/* ============================================
   Clash Verge 教程 — 清新教程风格
   主色调：清新绿→蓝 (#27AE60 → #2980B9)
   排版：极简教程风，步骤清晰，代码块友好
   ============================================ */

/* ===== CSS 变量系统 ===== */
:root {
  /* 主色调 — 清新绿蓝系 */
  --primary: #27AE60;
  --primary-dark: #1E8449;
  --primary-light: #58D68D;
  --secondary: #2980B9;
  --secondary-dark: #1F618D;
  --accent: #8E44AD;
  --gradient-start: #27AE60;
  --gradient-end: #2980B9;

  /* 功能色 */
  --success: #27AE60;
  --warning: #F39C12;
  --danger: #E74C3C;
  --info: #3498DB;

  /* 文字色 */
  --text-primary: #2C3E50;
  --text-secondary: #5D6D7E;
  --text-muted: #95A5A6;

  /* 背景色 — 浅色清爽 */
  --bg: #FDFEFE;
  --bg-card: #FFFFFF;
  --bg-secondary: #F8F9FA;
  --bg-tertiary: #ECF0F1;

  /* 教程专用色 */
  --step-num-bg: #27AE60;
  --code-bg: #F4F6F7;
  --code-border: #D5D8DC;
  --highlight-bg: #E8F8F5;
  --tip-bg: #EBF5FB;
  --tip-border: #85C1E9;
  --warn-bg: #FEF9E7;
  --warn-border: #F9E79F;

  /* 边框/阴影 */
  --border: #DFE6E9;
  --border-light: #F0F3F4;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.06);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.08);
  --shadow-lg: 0 10px 30px rgba(0,0,0,0.1);

  /* 圆角 */
  --radius-sm: 6px;
  --radius: 10px;
  --radius-lg: 14px;
  --radius-xl: 18px;

  /* 过渡 */
  --transition: 0.25s ease;
  --transition-fast: 150ms ease;
}

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

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Noto Sans SC", "PingFang SC", sans-serif;
  color: var(--text-primary);
  background: var(--bg);
  line-height: 1.8;
  font-size: 15px;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  overflow-x: hidden;
}

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

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

ul, ol { padding-left: 1.4em; }

/* ===== 容器 ===== */
.container { width: 100%; max-width: 1140px; margin: 0 auto; padding: 0 24px; }
.container-sm { max-width: 800px; margin: 0 auto; padding: 0 24px; }

/* ===== 导航栏 ===== */
.navbar {
  position: fixed; top: 0; left: 0; right: 0; z-index: 1000;
  background: rgba(253,254,254,0.92);
  backdrop-filter: blur(16px); -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid transparent;
  transition: all var(--transition);
}
.navbar.scrolled {
  background: rgba(253,254,254,0.97);
  border-bottom-color: var(--border);
  box-shadow: var(--shadow-sm);
}
.navbar .container { display: flex; align-items: center; justify-content: space-between; height: 64px; }

.logo { display: flex; align-items: center; gap: 10px; font-size: 18px; font-weight: 700; color: var(--text-primary); }
.logo:hover { color: var(--text-primary); }
.logo-icon {
  width: 36px; height: 36px; border-radius: var(--radius);
  background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
  display: flex; align-items: center; justify-content: center;
  font-size: 20px; flex-shrink: 0;
}

.navbar-nav {
  display: flex; align-items: center; gap: 6px;
  list-style: none; margin: 0; padding: 0;
}
.nav-link {
  padding: 8px 16px; font-size: 14px; font-weight: 500; color: var(--text-secondary);
  border-radius: var(--radius-sm); transition: all var(--transition-fast);
}
.nav-link:hover, .nav-link.active { color: var(--primary); background: var(--highlight-bg); }

.mobile-menu-btn {
  display: none; width: 40px; height: 40px; align-items: center; justify-content: center;
  cursor: pointer; border-radius: var(--radius-sm); border: none; background: transparent;
}
.mobile-menu-btn span {
  display: block; width: 22px; height: 2px; background: var(--text-primary);
  position: relative; transition: all var(--transition);
}
.mobile-menu-btn span::before, .mobile-menu-btn span::after {
  content: ''; position: absolute; width: 22px; height: 2px; background: var(--text-primary);
  left: 0; transition: all var(--transition);
}
.mobile-menu-btn span::before { top: -7px; }
.mobile-menu-btn span::after { top: 7px; }

@media (max-width: 768px) {
  .mobile-menu-btn { display: flex; }
  .navbar-nav {
    position: fixed; top: 64px; left: 0; right: 0;
    background: rgba(253,254,254,0.98); backdrop-filter: blur(16px);
    flex-direction: column; padding: 16px; gap: 4px;
    transform: translateY(-120%); opacity: 0;
    transition: all 0.3s ease; border-bottom: 1px solid var(--border);
    box-shadow: var(--shadow-lg);
  }
  .navbar-nav.active, .navbar-nav.open { transform: translateY(0); opacity: 1; }
  .navbar-nav .nav-link { width: 100%; padding: 12px 16px; }
}

/* ===== Hero 区域 — 教程风格 ===== */
.hero-section {
  padding: 120px 0 70px;
  background: linear-gradient(160deg, #E8F8F5 0%, #EBF5FB 50%, #F4ECF7 100%);
  position: relative; overflow: hidden;
}
.hero-section::before {
  content: ''; position: absolute; top: -50%; right: -20%;
  width: 600px; height: 600px; border-radius: 50%;
  background: radial-gradient(circle, rgba(39,174,96,0.08) 0%, transparent 70%);
}
.hero-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 48px; align-items: center; position: relative; z-index: 1; }

.hero-content h1 {
  font-size: clamp(32px, 4vw, 46px); font-weight: 800; line-height: 1.2;
  color: var(--text-primary); margin-bottom: 16px;
}
.hero-content h1 span.highlight { background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end)); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; }

.hero-subtitle { font-size: 17px; color: var(--text-secondary); margin-bottom: 28px; line-height: 1.7; max-width: 480px; }

.hero-actions { display: flex; gap: 14px; flex-wrap: wrap; margin-bottom: 36px; }

.btn-primary {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 13px 28px; font-size: 15px; font-weight: 600;
  background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
  color: #fff; border-radius: var(--radius); border: none; cursor: pointer;
  transition: all var(--transition); box-shadow: 0 4px 15px rgba(39,174,96,0.25);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 6px 20px rgba(39,174,96,0.35); color: #fff; }
.btn-primary svg { width: 18px; height: 18px; flex-shrink: 0; }

.btn-outline {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 13px 28px; font-size: 15px; font-weight: 600;
  background: transparent; color: var(--primary); border: 2px solid var(--primary);
  border-radius: var(--radius); cursor: pointer; transition: all var(--transition);
}
.btn-outline:hover { background: var(--primary); color: #fff; }

.hero-stats { display: flex; gap: 32px; }
.stat-item { text-align: center; }
.stat-number { font-size: 26px; font-weight: 800; color: var(--primary); }
.stat-label { font-size: 13px; color: var(--text-muted); margin-top: 2px; }

/* Hero 右侧：教程目录预览卡片 */
.hero-preview {
  background: var(--bg-card); border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg); padding: 28px; border: 1px solid var(--border-light);
}
.preview-header { font-size: 13px; font-weight: 600; color: var(--primary); text-transform: uppercase; letter-spacing: 1px; margin-bottom: 16px; display: flex; align-items: center; gap: 8px; }
.preview-list { list-style: none !important; padding: 0 !important; }
.preview-item {
  display: flex; align-items: flex-start; gap: 12px; padding: 11px 0;
  border-bottom: 1px solid var(--border-light); transition: background var(--transition-fast);
  cursor: default;
}
.preview-item:last-child { border-bottom: none; }
.preview-item:hover { background: var(--bg-secondary); margin: 0 -12px; padding-left: 12px; padding-right: 12px; border-radius: var(--radius-sm); }
.preview-step {
  width: 26px; height: 26px; min-width: 26px; border-radius: 50%;
  background: var(--primary); color: #fff; font-size: 12px; font-weight: 700;
  display: flex; align-items: center; justify-content: center;
}
.preview-info h4 { font-size: 14px; font-weight: 600; color: var(--text-primary); margin-bottom: 2px; }
.preview-info p { font-size: 12px; color: var(--text-muted); }

@media (max-width: 900px) {
  .hero-grid { grid-template-columns: 1fr; gap: 36px; }
  .hero-stats { gap: 24px; }
  .hero-subtitle { max-width: 100%; }
  .hero-section { padding: 100px 0 56px; }
}

/* ===== 章节通用 ===== */
.section { padding: 72px 0; }
.section-alt { background: var(--bg-secondary); }

.section-header { text-align: center; margin-bottom: 48px; }
.section-tag {
  display: inline-block; padding: 5px 16px; font-size: 12px; font-weight: 600;
  color: var(--primary); background: var(--highlight-bg); border-radius: 20px;
  letter-spacing: 0.5px; margin-bottom: 12px;
}
.section-header h2 { font-size: clamp(26px, 3vw, 34px); font-weight: 700; color: var(--text-primary); margin-bottom: 12px; }
.section-header p { font-size: 15px; color: var(--text-secondary); max-width: 560px; margin: 0 auto; line-height: 1.7; }

/* ===== 快速入门步骤 ===== */
.steps-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 24px; }
.step-card {
  background: var(--bg-card); border-radius: var(--radius-lg);
  padding: 30px 26px; border: 1px solid var(--border-light);
  transition: all var(--transition); position: relative;
}
.step-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); border-color: var(--primary-light); }
.step-number {
  position: absolute; top: -14px; left: 24px;
  width: 36px; height: 36px; border-radius: 50%;
  background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
  color: #fff; font-size: 16px; font-weight: 700;
  display: flex; align-items: center; justify-content: center;
  box-shadow: 0 3px 10px rgba(39,174,96,0.3);
}
.step-card h3 { font-size: 17px; font-weight: 700; color: var(--text-primary); margin-top: 12px; margin-bottom: 10px; }
.step-card p { font-size: 14px; color: var(--text-secondary); line-height: 1.7; }

/* ===== 教程目录导航 ===== */
.tutorial-catalog { display: grid; grid-template-columns: repeat(2, 1fr); gap: 20px; }
.catalog-card {
  background: var(--bg-card); border-radius: var(--radius-lg);
  padding: 28px 24px; border: 1px solid var(--border-light);
  transition: all var(--transition); display: flex; gap: 18px; align-items: flex-start;
}
.catalog-card:hover { transform: translateY(-3px); box-shadow: var(--shadow-lg); border-color: var(--primary-light); }
.catalog-icon {
  width: 52px; height: 52px; min-width: 52px; border-radius: var(--radius);
  display: flex; align-items: center; justify-content: center; font-size: 26px;
  flex-shrink: 0;
}
.catalog-icon.green { background: #E8F8F5; }
.catalog-icon.blue { background: #EBF5FB; }
.catalog-icon.purple { background: #F4ECF7; }
.catalog-icon.orange { background: #FEF9E7; }
.catalog-info h3 { font-size: 16px; font-weight: 700; color: var(--text-primary); margin-bottom: 6px; }
.catalog-info p { font-size: 13px; color: var(--text-secondary); line-height: 1.6; margin-bottom: 10px; }
.catalog-meta { display: flex; gap: 14px; font-size: 12px; color: var(--text-muted); }
.catalog-meta span { display: flex; align-items: center; gap: 4px; }

@media (max-width: 700px) {
  .tutorial-catalog { grid-template-columns: 1fr; }
}

/* ===== 代码块 ===== */
.code-block {
  background: var(--code-bg); border: 1px solid var(--code-border);
  border-radius: var(--radius); padding: 20px 24px; margin: 16px 0;
  font-family: "SF Mono", "Fira Code", "Consolas", "Monaco", monospace;
  font-size: 13px; line-height: 1.7; color: var(--text-primary);
  overflow-x: auto; white-space: pre; position: relative;
}
.code-block .code-comment { color: var(--text-muted); }
.code-block .code-cmd { color: var(--primary-dark); font-weight: 600; }
.code-block .code-string { color: var(--accent); }
.code-block .code-keyword { color: var(--secondary); }

/* 提示框 */
.tip-box {
  background: var(--tip-bg); border-left: 4px solid var(--secondary);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  padding: 16px 20px; margin: 16px 0; font-size: 14px; line-height: 1.7;
}
.tip-box strong { color: var(--secondary); }
.warn-box {
  background: var(--warn-bg); border-left: 4px solid var(--warning);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  padding: 16px 20px; margin: 16px 0; font-size: 14px; line-height: 1.7;
}
.warn-box strong { color: var(--warning); }
.success-box {
  background: var(--highlight-bg); border-left: 4px solid var(--success);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  padding: 16px 20px; margin: 16px 0; font-size: 14px; line-height: 1.7;
}
.success-box strong { color: var(--success); }

/* ===== FAQ ===== */
.faq-section { max-width: 760px; margin: 0 auto; }
.faq-list { list-style: none !important; padding: 0 !important; }
.faq-item {
  background: var(--bg-card); border: 1px solid var(--border-light);
  border-radius: var(--radius); margin-bottom: 12px; overflow: hidden;
  transition: all var(--transition);
}
.faq-item.active, .faq-item.open { border-color: var(--primary-light); box-shadow: var(--shadow-md); }
.faq-question {
  display: flex; align-items: center; justify-content: space-between;
  width: 100%; padding: 18px 22px; font-size: 15px; font-weight: 600;
  color: var(--text-primary); background: none; border: none; cursor: pointer;
  text-align: left; gap: 16px; transition: color var(--transition-fast);
}
.faq-question:hover { color: var(--primary); }
.faq-icon {
  width: 24px; height: 24px; min-width: 24px; border-radius: 50%;
  background: var(--bg-secondary); display: flex; align-items: center; justify-content: center;
  font-size: 14px; color: var(--text-muted); transition: all var(--transition);
  font-weight: 700; line-height: 1;
}
.faq-item.active .faq-icon, .faq-item.open .faq-icon { background: var(--primary); color: #fff; transform: rotate(45deg); }
.faq-answer {
  max-height: 0; overflow: hidden; transition: max-height 0.35s ease, padding 0.35s ease;
  padding: 0 22px;
}
.faq-item.active .faq-answer, .faq-item.open .faq-answer {
  max-height: 400px; padding: 0 22px 18px;
}
.faq-answer p { font-size: 14px; color: var(--text-secondary); line-height: 1.75; }

/* ===== 友链区域 ===== */
.friend-links {
  background: var(--bg-secondary); border-top: 1px solid var(--border-light);
  padding: 36px 0;
}
.friend-links .container { text-align: center; }
.friend-links h3 { font-size: 15px; font-weight: 600; color: var(--text-primary); margin-bottom: 16px; }
.friend-links-row { display: flex; flex-wrap: wrap; justify-content: center; gap: 10px; }
.friend-link {
  padding: 7px 18px; font-size: 13px; color: var(--text-secondary);
  background: var(--bg-card); border: 1px solid var(--border-light);
  border-radius: 20px; transition: all var(--transition-fast);
}
.friend-link:hover { color: var(--primary); border-color: var(--primary-light); background: var(--highlight-bg); }

/* ===== CTA 区域 ===== */
.cta-section {
  padding: 72px 0; background: linear-gradient(135deg, #E8F8F5, #EBF5FB);
  text-align: center;
}
.cta-section h2 { font-size: clamp(24px, 3vw, 32px); font-weight: 700; color: var(--text-primary); margin-bottom: 12px; }
.cta-section p { font-size: 15px; color: var(--text-secondary); margin-bottom: 28px; max-width: 500px; margin-left: auto; margin-right: auto; }
.cta-buttons { display: flex; gap: 14px; justify-content: center; flex-wrap: wrap; }

/* ===== Footer ===== */
.footer { background: var(--text-primary); color: rgba(255,255,255,0.65); padding: 56px 0 28px; margin-top: auto; }
.footer-grid { display: grid; grid-template-columns: 1.6fr 1fr 1fr 1fr; gap: 36px; margin-bottom: 40px; }
.footer-brand .logo { color: #fff; margin-bottom: 14px; }
.footer-brand p { font-size: 14px; line-height: 1.7; opacity: 0.7; }
.footer-col h4 { color: #fff; font-size: 15px; font-weight: 600; margin-bottom: 16px; }
.footer-col a { display: block; font-size: 14px; color: rgba(255,255,255,0.55); padding: 5px 0; transition: color var(--transition-fast); }
.footer-col a:hover { color: var(--primary-light); }
.footer-bottom { border-top: 1px solid rgba(255,255,255,0.1); padding-top: 20px; display: flex; justify-content: space-between; font-size: 13px; flex-wrap: wrap; gap: 8px; }

@media (max-width: 768px) {
  .footer-grid { grid-template-columns: 1fr 1fr; gap: 28px; }
  .footer-bottom { flex-direction: column; text-align: center; }
}

/* ===== 回到顶部 ===== */
.back-to-top {
  position: fixed; bottom: 30px; right: 30px; z-index: 999;
  width: 42px; height: 42px; border-radius: 50%;
  background: var(--primary); color: #fff; border: none; cursor: pointer;
  font-size: 20px; display: flex; align-items: center; justify-content: center;
  box-shadow: 0 3px 12px rgba(39,174,96,0.3);
  opacity: 0; visibility: hidden; transform: translateY(10px);
  transition: all var(--transition);
}
.back-to-top.visible { opacity: 1; visibility: visible; transform: translateY(0); }
.back-to-top:hover { background: var(--primary-dark); transform: translateY(-2px); }

/* ===== 滚动显示动画 ===== */
.reveal { opacity: 0; transform: translateY(24px); transition: opacity 0.55s ease, transform 0.55s ease; }
.reveal.visible, .reveal.active { opacity: 1; transform: translateY(0); }

/* ===== 下载页样式 ===== */
.download-platform { padding: 48px 0; border-bottom: 1px solid var(--border-light); scroll-margin-top: 80px; }
.download-platform:last-child { border-bottom: none; }
.platform-header { display: flex; align-items: center; gap: 14px; margin-bottom: 28px; }
.platform-icon {
  width: 52px; height: 52px; border-radius: var(--radius);
  display: flex; align-items: center; justify-content: center; font-size: 28px; flex-shrink: 0;
}
.platform-header h3 { font-size: 22px; font-weight: 700; }
.platform-header p { font-size: 14px; color: var(--text-muted); }

.download-cards { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 16px; }
.download-card {
  background: var(--bg-card); border: 1px solid var(--border-light);
  border-radius: var(--radius); padding: 24px; text-align: center;
  transition: all var(--transition);
}
.download-card:hover { transform: translateY(-3px); box-shadow: var(--shadow-md); border-color: var(--primary-light); }
.download-card .card-icon { font-size: 36px; margin-bottom: 12px; }
.download-card h4 { font-size: 16px; font-weight: 700; margin-bottom: 6px; }
.download-card p { font-size: 13px; color: var(--text-muted); margin-bottom: 14px; }
.download-card .btn-primary { padding: 10px 24px; font-size: 14px; }

/* 版本对比表 */
.compare-table-wrapper { overflow-x: auto; border-radius: var(--radius-lg); border: 1px solid var(--border-light); }
.compare-table { width: 100%; border-collapse: collapse; font-size: 14px; min-width: 600px; }
.compare-table th, .compare-table td { padding: 14px 18px; text-align: left; border-bottom: 1px solid var(--border-light); }
.compare-table th { background: var(--bg-secondary); font-weight: 700; color: var(--text-primary); font-size: 13px; text-transform: uppercase; letter-spacing: 0.5px; }
.compare-table tr:hover td { background: var(--bg-secondary); }
.compare-table tr:last-child td { border-bottom: none; }
.compare-table td:first-child { font-weight: 600; color: var(--text-primary); }

/* 平台标签 */
.platform-tabs { display: flex; gap: 6px; justify-content: center; margin-bottom: 40px; flex-wrap: wrap; }
.platform-tab {
  padding: 8px 20px; font-size: 14px; font-weight: 500;
  color: var(--text-secondary); background: var(--bg-card);
  border: 1px solid var(--border); border-radius: 24px; cursor: pointer;
  transition: all var(--transition-fast);
}
.platform-tab:hover { color: var(--primary); border-color: var(--primary-light); }
.platform-tab.active { background: var(--primary); color: #fff; border-color: var(--primary); }

/* ===== 教程详情页专属 ===== */
.tutorial-hero { padding: 110px 0 50px; background: var(--bg-secondary); }
.tutorial-breadcrumb { font-size: 13px; color: var(--text-muted); margin-bottom: 16px; }
.tutorial-breadcrumb a { color: var(--text-secondary); }
.tutorial-breadcrumb a:hover { color: var(--primary); }
.tutorial-title { font-size: clamp(28px, 3.5vw, 38px); font-weight: 800; color: var(--text-primary); margin-bottom: 10px; }
.tutorial-desc { font-size: 15px; color: var(--text-secondary); max-width: 600px; line-height: 1.7; }
.tutorial-meta { display: flex; gap: 20px; margin-top: 16px; font-size: 13px; color: var(--text-muted); }

/* 教程正文 */
.tutorial-body { padding: 48px 0; }
.tutorial-article { max-width: 800px; margin: 0 auto; }
.tutorial-article h2 { font-size: 24px; font-weight: 700; color: var(--text-primary); margin: 36px 0 16px; padding-bottom: 8px; border-bottom: 2px solid var(--primary-light); }
.tutorial-article h3 { font-size: 19px; font-weight: 700; color: var(--text-primary); margin: 28px 0 12px; }
.tutorial-article p { font-size: 15px; color: var(--text-secondary); line-height: 1.8; margin-bottom: 14px; }
.tutorial-article ul, .tutorial-article ol { margin-bottom: 14px; }
.tutorial-article li { margin-bottom: 6px; color: var(--text-secondary); font-size: 15px; }

/* 步骤编号列表 */
.step-list { counter-reset: step-counter; list-style: none !important; padding: 0 !important; }
.step-list > li {
  position: relative; padding: 20px 20px 20px 68px; margin-bottom: 16px;
  background: var(--bg-card); border-radius: var(--radius);
  border: 1px solid var(--border-light); counter-increment: step-counter;
}
.step-list > li::before {
  content: counter(step-counter); position: absolute; left: 18px; top: 20px;
  width: 34px; height: 34px; border-radius: 50%;
  background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
  color: #fff; font-size: 15px; font-weight: 700;
  display: flex; align-items: center; justify-content: center;
}
.step-list > li h4 { font-size: 16px; font-weight: 700; color: var(--text-primary); margin-bottom: 6px; }
.step-list > li p { font-size: 14px; color: var(--text-secondary); line-height: 1.7; margin-bottom: 0; }

/* 目录侧边导航 */
.toc-nav {
  position: sticky; top: 84px; background: var(--bg-card);
  border: 1px solid var(--border-light); border-radius: var(--radius);
  padding: 20px; max-width: 260px;
}
.toc-nav h4 { font-size: 14px; font-weight: 700; color: var(--text-primary); margin-bottom: 12px; padding-bottom: 8px; border-bottom: 1px solid var(--border-light); }
.toc-nav ul { list-style: none !important; padding: 0 !important; }
.toc-nav li { margin-bottom: 0; }
.toc-nav a {
  display: block; padding: 7px 12px; font-size: 13px; color: var(--text-secondary);
  border-radius: var(--radius-sm); transition: all var(--transition-fast);
}
.toc-nav a:hover, .toc-nav a.active { color: var(--primary); background: var(--highlight-bg); }

.tutorials-layout { display: grid; grid-template-columns: 1fr 280px; gap: 36px; align-items: start; }
@media (max-width: 900px) {
  .tutorials-layout { grid-template-columns: 1fr; }
  .toc-nav { position: static; max-width: 100%; }
}

/* 教程卡片网格（教程列表页） */
.tutorials-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(340px, 1fr)); gap: 24px; }
.tutorial-card {
  background: var(--bg-card); border: 1px solid var(--border-light);
  border-radius: var(--radius-lg); overflow: hidden; transition: all var(--transition);
}
.tutorial-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); }
.tutorial-card-thumb {
  height: 180px; background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
  display: flex; align-items: center; justify-content: center; font-size: 48px; flex-shrink: 0;
}
.tutorial-card-body { padding: 24px; }
.tutorial-card-tag {
  display: inline-block; padding: 3px 10px; font-size: 11px; font-weight: 600;
  color: var(--primary); background: var(--highlight-bg); border-radius: 12px; margin-bottom: 10px;
}
.tutorial-card-body h3 { font-size: 18px; font-weight: 700; color: var(--text-primary); margin-bottom: 8px; }
.tutorial-card-body p { font-size: 14px; color: var(--text-secondary); line-height: 1.6; margin-bottom: 14px; }
.tutorial-card-footer { display: flex; justify-content: space-between; align-items: center; font-size: 12px; color: var(--text-muted); }
.tutorial-card-footer a { font-weight: 600; color: var(--primary); font-size: 14px; display: flex; align-items: center; gap: 4px; }
.tutorial-card-footer a:hover { color: var(--primary-dark); }

/* 关于页时间线 */
.timeline { position: relative; padding-left: 36px; max-width: 650px; margin: 0 auto; }
.timeline::before { content: ''; position: absolute; left: 11px; top: 0; bottom: 0; width: 2px; background: var(--border); }
.timeline-item { position: relative; padding-bottom: 32px; }
.timeline-item:last-child { padding-bottom: 0; }
.timeline-dot {
  position: absolute; left: -29px; top: 4px; width: 16px; height: 16px;
  border-radius: 50%; background: var(--primary); border: 3px solid var(--bg);
}
.timeline-item h4 { font-size: 16px; font-weight: 700; color: var(--text-primary); margin-bottom: 4px; }
.timeline-item p { font-size: 14px; color: var(--text-secondary); line-height: 1.7; }

/* 特性网格 */
.features-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(250px, 1fr)); gap: 20px; }
.feature-card {
  background: var(--bg-card); border: 1px solid var(--border-light);
  border-radius: var(--radius); padding: 26px; transition: all var(--transition);
}
.feature-card:hover { border-color: var(--primary-light); box-shadow: var(--shadow-md); }
.feature-icon { font-size: 32px; margin-bottom: 12px; }
.feature-card h4 { font-size: 16px; font-weight: 700; color: var(--text-primary); margin-bottom: 8px; }
.feature-card p { font-size: 14px; color: var(--text-secondary); line-height: 1.7; }

/* 响应式调整 */
@media (max-width: 480px) {
  .hero-stats { flex-direction: column; gap: 16px; align-items: flex-start; }
  .stat-item { text-align: left; }
  .btn-primary, .btn-outline { padding: 11px 22px; font-size: 14px; }
  .section { padding: 52px 0; }
  .cta-section { padding: 52px 0; }
}