/* 瑜伽网站样式 - 教程风格 */
:root {
  --accent-color: #20c997;
  --accent-dark: #1ba87e;
  --text-primary: #333;
  --text-secondary: #666;
  --text-light: #999;
  --bg-primary: #fff;
  --bg-secondary: #f8f9fa;
  --bg-dark: #e9ecef;
  --border-color: #dee2e6;
  --shadow: 0 2px 8px rgba(0,0,0,0.1);
  --shadow-hover: 0 4px 16px rgba(0,0,0,0.15);
  --radius: 8px;
  --max-width: 1200px;
  --header-height: 64px;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

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;
}

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

/* Header */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--header-height);
  background: var(--bg-primary);
  border-bottom: 1px solid var(--border-color);
  z-index: 1000;
}

.header-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 20px;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  font-size: 24px;
  font-weight: 700;
  color: var(--accent-color);
}

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

.nav a {
  color: var(--text-primary);
  font-weight: 500;
}

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

.search-box {
  display: flex;
  align-items: center;
  gap: 8px;
}

.search-box input {
  padding: 8px 12px;
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  width: 200px;
  font-size: 14px;
}

.search-box button {
  padding: 8px 16px;
  background: var(--accent-color);
  color: white;
  border: none;
  border-radius: var(--radius);
  cursor: pointer;
  font-size: 14px;
}

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

/* Main Content */
.main {
  margin-top: var(--header-height);
  min-height: calc(100vh - var(--header-height) - 200px);
}

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 20px;
}

/* Hero Section */
.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: 48px;
  margin-bottom: 16px;
  font-weight: 700;
}

.hero p {
  font-size: 20px;
  opacity: 0.9;
  max-width: 600px;
  margin: 0 auto;
}

/* Stats Section */
.stats {
  padding: 40px 0;
  background: var(--bg-secondary);
}

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

.stat-card {
  background: var(--bg-primary);
  padding: 32px;
  border-radius: var(--radius);
  text-align: center;
  box-shadow: var(--shadow);
}

.stat-number {
  font-size: 36px;
  font-weight: 700;
  color: var(--accent-color);
}

.stat-label {
  color: var(--text-secondary);
  margin-top: 8px;
}

/* Section Title */
.section-title {
  font-size: 28px;
  font-weight: 700;
  margin-bottom: 24px;
  color: var(--text-primary);
}

/* Section */
.section {
  padding: 60px 0;
}

.section-alt {
  background: var(--bg-secondary);
}

/* Course Cards */
.course-card {
  background: var(--bg-primary);
  border-radius: var(--radius);
  padding: 24px;
  box-shadow: var(--shadow);
  margin-bottom: 20px;
}

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

.course-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: 16px;
}

.course-title {
  font-size: 20px;
  font-weight: 600;
  color: var(--text-primary);
}

.course-level {
  padding: 4px 12px;
  background: var(--bg-secondary);
  border-radius: 20px;
  font-size: 12px;
  color: var(--text-secondary);
}

.course-level.beginner {
  background: #d4edda;
  color: #155724;
}

.course-level.intermediate {
  background: #fff3cd;
  color: #856404;
}

.course-level.advanced {
  background: #f8d7da;
  color: #721c24;
}

.course-desc {
  color: var(--text-secondary);
  margin-bottom: 16px;
  line-height: 1.6;
}

/* Progress Bar */
.progress-bar {
  height: 8px;
  background: var(--bg-dark);
  border-radius: 4px;
  overflow: hidden;
  margin-bottom: 8px;
}

.progress-fill {
  height: 100%;
  background: var(--accent-color);
  border-radius: 4px;
  transition: width 0.3s ease;
}

.progress-text {
  font-size: 14px;
  color: var(--text-secondary);
}

/* Course Grid */
.course-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.course-item {
  background: var(--bg-primary);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
}

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

.course-thumb {
  height: 160px;
  background: linear-gradient(135deg, var(--accent-color) 0%, var(--accent-dark) 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: 48px;
}

.course-info {
  padding: 20px;
}

.course-info h3 {
  font-size: 18px;
  margin-bottom: 8px;
}

.course-info p {
  color: var(--text-secondary);
  font-size: 14px;
}

/* Article Lists */
.article-lists {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
}

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

.article-list h3 {
  font-size: 18px;
  margin-bottom: 16px;
  padding-bottom: 12px;
  border-bottom: 2px solid var(--accent-color);
}

.article-list ul {
  list-style: none;
}

.article-list li {
  padding: 12px 0;
  border-bottom: 1px solid var(--border-color);
}

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

.article-list a {
  color: var(--text-primary);
  display: block;
}

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

/* Breadcrumb */
.breadcrumb {
  padding: 20px 0;
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--border-color);
}

.breadcrumb-inner {
  color: var(--text-secondary);
  font-size: 14px;
}

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

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

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

/* Category Header */
.category-header {
  padding: 40px 0;
  background: var(--bg-secondary);
  text-align: center;
}

.category-header h1 {
  font-size: 36px;
  margin-bottom: 12px;
}

.category-header p {
  color: var(--text-secondary);
  max-width: 600px;
  margin: 0 auto;
}

/* Filter Tabs */
.filter-tabs {
  display: flex;
  gap: 12px;
  margin-bottom: 32px;
  flex-wrap: wrap;
}

.filter-tab {
  padding: 10px 20px;
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: 20px;
  color: var(--text-secondary);
  cursor: pointer;
  font-size: 14px;
}

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

/* Article Page */
.article-container {
  max-width: 800px;
  margin: 0 auto;
  padding: 40px 20px;
}

.article-header {
  margin-bottom: 40px;
}

.article-header h1 {
  font-size: 36px;
  margin-bottom: 16px;
  line-height: 1.3;
}

.article-meta {
  display: flex;
  gap: 20px;
  color: var(--text-secondary);
  font-size: 14px;
}

.article-content {
  font-size: 18px;
  line-height: 1.8;
  color: var(--text-primary);
}

.article-content h2 {
  font-size: 28px;
  margin: 40px 0 20px;
  padding-bottom: 12px;
  border-bottom: 2px solid var(--border-color);
}

.article-content h3 {
  font-size: 22px;
  margin: 32px 0 16px;
}

.article-content p {
  margin-bottom: 20px;
}

.article-content ul,
.article-content ol {
  margin-bottom: 20px;
  padding-left: 24px;
}

.article-content li {
  margin-bottom: 8px;
}

/* Chapter Nav */
.chapter-nav {
  background: var(--bg-secondary);
  border-radius: var(--radius);
  padding: 24px;
  margin: 40px 0;
}

.chapter-nav h3 {
  font-size: 18px;
  margin-bottom: 16px;
}

.chapter-nav ul {
  list-style: none;
}

.chapter-nav li {
  padding: 12px 0;
  border-bottom: 1px solid var(--border-color);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.chapter-nav li:last-child {
  border-bottom: none;
}

.chapter-nav a {
  color: var(--text-primary);
}

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

.chapter-status {
  font-size: 12px;
  padding: 4px 8px;
  border-radius: 4px;
  background: var(--bg-dark);
  color: var(--text-secondary);
}

.chapter-status.completed {
  background: #d4edda;
  color: #155724;
}

/* 404 Page */
.error-page {
  text-align: center;
  padding: 100px 20px;
}

.error-code {
  font-size: 120px;
  font-weight: 700;
  color: var(--accent-color);
  line-height: 1;
  margin-bottom: 20px;
}

.error-title {
  font-size: 32px;
  margin-bottom: 16px;
}

.error-desc {
  color: var(--text-secondary);
  margin-bottom: 32px;
  font-size: 18px;
}

.btn {
  display: inline-block;
  padding: 12px 32px;
  background: var(--accent-color);
  color: white;
  border-radius: var(--radius);
  font-weight: 500;
}

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

/* 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 h3 {
  font-size: 24px;
  margin-bottom: 16px;
  color: var(--accent-color);
}

.footer-brand p {
  color: var(--text-light);
  line-height: 1.6;
}

.footer-links h4 {
  font-size: 16px;
  margin-bottom: 16px;
}

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

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

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

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

.footer-bottom {
  border-top: 1px solid #444;
  padding-top: 30px;
  text-align: center;
  color: var(--text-light);
  font-size: 14px;
}

/* Responsive */
@media (max-width: 1024px) {
  .course-grid,
  .article-lists {
    grid-template-columns: repeat(2, 1fr);
  }

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

@media (max-width: 768px) {
  .header-inner {
    flex-wrap: wrap;
    padding: 10px 16px;
  }

  .nav {
    display: none;
  }

  .search-box input {
    width: 140px;
  }

  .hero {
    padding: 60px 0;
  }

  .hero h1 {
    font-size: 32px;
  }

  .hero p {
    font-size: 16px;
  }

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

  .course-grid,
  .article-lists {
    grid-template-columns: 1fr;
  }

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

  .article-header h1 {
    font-size: 28px;
  }

  .article-content {
    font-size: 16px;
  }

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