/**
 * ============================================
 * 烹饪学科 - 暖橙色美食风格样式表
 * Cooking Subject - Warm Orange Food Style
 * ============================================
 */

/* ============================================
   1. CSS 变量定义 (Color System & Design Tokens)
   ============================================ */
:root {
  /* 主色调 - 暖橙色系 */
  --color-primary-start: #ff8c42;
  --color-primary-end: #ff6b35;
  --color-primary: linear-gradient(135deg, #ff8c42 0%, #ff6b35 100%);
  
  /* 辅色调 - 金黄色系 */
  --color-secondary-start: #f4d03f;
  --color-secondary-end: #f39c12;
  --color-secondary: linear-gradient(135deg, #f4d03f 0%, #f39c12 100%);
  
  /* 强调色 - 番茄红 */
  --color-accent-start: #e74c3c;
  --color-accent-end: #c0392b;
  --color-accent: linear-gradient(135deg, #e74c3c 0%, #c0392b 100%);
  
  /* 食物主题色 */
  --color-food-green: #27ae60;
  --color-food-brown: #8d6e63;
  --color-food-cream: #fff8e7;
  --color-food-chocolate: #5d4037;
  
  /* 背景色 */
  --color-bg-primary: #fff8f0;
  --color-bg-secondary: #ffffff;
  --color-bg-warm: #ffecd2;
  --color-bg-dark: #3e2723;
  
  /* 文字色 */
  --color-text-primary: #3e2723;
  --color-text-secondary: #5d4037;
  --color-text-muted: #8d6e63;
  --color-text-light: #a1887f;
  --color-text-white: #ffffff;
  
  /* 阴影 */
  --shadow-sm: 0 2px 4px rgba(255, 107, 53, 0.1);
  --shadow-md: 0 4px 12px rgba(255, 107, 53, 0.15);
  --shadow-lg: 0 8px 24px rgba(255, 107, 53, 0.2);
  --shadow-xl: 0 16px 40px rgba(255, 107, 53, 0.25);
  --shadow-primary: 0 10px 30px rgba(255, 107, 53, 0.3);
  
  /* 圆角 */
  --radius-sm: 8px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --radius-xl: 32px;
  --radius-full: 50%;
  
  /* 间距 */
  --space-xs: 4px;
  --space-sm: 8px;
  --space-md: 16px;
  --space-lg: 24px;
  --space-xl: 32px;
  --space-2xl: 48px;
  --space-3xl: 64px;
  
  /* 字体大小 */
  --text-xs: 12px;
  --text-sm: 14px;
  --text-md: 16px;
  --text-lg: 18px;
  --text-xl: 24px;
  --text-2xl: 32px;
  --text-3xl: 48px;
  
  /* 过渡 */
  --transition-fast: 0.15s ease;
  --transition-normal: 0.3s ease;
  --transition-slow: 0.5s ease;
  
  /* 字体 */
  --font-family: 'Noto Sans SC', 'Microsoft YaHei', -apple-system, BlinkMacSystemFont, sans-serif;
  
  /* 侧边栏宽度 */
  --sidebar-width: 260px;
}

/* ============================================
   2. 重置样式 & 基础样式
   ============================================ */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

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

body {
  font-family: var(--font-family);
  font-size: var(--text-md);
  line-height: 1.6;
  color: var(--color-text-primary);
  background-color: var(--color-bg-primary);
  min-height: 100vh;
}

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

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

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

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

/* ============================================
   3. 布局容器 - 侧边栏 + 内容区
   ============================================ */
.page-wrapper {
  display: flex;
  min-height: 100vh;
}

/* 侧边栏 */
.sidebar {
  width: var(--sidebar-width);
  background: linear-gradient(180deg, #3e2723 0%, #5d4037 100%);
  color: var(--color-text-white);
  position: fixed;
  top: 0;
  left: 0;
  bottom: 0;
  overflow-y: auto;
  z-index: 1000;
  padding: var(--space-lg);
  box-shadow: 4px 0 20px rgba(0, 0, 0, 0.2);
}

.sidebar-header {
  text-align: center;
  padding-bottom: var(--space-lg);
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  margin-bottom: var(--space-lg);
}

.sidebar-logo {
  font-size: var(--text-2xl);
  font-weight: 900;
  margin-bottom: var(--space-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
}

.sidebar-logo-icon {
  font-size: 2.5rem;
}

.sidebar-subtitle {
  font-size: var(--text-sm);
  color: rgba(255, 255, 255, 0.6);
}

/* 导航菜单 */
.sidebar-nav {
  list-style: none;
}

.sidebar-nav-item {
  margin-bottom: var(--space-xs);
}

.sidebar-nav-link {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  padding: var(--space-md) var(--space-lg);
  color: rgba(255, 255, 255, 0.8);
  border-radius: var(--radius-md);
  transition: all var(--transition-normal);
  font-weight: 500;
}

.sidebar-nav-link:hover,
.sidebar-nav-link.active {
  background: rgba(255, 140, 66, 0.2);
  color: var(--color-text-white);
}

.sidebar-nav-link.active {
  background: var(--color-primary);
}

.sidebar-nav-icon {
  font-size: 1.5rem;
  width: 32px;
  text-align: center;
}

/* 子菜单 */
.sidebar-submenu {
  list-style: none;
  padding-left: var(--space-xl);
  margin-top: var(--space-xs);
}

.sidebar-submenu-link {
  display: block;
  padding: var(--space-sm) var(--space-md);
  color: rgba(255, 255, 255, 0.6);
  font-size: var(--text-sm);
  border-radius: var(--radius-sm);
  transition: all var(--transition-fast);
}

.sidebar-submenu-link:hover {
  color: var(--color-text-white);
  background: rgba(255, 255, 255, 0.1);
}

/* 返回主站链接 */
.sidebar-footer {
  margin-top: auto;
  padding-top: var(--space-lg);
  border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.back-home-link {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  padding: var(--space-md);
  background: rgba(255, 255, 255, 0.1);
  color: var(--color-text-white);
  border-radius: var(--radius-md);
  font-weight: 600;
  transition: all var(--transition-normal);
}

.back-home-link:hover {
  background: rgba(255, 255, 255, 0.2);
  color: var(--color-text-white);
}

/* 主内容区 */
.main-content {
  flex: 1;
  margin-left: var(--sidebar-width);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.content-wrapper {
  flex: 1;
  padding: var(--space-2xl);
}

/* ============================================
   4. 页头区域
   ============================================ */
.page-header {
  background: linear-gradient(135deg, #fff8f0 0%, #ffecd2 100%);
  padding: var(--space-3xl) var(--space-2xl);
  border-radius: var(--radius-xl);
  margin-bottom: var(--space-2xl);
  position: relative;
  overflow: hidden;
}

.page-header::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -10%;
  width: 400px;
  height: 400px;
  background: radial-gradient(circle, rgba(255, 140, 66, 0.1) 0%, transparent 70%);
  animation: pulse 8s ease-in-out infinite;
}

@keyframes pulse {
  0%, 100% { transform: scale(1); }
  50% { transform: scale(1.1); }
}

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

.page-title {
  font-size: var(--text-3xl);
  font-weight: 900;
  margin-bottom: var(--space-md);
  background: linear-gradient(135deg, #ff6b35 0%, #e74c3c 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.page-description {
  font-size: var(--text-lg);
  color: var(--color-text-secondary);
  max-width: 700px;
  line-height: 1.8;
}

/* 装饰食材元素 */
.food-decoration {
  position: absolute;
  font-size: 4rem;
  opacity: 0.15;
  animation: float-food 6s ease-in-out infinite;
}

.food-decoration:nth-child(1) {
  top: 20%;
  right: 5%;
  animation-delay: 0s;
}

.food-decoration:nth-child(2) {
  top: 60%;
  right: 15%;
  animation-delay: 2s;
}

.food-decoration:nth-child(3) {
  bottom: 10%;
  right: 8%;
  animation-delay: 4s;
}

@keyframes float-food {
  0%, 100% { transform: translateY(0) rotate(0deg); }
  50% { transform: translateY(-15px) rotate(5deg); }
}

/* ============================================
   5. 知识模块卡片
   ============================================ */
.modules-section {
  margin-bottom: var(--space-3xl);
}

.section-title {
  font-size: var(--text-2xl);
  font-weight: 700;
  margin-bottom: var(--space-xl);
  display: flex;
  align-items: center;
  gap: var(--space-md);
  color: var(--color-text-primary);
}

.section-title-icon {
  font-size: 2rem;
}

.modules-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--space-xl);
}

.module-card {
  background: var(--color-bg-secondary);
  border-radius: var(--radius-lg);
  padding: var(--space-xl);
  box-shadow: var(--shadow-md);
  transition: all var(--transition-normal);
  position: relative;
  overflow: hidden;
  border: 2px solid transparent;
}

.module-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 5px;
  background: var(--color-primary);
}

.module-card:hover {
  transform: translateY(-8px);
  box-shadow: var(--shadow-xl);
  border-color: rgba(255, 140, 66, 0.3);
}

.module-card-icon {
  width: 80px;
  height: 80px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2.5rem;
  margin-bottom: var(--space-lg);
  background: var(--color-warm);
}

/* 不同模块的图标背景色 */
.module-card:nth-child(1) .module-card-icon {
  background: linear-gradient(135deg, #ffecd2 0%, #fcb69f 100%);
}

.module-card:nth-child(2) .module-card-icon {
  background: linear-gradient(135deg, #a8e6cf 0%, #7fcdbb 100%);
}

.module-card:nth-child(3) .module-card-icon {
  background: linear-gradient(135deg, #ffd3b6 0%, #ffaaa5 100%);
}

.module-card:nth-child(4) .module-card-icon {
  background: linear-gradient(135deg, #dcedc1 0%, #aed581 100%);
}

.module-card-title {
  font-size: var(--text-xl);
  font-weight: 700;
  margin-bottom: var(--space-sm);
  color: var(--color-text-primary);
}

.module-card-desc {
  color: var(--color-text-muted);
  font-size: var(--text-md);
  margin-bottom: var(--space-lg);
  line-height: 1.6;
}

.module-card-btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-md) var(--space-lg);
  background: var(--color-primary);
  color: var(--color-text-white);
  border-radius: var(--radius-md);
  font-weight: 600;
  transition: all var(--transition-normal);
}

.module-card-btn:hover {
  background: linear-gradient(135deg, #ff6b35 0%, #e74c3c 100%);
  color: var(--color-text-white);
  transform: translateX(5px);
}

/* ============================================
   6. 食谱卡片展示区
   ============================================ */
.recipes-section {
  margin-bottom: var(--space-3xl);
}

.recipes-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: var(--space-xl);
}

.recipe-card {
  background: var(--color-bg-secondary);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-md);
  transition: all var(--transition-normal);
}

.recipe-card:hover {
  transform: translateY(-8px);
  box-shadow: var(--shadow-xl);
}

.recipe-image-placeholder {
  height: 200px;
  background: linear-gradient(135deg, #ffecd2 0%, #fcb69f 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 4rem;
  position: relative;
  overflow: hidden;
}

.recipe-image-placeholder::after {
  content: '食谱图片';
  position: absolute;
  bottom: 10px;
  right: 10px;
  background: rgba(0, 0, 0, 0.5);
  color: white;
  padding: 4px 8px;
  border-radius: var(--radius-sm);
  font-size: var(--text-xs);
}

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

.recipe-category {
  display: inline-block;
  padding: var(--space-xs) var(--space-md);
  background: rgba(255, 140, 66, 0.1);
  color: var(--color-primary-start);
  border-radius: var(--radius-xl);
  font-size: var(--text-xs);
  font-weight: 600;
  margin-bottom: var(--space-sm);
}

.recipe-title {
  font-size: var(--text-lg);
  font-weight: 700;
  margin-bottom: var(--space-sm);
  color: var(--color-text-primary);
}

.recipe-meta {
  display: flex;
  gap: var(--space-lg);
  color: var(--color-text-muted);
  font-size: var(--text-sm);
}

.recipe-meta-item {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
}

/* ============================================
   7. 学习路径
   ============================================ */
.learning-path-section {
  margin-bottom: var(--space-3xl);
}

.path-timeline {
  position: relative;
  padding-left: var(--space-xl);
}

.path-timeline::before {
  content: '';
  position: absolute;
  left: 20px;
  top: 0;
  bottom: 0;
  width: 4px;
  background: linear-gradient(180deg, var(--color-primary-start) 0%, var(--color-secondary-end) 100%);
  border-radius: var(--radius-full);
}

.path-item {
  position: relative;
  padding: var(--space-lg);
  margin-bottom: var(--space-lg);
  background: var(--color-bg-secondary);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  transition: all var(--transition-normal);
}

.path-item:hover {
  box-shadow: var(--shadow-md);
}

.path-item::before {
  content: '';
  position: absolute;
  left: -28px;
  top: 50%;
  transform: translateY(-50%);
  width: 16px;
  height: 16px;
  background: var(--color-primary);
  border-radius: var(--radius-full);
  border: 4px solid var(--color-bg-secondary);
  box-shadow: 0 0 0 4px rgba(255, 140, 66, 0.3);
}

.path-item-number {
  position: absolute;
  left: -50px;
  top: 50%;
  transform: translateY(-50%);
  font-size: var(--text-sm);
  font-weight: 700;
  color: var(--color-primary-start);
}

.path-item-title {
  font-size: var(--text-lg);
  font-weight: 700;
  margin-bottom: var(--space-sm);
  color: var(--color-text-primary);
}

.path-item-desc {
  color: var(--color-text-muted);
  font-size: var(--text-md);
}

/* ============================================
   8. 页脚
   ============================================ */
.footer {
  background: var(--color-bg-dark);
  color: rgba(255, 255, 255, 0.8);
  padding: var(--space-xl) var(--space-2xl);
  margin-top: auto;
}

.footer-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--space-md);
}

.footer-left {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

.footer-brand {
  font-size: var(--text-lg);
  font-weight: 700;
  color: var(--color-text-white);
}

.footer-links {
  display: flex;
  gap: var(--space-lg);
}

.footer-link {
  color: rgba(255, 255, 255, 0.6);
  font-size: var(--text-sm);
  transition: color var(--transition-fast);
}

.footer-link:hover {
  color: var(--color-text-white);
}

.footer-right {
  text-align: right;
}

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

.beian-link {
  color: rgba(255, 255, 255, 0.5);
  text-decoration: none;
  transition: color var(--transition-fast);
}

.beian-link:hover {
  color: var(--color-text-white);
}

.copyright {
  font-size: var(--text-xs);
  color: rgba(255, 255, 255, 0.4);
  margin-top: var(--space-xs);
}

/* ============================================
   9. 响应式设计
   ============================================ */
@media (max-width: 1024px) {
  :root {
    --sidebar-width: 220px;
  }
}

@media (max-width: 768px) {
  .sidebar {
    transform: translateX(-100%);
    transition: transform var(--transition-normal);
  }
  
  .sidebar.active {
    transform: translateX(0);
  }
  
  .main-content {
    margin-left: 0;
  }
  
  .content-wrapper {
    padding: var(--space-lg);
  }
  
  .page-header {
    padding: var(--space-xl) var(--space-lg);
  }
  
  .page-title {
    font-size: var(--text-2xl);
  }
  
  .modules-grid,
  .recipes-grid {
    grid-template-columns: 1fr;
  }
  
  .mobile-menu-toggle {
    display: block;
    position: fixed;
    top: var(--space-md);
    left: var(--space-md);
    z-index: 1001;
    width: 48px;
    height: 48px;
    background: var(--color-primary);
    color: white;
    border-radius: var(--radius-md);
    font-size: 1.5rem;
    box-shadow: var(--shadow-lg);
  }
}

/* 移动端菜单按钮 */
.mobile-menu-toggle {
  display: none;
}

/* ============================================
   10. 食材图标装饰元素
   ============================================ */
.ingredient-icons {
  position: fixed;
  pointer-events: none;
  z-index: 0;
  opacity: 0.05;
}

.ingredient-icons-left {
  left: var(--sidebar-width);
  top: 0;
  bottom: 0;
  width: 100px;
}

.ingredient-icons-right {
  right: 0;
  top: 0;
  bottom: 0;
  width: 100px;
}

.ingredient-icon {
  position: absolute;
  font-size: 2rem;
  animation: ingredient-float 10s ease-in-out infinite;
}

@keyframes ingredient-float {
  0%, 100% { 
    transform: translateY(0) rotate(0deg); 
    opacity: 0.05;
  }
  50% { 
    transform: translateY(-20px) rotate(10deg); 
    opacity: 0.1;
  }
}