font-size: 1.0625rem;
    line-height: 1.85;
    color: var(--text);
    letter-spacing: 0.01em;
}

.article-body p {
    margin-bottom: var(--space-lg);
}

.article-body h2,
.article-body h3,
.article-body h4 {
    margin: var(--space-2xl) 0 var(--space-md);
    color: var(--secondary);
    font-weight: 700;
}

.article-body h2 {
    font-size: 1.5rem;
    padding-bottom: var(--space-md);
    border-bottom: 1px solid var(--border);
    letter-spacing: -0.02em;
}

.article-body h3 {
    font-size: 1.25rem;
    letter-spacing: -0.01em;
}

.article-body h4 {
    font-size: 1.125rem;
}

.article-body img {
    margin: var(--space-lg) 0;
    border-radius: var(--radius-md);
    border: 1px solid var(--border);
}

.article-body a {
    color: var(--primary);
    text-decoration: underline;
    text-underline-offset: 3px;
}

.article-body a:hover {
    color: var(--primary-dark);
}

.article-body blockquote {
    padding: var(--space-md) var(--space-lg);
    margin: var(--space-lg) 0;
    background: var(--surface);
    border-left: 4px solid var(--primary);
    border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
    color: var(--text-secondary);
}

.article-body code {
    background: var(--surface);
    padding: 2px 6px;
    font-size: 0.875rem;
    font-family: monospace;
    border-radius: var(--radius-sm);
}

.article-body pre {
    background: var(--secondary);
    color: #e2e8f0;
    padding: var(--space-lg);
    overflow-x: auto;
    margin: var(--space-lg) 0;
    font-size: 0.875rem;
    border-radius: var(--radius-md);
}

.article-body pre code {
    background: none;
    padding: 0;
    color: inherit;
}

.article-body ul,
.article-body ol {
    padding-left: var(--space-xl);
    margin-bottom: var(--space-md);
}

.article-body li {
    margin-bottom: var(--space-sm);
}

.article-tags {
    margin-top: var(--space-xl);
    padding-top: var(--space-lg);
    border-top: 1px solid var(--border);
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    flex-wrap: wrap;
}

.article-tags .tags-label {
    font-size: 0.875rem;
    color: var(--text-muted);
    font-weight: 500;
}

.article-tags .tag-list {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-sm);
}

.article-tags .tag-item {
    display: inline-block;
    padding: 6px 14px;
    background: var(--surface);
    color: var(--text-secondary);
    font-size: 0.8125rem;
    border-radius: var(--radius-full);
    text-decoration: none;
    transition: var(--transition);
}

.article-tags .tag-item:hover {
    background: var(--primary);
    color: white;
}

.page-content {
    background: white;
    border-radius: var(--radius-lg);
    padding: var(--space-2xl);
    border: 1px solid var(--border);
    margin-top: var(--space-2xl);
    margin-bottom: var(--space-xl);
}

.page-header {
    margin-bottom: var(--space-xl);
    padding-bottom: var(--space-lg);
    border-bottom: 2px solid var(--primary);
}

.page-header h1 {
    font-size: 1.5rem;
    font-weight: 800;
    color: var(--secondary);
    letter-spacing: -0.02em;
    margin-bottom: var(--space-sm);
}

.page-meta {
    font-size: 0.875rem;
    color: var(--text-muted);
}

.category-header {
    padding: var(--space-2xl);
    background: linear-gradient(135deg, var(--primary) 0%, #1a5a3a 100%);
    border-radius: var(--radius-md);
    margin-bottom: var(--space-xl);
}

.category-header h1 {
    font-size: 1.375rem;
    font-weight: 800;
    color: var(--secondary);
    margin-bottom: var(--space-sm);
    letter-spacing: -0.01em;
}

.category-header p {
    font-size: 0.9375rem;
    color: var(--text-secondary);
}

.tag-page {
    padding-bottom: var(--space-4xl);
}

.tag-header {
    background: linear-gradient(135deg, var(--primary) 0%, #1a5a3a 100%);
    padding: var(--space-2xl) 0;
    margin-bottom: var(--space-xl);
    background-size: cover;
    background-position: center;
}

.tag-header-inner {
    display: flex;
    align-items: center;
    gap: var(--space-lg);
}

.tag-icon {
    width: 64px;
    height: 64px;
    background: rgba(255, 255, 255, 0.2);
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
}

.tag-info h1 {
    font-size: 1.5rem;
    font-weight: 800;
    color: white;
    margin-bottom: var(--space-xs);
    letter-spacing: -0.01em;
}

.tag-info p {
    font-size: 0.9375rem;
    color: rgba(255, 255, 255, 0.9);
}

.tag-info strong {
    font-weight: 700;
    color: white;
}

.pagination-wrapper {
    margin-top: var(--space-2xl);
    display: flex;
    justify-content: center;
}

.tag-page .no-data {
    text-align: center;
    padding: var(--space-4xl) 0;
    color: var(--text-muted);
}

.tag-page .no-data svg {
    margin-bottom: var(--space-lg);
    opacity: 0.5;
}

@media (max-width: 640px) {
    .tag-header {
        padding: var(--space-lg) 0;
    }

    .tag-header-inner {
        flex-direction: column;
        text-align: center;
    }

    .tag-icon {
        width: 56px;
        height: 56px;
    }

    .tag-info h1 {
        font-size: 1.25rem;
    }
}

.search-header {
    padding: var(--space-xl) 0;
    margin-bottom: var(--space-xl);
}

.search-header h1 {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--secondary);
    margin-bottom: var(--space-sm);
}

.search-header p {
    font-size: 0.875rem;
    color: var(--text-muted);
}

.search-box {
    margin-bottom: var(--space-lg);
}

.search-box input {
    width: 100%;
    padding: 14px 20px;
    background: var(--surface);
    font-size: 1rem;
    outline: none;
    border: 2px solid var(--border);
    border-radius: var(--radius-full);
    transition: var(--transition);
}

.search-box input:focus {
    background: white;
    border-color: var(--primary);
}

.pagination {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-xs);
    margin: var(--space-xl) 0;
}

.page-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 40px;
    height: 40px;
    padding: 0 var(--space-md);
    background: white;
    color: var(--text);
    font-size: 0.875rem;
    font-weight: 600;
    border: 1px solid var(--border);
    border-radius: var(--radius-full);
    transition: var(--transition);
}

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

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

.page-dots {
    padding: 0 var(--space-sm);
    color: var(--text-muted);
}

.footer {
    background: var(--secondary);
    color: #94a3b8;
    padding: var(--space-3xl) 0 var(--space-xl);
    margin-top: var(--space-4xl);
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: var(--space-2xl);
    margin-bottom: var(--space-2xl);
}

.footer-brand .site-logo {
    color: white;
    margin-bottom: var(--space-md);
}

.footer-brand .logo-icon {
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
}

.footer-desc {
    font-size: 0.875rem;
    line-height: 1.75;
    color: #94a3b8;
}

.footer-title {
    font-size: 0.8125rem;
    font-weight: 700;
    color: white;
    margin-bottom: var(--space-md);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

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

.footer-links li {
    margin-bottom: var(--space-sm);
}

.footer-links a {
    color: #94a3b8;
    font-size: 0.875rem;
    transition: var(--transition);
}

.footer-links a:hover {
    color: var(--primary-light);
}

.footer-contact li {
    display: flex;
    align-items: center;
    gap: 4px;
    font-size: 0.875rem;
    color: #94a3b8;
    margin-bottom: var(--space-sm);
}

.footer-contact .contact-label {
    color: #64748b;
}

.footer-contact a {
    color: #94a3b8;
}

.footer-contact a:hover {
    color: var(--primary-light);
}

.footer-icp {
    display: flex;
    gap: var(--space-md);
    font-size: 0.8125rem;
}

.footer-icp a {
    color: #64748b;
}

.footer-icp a:hover {
    color: var(--primary-light);
}

.footer-bottom {
    padding-top: var(--space-xl);
    border-top: 1px solid #334155;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: var(--space-md);
}

.footer-copy {
    font-size: 0.8125rem;
    color: #64748b;
}

.error-page {
    text-align: center;
    padding: var(--space-4xl) var(--space-lg);
    min-height: 60vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
}

.error-page h1 {
    font-size: 8rem;
    font-weight: 800;
    color: var(--border-dark);
    line-height: 1;
    letter-spacing: -0.05em;
}

.error-page p {
    font-size: 1.125rem;
    color: var(--text-secondary);
    margin-bottom: var(--space-xl);
    font-weight: 500;
}

.no-data {
    text-align: center;
    padding: var(--space-3xl);
    color: var(--text-muted);
    font-size: 0.9375rem;
    background: var(--surface);
    border-radius: var(--radius-md);
    font-weight: 500;
}

.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 48px;
    height: 48px;
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
    z-index: 999;
    border-radius: var(--radius-full);
    box-shadow: 0 4px 14px rgba(16, 185, 129, 0.4);
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
}

.back-to-top:hover {
    transform: translateY(-4px);
    box-shadow: 0 6px 20px rgba(16, 185, 129, 0.5);
    color: white;
}

.back-to-top svg {
    width: 20px;
    height: 20px;
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.article-card {
    animation: fadeInUp 0.5s ease forwards;
}

.article-card:nth-child(1) { animation-delay: 0s; }
.article-card:nth-child(2) { animation-delay: 0.1s; }
.article-card:nth-child(3) { animation-delay: 0.2s; }
.article-card:nth-child(4) { animation-delay: 0.3s; }
.article-card:nth-child(5) { animation-delay: 0.4s; }
.article-card:nth-child(6) { animation-delay: 0.5s; }

@media (max-width: 1024px) {
    .hero-grid {
        grid-template-columns: 1fr;
        gap: var(--space-xl);
    }

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

    .hero-actions {
        justify-content: center;
        flex-wrap: nowrap;
    }

    .hero-actions .btn {
        flex-shrink: 1;
        padding: 10px 18px;
        font-size: 0.875rem;
    }

    .hero-featured {
        max-width: 500px;
        margin: 0 auto;
    }

    .sidebar {
        display: none;
    }

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

    .friend-links-grid {
        grid-template-columns: repeat(4, 1fr);
    }

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

@media (max-width: 768px) {
    .container {
        padding: 0 var(--space-md);
    }

    .header-inner {
        height: 56px;
    }

    .site-nav {
        display: none;
        position: absolute;
        top: 56px;
        left: 0;
        right: 0;
        background: white;
        flex-direction: column;
        padding: var(--space-md);
        gap: var(--space-xs);
        border-bottom: 1px solid var(--border);
        box-shadow: var(--shadow);
    }

    .site-nav.active {
        display: flex;
    }

    .site-nav a {
        width: 100%;
        padding: var(--space-md);
    }

    .nav-search {
        display: none;
        position: absolute;
        top: 56px;
        left: 0;
        right: 0;
        background: white;
        padding: var(--space-md);
        border-bottom: 1px solid var(--border);
        box-shadow: var(--shadow);
    }

    .nav-search.active {
        display: block;
    }

    .nav-search form {
        width: 100%;
    }

    .nav-search input {
        width: 100%;
        flex: 1;
        border-radius: var(--radius-full);
    }

    .nav-search button {
        border-radius: var(--radius-full);
    }

    .menu-toggle {
        display: block;
    }

    .hero-section {
        padding: var(--space-2xl) 0;
    }

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

    .hero-actions {
        flex-wrap: nowrap;
        justify-content: center;
    }

    .hero-actions .btn {
        flex-shrink: 0;
        padding: 8px 14px;
        font-size: 0.8125rem;
    }

    .hero-featured-thumb {
        height: 160px;
    }

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

    .friend-links-grid {
        grid-template-columns: repeat(3, 1fr);
    }

    .article-content,
    .page-content {
        padding: var(--space-lg);
        margin-top: var(--space-lg);
    }

    .article-header h1,
    .page-content h1 {
        font-size: 1.375rem;
    }

    .footer-grid {
        grid-template-columns: 1fr;
        gap: var(--space-xl);
    }

    .footer-bottom {
        flex-direction: column;
        text-align: center;
    }

    .error-page h1 {
        font-size: 4rem;
    }
}

@media (max-width: 480px) {
    .hero-section {
        padding: var(--space-xl) 0;
    }

    .hero-grid {
        gap: var(--space-lg);
    }

    .hero-title {
        font-size: 1.5rem;
        margin-bottom: var(--space-md);
    }

    .hero-badge {
        font-size: 0.6875rem;
        padding: 4px 10px;
        margin-bottom: var(--space-md);
    }

    .hero-desc {
        font-size: 0.9375rem;
        margin-bottom: var(--space-lg);
    }

    .hero-actions {
        flex-direction: column;
        gap: var(--space-sm);
    }

    .hero-actions .btn {
        width: 100%;
        flex-shrink: 0;
        padding: 12px 20px;
        font-size: 0.875rem;
    }

    .article-meta {
        flex-direction: column;
        align-items: flex-start;
        gap: var(--space-sm);
    }

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

    .back-to-top {
        bottom: 16px;
        right: 16px;
        width: 40px;
        height: 40px;
    }
}

.article-nav {
    display: flex;
    justify-content: space-between;
    gap: var(--space-lg);
    margin-top: var(--space-xl);
    padding-top: var(--space-lg);
    border-top: 1px solid var(--border);
}

.article-nav .nav-item {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: var(--space-xs);
    padding: var(--space-md);
    background: var(--surface);
    border-radius: var(--radius-md);
    text-decoration: none;
    transition: var(--transition);
    border: 1px solid var(--border);
}

.article-nav .nav-item:hover {
    background: var(--primary);
    border-color: var(--primary);
}

.article-nav .nav-item.nav-disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.article-nav .nav-item.nav-next {
    text-align: right;
}

.article-nav .nav-label {
    font-size: 0.75rem;
    color: var(--text-muted);
    transition: color 0.2s;
}

.article-nav .nav-title {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text);
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    transition: color 0.2s;
}

.article-nav .nav-item:hover .nav-label,
.article-nav .nav-item:hover .nav-title {
    color: white;
}

@media (max-width: 640px) {
    .article-nav {
        flex-direction: column;
    }

    .article-nav .nav-item.nav-next {
        text-align: left;
    }
}

.related-articles {
    margin-top: var(--space-2xl);
}

.related-title {
    font-size: 1.125rem;
    font-weight: 700;
    color: var(--secondary);
    margin-bottom: var(--space-lg);
    padding-bottom: var(--space-sm);
    border-bottom: 2px solid var(--primary);
}

.article-card-date {
    font-size: 0.75rem;
    color: var(--text-muted);
}

.article-content .article-cover {
    margin-top: calc(-1 * var(--space-2xl));
    margin-left: calc(-1 * var(--space-2xl));
    margin-right: calc(-1 * var(--space-2xl));
    margin-bottom: var(--space-xl);
}