/* 刺绣工艺 - 教程风格样式表 */
/* 主色调: #20c997 */

/* ===== CSS 变量 ===== */
:root {
  --accent-color: #20c997;
  --accent-dark: #1ba87e;
  --accent-light: #d1f2eb;
  --text-primary: #2c3e50;
  --text-secondary: #5a6c7d;
  --text-muted: #95a5a6;
  --bg-primary: #ffffff;
  --bg-secondary: #f8f9fa;
  --bg-tertiary: #e9ecef;
  --border-color: #dee2e6;
  --shadow-sm: 0 2px 4px rgba(0,0,0,0.05);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.08);
  --shadow-lg: 0 8px 24px rgba(0,0,0,0.12);
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --transition: all 0.3s ease;
}

/* ===== 基础重置 ===== */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  line-height: 1.6;
  color: var(--text-primary);
  background-color: var(--bg-primary);
}

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

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

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

/* ===== 布局容器 ===== */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

.section {
  padding: 60px 0;
}

.section-title {
  font-size: 1.75rem;
  font-weight: 600;
  margin-bottom: 1.5rem;
  color: var(--text-primary);
}

/* ===== 页头 Header ===== */
.header {
  background: var(--bg-primary);
  border-bottom: 1px solid var(--border-color);
  position: sticky;
  top: 0;
  z-index: 100;
}

.header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--text-primary);
}

.logo-icon {
  width: 36px;
  height: 36px;
  background: var(--accent-color);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: 1.1rem;
}

.nav {
  display: flex;
  gap: 30px;
}

.nav a {
  color: var(--text-secondary);
  font-weight: 500;
  padding: 8px 0;
  position: relative;
}

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

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

.search-box {
  display: flex;
  align-items: center;
  background: var(--bg-secondary);
  border-radius: var(--radius-md);
  padding: 8px 16px;
  gap: 8px;
}

.search-box input {
  border: none;
  background: none;
  outline: none;
  font-size: 0.9rem;
  width: 180px;
}

.search-box input::placeholder {
  color: var(--text-muted);
}

/* ===== Hero 区域 ===== */
.hero {
  background: linear-gradient(135deg, var(--accent-light) 0%, var(--bg-primary) 100%);
  padding: 80px 0;
  text-align: center;
}

.hero-title {
  font-size: 2.5rem;
  font-weight: 700;
  margin-bottom: 1rem;
  color: var(--text-primary);
}

.hero-subtitle {
  font-size: 1.125rem;
  color: var(--text-secondary);
  max-width: 600px;
  margin: 0 auto 2rem;
}

.hero-cta {
  display: inline-flex;
  gap: 12px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 24px;
  border-radius: var(--radius-md);
  font-weight: 500;
  font-size: 1rem;
  cursor: pointer;
  border: none;
  transition: var(--transition);
}

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

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

.btn-secondary {
  background: white;
  color: var(--accent-color);
  border: 1px solid var(--accent-color);
}

.btn-secondary:hover {
  background: var(--accent-light);
}

/* ===== 统计卡片 ===== */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-top: -40px;
  position: relative;
  z-index: 10;
}

.stat-card {
  background: white;
  padding: 30px;
  border-radius: var(--radius-lg);
  text-align: center;
  box-shadow: var(--shadow-md);
}

.stat-number {
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--accent-color);
  margin-bottom: 8px;
}

.stat-label {
  color: var(--text-secondary);
  font-size: 0.95rem;
}

/* ===== 课程卡片 ===== */
.course-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 24px;
}

.course-card {
  background: white;
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
  border: 1px solid var(--border-color);
}

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

.course-image {
  width: 100%;
  height: 160px;
  background: var(--bg-secondary);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-muted);
  font-size: 3rem;
}

.course-content {
  padding: 20px;
}

.course-category {
  font-size: 0.75rem;
  color: var(--accent-color);
  font-weight: 600;
  text-transform: uppercase;
  margin-bottom: 8px;
}

.course-title {
  font-size: 1.125rem;
  font-weight: 600;
  margin-bottom: 8px;
  color: var(--text-primary);
}

.course-meta {
  font-size: 0.875rem;
  color: var(--text-muted);
  margin-bottom: 12px;
}

.course-progress {
  margin-top: 12px;
}

.progress-bar {
  height: 6px;
  background: var(--bg-tertiary);
  border-radius: 3px;
  overflow: hidden;
}

.progress-fill {
  height: 100%;
  background: var(--accent-color);
  border-radius: 3px;
  transition: width 0.3s ease;
}

.progress-text {
  font-size: 0.8rem;
  color: var(--text-secondary);
  margin-top: 6px;
}

.course-status {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 0.875rem;
  font-weight: 500;
  margin-top: 12px;
}

.status-completed {
  color: var(--accent-color);
}

.status-reading {
  color: #f39c12;
}

.status-toread {
  color: var(--text-muted);
}

/* ===== 文章列表 ===== */
.article-list {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.article-item {
  display: flex;
  gap: 16px;
  padding: 16px;
  background: white;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
  transition: var(--transition);
}

.article-item:hover {
  border-color: var(--accent-color);
  box-shadow: var(--shadow-sm);
}

.article-thumb {
  width: 80px;
  height: 80px;
  background: var(--bg-secondary);
  border-radius: var(--radius-sm);
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-muted);
  font-size: 1.5rem;
}

.article-info {
  flex: 1;
}

.article-title {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 6px;
  color: var(--text-primary);
}

.article-desc {
  font-size: 0.875rem;
  color: var(--text-secondary);
  line-height: 1.5;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

/* ===== 三栏内容区 ===== */
.content-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 30px;
}

.content-column h3 {
  font-size: 1.125rem;
  font-weight: 600;
  margin-bottom: 16px;
  padding-bottom: 12px;
  border-bottom: 2px solid var(--accent-color);
}

.column-list {
  list-style: none;
}

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

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

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

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

.column-list .num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 20px;
  height: 20px;
  background: var(--bg-tertiary);
  border-radius: 4px;
  font-size: 0.75rem;
  color: var(--text-secondary);
}

/* ===== 面包屑 ===== */
.breadcrumb {
  background: var(--bg-secondary);
  padding: 16px 0;
  font-size: 0.875rem;
}

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

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

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

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

/* ===== 分类页头部 ===== */
.category-header {
  padding: 40px 0;
  background: var(--bg-secondary);
}

.category-title {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 8px;
}

.category-desc {
  color: var(--text-secondary);
  margin-bottom: 20px;
}

.filter-tabs {
  display: flex;
  gap: 8px;
}

.filter-tab {
  padding: 8px 16px;
  border-radius: var(--radius-md);
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-secondary);
  background: white;
  border: 1px solid var(--border-color);
  cursor: pointer;
  transition: var(--transition);
}

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

/* ===== 文章详情页 ===== */
.article-header {
  padding: 40px 0;
  background: var(--bg-secondary);
}

.article-meta-header {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-top: 16px;
  font-size: 0.9rem;
  color: var(--text-secondary);
}

.article-meta-header span {
  display: flex;
  align-items: center;
  gap: 6px;
}

.article-body {
  display: grid;
  grid-template-columns: 1fr 300px;
  gap: 40px;
  padding: 40px 0;
}

.article-main {
  background: white;
  padding: 40px;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
}

.article-content h2 {
  font-size: 1.5rem;
  font-weight: 600;
  margin: 32px 0 16px;
  color: var(--text-primary);
}

.article-content h3 {
  font-size: 1.25rem;
  font-weight: 600;
  margin: 24px 0 12px;
  color: var(--text-primary);
}

.article-content p {
  margin-bottom: 16px;
  color: var(--text-secondary);
  line-height: 1.8;
}

.article-content ul,
.article-content ol {
  margin-bottom: 16px;
  padding-left: 24px;
  color: var(--text-secondary);
}

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

.article-sidebar {
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.sidebar-card {
  background: white;
  padding: 24px;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border-color);
}

.sidebar-card h3 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 16px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--border-color);
}

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

.chapter-list li {
  padding: 10px 0;
  border-bottom: 1px solid var(--border-color);
  font-size: 0.9rem;
}

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

.chapter-list a {
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.chapter-list a:hover,
.chapter-list a.active {
  color: var(--accent-color);
}

.chapter-list .check {
  color: var(--accent-color);
}

/* ===== 404 页面 ===== */
.error-page {
  min-height: calc(100vh - 64px);
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 40px 20px;
}

.error-content {
  max-width: 500px;
}

.error-code {
  font-size: 8rem;
  font-weight: 700;
  color: var(--accent-color);
  line-height: 1;
  margin-bottom: 16px;
  opacity: 0.8;
}

.error-title {
  font-size: 1.5rem;
  font-weight: 600;
  margin-bottom: 12px;
}

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

/* ===== 页脚 ===== */
.footer {
  background: var(--text-primary);
  color: white;
  padding: 60px 0 30px;
  margin-top: 60px;
}

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

.footer-brand {
  max-width: 300px;
}

.footer-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: 16px;
}

.footer-desc {
  color: rgba(255,255,255,0.7);
  font-size: 0.9rem;
  line-height: 1.6;
}

.footer-column h4 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 16px;
}

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

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

.footer-links a {
  color: rgba(255,255,255,0.7);
  font-size: 0.9rem;
}

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

.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.1);
  padding-top: 30px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.875rem;
  color: rgba(255,255,255,0.5);
}

/* ===== 响应式设计 ===== */
@media (max-width: 992px) {
  .content-grid {
    grid-template-columns: 1fr;
  }

  .article-body {
    grid-template-columns: 1fr;
  }

  .article-sidebar {
    order: -1;
  }

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

@media (max-width: 768px) {
  .nav {
    display: none;
  }

  .search-box {
    display: none;
  }

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

  .stats-grid {
    grid-template-columns: 1fr;
    margin-top: -20px;
  }

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

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

  .footer-bottom {
    flex-direction: column;
    gap: 16px;
    text-align: center;
  }

  .article-main {
    padding: 24px;
  }
}

@media (max-width: 480px) {
  .hero-cta {
    flex-direction: column;
    width: 100%;
    padding: 0 20px;
  }

  .btn {
    width: 100%;
  }

  .filter-tabs {
    flex-wrap: wrap;
  }

  .error-code {
    font-size: 5rem;
  }
}