/* ========================================
   口腔护理 - 内容中心风格样式
   主色调: #2196f3 (蓝色)
   ======================================== */

/* CSS 变量 */
:root {
  --accent-color: #2196f3;
  --accent-dark: #1976d2;
  --accent-light: #e3f2fd;
  --text-primary: #333;
  --text-secondary: #666;
  --text-muted: #999;
  --bg-white: #fff;
  --bg-light: #f5f7fa;
  --border-color: #e8e8e8;
  --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: 14px;
  line-height: 1.6;
  color: var(--text-primary);
  background: var(--bg-light);
}

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

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

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

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

/* ========================================
   页头 Header
   ======================================== */
.header {
  background: var(--bg-white);
  box-shadow: var(--shadow);
  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: 10px;
  font-size: 20px;
  font-weight: 700;
  color: var(--text-primary);
}

.logo-icon {
  width: 36px;
  height: 36px;
  background: var(--accent-color);
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-size: 18px;
}

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

.nav a {
  color: var(--text-secondary);
  font-weight: 500;
  padding: 8px 0;
  border-bottom: 2px solid transparent;
  transition: all 0.2s;
}

.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-light);
  border-radius: 20px;
  padding: 6px 16px;
  width: 200px;
}

.search-box input {
  border: none;
  background: none;
  outline: none;
  width: 100%;
  font-size: 13px;
}

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

/* ========================================
   Hero Section
   ======================================== */
.hero {
  background: linear-gradient(135deg, var(--accent-color) 0%, var(--accent-dark) 100%);
  color: #fff;
  padding: 60px 0;
  text-align: center;
}

.hero-title {
  font-size: 36px;
  font-weight: 700;
  margin-bottom: 16px;
}

.hero-desc {
  font-size: 16px;
  opacity: 0.9;
  max-width: 600px;
  margin: 0 auto;
}

/* ========================================
   内容区块
   ======================================== */
.section {
  padding: 40px 0;
}

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

.section-title {
  font-size: 20px;
  font-weight: 600;
  display: flex;
  align-items: center;
  gap: 8px;
}

.section-title::before {
  content: '';
  width: 4px;
  height: 20px;
  background: var(--accent-color);
  border-radius: 2px;
}

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

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

/* ========================================
   分类入口 Category Entry
   ======================================== */
.category-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  margin-bottom: 40px;
}

.category-card {
  background: var(--bg-white);
  border-radius: var(--radius-lg);
  padding: 24px;
  text-align: center;
  box-shadow: var(--shadow);
  transition: all 0.3s;
}

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

.category-icon {
  width: 56px;
  height: 56px;
  background: var(--accent-light);
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 12px;
  font-size: 24px;
}

.category-name {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 4px;
}

.category-count {
  font-size: 12px;
  color: var(--text-muted);
}

/* ========================================
   文章列表
   ======================================== */
.article-list {
  background: var(--bg-white);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow);
  overflow: hidden;
}

.article-item {
  display: flex;
  gap: 16px;
  padding: 20px;
  border-bottom: 1px solid var(--border-color);
  transition: background 0.2s;
}

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

.article-item:hover {
  background: var(--bg-light);
}

.article-thumb {
  width: 160px;
  height: 100px;
  background: var(--accent-light);
  border-radius: var(--radius);
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--accent-color);
  font-size: 32px;
}

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

.article-title {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 8px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

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

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

.article-summary {
  font-size: 13px;
  color: var(--text-secondary);
  line-height: 1.6;
  overflow: hidden;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  margin-bottom: 8px;
}

.article-meta {
  display: flex;
  align-items: center;
  gap: 16px;
  font-size: 12px;
  color: var(--text-muted);
}

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

/* ========================================
   三栏布局 (推荐/热门/最新)
   ======================================== */
.three-col-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.col-card {
  background: var(--bg-white);
  border-radius: var(--radius-lg);
  padding: 20px;
  box-shadow: var(--shadow);
}

.col-title {
  font-size: 15px;
  font-weight: 600;
  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);
}

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

.col-list a {
  color: var(--text-primary);
  font-size: 13px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.col-list a::before {
  content: '•';
  color: var(--accent-color);
}

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

/* ========================================
   面包屑 Breadcrumb
   ======================================== */
.breadcrumb {
  background: var(--bg-white);
  padding: 16px 0;
  border-bottom: 1px solid var(--border-color);
}

.breadcrumb-inner {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  color: var(--text-muted);
}

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

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

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

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

/* ========================================
   分类页特定样式
   ======================================== */
.category-header {
  background: var(--bg-white);
  padding: 32px 0;
  margin-bottom: 24px;
}

.category-title {
  font-size: 28px;
  font-weight: 700;
  margin-bottom: 8px;
}

.category-stats {
  color: var(--text-muted);
  font-size: 14px;
}

.filter-bar {
  display: flex;
  gap: 8px;
  margin-bottom: 20px;
  flex-wrap: wrap;
}

.filter-btn {
  padding: 6px 16px;
  border: 1px solid var(--border-color);
  background: var(--bg-white);
  border-radius: 16px;
  font-size: 13px;
  cursor: pointer;
  transition: all 0.2s;
}

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

.load-more {
  text-align: center;
  padding: 24px;
}

.load-more-btn {
  padding: 10px 32px;
  border: 1px solid var(--border-color);
  background: var(--bg-white);
  border-radius: 20px;
  font-size: 14px;
  cursor: pointer;
  transition: all 0.2s;
}

.load-more-btn:hover {
  border-color: var(--accent-color);
  color: var(--accent-color);
}

/* ========================================
   文章详情页
   ======================================== */
.article-header {
  background: var(--bg-white);
  padding: 32px 0;
  margin-bottom: 24px;
}

.article-page-title {
  font-size: 28px;
  font-weight: 700;
  line-height: 1.4;
  margin-bottom: 16px;
}

.article-page-meta {
  display: flex;
  align-items: center;
  gap: 16px;
  color: var(--text-muted);
  font-size: 13px;
}

.article-source {
  background: var(--accent-light);
  color: var(--accent-color);
  padding: 4px 12px;
  border-radius: 12px;
  font-size: 12px;
}

.article-body {
  background: var(--bg-white);
  border-radius: var(--radius-lg);
  padding: 32px;
  box-shadow: var(--shadow);
}

.article-featured-img {
  width: 100%;
  height: 300px;
  background: var(--accent-light);
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--accent-color);
  font-size: 64px;
  margin-bottom: 24px;
}

.article-summary-box {
  background: var(--bg-light);
  border-left: 4px solid var(--accent-color);
  padding: 16px 20px;
  border-radius: 0 var(--radius) var(--radius) 0;
  margin-bottom: 24px;
}

.article-summary-box h3 {
  font-size: 14px;
  margin-bottom: 8px;
  color: var(--text-primary);
}

.article-summary-box p {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.8;
}

.key-points {
  margin-bottom: 24px;
}

.key-points h3 {
  font-size: 16px;
  margin-bottom: 12px;
}

.key-points ul {
  list-style: none;
  padding-left: 0;
}

.key-points li {
  padding: 8px 0;
  padding-left: 24px;
  position: relative;
  font-size: 14px;
  color: var(--text-secondary);
}

.key-points li::before {
  content: '✓';
  position: absolute;
  left: 0;
  color: var(--accent-color);
  font-weight: bold;
}

.article-content-full {
  font-size: 15px;
  line-height: 1.8;
  color: var(--text-primary);
}

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

.read-source-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: var(--accent-color);
  color: #fff;
  padding: 12px 24px;
  border-radius: var(--radius);
  font-weight: 500;
  margin: 24px 0;
}

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

/* 相关文章 */
.related-section {
  margin-top: 32px;
  padding-top: 32px;
  border-top: 1px solid var(--border-color);
}

.related-title {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 16px;
}

.related-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}

.related-card {
  background: var(--bg-light);
  border-radius: var(--radius);
  padding: 16px;
  transition: all 0.2s;
}

.related-card:hover {
  background: var(--accent-light);
}

.related-card-title {
  font-size: 14px;
  font-weight: 500;
  margin-bottom: 8px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.related-card-title a {
  color: var(--text-primary);
}

.related-card-title a:hover {
  color: var(--accent-color);
}

.related-card-source {
  font-size: 12px;
  color: var(--text-muted);
}

/* ========================================
   404 页面
   ======================================== */
.error-page {
  min-height: calc(100vh - var(--header-height) - 200px);
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 40px 20px;
}

.error-code {
  font-size: 120px;
  font-weight: 700;
  color: var(--accent-color);
  line-height: 1;
  margin-bottom: 16px;
}

.error-title {
  font-size: 24px;
  font-weight: 600;
  margin-bottom: 12px;
}

.error-desc {
  color: var(--text-secondary);
  margin-bottom: 24px;
}

.error-actions {
  display: flex;
  gap: 12px;
  justify-content: center;
}

.btn {
  padding: 10px 24px;
  border-radius: var(--radius);
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.2s;
}

.btn-primary {
  background: var(--accent-color);
  color: #fff;
  border: none;
}

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

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

.btn-default:hover {
  border-color: var(--accent-color);
  color: var(--accent-color);
}

/* ========================================
   页脚 Footer
   ======================================== */
.footer {
  background: var(--bg-white);
  border-top: 1px solid var(--border-color);
  padding: 40px 0 24px;
  margin-top: 40px;
}

.footer-inner {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px;
  margin-bottom: 32px;
}

.footer-brand {
  max-width: 280px;
}

.footer-logo {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 18px;
  font-weight: 700;
  margin-bottom: 12px;
}

.footer-desc {
  font-size: 13px;
  color: var(--text-secondary);
  line-height: 1.6;
}

.footer-title {
  font-size: 14px;
  font-weight: 600;
  margin-bottom: 16px;
}

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

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

.footer-links a {
  font-size: 13px;
  color: var(--text-secondary);
}

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

.footer-bottom {
  border-top: 1px solid var(--border-color);
  padding-top: 20px;
  text-align: center;
  font-size: 12px;
  color: var(--text-muted);
}

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

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

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

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

  .nav {
    order: 3;
    width: 100%;
    gap: 16px;
    margin-top: 12px;
    overflow-x: auto;
  }

  .search-box {
    width: 140px;
  }

  .hero {
    padding: 40px 0;
  }

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

  .category-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 12px;
  }

  .category-card {
    padding: 16px;
  }

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

  .article-thumb {
    width: 100%;
    height: 160px;
  }

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

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

  .footer-inner {
    grid-template-columns: 1fr;
    gap: 24px;
  }

  .article-page-title {
    font-size: 20px;
  }

  .article-body {
    padding: 20px;
  }

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

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

  .article-meta {
    flex-wrap: wrap;
    gap: 8px;
  }
}