/* ==========================================================================
   悠兔机场 (Youtu Airport) - 核心样式表
   风格: 浅色系科技风 (Premium Light-Tech)
   ========================================================================== */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&family=Noto+Sans+SC:wght@300;400;500;700&display=swap');

:root {
  /* 颜色系统 */
  --primary: #2563eb;
  --primary-hover: #1d4ed8;
  --primary-light: #eff6ff;
  --secondary: #0ea5e9;
  --secondary-hover: #0284c7;
  --accent: #10b981;
  --accent-light: #ecfdf5;
  
  --bg-main: #f8fafc;
  --bg-card: #ffffff;
  --bg-header: rgba(255, 255, 255, 0.8);
  
  --text-primary: #0f172a;
  --text-secondary: #334155;
  --text-muted: #64748b;
  --border-color: #e2e8f0;
  
  /* 阴影 & 圆角 */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(15, 23, 42, 0.05), 0 2px 4px -2px rgba(15, 23, 42, 0.05);
  --shadow-lg: 0 10px 15px -3px rgba(15, 23, 42, 0.08), 0 4px 6px -4px rgba(15, 23, 42, 0.08);
  --shadow-hover: 0 20px 25px -5px rgba(37, 99, 235, 0.1), 0 8px 10px -6px rgba(37, 99, 235, 0.05);
  
  --radius-sm: 6px;
  --radius-md: 12px;
  --radius-lg: 20px;
  --radius-full: 9999px;
  
  /* 布局 */
  --max-width: 1200px;
  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* ==========================================================================
   基础样式重置 (CSS Reset)
   ========================================================================== */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: 'Inter', 'Noto Sans SC', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  background-color: var(--bg-main);
  color: var(--text-secondary);
  line-height: 1.6;
  overflow-x: hidden;
}

h1, h2, h3, h4, h5, h6 {
  color: var(--text-primary);
  font-weight: 700;
  line-height: 1.25;
  margin-bottom: 0.5em;
}

p {
  margin-bottom: 1rem;
}

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

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

ul, ol {
  list-style: none;
}

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

/* ==========================================================================
   全局通用组件 (Utility Components)
   ========================================================================== */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.5rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.75rem 1.5rem;
  font-size: 0.95rem;
  font-weight: 600;
  border-radius: var(--radius-md);
  border: 1px solid transparent;
  cursor: pointer;
  transition: var(--transition);
  gap: 0.5rem;
}

.btn-primary {
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  color: #ffffff;
  box-shadow: 0 4px 14px rgba(37, 99, 235, 0.3);
}

.btn-primary:hover {
  background: linear-gradient(135deg, var(--primary-hover), var(--secondary-hover));
  color: #ffffff;
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(37, 99, 235, 0.4);
}

.btn-secondary {
  background-color: var(--primary-light);
  color: var(--primary);
  border: 1px solid rgba(37, 99, 235, 0.1);
}

.btn-secondary:hover {
  background-color: rgba(37, 99, 235, 0.15);
  transform: translateY(-2px);
}

.btn-outline {
  background-color: transparent;
  border: 1px solid var(--border-color);
  color: var(--text-secondary);
}

.btn-outline:hover {
  border-color: var(--primary);
  color: var(--primary);
  background-color: var(--primary-light);
}

.badge {
  display: inline-flex;
  align-items: center;
  padding: 0.25rem 0.75rem;
  font-size: 0.8rem;
  font-weight: 600;
  border-radius: var(--radius-full);
  margin-bottom: 1rem;
}

.badge-primary {
  background-color: var(--primary-light);
  color: var(--primary);
  border: 1px solid rgba(37, 99, 235, 0.1);
}

.badge-accent {
  background-color: var(--accent-light);
  color: var(--accent);
  border: 1px solid rgba(16, 185, 129, 0.1);
}

.text-gradient {
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.section {
  padding: 5rem 0;
}

.section-title {
  text-align: center;
  max-width: 700px;
  margin: 0 auto 3.5rem;
}

.section-title h2 {
  font-size: 2.25rem;
  margin-bottom: 1rem;
}

.section-title p {
  color: var(--text-muted);
  font-size: 1.1rem;
}

/* ==========================================================================
   页眉 & 导航栏 (Header & Navbar)
   ========================================================================== */
.header {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: var(--bg-header);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-color);
  transition: var(--transition);
}

.navbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 4.5rem;
}

.logo {
  display: flex;
  align-items: center;
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--text-primary);
  gap: 0.5rem;
}

.logo img {
  height: 2rem;
  width: auto;
}

.logo-dot {
  width: 8px;
  height: 8px;
  background-color: var(--primary);
  border-radius: 50%;
  display: inline-block;
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 2rem;
}

.nav-link {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--text-secondary);
}

.nav-link:hover, .nav-link.active {
  color: var(--primary);
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 1rem;
}

/* 移动端菜单按钮 */
.menu-toggle {
  display: none;
  flex-direction: column;
  justify-content: space-between;
  width: 24px;
  height: 18px;
  background: transparent;
  border: none;
  cursor: pointer;
  z-index: 101;
}

.menu-toggle span {
  width: 100%;
  height: 2px;
  background-color: var(--text-primary);
  border-radius: 2px;
  transition: var(--transition);
}

/* ==========================================================================
   首屏介绍 (Hero Section)
   ========================================================================== */
.hero {
  padding: 6rem 0 4rem;
  position: relative;
  overflow: hidden;
  background: radial-gradient(circle at top right, rgba(37, 99, 235, 0.05), transparent 400px),
              radial-gradient(circle at bottom left, rgba(14, 165, 233, 0.05), transparent 400px);
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 3rem;
  align-items: center;
}

.hero-content h1 {
  font-size: 3.5rem;
  line-height: 1.15;
  margin-bottom: 1.5rem;
}

.hero-content p {
  font-size: 1.2rem;
  color: var(--text-secondary);
  margin-bottom: 2rem;
  max-width: 540px;
}

.hero-buttons {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  margin-bottom: 2.5rem;
}

.hero-features {
  display: flex;
  flex-wrap: wrap;
  gap: 1.5rem;
}

.hero-feature-item {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.9rem;
  color: var(--text-muted);
}

.hero-feature-item svg {
  color: var(--accent);
}

.hero-image-wrapper {
  position: relative;
}

.hero-image-card {
  background-color: var(--bg-card);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-lg);
  padding: 1.5rem;
  position: relative;
  z-index: 1;
}

.hero-image-card img {
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
}

.hero-image-bg {
  position: absolute;
  top: -10%;
  right: -10%;
  width: 120%;
  height: 120%;
  background: linear-gradient(135deg, rgba(37, 99, 235, 0.05), rgba(14, 165, 233, 0.05));
  border-radius: 40% 60% 60% 40% / 50% 30% 70% 50%;
  z-index: 0;
  animation: morph 12s ease-in-out infinite alternate;
}

@keyframes morph {
  0% { border-radius: 40% 60% 60% 40% / 50% 30% 70% 50%; }
  100% { border-radius: 60% 40% 40% 60% / 30% 60% 40% 70%; }
}

/* ==========================================================================
   核心优势 (Advantages Section)
   ========================================================================== */
.advantages-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 2rem;
}

.advantage-card {
  background-color: var(--bg-card);
  padding: 2.5rem 2rem;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-md);
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}

.advantage-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 4px;
  background: linear-gradient(90deg, var(--primary), var(--secondary));
  opacity: 0;
  transition: var(--transition);
}

.advantage-card:hover {
  transform: translateY(-8px);
  box-shadow: var(--shadow-hover);
  border-color: rgba(37, 99, 235, 0.2);
}

.advantage-card:hover::before {
  opacity: 1;
}

.advantage-icon {
  width: 3.5rem;
  height: 3.5rem;
  background-color: var(--primary-light);
  color: var(--primary);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1.5rem;
  font-size: 1.5rem;
}

.advantage-card h3 {
  font-size: 1.25rem;
  margin-bottom: 0.75rem;
}

.advantage-card p {
  color: var(--text-muted);
  font-size: 0.95rem;
  margin-bottom: 0;
}

/* ==========================================================================
   套餐价格 (Pricing Section)
   ========================================================================== */
.pricing-section {
  background-color: #f1f5f9;
}

.pricing-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 2rem;
  align-items: stretch;
}

.pricing-card {
  background-color: var(--bg-card);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-md);
  padding: 2.5rem 2rem;
  display: flex;
  flex-direction: column;
  position: relative;
  transition: var(--transition);
}

.pricing-card.featured {
  border: 2px solid var(--primary);
  box-shadow: var(--shadow-lg);
  transform: scale(1.03);
  z-index: 2;
}

.pricing-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-hover);
}

.pricing-card.featured:hover {
  transform: translateY(-8px) scale(1.03);
}

.pricing-ribbon {
  position: absolute;
  top: 1.25rem;
  right: 1.25rem;
}

.pricing-name {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
  color: var(--text-primary);
}

.pricing-desc {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 1.5rem;
}

.pricing-rates {
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 1.5rem;
  margin-bottom: 1.5rem;
}

.pricing-rate-row {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  margin-bottom: 0.5rem;
}

.pricing-rate-row:last-child {
  margin-bottom: 0;
}

.rate-label {
  font-size: 0.9rem;
  color: var(--text-secondary);
}

.rate-value {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text-primary);
}

.rate-value span {
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--text-muted);
}

.rate-unit {
  font-size: 0.8rem;
  color: var(--text-muted);
  background-color: var(--bg-main);
  padding: 0.1rem 0.4rem;
  border-radius: var(--radius-sm);
}

.pricing-features {
  margin-bottom: 2rem;
  flex-grow: 1;
}

.pricing-feature-item {
  display: flex;
  align-items: flex-start;
  gap: 0.75rem;
  margin-bottom: 0.75rem;
  font-size: 0.9rem;
}

.pricing-feature-item svg {
  flex-shrink: 0;
  color: var(--accent);
  margin-top: 0.2rem;
}

.pricing-feature-item.disabled {
  color: var(--text-muted);
  text-decoration: line-through;
  opacity: 0.65;
}

.pricing-feature-item.disabled svg {
  color: var(--text-muted);
}

/* ==========================================================================
   适合人群 (Audience Section)
   ========================================================================== */
.audience-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 2rem;
}

.audience-card {
  background-color: var(--bg-card);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-color);
  padding: 2rem;
  text-align: center;
  transition: var(--transition);
  box-shadow: var(--shadow-sm);
}

.audience-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-md);
  border-color: rgba(37, 99, 235, 0.15);
}

.audience-icon {
  width: 4rem;
  height: 4rem;
  background-color: var(--primary-light);
  color: var(--primary);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 1.5rem;
  font-size: 1.75rem;
}

.audience-card h3 {
  font-size: 1.15rem;
  margin-bottom: 0.75rem;
}

.audience-card p {
  font-size: 0.9rem;
  color: var(--text-muted);
  margin-bottom: 0;
}

/* ==========================================================================
   极速教程版块 (Tutorial Section)
   ========================================================================== */
.tutorial-tabs {
  display: flex;
  justify-content: center;
  gap: 1rem;
  margin-bottom: 3rem;
}

.tab-btn {
  padding: 0.75rem 1.5rem;
  font-weight: 600;
  font-size: 1rem;
  border-radius: var(--radius-full);
  border: 1px solid var(--border-color);
  background-color: var(--bg-card);
  color: var(--text-secondary);
  cursor: pointer;
  transition: var(--transition);
}

.tab-btn.active, .tab-btn:hover {
  background-color: var(--primary);
  color: #ffffff;
  border-color: var(--primary);
  box-shadow: 0 4px 10px rgba(37, 99, 235, 0.2);
}

.tab-content {
  display: none;
}

.tab-content.active {
  display: block;
  animation: fadeIn 0.4s ease;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

.tutorial-steps-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 2rem;
  margin-bottom: 3rem;
}

.step-card {
  background-color: var(--bg-card);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-color);
  padding: 2rem;
  position: relative;
  box-shadow: var(--shadow-sm);
}

.step-number {
  position: absolute;
  top: 1.5rem;
  right: 1.5rem;
  font-size: 2.5rem;
  font-weight: 800;
  color: rgba(37, 99, 235, 0.1);
  line-height: 1;
}

.step-card h3 {
  font-size: 1.15rem;
  margin-bottom: 0.75rem;
  padding-right: 2rem;
}

.step-card p {
  font-size: 0.9rem;
  color: var(--text-secondary);
  margin-bottom: 1.25rem;
}

.step-code-box {
  background-color: var(--bg-main);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 0.5rem 0.75rem;
  font-family: monospace;
  font-size: 0.8rem;
  word-break: break-all;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 0.5rem;
}

.copy-btn {
  background: transparent;
  border: none;
  color: var(--primary);
  cursor: pointer;
  flex-shrink: 0;
  padding: 0.25rem;
  display: flex;
  align-items: center;
  justify-content: center;
}

.copy-btn:hover {
  color: var(--primary-hover);
}

.tutorial-summary-box {
  background: linear-gradient(135deg, var(--primary-light), rgba(14, 165, 233, 0.05));
  border: 1px dashed rgba(37, 99, 235, 0.3);
  border-radius: var(--radius-lg);
  padding: 2.5rem;
  text-align: center;
  max-width: 800px;
  margin: 0 auto;
}

.tutorial-summary-box h4 {
  font-size: 1.25rem;
  margin-bottom: 0.75rem;
}

.tutorial-summary-box p {
  color: var(--text-secondary);
  max-width: 600px;
  margin: 0 auto 1.5rem;
  font-size: 0.95rem;
}

/* ==========================================================================
   用户评价 (Reviews Section)
   ========================================================================== */
.reviews-section {
  background-color: #f1f5f9;
}

.reviews-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 2rem;
}

.review-card {
  background-color: var(--bg-card);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-color);
  padding: 2.5rem;
  box-shadow: var(--shadow-sm);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.review-stars {
  color: #fbbf24;
  margin-bottom: 1.25rem;
  font-size: 1rem;
}

.review-content {
  font-size: 0.95rem;
  font-style: italic;
  color: var(--text-secondary);
  margin-bottom: 1.5rem;
  position: relative;
}

.review-content::before {
  content: '“';
  font-size: 3rem;
  color: rgba(37, 99, 235, 0.08);
  position: absolute;
  top: -1.5rem;
  left: -0.75rem;
  font-family: serif;
}

.review-user {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.review-avatar {
  width: 2.75rem;
  height: 2.75rem;
  border-radius: 50%;
  background-color: var(--primary-light);
  color: var(--primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 1rem;
}

.review-user-info h4 {
  font-size: 0.95rem;
  margin-bottom: 0.15rem;
}

.review-user-info span {
  font-size: 0.8rem;
  color: var(--text-muted);
}

/* ==========================================================================
   常见问题 (FAQ Section)
   ========================================================================== */
.faq-list {
  max-width: 800px;
  margin: 0 auto;
}

.faq-item {
  background-color: var(--bg-card);
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
  margin-bottom: 1rem;
  overflow: hidden;
  transition: var(--transition);
}

.faq-item:hover {
  border-color: rgba(37, 99, 235, 0.2);
  box-shadow: var(--shadow-sm);
}

.faq-question {
  width: 100%;
  padding: 1.25rem 1.5rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: transparent;
  border: none;
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text-primary);
  text-align: left;
  cursor: pointer;
}

.faq-question span {
  padding-right: 1.5rem;
}

.faq-icon {
  flex-shrink: 0;
  transition: var(--transition);
  color: var(--text-muted);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s cubic-bezier(0, 1, 0, 1);
  padding: 0 1.5rem;
  color: var(--text-secondary);
  font-size: 0.95rem;
}

.faq-answer-inner {
  padding-bottom: 1.25rem;
}

.faq-item.active {
  border-color: var(--primary);
  box-shadow: var(--shadow-md);
}

.faq-item.active .faq-icon {
  transform: rotate(180deg);
  color: var(--primary);
}

.faq-item.active .faq-answer {
  max-height: 500px; /* 足够容纳内容的高度 */
  transition: max-height 0.3s cubic-bezier(1, 0, 1, 0);
}

/* ==========================================================================
   文章与教程目录 (Directory Sections)
   ========================================================================== */
.directory-section {
  background-color: #f8fafc;
}

.directory-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(340px, 1fr));
  gap: 2rem;
}

.directory-card {
  background-color: var(--bg-card);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-color);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  display: flex;
  flex-direction: column;
  transition: var(--transition);
}

.directory-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-md);
}

.directory-card-img {
  height: 200px;
  background: linear-gradient(135deg, rgba(37, 99, 235, 0.05), rgba(14, 165, 233, 0.1));
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 3rem;
  color: var(--primary);
  border-bottom: 1px solid var(--border-color);
}

.directory-card-content {
  padding: 1.5rem;
  flex-grow: 1;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.directory-card-content h3 {
  font-size: 1.15rem;
  margin-bottom: 0.75rem;
}

.directory-card-content p {
  font-size: 0.9rem;
  color: var(--text-muted);
  margin-bottom: 1.25rem;
}

.directory-card-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-top: 1px solid var(--border-color);
  padding-top: 1rem;
  font-size: 0.8rem;
  color: var(--text-muted);
}

.directory-card-link {
  font-weight: 600;
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
}

/* ==========================================================================
   法律条款 & 通用子页面样式 (Inner Pages Layout)
   ========================================================================== */
.breadcrumbs {
  padding: 1.5rem 0;
  font-size: 0.85rem;
  color: var(--text-muted);
  border-bottom: 1px solid var(--border-color);
  margin-bottom: 2rem;
}

.breadcrumbs a {
  color: var(--text-muted);
}

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

.breadcrumbs span {
  margin: 0 0.5rem;
}

.inner-page-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: 3rem;
  padding: 2rem 0 5rem;
}

@media(min-width: 992px) {
  .inner-page-layout {
    grid-template-columns: 2.6fr 1fr;
  }
}

.article-body {
  background-color: var(--bg-card);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-sm);
  padding: 2rem 1.5rem;
}

@media(min-width: 768px) {
  .article-body {
    padding: 3rem;
  }
}

.article-header {
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 1.5rem;
  margin-bottom: 2rem;
}

.article-header h1 {
  font-size: 2.2rem;
  margin-bottom: 1rem;
}

.article-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 1.5rem;
  font-size: 0.85rem;
  color: var(--text-muted);
}

.article-meta-item {
  display: flex;
  align-items: center;
  gap: 0.35rem;
}

/* 富文本内容排版样式 */
.prose {
  color: var(--text-secondary);
  font-size: 1.05rem;
  line-height: 1.8;
}

.prose p {
  margin-bottom: 1.5rem;
}

.prose h2 {
  font-size: 1.6rem;
  margin: 2.5rem 0 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--border-color);
}

.prose h3 {
  font-size: 1.25rem;
  margin: 2rem 0 0.75rem;
}

.prose ul, .prose ol {
  margin-bottom: 1.5rem;
  padding-left: 1.5rem;
}

.prose ul {
  list-style-type: disc;
}

.prose ol {
  list-style-type: decimal;
}

.prose li {
  margin-bottom: 0.5rem;
}

.prose blockquote {
  border-left: 4px solid var(--primary);
  background-color: var(--bg-main);
  padding: 1rem 1.5rem;
  margin-bottom: 1.5rem;
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  font-style: italic;
}

.prose table {
  width: 100%;
  border-collapse: collapse;
  margin-bottom: 1.5rem;
  font-size: 0.95rem;
}

.prose th, .prose td {
  border: 1px solid var(--border-color);
  padding: 0.75rem 1rem;
  text-align: left;
}

.prose th {
  background-color: var(--bg-main);
  font-weight: 700;
  color: var(--text-primary);
}

.prose tr:nth-child(even) {
  background-color: rgba(248, 250, 252, 0.5);
}

.prose img {
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  margin: 2rem auto;
}

.prose a {
  text-decoration: underline;
}

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

/* 侧边栏 (Sidebar) */
.sidebar {
  display: flex;
  flex-direction: column;
  gap: 2rem;
}

.sidebar-widget {
  background-color: var(--bg-card);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-color);
  padding: 2rem;
  box-shadow: var(--shadow-sm);
}

.sidebar-widget h3 {
  font-size: 1.15rem;
  margin-bottom: 1.25rem;
  border-left: 4px solid var(--primary);
  padding-left: 0.75rem;
}

.widget-link-list li {
  margin-bottom: 0.75rem;
  padding-bottom: 0.75rem;
  border-bottom: 1px dashed var(--border-color);
}

.widget-link-list li:last-child {
  margin-bottom: 0;
  padding-bottom: 0;
  border-bottom: none;
}

.widget-link-list a {
  color: var(--text-secondary);
  font-size: 0.9rem;
  font-weight: 500;
  display: block;
}

.widget-link-list a:hover {
  color: var(--primary);
  transform: translateX(3px);
}

.sidebar-cta {
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  color: #ffffff;
  border: none;
  text-align: center;
  position: relative;
  overflow: hidden;
  z-index: 1;
}

.sidebar-cta h3 {
  color: #ffffff;
  border-left: none;
  padding-left: 0;
  font-size: 1.35rem;
  margin-bottom: 0.75rem;
}

.sidebar-cta p {
  font-size: 0.9rem;
  opacity: 0.9;
  margin-bottom: 1.5rem;
}

.sidebar-cta .btn {
  width: 100%;
}

.sidebar-cta::after {
  content: '';
  position: absolute;
  width: 150px;
  height: 150px;
  background-color: rgba(255, 255, 255, 0.05);
  border-radius: 50%;
  bottom: -50px;
  right: -50px;
  z-index: -1;
}

/* ==========================================================================
   免责/隐私/条款专用简易布局 (Legal Layout)
   ========================================================================== */
.legal-container {
  max-width: 900px;
  margin: 0 auto;
  padding: 4rem 1.5rem;
}

.legal-card {
  background-color: var(--bg-card);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-color);
  padding: 3rem 2rem;
  box-shadow: var(--shadow-md);
}

@media(min-width: 768px) {
  .legal-card {
    padding: 4rem;
  }
}

/* ==========================================================================
   页脚部分 (Footer)
   ========================================================================== */
.footer {
  background-color: #0f172a;
  color: #94a3b8;
  padding: 5rem 0 2rem;
  border-top: 1px solid #1e293b;
  font-size: 0.9rem;
}

.footer h1, .footer h2, .footer h3, .footer h4 {
  color: #ffffff;
}

.footer-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 3rem;
  margin-bottom: 4rem;
}

.footer-brand {
  grid-column: span 1;
}

@media(min-width: 992px) {
  .footer-brand {
    grid-column: span 2;
  }
}

.footer-brand-logo {
  display: flex;
  align-items: center;
  font-size: 1.35rem;
  font-weight: 700;
  color: #ffffff;
  gap: 0.5rem;
  margin-bottom: 1.25rem;
}

.footer-brand-logo .logo-dot {
  background-color: var(--secondary);
}

.footer-brand p {
  color: #64748b;
  max-width: 300px;
  font-size: 0.85rem;
  line-height: 1.6;
}

.footer-title {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 1.5rem;
  position: relative;
}

.footer-links li {
  margin-bottom: 0.75rem;
}

.footer-links a {
  color: #94a3b8;
}

.footer-links a:hover {
  color: #ffffff;
}

.footer-bottom {
  border-top: 1px solid #1e293b;
  padding-top: 2rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
  align-items: center;
  justify-content: space-between;
}

@media(min-width: 768px) {
  .footer-bottom {
    flex-direction: row;
  }
}

.footer-copy {
  font-size: 0.8rem;
  color: #64748b;
}

.footer-legal-links {
  display: flex;
  gap: 1.5rem;
  font-size: 0.8rem;
}

.footer-legal-links a {
  color: #64748b;
}

.footer-legal-links a:hover {
  color: #ffffff;
}

/* 返回顶部按钮 */
.back-to-top {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  background-color: var(--primary);
  color: #ffffff;
  width: 2.75rem;
  height: 2.75rem;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  border: none;
  cursor: pointer;
  box-shadow: var(--shadow-lg);
  opacity: 0;
  visibility: hidden;
  transition: var(--transition);
  z-index: 99;
}

.back-to-top.show {
  opacity: 1;
  visibility: visible;
}

.back-to-top:hover {
  background-color: var(--primary-hover);
  transform: translateY(-3px);
}

/* ==========================================================================
   响应式断点媒体查询 (Responsive Media Queries)
   ========================================================================== */

@media(max-width: 991px) {
  .nav-menu {
    position: fixed;
    top: 4.5rem;
    left: -100%;
    width: 100%;
    height: calc(100vh - 4.5rem);
    background-color: var(--bg-card);
    flex-direction: column;
    padding: 3rem 2rem;
    gap: 2rem;
    align-items: flex-start;
    transition: var(--transition);
    border-top: 1px solid var(--border-color);
    box-shadow: var(--shadow-lg);
  }
  
  .nav-menu.active {
    left: 0;
  }
  
  .nav-actions {
    display: none; /* 在移动端折叠或者合并到菜单 */
  }
  
  .menu-toggle {
    display: flex;
  }
  
  /* 移动端菜单激活状态下的图标转换 */
  .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(6px, -6px);
  }

  .hero-grid {
    grid-template-columns: 1fr;
    text-align: center;
    gap: 4rem;
  }
  
  .hero-content h1 {
    font-size: 2.75rem;
  }
  
  .hero-content p {
    margin: 0 auto 2rem;
  }
  
  .hero-buttons {
    justify-content: center;
  }
  
  .hero-features {
    justify-content: center;
  }
  
  .pricing-card.featured {
    transform: none;
  }
  
  .pricing-card.featured:hover {
    transform: translateY(-5px);
  }
}

@media(max-width: 767px) {
  :root {
    font-size: 15px;
  }
  
  .section {
    padding: 4rem 0;
  }
  
  .hero-content h1 {
    font-size: 2.25rem;
  }
  
  .section-title h2 {
    font-size: 1.85rem;
  }
  
  .pricing-grid {
    grid-template-columns: 1fr;
    max-width: 450px;
    margin: 0 auto;
  }
}