/* ===== 基础变量 ===== */
:root {
  --accent-color: #795548;
  --accent-light: #a1887f;
  --accent-dark: #5d4037;
  --text-primary: #333;
  --text-secondary: #666;
  --text-muted: #999;
  --bg-primary: #faf8f5;
  --bg-secondary: #f5f2ed;
  --bg-card: #fff;
  --border-color: #e8e4de;
  --shadow: 0 2px 8px rgba(0,0,0,0.08);
  --shadow-hover: 0 4px 16px rgba(0,0,0,0.12);
  --radius: 8px;
  --radius-lg: 12px;
  --max-width: 1200px;
  --header-height: 64px;
}

/* ===== 重置样式 ===== */
* {
  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: 1.7;
  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;
  display: block;
}

ul, ol {
  list-style: none;
}

/* ===== 布局容器 ===== */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 20px;
}

/* ===== 页头 ===== */
.header {
  background: var(--bg-card);
  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 {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--text-primary);
}

.logo-icon {
  width: 40px;
  height: 40px;
  background: var(--accent-color);
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-size: 1.2rem;
}

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

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

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

.search-box {
  display: flex;
  align-items: center;
  gap: 8px;
  background: var(--bg-secondary);
  padding: 8px 16px;
  border-radius: 24px;
  border: 1px solid var(--border-color);
}

.search-box input {
  border: none;
  background: none;
  outline: none;
  width: 160px;
  font-size: 0.9rem;
}

.search-box button {
  border: none;
  background: none;
  cursor: pointer;
  color: var(--text-muted);
}

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

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

.hero-desc {
  font-size: 1.1rem;
  color: var(--text-secondary);
  max-width: 600px;
  margin: 0 auto 32px;
}

.hero-stats {
  display: flex;
  justify-content: center;
  gap: 48px;
  margin-top: 40px;
}

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

.stat-num {
  font-size: 2rem;
  font-weight: 700;
  color: var(--accent-color);
}

.stat-label {
  font-size: 0.9rem;
  color: var(--text-muted);
}

/* ===== 区块标题 ===== */
.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;
}

/* ===== 卡片网格 ===== */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 24px;
}

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

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

.card-cover {
  aspect-ratio: 4/3;
  background: var(--bg-secondary);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-muted);
  font-size: 3rem;
}

.card-body {
  padding: 20px;
}

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

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

.card-desc {
  font-size: 0.9rem;
  color: var(--text-secondary);
  margin-top: 12px;
  line-height: 1.6;
}

/* ===== 分类标签 ===== */
.category-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 32px;
}

.tag {
  padding: 8px 20px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 24px;
  font-size: 0.9rem;
  color: var(--text-secondary);
  transition: all 0.2s;
}

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

/* ===== 列表样式 ===== */
.list-section {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  padding: 24px;
  margin-bottom: 24px;
}

.list-item {
  display: flex;
  gap: 16px;
  padding: 16px 0;
  border-bottom: 1px solid var(--border-color);
}

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

.list-thumb {
  width: 80px;
  height: 60px;
  background: var(--bg-secondary);
  border-radius: var(--radius);
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-muted);
}

.list-content {
  flex: 1;
}

.list-title {
  font-weight: 600;
  margin-bottom: 4px;
}

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

/* ===== 面包屑 ===== */
.breadcrumb {
  padding: 16px 0;
  font-size: 0.9rem;
  color: var(--text-muted);
}

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

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

.breadcrumb span {
  margin: 0 8px;
}

/* ===== 页面头部 ===== */
.page-header {
  background: var(--bg-secondary);
  padding: 40px 0;
  margin-bottom: 32px;
}

.page-title {
  font-size: 1.75rem;
  font-weight: 600;
  margin-bottom: 8px;
}

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

/* ===== 筛选排序 ===== */
.filter-bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 24px;
  padding: 16px;
  background: var(--bg-card);
  border-radius: var(--radius);
}

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

.filter-btn {
  padding: 6px 16px;
  border: 1px solid var(--border-color);
  background: var(--bg-card);
  border-radius: 4px;
  cursor: pointer;
  font-size: 0.9rem;
  color: var(--text-secondary);
}

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

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

.page-btn {
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--border-color);
  background: var(--bg-card);
  border-radius: var(--radius);
  cursor: pointer;
  font-size: 0.9rem;
  color: var(--text-secondary);
}

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

/* ===== 文章详情页布局 ===== */
.article-layout {
  display: grid;
  grid-template-columns: 1fr 320px;
  gap: 40px;
}

.article-main {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  padding: 40px;
}

.article-sidebar {
  position: sticky;
  top: calc(var(--header-height) + 20px);
  height: fit-content;
}

/* ===== 文章内容 ===== */
.article-header {
  margin-bottom: 32px;
  padding-bottom: 24px;
  border-bottom: 1px solid var(--border-color);
}

.article-title {
  font-size: 1.75rem;
  font-weight: 700;
  margin-bottom: 16px;
  line-height: 1.4;
}

.article-meta {
  display: flex;
  gap: 24px;
  color: var(--text-muted);
  font-size: 0.9rem;
}

.article-content {
  font-size: 1.05rem;
  line-height: 1.9;
}

.article-content h2 {
  font-size: 1.4rem;
  font-weight: 600;
  margin: 32px 0 16px;
  color: var(--text-primary);
}

.article-content h3 {
  font-size: 1.2rem;
  font-weight: 600;
  margin: 24px 0 12px;
}

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

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

.article-content ul li {
  list-style: disc;
  margin-bottom: 8px;
}

.article-content ol li {
  list-style: decimal;
  margin-bottom: 8px;
}

/* ===== 目录 ===== */
.toc {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  padding: 24px;
  margin-bottom: 24px;
}

.toc-title {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 16px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--border-color);
}

.toc-list li {
  margin-bottom: 8px;
}

.toc-list a {
  color: var(--text-secondary);
  font-size: 0.95rem;
  display: block;
  padding: 4px 0;
}

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

/* ===== 侧边栏区块 ===== */
.sidebar-section {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  padding: 20px;
  margin-bottom: 20px;
}

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

.sidebar-list li {
  margin-bottom: 12px;
}

.sidebar-list a {
  color: var(--text-secondary);
  font-size: 0.9rem;
  display: flex;
  justify-content: space-between;
}

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

/* ===== 三栏底部 ===== */
.three-col {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin: 40px 0;
}

.col-section {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  padding: 24px;
}

.col-title {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 16px;
  color: var(--accent-color);
}

.col-list li {
  margin-bottom: 10px;
}

.col-list a {
  color: var(--text-secondary);
  font-size: 0.9rem;
}

/* ===== 页脚 ===== */
.footer {
  background: var(--bg-secondary);
  border-top: 1px solid var(--border-color);
  padding: 40px 0;
  margin-top: 60px;
}

.footer-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.footer-links {
  display: flex;
  gap: 24px;
}

.footer-links a {
  color: var(--text-secondary);
  font-size: 0.9rem;
}

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

/* ===== 404页面 ===== */
.error-page {
  min-height: 60vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 60px 20px;
}

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

.error-title {
  font-size: 1.5rem;
  font-weight: 600;
  margin-bottom: 16px;
}

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

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

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

/* ===== 响应式设计 ===== */
@media (max-width: 1024px) {
  .article-layout {
    grid-template-columns: 1fr;
  }

  .article-sidebar {
    position: static;
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
  }

  .toc {
    grid-column: span 2;
  }
}

@media (max-width: 768px) {
  .header-inner {
    flex-wrap: wrap;
    height: auto;
    padding: 12px 0;
    gap: 12px;
  }

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

  .hero {
    padding: 48px 0;
  }

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

  .hero-stats {
    gap: 24px;
  }

  .stat-num {
    font-size: 1.5rem;
  }

  .card-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
  }

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

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

  .toc {
    grid-column: span 1;
  }

  .article-main {
    padding: 24px;
  }

  .article-title {
    font-size: 1.4rem;
  }

  .footer-inner {
    flex-direction: column;
    gap: 20px;
    text-align: center;
  }
}

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

  .filter-bar {
    flex-direction: column;
    gap: 12px;
  }

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