/* ========================================
   中医小笔记 - 倪海厦中医学习门户
   传统中式风格 CSS 样式表
   ======================================== */

/* CSS变量定义 */
:root {
  /* 传统中式配色 */
  --color-primary: #8B4513;      /* 深棕 - 主色调 */
  --color-secondary: #D4A574;    /* 米黄 - 辅助色 */
  --color-accent: #C41E3A;       /* 中国红 - 强调色 */
  --color-bg: #FDF8F0;           /* 米白 - 背景色 */
  --color-bg-alt: #F5EDE0;       /* 浅米色 */
  --color-text: #3D2914;         /* 深棕文字 */
  --color-text-light: #6B5344;   /* 浅棕文字 */
  --color-white: #FFFFFF;
  --color-border: #E5D9C9;       /* 边框色 */
  
  /* 渐变色 */
  --gradient-hero: linear-gradient(135deg, #3D2914 0%, #5C3D2E 25%, #8B4513 50%, #6B3D2E 75%, #3D2914 100%);
  --gradient-card: linear-gradient(180deg, rgba(139, 69, 19, 0.05) 0%, rgba(139, 69, 19, 0.1) 100%);
  --gradient-btn: linear-gradient(135deg, #C41E3A 0%, #A01830 100%);
  
  /* 阴影 */
  --shadow-sm: 0 2px 8px rgba(61, 41, 20, 0.08);
  --shadow-md: 0 4px 16px rgba(61, 41, 20, 0.12);
  --shadow-lg: 0 8px 32px rgba(61, 41, 20, 0.16);
  --shadow-card: 0 4px 20px rgba(139, 69, 19, 0.1);
  
  /* 圆角 */
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-xl: 20px;
  
  /* 间距 */
  --space-xs: 4px;
  --space-sm: 8px;
  --space-md: 16px;
  --space-lg: 24px;
  --space-xl: 32px;
  --space-2xl: 48px;
  --space-3xl: 64px;
  
  /* 字体 */
  --font-family: 'Georgia', 'Times New Roman', 'STSong', 'SimSun', serif;
  --font-family-body: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  --font-size-xs: 12px;
  --font-size-sm: 14px;
  --font-size-md: 16px;
  --font-size-lg: 18px;
  --font-size-xl: 20px;
  --font-size-2xl: 24px;
  --font-size-3xl: 30px;
  --font-size-4xl: 36px;
  --font-size-5xl: 48px;
  
  /* 过渡 */
  --transition-fast: 0.2s ease;
  --transition-normal: 0.3s ease;
  --transition-slow: 0.5s ease;
  
  /* 导航高度 */
  --nav-height: 70px;
}

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

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

body {
  font-family: var(--font-family-body);
  background-color: var(--color-bg);
  color: var(--color-text);
  line-height: 1.6;
  min-height: 100vh;
  overflow-x: hidden;
}

a {
  text-decoration: none;
  color: inherit;
  transition: color var(--transition-fast);
}

ul, ol {
  list-style: none;
}

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

button {
  cursor: pointer;
  border: none;
  background: none;
  font-family: inherit;
}

input, textarea {
  font-family: inherit;
  font-size: inherit;
}

/* ========================================
   页面加载动画
   ======================================== */
.page-loader {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: var(--color-bg);
  display: flex;
  justify-content: center;
  align-items: center;
  z-index: 9999;
  transition: opacity 0.5s ease, visibility 0.5s ease;
}

.page-loader.hidden {
  opacity: 0;
  visibility: hidden;
}

.loader-content {
  text-align: center;
}

.loader-symbol {
  font-size: 48px;
  animation: pulse 1.5s ease-in-out infinite;
}

.loader-text {
  margin-top: var(--space-md);
  color: var(--color-primary);
  font-family: var(--font-family);
  font-size: var(--font-size-lg);
}

@keyframes pulse {
  0%, 100% { transform: scale(1); opacity: 1; }
  50% { transform: scale(1.2); opacity: 0.7; }
}

/* ========================================
   导航栏
   ======================================== */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: var(--nav-height);
  background: rgba(253, 248, 240, 0.95);
  backdrop-filter: blur(10px);
  z-index: 1000;
  transition: all var(--transition-normal);
  border-bottom: 1px solid transparent;
}

.navbar.scrolled {
  background: rgba(253, 248, 240, 0.98);
  border-bottom-color: var(--color-border);
  box-shadow: var(--shadow-sm);
}

.navbar-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--space-lg);
  height: 100%;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.logo-icon {
  font-size: 32px;
}

.logo-text {
  font-family: var(--font-family);
  font-size: var(--font-size-xl);
  font-weight: bold;
  color: var(--color-primary);
}

.logo-sub {
  font-size: var(--font-size-xs);
  color: var(--color-text-light);
  font-family: var(--font-family-body);
}

.nav-links {
  display: flex;
  gap: var(--space-xl);
}

.nav-links a {
  position: relative;
  padding: var(--space-sm) 0;
  color: var(--color-text);
  font-size: var(--font-size-md);
  font-weight: 500;
  transition: color var(--transition-fast);
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--color-accent);
  transition: width var(--transition-normal);
}

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

.nav-links a:hover::after,
.nav-links a.active::after {
  width: 100%;
}

/* 汉堡菜单按钮 */
.menu-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  padding: var(--space-sm);
}

.menu-toggle span {
  display: block;
  width: 25px;
  height: 3px;
  background: var(--color-primary);
  border-radius: 2px;
  transition: all var(--transition-fast);
}

.menu-toggle.active span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}

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

.menu-toggle.active span:nth-child(3) {
  transform: rotate(-45deg) translate(7px, -6px);
}

/* 移动端菜单 */
.mobile-menu {
  display: none;
  position: fixed;
  top: var(--nav-height);
  left: 0;
  width: 100%;
  background: var(--color-white);
  padding: var(--space-lg);
  box-shadow: var(--shadow-md);
  transform: translateY(-100%);
  opacity: 0;
  transition: all var(--transition-normal);
}

.mobile-menu.active {
  transform: translateY(0);
  opacity: 1;
}

.mobile-menu a {
  display: block;
  padding: var(--space-md) 0;
  color: var(--color-text);
  font-size: var(--font-size-lg);
  border-bottom: 1px solid var(--color-border);
}

.mobile-menu a:last-child {
  border-bottom: none;
}

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

/* ========================================
   Hero 区域
   ======================================== */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--nav-height) var(--space-lg) var(--space-3xl);
  background: var(--gradient-hero);
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.03'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
  opacity: 0.5;
}

/* 水墨纹理效果 */
.hero::after {
  content: '';
  position: absolute;
  top: -50%;
  right: -20%;
  width: 80%;
  height: 150%;
  background: radial-gradient(ellipse at center, rgba(212, 165, 116, 0.15) 0%, transparent 70%);
  pointer-events: none;
}

.hero-content {
  position: relative;
  z-index: 1;
  text-align: center;
  max-width: 800px;
  animation: fadeInUp 1s ease-out;
}

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.hero-badge {
  display: inline-block;
  padding: var(--space-sm) var(--space-lg);
  background: rgba(196, 30, 58, 0.2);
  border: 1px solid rgba(196, 30, 58, 0.3);
  border-radius: var(--radius-xl);
  color: var(--color-secondary);
  font-size: var(--font-size-sm);
  margin-bottom: var(--space-lg);
  animation: fadeInUp 1s ease-out 0.2s both;
}

.hero-title {
  font-family: var(--font-family);
  font-size: var(--font-size-5xl);
  color: var(--color-white);
  margin-bottom: var(--space-lg);
  line-height: 1.2;
  animation: fadeInUp 1s ease-out 0.4s both;
}

.hero-title span {
  color: var(--color-accent);
}

.hero-subtitle {
  font-size: var(--font-size-xl);
  color: rgba(255, 255, 255, 0.8);
  margin-bottom: var(--space-2xl);
  animation: fadeInUp 1s ease-out 0.6s both;
}

.hero-buttons {
  display: flex;
  gap: var(--space-lg);
  justify-content: center;
  flex-wrap: wrap;
  animation: fadeInUp 1s ease-out 0.8s both;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-md) var(--space-xl);
  font-size: var(--font-size-md);
  font-weight: 600;
  border-radius: var(--radius-md);
  transition: all var(--transition-normal);
}

.btn-primary {
  background: var(--gradient-btn);
  color: var(--color-white);
  box-shadow: 0 4px 15px rgba(196, 30, 58, 0.4);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(196, 30, 58, 0.5);
}

.btn-secondary {
  background: rgba(255, 255, 255, 0.1);
  color: var(--color-white);
  border: 1px solid rgba(255, 255, 255, 0.3);
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.2);
  border-color: rgba(255, 255, 255, 0.5);
}

.hero-decoration {
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 120px;
  background: linear-gradient(to top, var(--color-bg), transparent);
}

/* ========================================
   通用容器
   ======================================== */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--space-lg);
}

.section {
  padding: var(--space-3xl) 0;
}

.section-header {
  text-align: center;
  margin-bottom: var(--space-2xl);
}

.section-title {
  font-family: var(--font-family);
  font-size: var(--font-size-3xl);
  color: var(--color-primary);
  margin-bottom: var(--space-md);
  position: relative;
  display: inline-block;
}

.section-title::after {
  content: '';
  position: absolute;
  bottom: -8px;
  left: 50%;
  transform: translateX(-50%);
  width: 60px;
  height: 3px;
  background: var(--color-accent);
  border-radius: 2px;
}

.section-subtitle {
  color: var(--color-text-light);
  font-size: var(--font-size-lg);
  max-width: 600px;
  margin: 0 auto;
}

/* ========================================
   倪海厦简介区
   ======================================== */
.about-intro {
  background: var(--color-white);
}

.about-intro-grid {
  display: grid;
  grid-template-columns: 1fr 400px;
  gap: var(--space-3xl);
  align-items: center;
}

.about-intro-content h2 {
  font-family: var(--font-family);
  font-size: var(--font-size-3xl);
  color: var(--color-primary);
  margin-bottom: var(--space-lg);
}

.about-intro-content p {
  color: var(--color-text);
  line-height: 1.8;
  margin-bottom: var(--space-md);
}

.about-intro-image {
  position: relative;
}

.image-frame {
  background: var(--gradient-card);
  border: 3px solid var(--color-secondary);
  border-radius: var(--radius-lg);
  padding: var(--space-md);
  box-shadow: var(--shadow-card);
}

.image-placeholder {
  background: linear-gradient(135deg, var(--color-bg-alt) 0%, var(--color-border) 100%);
  border-radius: var(--radius-md);
  height: 400px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  color: var(--color-text-light);
}

.image-placeholder-icon {
  font-size: 64px;
  margin-bottom: var(--space-md);
  opacity: 0.5;
}

.image-placeholder-text {
  font-family: var(--font-family);
  font-size: var(--font-size-lg);
}

/* ========================================
   分类卡片区
   ======================================== */
.categories {
  background: var(--color-bg);
}

.categories-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-lg);
}

.category-card {
  background: var(--color-white);
  border-radius: var(--radius-lg);
  padding: var(--space-xl);
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--color-border);
  transition: all var(--transition-normal);
  position: relative;
  overflow: hidden;
}

.category-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 4px;
  background: var(--gradient-btn);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--transition-normal);
}

.category-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-lg);
  border-color: var(--color-secondary);
}

.category-card:hover::before {
  transform: scaleX(1);
}

.category-icon {
  width: 60px;
  height: 60px;
  background: var(--gradient-card);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 28px;
  margin-bottom: var(--space-md);
}

.category-title {
  font-family: var(--font-family);
  font-size: var(--font-size-xl);
  color: var(--color-primary);
  margin-bottom: var(--space-sm);
}

.category-desc {
  color: var(--color-text-light);
  font-size: var(--font-size-sm);
  line-height: 1.6;
  margin-bottom: var(--space-md);
}

.category-link {
  display: inline-flex;
  align-items: center;
  gap: var(--space-xs);
  color: var(--color-accent);
  font-weight: 600;
  font-size: var(--font-size-sm);
  transition: gap var(--transition-fast);
}

.category-link:hover {
  gap: var(--space-sm);
}

/* ========================================
   推荐学习区
   ======================================== */
.articles {
  background: var(--color-white);
}

.articles-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-lg);
}

.article-card {
  background: var(--color-bg);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  transition: all var(--transition-normal);
  border: 1px solid transparent;
}

.article-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-md);
  border-color: var(--color-secondary);
}

.article-image {
  height: 180px;
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-secondary) 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 48px;
  color: rgba(255, 255, 255, 0.8);
}

.article-content {
  padding: var(--space-lg);
}

.article-category {
  display: inline-block;
  padding: var(--space-xs) var(--space-sm);
  background: rgba(196, 30, 58, 0.1);
  color: var(--color-accent);
  font-size: var(--font-size-xs);
  border-radius: var(--radius-sm);
  margin-bottom: var(--space-sm);
}

.article-title {
  font-family: var(--font-family);
  font-size: var(--font-size-lg);
  color: var(--color-primary);
  margin-bottom: var(--space-sm);
  line-height: 1.4;
  transition: color var(--transition-fast);
}

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

.article-excerpt {
  color: var(--color-text-light);
  font-size: var(--font-size-sm);
  line-height: 1.6;
  margin-bottom: var(--space-md);
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.article-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-top: var(--space-md);
  border-top: 1px solid var(--color-border);
}

.article-date {
  color: var(--color-text-light);
  font-size: var(--font-size-xs);
}

.article-read {
  color: var(--color-accent);
  font-size: var(--font-size-sm);
  font-weight: 500;
}

/* ========================================
   分类页面 - 文章列表
   ======================================== */
.category-header {
  background: var(--gradient-hero);
  padding: calc(var(--nav-height) + var(--space-3xl)) 0 var(--space-3xl);
  text-align: center;
  position: relative;
  overflow: hidden;
}

.category-header::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: url("data:image/svg+xml,%3Csvg width='100' height='100' viewBox='0 0 100 100' xmlns='http://www.w3.org/2000/svg'%3E%3Cpath d='M11 18c3.866 0 7-3.134 7-7s-3.134-7-7-7-7 3.134-7 7 3.134 7 7 7zm48 25c3.866 0 7-3.134 7-7s-3.134-7-7-7-7 3.134-7 7 3.134 7 7 7zm-43-7c1.657 0 3-1.343 3-3s-1.343-3-3-3-3 1.343-3 3 1.343 3 3 3zm63 31c1.657 0 3-1.343 3-3s-1.343-3-3-3-3 1.343-3 3 1.343 3 3 3zM34 90c1.657 0 3-1.343 3-3s-1.343-3-3-3-3 1.343-3 3 1.343 3 3 3zm56-76c1.657 0 3-1.343 3-3s-1.343-3-3-3-3 1.343-3 3 1.343 3 3 3zM12 86c2.21 0 4-1.79 4-4s-1.79-4-4-4-4 1.79-4 4 1.79 4 4 4zm28-65c2.21 0 4-1.79 4-4s-1.79-4-4-4-4 1.79-4 4 1.79 4 4 4zm23-11c2.76 0 5-2.24 5-5s-2.24-5-5-5-5 2.24-5 5 2.24 5 5 5zm-6 60c2.21 0 4-1.79 4-4s-1.79-4-4-4-4 1.79-4 4 1.79 4 4 4zm29 22c2.76 0 5-2.24 5-5s-2.24-5-5-5-5 2.24-5 5 2.24 5 5 5zM32 63c2.76 0 5-2.24 5-5s-2.24-5-5-5-5 2.24-5 5 2.24 5 5 5zm57-13c2.76 0 5-2.24 5-5s-2.24-5-5-5-5 2.24-5 5 2.24 5 5 5zm-9-21c1.105 0 2-.895 2-2s-.895-2-2-2-2 .895-2 2 .895 2 2 2zM60 91c1.105 0 2-.895 2-2s-.895-2-2-2-2 .895-2 2 .895 2 2 2zM35 41c1.105 0 2-.895 2-2s-.895-2-2-2-2 .895-2 2 .895 2 2 2zM12 60c1.105 0 2-.895 2-2s-.895-2-2-2-2 .895-2 2 .895 2 2 2z' fill='%23ffffff' fill-opacity='0.03' fill-rule='evenodd'/%3E%3C/svg%3E");
}

.category-header-content {
  position: relative;
  z-index: 1;
}

.category-header-icon {
  font-size: 64px;
  margin-bottom: var(--space-md);
}

.category-header h1 {
  font-family: var(--font-family);
  font-size: var(--font-size-4xl);
  color: var(--color-white);
  margin-bottom: var(--space-md);
}

.category-header p {
  color: rgba(255, 255, 255, 0.8);
  font-size: var(--font-size-lg);
  max-width: 600px;
  margin: 0 auto;
}

/* 面包屑导航 */
.breadcrumb {
  padding: var(--space-md) 0;
  background: var(--color-bg);
}

.breadcrumb-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--space-lg);
}

.breadcrumb-list {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  font-size: var(--font-size-sm);
  color: var(--color-text-light);
}

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

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

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

/* 文章列表 */
.article-list {
  background: var(--color-bg);
}

.article-list-grid {
  display: grid;
  gap: var(--space-lg);
}

.article-list-item {
  background: var(--color-white);
  border-radius: var(--radius-lg);
  padding: var(--space-xl);
  display: grid;
  grid-template-columns: 80px 1fr auto;
  gap: var(--space-lg);
  align-items: center;
  box-shadow: var(--shadow-sm);
  border: 1px solid transparent;
  transition: all var(--transition-normal);
}

.article-list-item:hover {
  transform: translateX(5px);
  border-color: var(--color-secondary);
  box-shadow: var(--shadow-md);
}

.article-list-icon {
  width: 80px;
  height: 80px;
  background: var(--gradient-card);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 32px;
}

.article-list-content h3 {
  font-family: var(--font-family);
  font-size: var(--font-size-lg);
  color: var(--color-primary);
  margin-bottom: var(--space-sm);
}

.article-list-content p {
  color: var(--color-text-light);
  font-size: var(--font-size-sm);
  line-height: 1.6;
}

.article-list-meta {
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: var(--space-md);
}

.article-list-date {
  color: var(--color-text-light);
  font-size: var(--font-size-xs);
}

.btn-outline {
  display: inline-flex;
  align-items: center;
  gap: var(--space-xs);
  padding: var(--space-sm) var(--space-md);
  border: 2px solid var(--color-accent);
  color: var(--color-accent);
  font-weight: 600;
  font-size: var(--font-size-sm);
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
}

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

/* 敬请期待按钮样式 */
.btn-disabled {
  display: inline-flex;
  align-items: center;
  gap: var(--space-xs);
  padding: var(--space-sm) var(--space-md);
  border: 2px solid #999;
  color: #999;
  font-weight: 600;
  font-size: var(--font-size-sm);
  border-radius: var(--radius-md);
  opacity: 0.5;
  cursor: not-allowed;
  pointer-events: none;
}

/* ========================================
   关于页面
   ======================================== */
.about-hero {
  background: var(--gradient-hero);
  padding: calc(var(--nav-height) + var(--space-3xl)) 0 var(--space-3xl);
  text-align: center;
}

.about-hero h1 {
  font-family: var(--font-family);
  font-size: var(--font-size-4xl);
  color: var(--color-white);
  margin-bottom: var(--space-md);
}

.about-hero p {
  color: rgba(255, 255, 255, 0.8);
  font-size: var(--font-size-lg);
}

.about-content {
  background: var(--color-white);
}

.about-section {
  padding: var(--space-2xl) 0;
  border-bottom: 1px solid var(--color-border);
}

.about-section:last-child {
  border-bottom: none;
}

.about-section h2 {
  font-family: var(--font-family);
  font-size: var(--font-size-2xl);
  color: var(--color-primary);
  margin-bottom: var(--space-lg);
  position: relative;
  padding-left: var(--space-lg);
}

.about-section h2::before {
  content: '';
  position: absolute;
  left: 0;
  top: 50%;
  transform: translateY(-50%);
  width: 4px;
  height: 24px;
  background: var(--color-accent);
  border-radius: 2px;
}

.about-section p {
  color: var(--color-text);
  line-height: 1.8;
  margin-bottom: var(--space-md);
}

.about-section ul {
  list-style: disc;
  padding-left: var(--space-xl);
}

.about-section li {
  color: var(--color-text);
  line-height: 1.8;
  margin-bottom: var(--space-sm);
}

.disclaimer-box {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-left: 4px solid var(--color-accent);
  border-radius: var(--radius-md);
  padding: var(--space-lg);
  margin-top: var(--space-lg);
}

.disclaimer-box h4 {
  color: var(--color-accent);
  margin-bottom: var(--space-sm);
  font-size: var(--font-size-md);
}

.disclaimer-box p {
  font-size: var(--font-size-sm);
  color: var(--color-text-light);
  margin-bottom: 0;
}

/* ========================================
   Footer
   ======================================== */
.footer {
  background: var(--color-primary);
  color: var(--color-white);
  padding: var(--space-3xl) 0 var(--space-lg);
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: var(--space-3xl);
  margin-bottom: var(--space-2xl);
}

.footer-about h3,
.footer-links h3,
.footer-contact h3 {
  font-family: var(--font-family);
  font-size: var(--font-size-lg);
  margin-bottom: var(--space-lg);
  position: relative;
  padding-bottom: var(--space-sm);
}

.footer-about h3::after,
.footer-links h3::after,
.footer-contact h3::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 40px;
  height: 2px;
  background: var(--color-accent);
}

.footer-about p {
  color: rgba(255, 255, 255, 0.7);
  line-height: 1.8;
  margin-bottom: var(--space-md);
}

.footer-social {
  display: flex;
  gap: var(--space-md);
}

.footer-social a {
  width: 40px;
  height: 40px;
  background: rgba(255, 255, 255, 0.1);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 18px;
  transition: all var(--transition-fast);
}

.footer-social a:hover {
  background: var(--color-accent);
  transform: translateY(-3px);
}

.footer-links ul,
.footer-contact ul {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

.footer-links a {
  color: rgba(255, 255, 255, 0.7);
  transition: color var(--transition-fast);
  display: inline-block;
}

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

.footer-contact li {
  color: rgba(255, 255, 255, 0.7);
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.footer-contact li::before {
  content: '📍';
  font-size: 14px;
}

.footer-contact li:nth-child(2)::before {
  content: '📧';
}

.footer-contact li:nth-child(3)::before {
  content: '📱';
}

.footer-bottom {
  padding-top: var(--space-lg);
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--space-md);
}

.footer-copyright {
  color: rgba(255, 255, 255, 0.5);
  font-size: var(--font-size-sm);
}

.footer-icp {
  display: flex;
  gap: var(--space-lg);
  font-size: var(--font-size-sm);
}

.footer-icp a {
  color: rgba(255, 255, 255, 0.5);
  transition: color var(--transition-fast);
}

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

/* ========================================
   回到顶部按钮
   ======================================== */
.back-to-top {
  position: fixed;
  bottom: var(--space-xl);
  right: var(--space-xl);
  width: 50px;
  height: 50px;
  background: var(--gradient-btn);
  color: var(--color-white);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 24px;
  box-shadow: var(--shadow-md);
  opacity: 0;
  visibility: hidden;
  transform: translateY(20px);
  transition: all var(--transition-normal);
  z-index: 999;
  cursor: pointer;
}

.back-to-top.visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.back-to-top:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-lg);
}

/* ========================================
   响应式设计
   ======================================== */
@media (max-width: 992px) {
  .about-intro-grid {
    grid-template-columns: 1fr;
    gap: var(--space-2xl);
  }
  
  .about-intro-image {
    order: -1;
  }
  
  .image-placeholder {
    height: 300px;
  }
  
  .categories-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .articles-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 768px) {
  :root {
    --nav-height: 60px;
    --font-size-5xl: 36px;
    --font-size-4xl: 28px;
    --font-size-3xl: 24px;
  }
  
  .nav-links {
    display: none;
  }
  
  .menu-toggle {
    display: flex;
  }
  
  .mobile-menu {
    display: block;
  }
  
  .hero {
    min-height: auto;
    padding: calc(var(--nav-height) + var(--space-2xl)) var(--space-lg) var(--space-2xl);
  }
  
  .hero-title {
    font-size: var(--font-size-4xl);
  }
  
  .hero-subtitle {
    font-size: var(--font-size-md);
  }
  
  .hero-buttons {
    flex-direction: column;
    align-items: center;
  }
  
  .btn {
    width: 100%;
    max-width: 280px;
    justify-content: center;
  }
  
  .categories-grid {
    grid-template-columns: 1fr;
  }
  
  .articles-grid {
    grid-template-columns: 1fr;
  }
  
  .article-list-item {
    grid-template-columns: 60px 1fr;
    gap: var(--space-md);
  }
  
  .article-list-meta {
    grid-column: 1 / -1;
    flex-direction: row;
    justify-content: space-between;
    align-items: center;
  }
  
  .footer-grid {
    grid-template-columns: 1fr;
    gap: var(--space-2xl);
  }
  
  .footer-bottom {
    flex-direction: column;
    text-align: center;
  }
  
  .back-to-top {
    bottom: var(--space-md);
    right: var(--space-md);
    width: 44px;
    height: 44px;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 var(--space-md);
  }
  
  .section {
    padding: var(--space-2xl) 0;
  }
  
  .category-card {
    padding: var(--space-lg);
  }
  
  .article-content {
    padding: var(--space-md);
  }
  
  .about-section h2 {
    font-size: var(--font-size-xl);
    padding-left: var(--space-md);
  }
}

/* ========================================
   动画辅助类
   ======================================== */
.fade-in {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

.stagger-1 { transition-delay: 0.1s; }
.stagger-2 { transition-delay: 0.2s; }
.stagger-3 { transition-delay: 0.3s; }
.stagger-4 { transition-delay: 0.4s; }
.stagger-5 { transition-delay: 0.5s; }
.stagger-6 { transition-delay: 0.6s; }

/* ========================================
   首页主分类卡片（人纪+天纪）
   ======================================== */
.main-categories {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-xl);
  margin-top: var(--space-xl);
}

.main-category-card {
  background: var(--color-white);
  border-radius: var(--radius-lg);
  padding: var(--space-2xl);
  box-shadow: var(--shadow-md);
  border: 2px solid var(--color-border);
  transition: all var(--transition-normal);
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
}

.main-category-card:hover {
  transform: translateY(-8px);
  box-shadow: var(--shadow-lg);
  border-color: var(--color-secondary);
}

.main-category-icon {
  width: 80px;
  height: 80px;
  background: var(--gradient-card);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 36px;
  margin-bottom: var(--space-lg);
  box-shadow: var(--shadow-sm);
}

.main-category-content {
  width: 100%;
}

.main-category-title {
  font-family: var(--font-family);
  font-size: var(--font-size-2xl);
  color: var(--color-primary);
  margin-bottom: var(--space-md);
}

.main-category-desc {
  color: var(--color-text-light);
  font-size: var(--font-size-base);
  line-height: 1.7;
  margin-bottom: var(--space-lg);
}

.main-category-tags {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: var(--space-sm);
  margin-bottom: var(--space-lg);
}

.mini-tag {
  display: inline-block;
  padding: var(--space-xs) var(--space-sm);
  background: rgba(196, 30, 58, 0.08);
  color: var(--color-accent);
  font-size: var(--font-size-xs);
  border-radius: var(--radius-full);
  transition: all var(--transition-fast);
}

.main-category-card:hover .mini-tag {
  background: rgba(196, 30, 58, 0.15);
}

/* ========================================
   人纪页面样式
   ======================================== */
.intro-section {
  background: var(--color-white);
}

.intro-content {
  max-width: 800px;
  margin: 0 auto;
  text-align: center;
}

.intro-content h2 {
  font-family: var(--font-family);
  font-size: var(--font-size-2xl);
  color: var(--color-primary);
  margin-bottom: var(--space-lg);
}

.intro-content p {
  color: var(--color-text);
  font-size: var(--font-size-lg);
  line-height: 1.8;
  margin-bottom: var(--space-xl);
}

.intro-tags {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: var(--space-md);
}

.tag {
  display: inline-block;
  padding: var(--space-sm) var(--space-lg);
  background: var(--gradient-card);
  color: var(--color-white);
  font-size: var(--font-size-base);
  font-weight: 500;
  border-radius: var(--radius-full);
  box-shadow: var(--shadow-sm);
}

/* 人纪五大经典卡片 */
.renji-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-xl);
  margin-top: var(--space-xl);
}

.renji-grid .renji-card:nth-child(4),
.renji-grid .renji-card:nth-child(5) {
  grid-column: span 1;
}

.renji-card {
  background: var(--color-white);
  border-radius: var(--radius-lg);
  padding: var(--space-xl);
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--color-border);
  transition: all var(--transition-normal);
  text-align: center;
}

.renji-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-md);
  border-color: var(--color-secondary);
}

.renji-icon {
  width: 64px;
  height: 64px;
  background: var(--gradient-card);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 30px;
  margin: 0 auto var(--space-md);
}

.renji-title {
  font-family: var(--font-family);
  font-size: var(--font-size-xl);
  color: var(--color-primary);
  margin-bottom: var(--space-sm);
}

.renji-desc {
  color: var(--color-text-light);
  font-size: var(--font-size-sm);
  line-height: 1.6;
  margin-bottom: var(--space-md);
}

.renji-tags {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: var(--space-xs);
  margin-bottom: var(--space-lg);
}

.renji-tags span {
  padding: var(--space-xs) var(--space-sm);
  background: var(--color-bg);
  color: var(--color-text-light);
  font-size: var(--font-size-xs);
  border-radius: var(--radius-sm);
}

.renji-btn {
  width: 100%;
  justify-content: center;
}

/* 学习路径时间线 */
.path-section {
  background: var(--color-bg);
}

.path-timeline {
  display: flex;
  align-items: center;
  justify-content: center;
  flex-wrap: wrap;
  gap: var(--space-md);
  margin-top: var(--space-xl);
  padding: var(--space-xl) 0;
}

.path-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  min-width: 140px;
}

.path-number {
  width: 40px;
  height: 40px;
  background: var(--gradient-btn);
  color: var(--color-white);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--font-size-lg);
  font-weight: 700;
  margin-bottom: var(--space-sm);
}

.path-content h4 {
  font-family: var(--font-family);
  font-size: var(--font-size-base);
  color: var(--color-primary);
  margin-bottom: var(--space-xs);
}

.path-content p {
  font-size: var(--font-size-xs);
  color: var(--color-text-light);
}

.path-arrow {
  color: var(--color-accent);
  font-size: var(--font-size-xl);
  font-weight: bold;
}

/* 响应式适配 */
@media (max-width: 992px) {
  .main-categories {
    grid-template-columns: 1fr;
  }
  
  .renji-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .renji-grid .renji-card:nth-child(5) {
    grid-column: 1 / -1;
    max-width: 50%;
    margin: 0 auto;
  }
  
  .path-timeline {
    flex-direction: column;
  }
  
  .path-arrow {
    transform: rotate(90deg);
  }
}

@media (max-width: 768px) {
  .renji-grid {
    grid-template-columns: 1fr;
  }
  
  .renji-grid .renji-card:nth-child(5) {
    grid-column: auto;
    max-width: 100%;
  }
  
  .path-timeline {
    align-items: flex-start;
    padding-left: var(--space-xl);
  }
  
  .path-item {
    flex-direction: row;
    text-align: left;
    gap: var(--space-md);
  }
  
  .path-number {
    flex-shrink: 0;
  }
}

@media (max-width: 480px) {
  .main-category-card {
    padding: var(--space-xl);
  }
  
  .main-category-icon {
    width: 64px;
    height: 64px;
    font-size: 28px;
  }
  
  .intro-tags {
    gap: var(--space-sm);
  }
  
  .tag {
    padding: var(--space-xs) var(--space-md);
    font-size: var(--font-size-sm);
  }
}


/* ========================================
   初心专题横幅
   ======================================== */
.mission-banner {
  position: relative;
  background: linear-gradient(135deg, #8B0000 0%, #C41E3A 50%, #8B0000 100%);
  padding: 60px 20px;
  overflow: hidden;
}

.mission-banner::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.05'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
  opacity: 0.5;
}

.mission-container {
  position: relative;
  z-index: 1;
  max-width: 900px;
  margin: 0 auto;
  display: flex;
  align-items: flex-start;
  gap: 30px;
}

.mission-icon {
  flex-shrink: 0;
  font-size: 48px;
  filter: drop-shadow(0 2px 10px rgba(0,0,0,0.3));
}

.mission-content {
  flex: 1;
}

.mission-title {
  font-family: var(--font-family);
  font-size: 26px;
  color: #fff;
  margin-bottom: 16px;
  text-shadow: 0 2px 8px rgba(0,0,0,0.2);
}

.mission-quote {
  font-family: var(--font-family);
  font-size: 18px;
  color: rgba(255, 255, 255, 0.95);
  font-style: italic;
  line-height: 1.8;
  margin: 0 0 20px 0;
  padding: 16px 24px;
  background: rgba(0, 0, 0, 0.15);
  border-left: 4px solid rgba(255, 255, 255, 0.5);
  border-radius: 0 8px 8px 0;
  position: relative;
}

.mission-quote::before {
  content: '"';
  position: absolute;
  top: 5px;
  left: 10px;
  font-size: 40px;
  color: rgba(255, 255, 255, 0.3);
  font-family: Georgia, serif;
  line-height: 1;
}

.mission-desc {
  color: rgba(255, 255, 255, 0.85);
  font-size: 16px;
  line-height: 1.8;
  margin-bottom: 20px;
}

.btn-mission {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 28px;
  background: #fff;
  color: #8B0000;
  font-weight: 600;
  font-size: 15px;
  border-radius: 8px;
  transition: all 0.3s ease;
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
}

.btn-mission:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(0, 0, 0, 0.3);
  background: #f5f5f5;
}

.mission-decoration {
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 50px;
  background: linear-gradient(to top, var(--color-bg), transparent);
}

/* 响应式 */
@media (max-width: 768px) {
  .mission-banner {
    padding: 40px 20px;
  }
  
  .mission-container {
    flex-direction: column;
    align-items: center;
    text-align: center;
  }
  
  .mission-icon {
    font-size: 40px;
  }
  
  .mission-title {
    font-size: 22px;
  }
  
  .mission-quote {
    font-size: 16px;
    padding: 14px 18px;
  }
  
  .mission-desc {
    font-size: 15px;
  }
}

/* ========================================
   关于页初心入口框
   ======================================== */
.about-mission-box {
  display: flex;
  align-items: flex-start;
  gap: 24px;
  background: linear-gradient(135deg, #FFF9F5 0%, #FDF5F0 100%);
  border: 2px solid var(--color-secondary);
  border-radius: 16px;
  padding: 28px;
  margin-top: 24px;
  box-shadow: 0 4px 20px rgba(139, 69, 19, 0.1);
}

.mission-box-icon {
  flex-shrink: 0;
  font-size: 40px;
  filter: drop-shadow(0 2px 8px rgba(0,0,0,0.1));
}

.mission-box-content {
  flex: 1;
}

.mission-box-content h3 {
  font-family: var(--font-family);
  font-size: 20px;
  color: var(--color-primary);
  margin-bottom: 12px;
}

.mission-box-content p {
  color: var(--color-text);
  line-height: 1.8;
  margin-bottom: 16px;
  font-size: 15px;
}

.highlight-text {
  background: linear-gradient(180deg, transparent 60%, rgba(196, 30, 58, 0.2) 60%);
  padding: 0 3px;
  font-weight: 600;
  color: var(--color-accent);
}

.mission-box-quote {
  font-family: var(--font-family);
  font-size: 15px;
  color: var(--color-primary);
  font-style: italic;
  line-height: 1.7;
  margin: 0 0 18px 0;
  padding: 14px 20px;
  background: rgba(196, 30, 58, 0.08);
  border-left: 4px solid var(--color-accent);
  border-radius: 0 8px 8px 0;
}

.btn-outline {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 10px 20px;
  border: 2px solid var(--color-accent);
  color: var(--color-accent);
  font-weight: 600;
  font-size: 14px;
  border-radius: 8px;
  transition: all 0.3s ease;
}

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

@media (max-width: 768px) {
  .about-mission-box {
    flex-direction: column;
    align-items: center;
    text-align: center;
    padding: 24px;
  }
  
  .mission-box-icon {
    font-size: 36px;
  }
  
  .mission-box-content h3 {
    font-size: 18px;
  }
  
  .mission-box-content p {
    font-size: 14px;
  }
  
  .mission-box-quote {
    font-size: 14px;
    padding: 12px 16px;
  }
}

/* ========================================
   禁用按钮样式
   ======================================== */
.btn-disabled {
    opacity: 0.5;
    cursor: not-allowed;
    pointer-events: none;
    background: var(--color-border);
    color: var(--color-text-light);
    border-color: var(--color-border);
}