/* 皮革工艺 - 白皮书简报风格样式 */
/* CSS 变量定义 */
:root {
  --accent-color: #8B4513;
  --accent-light: #D2691E;
  --text-primary: #333333;
  --text-secondary: #666666;
  --text-muted: #999999;
  --bg-primary: #FFFFFF;
  --bg-secondary: #FAFAFA;
  --bg-tertiary: #F5F5F5;
  --border-color: #E5E5E5;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.1);
  --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;
}

/* 重置样式 */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

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

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

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

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

/* 容器 */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

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

.header-inner {
  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);
}

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

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

.nav a {
  color: var(--text-secondary);
  font-weight: 500;
  font-size: 0.95rem;
}

.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: var(--radius-md);
  font-size: 0.9rem;
  background-color: var(--bg-secondary);
  transition: all 0.2s ease;
}

.search-box input:focus {
  outline: none;
  border-color: var(--accent-color);
  background-color: var(--bg-primary);
}

.search-box::before {
  content: "🔍";
  position: absolute;
  left: 12px;
  top: 50%;
  transform: translateY(-50%);
  font-size: 0.9rem;
}

/* Hero 区域 */
.hero {
  background: linear-gradient(135deg, var(--bg-secondary) 0%, var(--bg-tertiary) 100%);
  padding: 80px 0 60px;
  text-align: center;
}

.hero-title {
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 16px;
}

.hero-subtitle {
  font-size: 1.1rem;
  color: var(--text-secondary);
  margin-bottom: 40px;
}

.hero-search {
  max-width: 600px;
  margin: 0 auto 48px;
}

.hero-search input {
  width: 100%;
  padding: 16px 24px;
  border: 2px solid var(--border-color);
  border-radius: var(--radius-lg);
  font-size: 1rem;
  background-color: var(--bg-primary);
  transition: all 0.2s ease;
}

.hero-search input:focus {
  outline: none;
  border-color: var(--accent-color);
  box-shadow: 0 0 0 4px rgba(139, 69, 19, 0.1);
}

/* 分类标签 */
.categories {
  display: flex;
  justify-content: center;
  gap: 16px;
  flex-wrap: wrap;
}

.category-tag {
  padding: 12px 24px;
  background-color: var(--bg-primary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  color: var(--text-secondary);
  font-weight: 500;
  transition: all 0.2s ease;
}

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

/* 区块标题 */
.section-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 24px;
}

.section-title {
  font-size: 1.5rem;
  font-weight: 600;
  color: var(--text-primary);
}

.section-more {
  font-size: 0.9rem;
  color: var(--accent-color);
}

/* 内容区块 */
.section {
  padding: 60px 0;
}

.section-alt {
  background-color: var(--bg-secondary);
}

/* 白皮书卡片列表 */
.whitepaper-list {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.whitepaper-card {
  display: flex;
  align-items: center;
  gap: 24px;
  padding: 24px;
  background-color: var(--bg-primary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  transition: all 0.2s ease;
}

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

.whitepaper-icon {
  width: 64px;
  height: 64px;
  background-color: var(--bg-tertiary);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  flex-shrink: 0;
}

.whitepaper-content {
  flex: 1;
}

.whitepaper-title {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 8px;
}

.whitepaper-meta {
  display: flex;
  gap: 16px;
  font-size: 0.85rem;
  color: var(--text-muted);
}

.whitepaper-meta span {
  display: flex;
  align-items: center;
  gap: 4px;
}

.whitepaper-actions {
  display: flex;
  gap: 12px;
}

/* 按钮 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 10px 20px;
  font-size: 0.9rem;
  font-weight: 500;
  border-radius: var(--radius-md);
  border: none;
  cursor: pointer;
  transition: all 0.2s ease;
}

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

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

.btn-outline {
  background-color: transparent;
  color: var(--accent-color);
  border: 1px solid var(--accent-color);
}

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

.btn-sm {
  padding: 6px 14px;
  font-size: 0.85rem;
}

/* 三栏文章列表 */
.three-columns {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
}

.column {
  background-color: var(--bg-primary);
  border-radius: var(--radius-md);
  padding: 24px;
}

.column-title {
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 16px;
  padding-bottom: 12px;
  border-bottom: 2px solid var(--accent-color);
}

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

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

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

.article-list a {
  color: var(--text-secondary);
  font-size: 0.95rem;
  display: block;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

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

/* 面包屑 */
.breadcrumb {
  padding: 20px 0;
  background-color: var(--bg-secondary);
  border-bottom: 1px solid var(--border-color);
}

.breadcrumb-inner {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.9rem;
  color: var(--text-muted);
}

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

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

.breadcrumb-separator {
  color: var(--text-muted);
}

.breadcrumb-current {
  color: var(--text-primary);
  font-weight: 500;
}

/* 页面头部 */
.page-header {
  padding: 48px 0 32px;
  text-align: center;
  background-color: var(--bg-secondary);
}

.page-title {
  font-size: 2rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 8px;
}

.page-desc {
  font-size: 1rem;
  color: var(--text-secondary);
}

/* 排序选项 */
.sort-bar {
  display: flex;
  justify-content: flex-end;
  gap: 16px;
  padding: 20px 0;
  border-bottom: 1px solid var(--border-color);
  margin-bottom: 24px;
}

.sort-option {
  font-size: 0.9rem;
  color: var(--text-muted);
  cursor: pointer;
  transition: color 0.2s ease;
}

.sort-option:hover,
.sort-option.active {
  color: var(--accent-color);
}

/* 分页 */
.pagination {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 8px;
  padding: 40px 0;
}

.pagination a,
.pagination span {
  display: flex;
  align-items: center;
  justify-content: center;
  min-width: 40px;
  height: 40px;
  padding: 0 12px;
  border-radius: var(--radius-md);
  font-size: 0.9rem;
  color: var(--text-secondary);
  background-color: var(--bg-primary);
  border: 1px solid var(--border-color);
  transition: all 0.2s ease;
}

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

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

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

/* 文章详情页 */
.article-header {
  padding: 48px 0 32px;
  text-align: center;
  background-color: var(--bg-secondary);
}

.article-title {
  font-size: 2rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 16px;
  max-width: 800px;
  margin-left: auto;
  margin-right: auto;
}

.article-meta-bar {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 24px;
  font-size: 0.9rem;
  color: var(--text-muted);
}

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

.article-cover {
  max-width: 600px;
  margin: 40px auto;
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-md);
}

.article-cover img {
  width: 100%;
  height: auto;
}

.article-body {
  max-width: 800px;
  margin: 0 auto;
  padding: 40px 0;
}

/* 执行摘要 */
.executive-summary {
  background-color: var(--bg-secondary);
  border-left: 4px solid var(--accent-color);
  padding: 24px;
  margin-bottom: 40px;
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
}

.executive-summary h2 {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 16px;
}

.executive-summary p {
  color: var(--text-secondary);
  line-height: 1.8;
}

/* 关键点 */
.key-points {
  margin-bottom: 40px;
}

.key-points h2 {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 20px;
}

.key-points-list {
  list-style: none;
}

.key-points-list li {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  padding: 16px 0;
  border-bottom: 1px solid var(--border-color);
}

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

.key-point-marker {
  width: 24px;
  height: 24px;
  background-color: var(--accent-color);
  color: white;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.8rem;
  font-weight: 600;
  flex-shrink: 0;
}

.key-point-content h4 {
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 4px;
}

.key-point-content p {
  font-size: 0.95rem;
  color: var(--text-secondary);
}

/* 目录 */
.table-of-contents {
  background-color: var(--bg-secondary);
  padding: 24px;
  border-radius: var(--radius-md);
  margin-bottom: 40px;
}

.table-of-contents h2 {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 16px;
}

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

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

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

.toc-list li::before {
  content: counter(toc) ". ";
  color: var(--accent-color);
  font-weight: 600;
}

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

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

/* 下载区域 */
.download-section {
  background-color: var(--bg-secondary);
  padding: 32px;
  border-radius: var(--radius-md);
  text-align: center;
  margin-bottom: 40px;
}

.download-section h2 {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 20px;
}

.download-buttons {
  display: flex;
  justify-content: center;
  gap: 16px;
  flex-wrap: wrap;
}

/* 相关推荐 */
.related-section {
  padding: 40px 0;
  border-top: 1px solid var(--border-color);
}

.related-title {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 24px;
}

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

.related-card {
  background-color: var(--bg-secondary);
  border-radius: var(--radius-md);
  padding: 20px;
  transition: all 0.2s ease;
}

.related-card:hover {
  box-shadow: var(--shadow-md);
}

.related-card-title {
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 8px;
}

.related-card-meta {
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* 推荐文章行 */
.recommended-row {
  background-color: var(--bg-secondary);
  padding: 24px 0;
  border-top: 1px solid var(--border-color);
  border-bottom: 1px solid var(--border-color);
}

.recommended-list {
  display: flex;
  justify-content: center;
  gap: 40px;
  flex-wrap: wrap;
}

.recommended-list a {
  color: var(--text-secondary);
  font-size: 0.95rem;
}

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

/* 页脚 */
.footer {
  background-color: var(--bg-tertiary);
  padding: 48px 0 24px;
  border-top: 1px solid var(--border-color);
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 48px;
  margin-bottom: 32px;
}

.footer-brand {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--accent-color);
  margin-bottom: 12px;
}

.footer-desc {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.7;
}

.footer-title {
  font-size: 0.95rem;
  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: 0.9rem;
  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: 0.85rem;
  color: var(--text-muted);
}

/* 404 页面 */
.error-page {
  min-height: calc(100vh - var(--header-height));
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 40px 24px;
}

.error-content {
  max-width: 500px;
}

.error-code {
  font-size: 8rem;
  font-weight: 700;
  color: var(--accent-color);
  line-height: 1;
  margin-bottom: 16px;
  opacity: 0.8;
}

.error-title {
  font-size: 1.75rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 12px;
}

.error-desc {
  font-size: 1rem;
  color: var(--text-secondary);
  margin-bottom: 32px;
}

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

/* 响应式设计 */
@media (max-width: 1024px) {
  .three-columns {
    grid-template-columns: repeat(2, 1fr);
  }

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

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

@media (max-width: 768px) {
  .header-inner {
    flex-wrap: wrap;
    height: auto;
    padding: 16px 0;
    gap: 16px;
  }

  .nav {
    order: 3;
    width: 100%;
    justify-content: center;
    gap: 20px;
  }

  .search-box {
    order: 2;
  }

  .search-box input {
    width: 180px;
  }

  .hero {
    padding: 48px 0 40px;
  }

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

  .hero-subtitle {
    font-size: 1rem;
  }

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

  .whitepaper-card {
    flex-direction: column;
    text-align: center;
  }

  .whitepaper-actions {
    width: 100%;
    justify-content: center;
  }

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

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

  .article-title {
    font-size: 1.5rem;
  }

  .article-meta-bar {
    flex-wrap: wrap;
    gap: 12px;
  }

  .download-buttons {
    flex-direction: column;
  }

  .btn {
    width: 100%;
  }

  .error-code {
    font-size: 5rem;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 16px;
  }

  .hero-title {
    font-size: 1.5rem;
  }

  .section-title {
    font-size: 1.25rem;
  }

  .categories {
    gap: 8px;
  }

  .category-tag {
    padding: 8px 16px;
    font-size: 0.9rem;
  }

  .page-title {
    font-size: 1.5rem;
  }

  .sort-bar {
    justify-content: flex-start;
    flex-wrap: wrap;
  }

  .recommended-list {
    flex-direction: column;
    gap: 12px;
  }
}