:root {
  --accent-color: #e67e22;
  --accent-hover: #d35400;
  --text-primary: #2c3e50;
  --text-secondary: #7f8c8d;
  --bg-primary: #ffffff;
  --bg-secondary: #f8f9fa;
  --bg-card: #ffffff;
  --border-color: #e9ecef;
  --shadow: 0 2px 8px rgba(0,0,0,0.08);
  --shadow-hover: 0 4px 16px rgba(0,0,0,0.12);
  --radius: 8px;
  --max-width: 1200px;
  --header-height: 64px;
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  font-size: 16px;
  line-height: 1.6;
  color: var(--text-primary);
  background: var(--bg-secondary);
}

a {
  color: var(--accent-color);
  text-decoration: none;
  transition: color 0.2s;
}

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

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 20px;
}

/* Header */
.header {
  background: var(--bg-primary);
  border-bottom: 1px solid var(--border-color);
  position: sticky;
  top: 0;
  z-index: 100;
}

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

.logo {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--accent-color);
}

.nav {
  display: flex;
  gap: 32px;
}

.nav a {
  color: var(--text-primary);
  font-weight: 500;
}

.nav a:hover {
  color: var(--accent-color);
}

/* Search Box */
.search-box {
  position: relative;
  max-width: 600px;
  margin: 0 auto;
}

.search-box input {
  width: 100%;
  padding: 16px 24px;
  font-size: 1rem;
  border: 2px solid var(--border-color);
  border-radius: var(--radius);
  outline: none;
  transition: border-color 0.2s, box-shadow 0.2s;
}

.search-box input:focus {
  border-color: var(--accent-color);
  box-shadow: 0 0 0 3px rgba(230,126,34,0.1);
}

.search-box button {
  position: absolute;
  right: 8px;
  top: 50%;
  transform: translateY(-50%);
  padding: 10px 24px;
  background: var(--accent-color);
  color: white;
  border: none;
  border-radius: var(--radius);
  cursor: pointer;
  font-weight: 500;
  transition: background 0.2s;
}

.search-box button:hover {
  background: var(--accent-hover);
}

/* Hero Section */
.hero {
  background: linear-gradient(135deg, #fff5eb 0%, #ffffff 100%);
  padding: 60px 0;
  text-align: center;
}

.hero h1 {
  font-size: 2.5rem;
  margin-bottom: 16px;
  color: var(--text-primary);
}

.hero p {
  font-size: 1.125rem;
  color: var(--text-secondary);
  margin-bottom: 32px;
}

/* Category Filter */
.category-filter {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  justify-content: center;
  margin: 32px 0;
}

.category-filter a {
  padding: 10px 20px;
  background: var(--bg-primary);
  border: 1px solid var(--border-color);
  border-radius: 24px;
  color: var(--text-primary);
  font-size: 0.875rem;
  transition: all 0.2s;
}

.category-filter a:hover,
.category-filter a.active {
  background: var(--accent-color);
  color: white;
  border-color: var(--accent-color);
}

/* Section Title */
.section-title {
  font-size: 1.5rem;
  font-weight: 600;
  margin-bottom: 24px;
  display: flex;
  align-items: center;
  gap: 12px;
}

.section-title::before {
  content: '';
  width: 4px;
  height: 24px;
  background: var(--accent-color);
  border-radius: 2px;
}

/* Cards */
.card {
  background: var(--bg-card);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  transition: box-shadow 0.2s, transform 0.2s;
  overflow: hidden;
}

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

.card-body {
  padding: 20px;
}

.card-title {
  font-size: 1.125rem;
  font-weight: 600;
  margin-bottom: 8px;
}

.card-text {
  color: var(--text-secondary);
  font-size: 0.875rem;
  line-height: 1.6;
}

.card-meta {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-top: 16px;
  font-size: 0.75rem;
  color: var(--text-secondary);
}

/* Link Cards */
.link-card {
  display: flex;
  align-items: flex-start;
  gap: 16px;
  padding: 20px;
  background: var(--bg-card);
  border-radius: var(--radius);
  border: 1px solid var(--border-color);
  transition: all 0.2s;
}

.link-card:hover {
  border-color: var(--accent-color);
  box-shadow: var(--shadow);
}

.link-icon {
  width: 48px;
  height: 48px;
  background: linear-gradient(135deg, var(--accent-color), var(--accent-hover));
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: 1.25rem;
  flex-shrink: 0;
}

.link-content {
  flex: 1;
}

.link-title {
  font-size: 1.125rem;
  font-weight: 600;
  margin-bottom: 4px;
}

.link-url {
  font-size: 0.875rem;
  color: var(--text-secondary);
  margin-bottom: 8px;
}

.link-desc {
  font-size: 0.875rem;
  color: var(--text-secondary);
  line-height: 1.5;
}

.link-badge {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 4px 10px;
  background: #e8f5e9;
  color: #2e7d32;
  font-size: 0.75rem;
  border-radius: 12px;
  margin-top: 8px;
}

/* Grid Layouts */
.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.grid-4 {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
}

/* Article List */
.article-list {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.article-item {
  display: flex;
  gap: 16px;
  padding: 16px;
  background: var(--bg-card);
  border-radius: var(--radius);
  border: 1px solid var(--border-color);
  transition: all 0.2s;
}

.article-item:hover {
  border-color: var(--accent-color);
}

.article-thumb {
  width: 120px;
  height: 80px;
  background: var(--bg-secondary);
  border-radius: var(--radius);
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-secondary);
  font-size: 0.75rem;
}

.article-content {
  flex: 1;
}

.article-title {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 8px;
  line-height: 1.4;
}

.article-meta {
  display: flex;
  gap: 16px;
  font-size: 0.75rem;
  color: var(--text-secondary);
}

/* Breadcrumb */
.breadcrumb {
  padding: 16px 0;
  font-size: 0.875rem;
  color: var(--text-secondary);
}

.breadcrumb a {
  color: var(--text-secondary);
}

.breadcrumb a:hover {
  color: var(--accent-color);
}

.breadcrumb span {
  margin: 0 8px;
}

/* Page Header */
.page-header {
  background: linear-gradient(135deg, #fff5eb 0%, #ffffff 100%);
  padding: 40px 0;
  margin-bottom: 32px;
}

.page-header h1 {
  font-size: 2rem;
  margin-bottom: 8px;
}

.page-header p {
  color: var(--text-secondary);
}

/* Sub Categories */
.sub-categories {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 32px;
}

.sub-category {
  padding: 12px 20px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  color: var(--text-primary);
  font-size: 0.875rem;
  transition: all 0.2s;
}

.sub-category:hover {
  border-color: var(--accent-color);
  color: var(--accent-color);
}

/* Pagination */
.pagination {
  display: flex;
  justify-content: center;
  gap: 8px;
  margin-top: 40px;
}

.pagination a,
.pagination span {
  padding: 10px 16px;
  border-radius: var(--radius);
  font-size: 0.875rem;
}

.pagination a {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  color: var(--text-primary);
}

.pagination a:hover {
  border-color: var(--accent-color);
  color: var(--accent-color);
}

.pagination .current {
  background: var(--accent-color);
  color: white;
}

/* Article Content */
.article-content-detail {
  background: var(--bg-card);
  border-radius: var(--radius);
  padding: 40px;
  box-shadow: var(--shadow);
}

.article-header {
  margin-bottom: 32px;
  padding-bottom: 24px;
  border-bottom: 1px solid var(--border-color);
}

.article-header h1 {
  font-size: 2rem;
  margin-bottom: 16px;
  line-height: 1.3;
}

.article-info {
  display: flex;
  gap: 24px;
  font-size: 0.875rem;
  color: var(--text-secondary);
}

.article-body {
  font-size: 1rem;
  line-height: 1.8;
}

.article-body h2 {
  font-size: 1.5rem;
  margin: 32px 0 16px;
}

.article-body h3 {
  font-size: 1.25rem;
  margin: 24px 0 12px;
}

.article-body p {
  margin-bottom: 16px;
}

.article-body ul,
.article-body ol {
  margin-bottom: 16px;
  padding-left: 24px;
}

.article-body li {
  margin-bottom: 8px;
}

/* Tags */
.tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 24px;
}

.tag {
  padding: 6px 14px;
  background: var(--bg-secondary);
  border-radius: 16px;
  font-size: 0.875rem;
  color: var(--text-secondary);
}

/* Sidebar */
.sidebar-section {
  background: var(--bg-card);
  border-radius: var(--radius);
  padding: 20px;
  margin-bottom: 24px;
  box-shadow: var(--shadow);
}

.sidebar-title {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 16px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--border-color);
}

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

.sidebar-list li {
  padding: 10px 0;
  border-bottom: 1px solid var(--border-color);
}

.sidebar-list li:last-child {
  border-bottom: none;
}

.sidebar-list a {
  color: var(--text-primary);
  font-size: 0.875rem;
  display: block;
}

.sidebar-list a:hover {
  color: var(--accent-color);
}

/* Stats */
.stats {
  display: flex;
  justify-content: center;
  gap: 40px;
  padding: 24px 0;
  margin-top: 32px;
  border-top: 1px solid var(--border-color);
}

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

.stat-value {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--accent-color);
}

.stat-label {
  font-size: 0.875rem;
  color: var(--text-secondary);
}

/* 404 Page */
.error-page {
  text-align: center;
  padding: 80px 20px;
}

.error-code {
  font-size: 8rem;
  font-weight: 700;
  color: var(--accent-color);
  line-height: 1;
  margin-bottom: 24px;
}

.error-title {
  font-size: 1.5rem;
  margin-bottom: 16px;
}

.error-desc {
  color: var(--text-secondary);
  margin-bottom: 32px;
}

.btn {
  display: inline-block;
  padding: 12px 32px;
  background: var(--accent-color);
  color: white;
  border-radius: var(--radius);
  font-weight: 500;
  transition: background 0.2s;
}

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

/* Footer */
.footer {
  background: var(--text-primary);
  color: white;
  padding: 40px 0;
  margin-top: 60px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px;
}

.footer-brand {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 16px;
}

.footer-desc {
  font-size: 0.875rem;
  color: rgba(255,255,255,0.7);
  line-height: 1.6;
}

.footer-title {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 16px;
}

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

.footer-links li {
  margin-bottom: 10px;
}

.footer-links a {
  color: rgba(255,255,255,0.7);
  font-size: 0.875rem;
}

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

.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.1);
  margin-top: 40px;
  padding-top: 20px;
  text-align: center;
  font-size: 0.875rem;
  color: rgba(255,255,255,0.5);
}

/* Responsive */
@media (max-width: 992px) {
  .grid-3,
  .grid-4 {
    grid-template-columns: repeat(2, 1fr);
  }

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

@media (max-width: 768px) {
  .nav {
    display: none;
  }

  .hero h1 {
    font-size: 1.75rem;
  }

  .grid-3,
  .grid-4 {
    grid-template-columns: 1fr;
  }

  .article-item {
    flex-direction: column;
  }

  .article-thumb {
    width: 100%;
    height: 160px;
  }

  .article-content-detail {
    padding: 24px;
  }

  .article-header h1 {
    font-size: 1.5rem;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 24px;
  }

  .stats {
    flex-direction: column;
    gap: 16px;
  }
}

/* Main Content */
.main {
  padding: 40px 0;
}

.section {
  margin-bottom: 48px;
}

/* Two Column Layout */
.two-column {
  display: grid;
  grid-template-columns: 1fr 320px;
  gap: 32px;
}

@media (max-width: 992px) {
  .two-column {
    grid-template-columns: 1fr;
  }
}