/* ================================
   徒步 www.tanxianxing.cn - 样式表
   指南文档风格 | 步骤教程布局
   ================================ */

/* CSS 变量 */
:root {
  --accent-color: #009688;
  --accent-light: #e0f2f1;
  --accent-dark: #00796b;
  --text-primary: #212121;
  --text-secondary: #616161;
  --text-muted: #9e9e9e;
  --bg-primary: #ffffff;
  --bg-secondary: #f5f5f5;
  --bg-card: #fafafa;
  --border-color: #e0e0e0;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.12);
  --shadow-md: 0 4px 6px rgba(0,0,0,0.1);
  --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: 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 {
  list-style: none;
}

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

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

.header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--accent-color);
}

.logo-icon {
  width: 36px;
  height: 36px;
  background: var(--accent-color);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: 1.2rem;
}

.nav {
  display: flex;
  gap: 30px;
}

.nav a {
  color: var(--text-secondary);
  font-weight: 500;
  padding: 8px 0;
  border-bottom: 2px solid transparent;
}

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

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

.search-box input {
  border: none;
  background: transparent;
  outline: none;
  width: 180px;
  font-size: 0.9rem;
}

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

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

.hero h1 {
  font-size: 2.5rem;
  margin-bottom: 16px;
  font-weight: 700;
}

.hero p {
  font-size: 1.2rem;
  opacity: 0.9;
  max-width: 600px;
  margin: 0 auto 30px;
}

.hero-search {
  max-width: 500px;
  margin: 0 auto;
  display: flex;
  background: white;
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-md);
}

.hero-search input {
  flex: 1;
  padding: 16px 20px;
  border: none;
  outline: none;
  font-size: 1rem;
}

.hero-search button {
  padding: 16px 30px;
  background: var(--accent-color);
  color: white;
  border: none;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.2s;
}

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

/* ================================
   面包屑导航
   ================================ */
.breadcrumb {
  background: var(--bg-secondary);
  padding: 16px 0;
  font-size: 0.9rem;
}

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

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

.breadcrumb .sep {
  margin: 0 8px;
  color: var(--text-muted);
}

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

/* ================================
   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: 700;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 10px;
}

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

.view-more {
  color: var(--accent-color);
  font-size: 0.9rem;
  font-weight: 500;
}

/* ================================
   分类卡片
   ================================ */
.categories-section {
  padding: 60px 0;
  background: var(--bg-secondary);
}

.categories-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.category-card {
  background: var(--bg-primary);
  border-radius: var(--radius-md);
  padding: 24px;
  text-align: center;
  box-shadow: var(--shadow-sm);
  transition: transform 0.2s, box-shadow 0.2s;
  border: 1px solid var(--border-color);
}

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

.category-icon {
  width: 56px;
  height: 56px;
  background: var(--accent-light);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 16px;
  font-size: 1.5rem;
  color: var(--accent-color);
}

.category-card h3 {
  font-size: 1.1rem;
  margin-bottom: 8px;
  color: var(--text-primary);
}

.category-card p {
  font-size: 0.85rem;
  color: var(--text-secondary);
}

/* ================================
   指南卡片 (步骤教程)
   ================================ */
.guides-section {
  padding: 60px 0;
}

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

.guide-card {
  background: var(--bg-primary);
  border-radius: var(--radius-md);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border-color);
  transition: transform 0.2s, box-shadow 0.2s;
}

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

.guide-image {
  height: 180px;
  background: var(--bg-secondary);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-muted);
  font-size: 3rem;
}

.guide-content {
  padding: 20px;
}

.guide-meta {
  display: flex;
  gap: 16px;
  margin-bottom: 12px;
  font-size: 0.85rem;
  color: var(--text-secondary);
}

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

.difficulty-easy { color: #4caf50; }
.difficulty-medium { color: #ff9800; }
.difficulty-hard { color: #f44336; }

.guide-card h3 {
  font-size: 1.1rem;
  margin-bottom: 10px;
  line-height: 1.4;
}

.guide-card p {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.5;
}

.guide-steps {
  margin-top: 16px;
  padding-top: 16px;
  border-top: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.85rem;
  color: var(--text-muted);
}

.step-number {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 24px;
  height: 24px;
  background: var(--accent-color);
  color: white;
  border-radius: 50%;
  font-size: 0.75rem;
  font-weight: 600;
}

/* ================================
   精选指南 (Featured)
   ================================ */
.featured-section {
  padding: 60px 0;
  background: var(--accent-light);
}

.featured-card {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 40px;
  background: var(--bg-primary);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-md);
}

.featured-image {
  min-height: 350px;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: 5rem;
}

.featured-content {
  padding: 40px;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.featured-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: var(--accent-color);
  color: white;
  padding: 6px 12px;
  border-radius: var(--radius-sm);
  font-size: 0.8rem;
  font-weight: 600;
  width: fit-content;
  margin-bottom: 16px;
}

.featured-content h2 {
  font-size: 1.8rem;
  margin-bottom: 16px;
  line-height: 1.3;
}

.featured-content p {
  color: var(--text-secondary);
  margin-bottom: 24px;
  line-height: 1.7;
}

.featured-meta {
  display: flex;
  gap: 24px;
  margin-bottom: 24px;
  font-size: 0.9rem;
  color: var(--text-secondary);
}

.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: var(--accent-color);
  color: white;
  padding: 12px 24px;
  border-radius: var(--radius-md);
  font-weight: 600;
  width: fit-content;
  transition: background 0.2s;
}

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

/* ================================
   三栏文章列表
   ================================ */
.articles-section {
  padding: 60px 0;
  background: var(--bg-secondary);
}

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

.article-column {
  background: var(--bg-primary);
  border-radius: var(--radius-md);
  padding: 24px;
  box-shadow: var(--shadow-sm);
}

.column-title {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 20px;
  padding-bottom: 12px;
  border-bottom: 2px solid var(--accent-color);
  color: var(--text-primary);
}

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

.article-item {
  display: flex;
  gap: 12px;
  align-items: flex-start;
}

.article-item .num {
  width: 24px;
  height: 24px;
  background: var(--accent-light);
  color: var(--accent-color);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.75rem;
  font-weight: 600;
  flex-shrink: 0;
}

.article-item a {
  color: var(--text-primary);
  font-size: 0.95rem;
  line-height: 1.5;
  flex: 1;
}

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

/* ================================
   分类页内容
   ================================ */
.category-header {
  padding: 40px 0;
  background: var(--bg-secondary);
}

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

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

.category-filters {
  display: flex;
  gap: 12px;
  margin-bottom: 24px;
  flex-wrap: wrap;
}

.filter-btn {
  padding: 8px 16px;
  border: 1px solid var(--border-color);
  background: var(--bg-primary);
  border-radius: var(--radius-md);
  font-size: 0.9rem;
  color: var(--text-secondary);
  cursor: pointer;
  transition: all 0.2s;
}

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

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

.pagination a,
.pagination span {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: var(--radius-md);
  font-size: 0.95rem;
  transition: all 0.2s;
}

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

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

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

.pagination .prev,
.pagination .next {
  width: auto;
  padding: 0 16px;
}

/* ================================
   文章详情页
   ================================ */
.article-header {
  padding: 40px 0;
  background: var(--bg-secondary);
}

.article-header h1 {
  font-size: 2rem;
  margin-bottom: 16px;
  line-height: 1.4;
}

.article-meta {
  display: flex;
  gap: 24px;
  color: var(--text-secondary);
  font-size: 0.95rem;
}

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

.article-main {
  padding: 40px 0;
}

.article-layout {
  display: grid;
  grid-template-columns: 250px 1fr;
  gap: 40px;
}

/* 步骤导航 */
.steps-nav {
  position: sticky;
  top: 100px;
  background: var(--bg-card);
  border-radius: var(--radius-md);
  padding: 20px;
  border: 1px solid var(--border-color);
  height: fit-content;
}

.steps-nav h3 {
  font-size: 1rem;
  margin-bottom: 16px;
  color: var(--text-primary);
}

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

.step-link {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px;
  border-radius: var(--radius-sm);
  color: var(--text-secondary);
  font-size: 0.9rem;
  transition: all 0.2s;
}

.step-link:hover {
  background: var(--accent-light);
  color: var(--accent-color);
}

.step-link.active {
  background: var(--accent-color);
  color: white;
}

.step-link .num {
  width: 24px;
  height: 24px;
  background: rgba(255,255,255,0.2);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.75rem;
  font-weight: 600;
}

.step-link.completed .num {
  background: #4caf50;
}

/* 文章内容 */
.article-content {
  max-width: 100%;
}

.article-content h2 {
  font-size: 1.5rem;
  margin: 32px 0 16px;
  padding-bottom: 12px;
  border-bottom: 2px solid var(--accent-color);
}

.article-content h3 {
  font-size: 1.2rem;
  margin: 24px 0 12px;
  color: var(--text-primary);
}

.article-content p {
  margin-bottom: 16px;
  line-height: 1.8;
  color: var(--text-secondary);
}

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

.article-content ul li,
.article-content ol li {
  margin-bottom: 8px;
  line-height: 1.7;
  color: var(--text-secondary);
}

.article-content ul li {
  list-style: disc;
}

.article-content ol li {
  list-style: decimal;
}

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

/* 提示框 */
.tip-box {
  background: var(--accent-light);
  border-left: 4px solid var(--accent-color);
  padding: 16px 20px;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  margin: 20px 0;
}

.tip-box-title {
  font-weight: 600;
  color: var(--accent-dark);
  margin-bottom: 8px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.tip-box p {
  margin: 0;
  color: var(--text-secondary);
}

/* 检查清单 */
.checklist {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 20px;
  margin: 20px 0;
}

.checklist h4 {
  margin-bottom: 16px;
  font-size: 1rem;
}

.checklist-item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 10px 0;
  border-bottom: 1px solid var(--border-color);
}

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

.checklist-item input[type="checkbox"] {
  width: 20px;
  height: 20px;
  accent-color: var(--accent-color);
}

.checklist-item label {
  color: var(--text-secondary);
  cursor: pointer;
}

/* 步骤详细 */
.step-detail {
  margin-bottom: 40px;
}

.step-header {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 20px;
}

.step-badge {
  width: 48px;
  height: 48px;
  background: var(--accent-color);
  color: white;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  font-weight: 700;
  flex-shrink: 0;
}

.step-header h3 {
  margin: 0;
  font-size: 1.3rem;
}

/* ================================
   推荐文章区块
   ================================ */
.recommended-section {
  padding: 40px 0;
  background: var(--bg-secondary);
  border-top: 1px solid var(--border-color);
}

.recommended-tags {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  margin-bottom: 30px;
}

.tag {
  padding: 8px 16px;
  background: var(--bg-primary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  font-size: 0.9rem;
  color: var(--text-secondary);
  transition: all 0.2s;
}

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

/* ================================
   页脚 Footer
   ================================ */
.footer {
  background: var(--text-primary);
  color: white;
  padding: 60px 0 30px;
}

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

.footer-brand .logo {
  color: white;
  margin-bottom: 16px;
}

.footer-brand p {
  color: rgba(255,255,255,0.7);
  font-size: 0.9rem;
  line-height: 1.7;
}

.footer-column h4 {
  font-size: 1rem;
  margin-bottom: 20px;
  color: white;
}

.footer-column ul {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.footer-column a {
  color: rgba(255,255,255,0.7);
  font-size: 0.9rem;
}

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

.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.1);
  padding-top: 30px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.85rem;
  color: rgba(255,255,255,0.5);
}

/* ================================
   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 20px;
}

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

.error-code {
  font-size: 8rem;
  font-weight: 700;
  color: var(--accent-color);
  line-height: 1;
  margin-bottom: 20px;
  opacity: 0.8;
}

.error-content h1 {
  font-size: 2rem;
  margin-bottom: 16px;
}

.error-content p {
  color: var(--text-secondary);
  margin-bottom: 30px;
  font-size: 1.1rem;
}

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

.btn-secondary {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: transparent;
  color: var(--accent-color);
  padding: 12px 24px;
  border-radius: var(--radius-md);
  font-weight: 600;
  border: 2px solid var(--accent-color);
  transition: all 0.2s;
}

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

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

  .steps-nav {
    position: static;
    margin-bottom: 30px;
  }

  .steps-list {
    flex-direction: row;
    flex-wrap: wrap;
  }

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

@media (max-width: 768px) {
  .header .container {
    flex-wrap: wrap;
    gap: 10px;
  }

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

  .search-box {
    display: none;
  }

  .hero {
    padding: 60px 0;
  }

  .hero h1 {
    font-size: 1.8rem;
  }

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

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

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

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

  .featured-image {
    min-height: 200px;
  }

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

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 30px;
  }

  .footer-bottom {
    flex-direction: column;
    gap: 16px;
    text-align: center;
  }

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

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

  .category-filters {
    justify-content: center;
  }

  .pagination a,
  .pagination span {
    width: 36px;
    height: 36px;
  }

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