/* ========================================
   认识中国 - 主样式表
   SEO友好 · 响应式设计 · 全静态网站
   ======================================== */

/* --- CSS 变量 --- */
:root {
  --color-primary: #C41E3A;
  --color-primary-dark: #A01830;
  --color-primary-light: #F8D7DA;
  --color-gold: #C8960C;
  --color-gold-light: #FDF5E1;
  --color-bg: #FAFAFA;
  --color-white: #FFFFFF;
  --color-text: #333333;
  --color-text-light: #666666;
  --color-text-lighter: #999999;
  --color-border: #E5E5E5;
  --color-border-light: #F0F0F0;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.08);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.1);
  --shadow-lg: 0 8px 24px rgba(0,0,0,0.12);
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --max-width: 1200px;
  --header-height: 64px;
  --font-family: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "Noto Sans SC", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
}

/* --- CSS Reset --- */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-family);
  color: var(--color-text);
  background-color: var(--color-bg);
  line-height: 1.7;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

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

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

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

ul, ol {
  list-style: none;
}

/* --- 顶部导航栏 --- */
.site-header {
  background: var(--color-white);
  border-bottom: 1px solid var(--color-border);
  position: sticky;
  top: 0;
  z-index: 1000;
  box-shadow: var(--shadow-sm);
}

.header-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 20px;
  height: var(--header-height);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.site-logo {
  display: flex;
  align-items: center;
  gap: 10px;
}

.site-logo .logo-icon {
  width: 40px;
  height: 40px;
  background: var(--color-primary);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-white);
  font-size: 22px;
  font-weight: bold;
}

.site-logo .logo-text {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--color-primary);
}

.site-logo a {
  display: flex;
  align-items: center;
  gap: 10px;
  color: inherit;
}

.site-logo a:hover {
  color: var(--color-primary-dark);
}

/* 桌面导航 */
.main-nav .nav-list {
  display: flex;
  gap: 4px;
}

.main-nav .nav-list a {
  display: block;
  padding: 8px 18px;
  border-radius: var(--radius-sm);
  color: var(--color-text);
  font-size: 0.95rem;
  font-weight: 500;
  transition: all 0.2s;
}

.main-nav .nav-list a:hover,
.main-nav .nav-list a.active {
  background: var(--color-primary);
  color: var(--color-white);
}

/* 移动端菜单按钮 */
.menu-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  padding: 8px;
  background: none;
  border: none;
}

.menu-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--color-text);
  border-radius: 2px;
  transition: all 0.3s;
}

.menu-toggle.active span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.menu-toggle.active span:nth-child(2) {
  opacity: 0;
}

.menu-toggle.active span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* --- 主要内容区 --- */
.site-main {
  flex: 1;
  max-width: var(--max-width);
  width: 100%;
  margin: 0 auto;
  padding: 32px 20px;
}

/* --- 首页 Hero --- */
.hero-section {
  background: linear-gradient(135deg, var(--color-primary) 0%, #8B1A2B 100%);
  color: var(--color-white);
  padding: 60px 40px;
  border-radius: var(--radius-lg);
  margin-bottom: 40px;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.hero-section::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -20%;
  width: 400px;
  height: 400px;
  background: rgba(255,255,255,0.03);
  border-radius: 50%;
}

.hero-section::after {
  content: '';
  position: absolute;
  bottom: -30%;
  left: -10%;
  width: 300px;
  height: 300px;
  background: rgba(255,255,255,0.04);
  border-radius: 50%;
}

.hero-title {
  font-size: 2.5rem;
  font-weight: 700;
  margin-bottom: 16px;
  position: relative;
  z-index: 1;
}

.hero-subtitle {
  font-size: 1.15rem;
  opacity: 0.9;
  max-width: 600px;
  margin: 0 auto;
  position: relative;
  z-index: 1;
  line-height: 1.8;
}

/* --- 区块标题 --- */
.section-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 24px;
  padding-bottom: 12px;
  border-bottom: 2px solid var(--color-primary);
}

.section-title {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--color-text);
  display: flex;
  align-items: center;
  gap: 8px;
}

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

.section-more {
  font-size: 0.9rem;
  color: var(--color-text-light);
  display: flex;
  align-items: center;
  gap: 4px;
}

.section-more:hover {
  color: var(--color-primary);
}

/* --- 文章卡片网格 --- */
.article-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
  gap: 24px;
  margin-bottom: 40px;
}

.article-card {
  background: var(--color-white);
  border-radius: var(--radius-md);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  transition: box-shadow 0.3s, transform 0.3s;
  display: flex;
  flex-direction: column;
}

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

.article-card .card-image {
  width: 100%;
  height: 200px;
  background: linear-gradient(135deg, #f0f0f0, #e0e0e0);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 3rem;
  color: #ccc;
  overflow: hidden;
}

.article-card .card-image.category-info {
  background: linear-gradient(135deg, #E3F2FD, #BBDEFB);
}

.article-card .card-image.category-travel {
  background: linear-gradient(135deg, #E8F5E9, #C8E6C9);
}

.article-card .card-image.category-food {
  background: linear-gradient(135deg, #FFF3E0, #FFE0B2);
}

.article-card .card-image.category-tech {
  background: linear-gradient(135deg, #F3E5F5, #E1BEE7);
}

.article-card .card-body {
  padding: 20px;
  flex: 1;
  display: flex;
  flex-direction: column;
}

.article-card .card-meta {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 10px;
  flex-wrap: wrap;
}

.article-card .card-category {
  display: inline-block;
  padding: 2px 10px;
  font-size: 0.75rem;
  font-weight: 600;
  border-radius: 20px;
  background: var(--color-primary-light);
  color: var(--color-primary);
  white-space: nowrap;
}

.article-card .card-date {
  font-size: 0.8rem;
  color: var(--color-text-lighter);
}

.article-card .card-title {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 8px;
  line-height: 1.5;
  color: var(--color-text);
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.article-card .card-title a {
  color: inherit;
}

.article-card .card-title a:hover {
  color: var(--color-primary);
}

.article-card .card-summary {
  font-size: 0.9rem;
  color: var(--color-text-light);
  line-height: 1.6;
  flex: 1;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.article-card .card-tags {
  display: flex;
  gap: 6px;
  margin-top: 12px;
  flex-wrap: wrap;
}

.article-card .card-tag {
  font-size: 0.75rem;
  padding: 2px 8px;
  background: var(--color-border-light);
  border-radius: 4px;
  color: var(--color-text-light);
}

/* --- 列表页布局 --- */
.list-layout {
  display: flex;
  gap: 32px;
  align-items: flex-start;
}

/* 侧边栏 - 标签筛选 */
.list-sidebar {
  width: 240px;
  flex-shrink: 0;
  position: sticky;
  top: calc(var(--header-height) + 20px);
}

.sidebar-block {
  background: var(--color-white);
  border-radius: var(--radius-md);
  padding: 20px;
  box-shadow: var(--shadow-sm);
  margin-bottom: 20px;
}

.sidebar-block h3 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 14px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--color-border-light);
  color: var(--color-text);
}

.tag-filter-list {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.tag-filter-item {
  display: block;
  padding: 8px 12px;
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  color: var(--color-text);
  cursor: pointer;
  transition: all 0.2s;
  border: none;
  background: none;
  text-align: left;
  width: 100%;
}

.tag-filter-item:hover {
  background: var(--color-border-light);
}

.tag-filter-item.active {
  background: var(--color-primary);
  color: var(--color-white);
}

.tag-filter-item .tag-count {
  float: right;
  font-size: 0.8rem;
  opacity: 0.7;
}

/* 列表主体 */
.list-main {
  flex: 1;
  min-width: 0;
}

.list-main .section-header {
  margin-bottom: 24px;
}

/* 列表项（行式布局） */
.article-list-item {
  display: flex;
  background: var(--color-white);
  border-radius: var(--radius-md);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  margin-bottom: 16px;
  transition: box-shadow 0.3s, transform 0.3s;
}

.article-list-item:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-1px);
}

.article-list-item .list-item-image {
  width: 240px;
  min-height: 160px;
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2.5rem;
}

.article-list-item .list-item-body {
  padding: 20px 24px;
  flex: 1;
  display: flex;
  flex-direction: column;
}

.article-list-item .list-item-meta {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 8px;
  flex-wrap: wrap;
}

.article-list-item .list-item-title {
  font-size: 1.15rem;
  font-weight: 600;
  margin-bottom: 8px;
  line-height: 1.5;
  color: var(--color-text);
}

.article-list-item .list-item-title a {
  color: inherit;
}

.article-list-item .list-item-title a:hover {
  color: var(--color-primary);
}

.article-list-item .list-item-summary {
  font-size: 0.9rem;
  color: var(--color-text-light);
  line-height: 1.6;
  flex: 1;
}

.article-list-item .list-item-tags {
  display: flex;
  gap: 6px;
  margin-top: 10px;
  flex-wrap: wrap;
}

/* --- 文章详情页 --- */
.article-detail {
  max-width: 800px;
  margin: 0 auto;
}

.article-detail .article-header {
  margin-bottom: 32px;
}

.article-detail .article-category {
  display: inline-block;
  padding: 4px 14px;
  font-size: 0.85rem;
  font-weight: 600;
  border-radius: 20px;
  background: var(--color-primary-light);
  color: var(--color-primary);
  margin-bottom: 16px;
}

.article-detail .article-title {
  font-size: 2rem;
  font-weight: 700;
  line-height: 1.4;
  margin-bottom: 16px;
  color: var(--color-text);
}

.article-detail .article-meta {
  display: flex;
  align-items: center;
  gap: 16px;
  color: var(--color-text-lighter);
  font-size: 0.9rem;
  padding-bottom: 20px;
  border-bottom: 1px solid var(--color-border-light);
}

.article-detail .article-meta .meta-date {
  display: flex;
  align-items: center;
  gap: 4px;
}

.article-detail .article-tags {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  margin-top: 16px;
}

.article-detail .article-tag {
  font-size: 0.8rem;
  padding: 4px 12px;
  background: var(--color-border-light);
  border-radius: 20px;
  color: var(--color-text-light);
}

.article-detail .article-content {
  font-size: 1.05rem;
  line-height: 1.9;
  color: var(--color-text);
  margin-bottom: 40px;
}

.article-detail .article-content p {
  margin-bottom: 20px;
  text-indent: 2em;
}

.article-detail .article-content h2 {
  font-size: 1.5rem;
  margin: 32px 0 16px;
  color: var(--color-text);
}

.article-detail .article-content h3 {
  font-size: 1.25rem;
  margin: 24px 0 12px;
  color: var(--color-text);
}

/* --- 推荐列表 --- */
.recommend-section {
  border-top: 2px solid var(--color-border);
  padding-top: 32px;
  margin-top: 20px;
}

.recommend-section .recommend-title {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 20px;
  color: var(--color-text);
}

.recommend-list {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 16px;
}

.recommend-card {
  background: var(--color-white);
  border-radius: var(--radius-sm);
  padding: 16px;
  box-shadow: var(--shadow-sm);
  transition: box-shadow 0.3s;
}

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

.recommend-card .rec-category {
  font-size: 0.7rem;
  color: var(--color-primary);
  font-weight: 600;
  margin-bottom: 6px;
}

.recommend-card .rec-title {
  font-size: 0.95rem;
  font-weight: 600;
  line-height: 1.5;
  color: var(--color-text);
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.recommend-card .rec-date {
  font-size: 0.75rem;
  color: var(--color-text-lighter);
  margin-top: 8px;
}

/* --- 页脚 --- */
.site-footer {
  background: var(--color-white);
  border-top: 1px solid var(--color-border);
  padding: 40px 20px 20px;
  margin-top: auto;
}

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

.footer-columns {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 32px;
  margin-bottom: 32px;
}

.footer-col h4 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 14px;
  color: var(--color-text);
}

.footer-col ul li {
  margin-bottom: 8px;
}

.footer-col ul li a {
  font-size: 0.9rem;
  color: var(--color-text-light);
}

.footer-col ul li a:hover {
  color: var(--color-primary);
}

.footer-bottom {
  text-align: center;
  padding-top: 20px;
  border-top: 1px solid var(--color-border-light);
  font-size: 0.85rem;
  color: var(--color-text-lighter);
}

/* --- 面包屑 --- */
.breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 24px;
  font-size: 0.9rem;
  color: var(--color-text-lighter);
  flex-wrap: wrap;
}

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

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

.breadcrumb .sep {
  color: var(--color-border);
}

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

/* --- 分页 --- */
.pagination {
  display: flex;
  justify-content: center;
  gap: 8px;
  margin-top: 32px;
  flex-wrap: wrap;
}

.pagination .page-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 36px;
  height: 36px;
  padding: 0 12px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  background: var(--color-white);
  color: var(--color-text);
  font-size: 0.9rem;
  cursor: pointer;
  transition: all 0.2s;
}

.pagination .page-btn:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
}

.pagination .page-btn.active {
  background: var(--color-primary);
  border-color: var(--color-primary);
  color: var(--color-white);
}

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

.pagination .page-info {
  font-size: 0.85rem;
  color: var(--color-text-lighter);
  align-self: center;
  margin-left: 8px;
}

/* --- 首页特色区块 --- */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
  margin-bottom: 40px;
}

.feature-card {
  background: var(--color-white);
  border-radius: var(--radius-md);
  padding: 28px 20px;
  text-align: center;
  box-shadow: var(--shadow-sm);
  transition: all 0.3s;
  cursor: pointer;
  border: 2px solid transparent;
}

.feature-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-4px);
  border-color: var(--color-primary-light);
}

.feature-card .feature-icon {
  font-size: 2.5rem;
  margin-bottom: 12px;
  display: block;
}

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

.feature-card .feature-desc {
  font-size: 0.85rem;
  color: var(--color-text-light);
  line-height: 1.5;
}

/* --- 响应式设计 --- */

/* 平板及以下 */
@media (max-width: 1024px) {
  .feature-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .list-sidebar {
    width: 200px;
  }

  .article-list-item .list-item-image {
    width: 180px;
  }
}

/* 手机端 */
@media (max-width: 768px) {
  :root {
    --header-height: 56px;
  }

  .menu-toggle {
    display: flex;
  }

  .main-nav {
    position: fixed;
    top: var(--header-height);
    left: 0;
    right: 0;
    background: var(--color-white);
    border-bottom: 1px solid var(--color-border);
    box-shadow: var(--shadow-md);
    transform: translateY(-100%);
    opacity: 0;
    pointer-events: none;
    transition: all 0.3s;
  }

  .main-nav.open {
    transform: translateY(0);
    opacity: 1;
    pointer-events: auto;
  }

  .main-nav .nav-list {
    flex-direction: column;
    padding: 8px 0;
  }

  .main-nav .nav-list a {
    padding: 12px 24px;
    border-radius: 0;
    font-size: 1rem;
  }

  .hero-section {
    padding: 40px 24px;
    border-radius: var(--radius-md);
  }

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

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

  .feature-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 10px;
  }

  .feature-card {
    padding: 20px 12px;
  }

  .feature-card .feature-icon {
    font-size: 2rem;
  }

  .feature-card .feature-name {
    font-size: 0.95rem;
  }

  .article-grid {
    grid-template-columns: 1fr;
    gap: 16px;
  }

  /* 列表页改为上下布局 */
  .list-layout {
    flex-direction: column;
  }

  .list-sidebar {
    width: 100%;
    position: static;
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
  }

  .sidebar-block {
    flex: 1;
    min-width: 140px;
    padding: 14px;
    margin-bottom: 0;
  }

  .tag-filter-list {
    flex-direction: row;
    flex-wrap: wrap;
  }

  .tag-filter-item {
    padding: 6px 12px;
    font-size: 0.85rem;
  }

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

  .article-list-item .list-item-image {
    width: 100%;
    min-height: 160px;
  }

  .article-list-item .list-item-body {
    padding: 16px;
  }

  /* 详情页 */
  .article-detail .article-title {
    font-size: 1.5rem;
  }

  .article-detail .article-content {
    font-size: 1rem;
  }

  .recommend-list {
    grid-template-columns: 1fr;
  }

  .footer-columns {
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
  }

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

  .pagination .page-btn {
    min-width: 32px;
    height: 32px;
    font-size: 0.85rem;
  }
}

/* 小屏手机 */
@media (max-width: 480px) {
  .feature-grid {
    grid-template-columns: 1fr 1fr;
    gap: 8px;
  }

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

  .hero-subtitle {
    font-size: 0.9rem;
  }

  .site-main {
    padding: 20px 12px;
  }

  .article-card .card-body {
    padding: 14px;
  }

  .breadcrumb {
    font-size: 0.8rem;
  }

  .article-detail .article-meta {
    flex-direction: column;
    align-items: flex-start;
    gap: 8px;
  }
}

/* --- 辅助类 --- */
.text-center { text-align: center; }
.mt-20 { margin-top: 20px; }
.mb-20 { margin-bottom: 20px; }
.empty-state {
  text-align: center;
  padding: 60px 20px;
  color: var(--color-text-lighter);
}
.empty-state .empty-icon {
  font-size: 3rem;
  display: block;
  margin-bottom: 16px;
}