/* 人体工学椅 - 电子书风格样式 */

:root {
  --accent-color: #795548;
  --accent-light: #a1887f;
  --accent-dark: #5d4037;
  --text-primary: #2c2c2c;
  --text-secondary: #666;
  --text-muted: #999;
  --bg-primary: #faf8f5;
  --bg-secondary: #f5f2ed;
  --bg-card: #fff;
  --border-color: #e8e4de;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.05);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.08);
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --max-width: 1200px;
  --header-height: 64px;
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  font-size: 16px;
  line-height: 1.7;
  color: var(--text-primary);
  background-color: var(--bg-primary);
}

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

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

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

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

.header-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
  height: var(--header-height);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  font-size: 20px;
  font-weight: 700;
  color: var(--accent-color);
  display: flex;
  align-items: center;
  gap: 8px;
}

.logo-icon {
  width: 32px;
  height: 32px;
  background: var(--accent-color);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-size: 14px;
}

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

.nav a {
  color: var(--text-secondary);
  font-size: 15px;
  font-weight: 500;
}

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

.search-box {
  position: relative;
}

.search-box input {
  width: 240px;
  padding: 8px 16px 8px 40px;
  border: 1px solid var(--border-color);
  border-radius: 20px;
  background: var(--bg-secondary);
  font-size: 14px;
  outline: none;
  transition: all 0.2s;
}

.search-box input:focus {
  border-color: var(--accent-light);
  background: var(--bg-card);
}

.search-box::before {
  content: "🔍";
  position: absolute;
  left: 14px;
  top: 50%;
  transform: translateY(-50%);
  font-size: 14px;
  opacity: 0.5;
}

/* Main Container */
.main {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 40px 24px;
}

/* Hero Section */
.hero {
  text-align: center;
  padding: 60px 20px;
  background: linear-gradient(135deg, var(--bg-secondary) 0%, var(--bg-primary) 100%);
  border-radius: var(--radius-lg);
  margin-bottom: 48px;
}

.hero h1 {
  font-size: 42px;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 16px;
  letter-spacing: -0.5px;
}

.hero p {
  font-size: 18px;
  color: var(--text-secondary);
  max-width: 600px;
  margin: 0 auto;
}

/* Section Title */
.section-title {
  font-size: 24px;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 24px;
  padding-bottom: 12px;
  border-bottom: 2px solid var(--accent-color);
  display: inline-block;
}

/* Card Grid */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 24px;
  margin-bottom: 48px;
}

.card {
  background: var(--bg-card);
  border-radius: var(--radius-md);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border-color);
  transition: all 0.3s;
}

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

.card-cover {
  aspect-ratio: 16/10;
  background: var(--bg-secondary);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-muted);
  font-size: 14px;
  overflow: hidden;
}

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

.card-body {
  padding: 20px;
}

.card-title {
  font-size: 18px;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 8px;
  line-height: 1.4;
}

.card-meta {
  font-size: 13px;
  color: var(--text-muted);
  display: flex;
  gap: 12px;
}

.card-desc {
  font-size: 14px;
  color: var(--text-secondary);
  margin-top: 12px;
  line-height: 1.6;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

/* Category Grid */
.category-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  margin-bottom: 48px;
}

.category-item {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 24px;
  text-align: center;
  transition: all 0.3s;
}

.category-item:hover {
  border-color: var(--accent-light);
  box-shadow: var(--shadow-md);
}

.category-icon {
  width: 48px;
  height: 48px;
  background: var(--bg-secondary);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 12px;
  font-size: 24px;
}

.category-name {
  font-size: 16px;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 4px;
}

.category-count {
  font-size: 13px;
  color: var(--text-muted);
}

/* List View */
.list-view {
  background: var(--bg-card);
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
  overflow: hidden;
  margin-bottom: 48px;
}

.list-item {
  display: flex;
  gap: 20px;
  padding: 20px 24px;
  border-bottom: 1px solid var(--border-color);
  transition: background 0.2s;
}

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

.list-item:hover {
  background: var(--bg-secondary);
}

.list-thumb {
  width: 120px;
  height: 80px;
  background: var(--bg-secondary);
  border-radius: var(--radius-sm);
  flex-shrink: 0;
  overflow: hidden;
}

.list-thumb img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.list-content {
  flex: 1;
  min-width: 0;
}

.list-title {
  font-size: 17px;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 6px;
}

.list-meta {
  font-size: 13px;
  color: var(--text-muted);
  margin-bottom: 8px;
}

.list-desc {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.6;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

/* Three Column Section */
.three-col {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-bottom: 48px;
}

.col-section {
  background: var(--bg-card);
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
  padding: 24px;
}

.col-title {
  font-size: 16px;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 16px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--border-color);
}

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

.col-list li {
  padding: 10px 0;
  border-bottom: 1px dashed var(--border-color);
  font-size: 14px;
}

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

.col-list a {
  color: var(--text-secondary);
  display: block;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

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

/* Breadcrumb */
.breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 14px;
  color: var(--text-muted);
  margin-bottom: 24px;
}

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

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

.breadcrumb-sep {
  opacity: 0.5;
}

/* Page Header */
.page-header {
  text-align: center;
  padding: 40px 20px;
  margin-bottom: 32px;
}

.page-header h1 {
  font-size: 32px;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 8px;
}

.page-header p {
  color: var(--text-secondary);
  font-size: 16px;
}

/* Filter Bar */
.filter-bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 16px 24px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  margin-bottom: 24px;
}

.filter-tabs {
  display: flex;
  gap: 8px;
}

.filter-tab {
  padding: 6px 16px;
  border-radius: 20px;
  font-size: 14px;
  color: var(--text-secondary);
  background: var(--bg-secondary);
  border: none;
  cursor: pointer;
  transition: all 0.2s;
}

.filter-tab:hover,
.filter-tab.active {
  background: var(--accent-color);
  color: #fff;
}

/* Pagination */
.pagination {
  display: flex;
  justify-content: center;
  gap: 8px;
  margin: 40px 0;
}

.page-btn {
  min-width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  font-size: 14px;
  color: var(--text-secondary);
  background: var(--bg-card);
  cursor: pointer;
  transition: all 0.2s;
}

.page-btn:hover,
.page-btn.active {
  background: var(--accent-color);
  border-color: var(--accent-color);
  color: #fff;
}

/* Article Layout */
.article-layout {
  display: grid;
  grid-template-columns: 1fr 320px;
  gap: 40px;
}

.article-main {
  background: var(--bg-card);
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
  padding: 40px;
}

.article-sidebar {
  position: sticky;
  top: calc(var(--header-height) + 40px);
  height: fit-content;
}

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

.article-title {
  font-size: 32px;
  font-weight: 700;
  color: var(--text-primary);
  line-height: 1.4;
  margin-bottom: 16px;
}

.article-meta {
  display: flex;
  gap: 20px;
  font-size: 14px;
  color: var(--text-muted);
}

/* Article Content */
.article-content {
  font-size: 16px;
  line-height: 1.9;
  color: var(--text-primary);
}

.article-content h2 {
  font-size: 24px;
  font-weight: 700;
  color: var(--text-primary);
  margin: 40px 0 20px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--border-color);
}

.article-content h3 {
  font-size: 20px;
  font-weight: 600;
  color: var(--text-primary);
  margin: 32px 0 16px;
}

.article-content p {
  margin-bottom: 20px;
}

.article-content ul,
.article-content ol {
  margin-bottom: 20px;
  padding-left: 24px;
}

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

.article-content img {
  border-radius: var(--radius-md);
  margin: 24px 0;
}

/* TOC */
.toc {
  background: var(--bg-card);
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
  padding: 24px;
}

.toc-title {
  font-size: 16px;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 16px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--border-color);
}

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

.toc-list li {
  padding: 8px 0;
  border-bottom: 1px dashed var(--border-color);
  font-size: 14px;
}

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

.toc-list a {
  color: var(--text-secondary);
  display: block;
}

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

.toc-list .toc-h2 {
  font-weight: 500;
}

.toc-list .toc-h3 {
  padding-left: 16px;
  font-size: 13px;
}

/* Info Box */
.info-box {
  background: var(--bg-secondary);
  border-radius: var(--radius-md);
  padding: 20px 24px;
  margin: 24px 0;
}

.info-box-title {
  font-size: 14px;
  font-weight: 600;
  color: var(--accent-color);
  margin-bottom: 12px;
}

.info-box-list {
  list-style: none;
  font-size: 14px;
}

.info-box-list li {
  padding: 6px 0;
  color: var(--text-secondary);
  display: flex;
  gap: 8px;
}

.info-box-list li::before {
  content: "•";
  color: var(--accent-light);
}

/* 404 Page */
.error-page {
  text-align: center;
  padding: 100px 20px;
}

.error-code {
  font-size: 120px;
  font-weight: 700;
  color: var(--accent-light);
  line-height: 1;
  margin-bottom: 24px;
  opacity: 0.5;
}

.error-title {
  font-size: 28px;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 16px;
}

.error-desc {
  font-size: 16px;
  color: var(--text-secondary);
  margin-bottom: 32px;
}

.error-actions {
  display: flex;
  gap: 16px;
  justify-content: center;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 24px;
  border-radius: var(--radius-md);
  font-size: 15px;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.2s;
  border: none;
}

.btn-primary {
  background: var(--accent-color);
  color: #fff;
}

.btn-primary:hover {
  background: var(--accent-dark);
  color: #fff;
}

.btn-secondary {
  background: var(--bg-secondary);
  color: var(--text-secondary);
  border: 1px solid var(--border-color);
}

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

/* Footer */
.footer {
  background: var(--bg-secondary);
  border-top: 1px solid var(--border-color);
  padding: 48px 24px 24px;
  margin-top: 80px;
}

.footer-inner {
  max-width: var(--max-width);
  margin: 0 auto;
}

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

.footer-brand {
  font-size: 18px;
  font-weight: 700;
  color: var(--accent-color);
  margin-bottom: 12px;
}

.footer-desc {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.7;
}

.footer-title {
  font-size: 14px;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 16px;
}

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

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

.footer-links a {
  font-size: 14px;
  color: var(--text-secondary);
}

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

.footer-bottom {
  padding-top: 24px;
  border-top: 1px solid var(--border-color);
  text-align: center;
  font-size: 13px;
  color: var(--text-muted);
}

/* Responsive */
@media (max-width: 1024px) {
  .article-layout {
    grid-template-columns: 1fr;
  }

  .article-sidebar {
    position: static;
    order: -1;
  }

  .toc {
    margin-bottom: 24px;
  }

  .three-col {
    grid-template-columns: 1fr;
  }

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

@media (max-width: 768px) {
  .header-inner {
    padding: 0 16px;
  }

  .nav {
    display: none;
  }

  .search-box input {
    width: 160px;
  }

  .hero {
    padding: 40px 16px;
  }

  .hero h1 {
    font-size: 28px;
  }

  .main {
    padding: 24px 16px;
  }

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

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

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

  .list-thumb {
    width: 100%;
    height: 180px;
  }

  .article-main {
    padding: 24px;
  }

  .article-title {
    font-size: 24px;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 32px;
  }

  .error-code {
    font-size: 80px;
  }
}

@media (max-width: 480px) {
  .category-grid {
    grid-template-columns: 1fr;
  }

  .filter-bar {
    flex-direction: column;
    gap: 16px;
    align-items: flex-start;
  }

  .error-actions {
    flex-direction: column;
  }
}