/* CSS Variables - 浅色白底科技风格 */
:root {
  --primary: #2563eb;
  --primary-light: #3b82f6;
  --primary-dark: #1d4ed8;
  --primary-bg: #eff6ff;
  --accent: #06b6d4;
  --accent-light: #22d3ee;
  --gradient-primary: linear-gradient(135deg, #2563eb 0%, #3b82f6 100%);
  --gradient-hero: linear-gradient(180deg, #f8fafc 0%, #eff6ff 100%);
  --gradient-section: linear-gradient(180deg, #ffffff 0%, #f8fafc 100%);
  --bg-white: #ffffff;
  --bg-light: #f8fafc;
  --bg-gray: #f1f5f9;
  --text-primary: #0f172a;
  --text-secondary: #475569;
  --text-muted: #94a3b8;
  --border-color: #e2e8f0;
  --border-light: #f1f5f9;
  --card-shadow: 0 1px 3px rgba(0, 0, 0, 0.05), 0 1px 2px rgba(0, 0, 0, 0.03);
  --card-shadow-md: 0 4px 12px rgba(0, 0, 0, 0.08);
  --card-shadow-lg: 0 12px 40px rgba(0, 0, 0, 0.12);
  --transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  --border-radius: 12px;
  --border-radius-lg: 16px;
}

/* Reset */
*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
  background: var(--bg-white);
  color: var(--text-primary);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

/* Utility Classes */
.container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 24px;
}

/* Card */
.card {
  background: var(--bg-white);
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius-lg);
  padding: 32px;
  box-shadow: var(--card-shadow);
  transition: var(--transition);
}

.card:hover {
  box-shadow: var(--card-shadow-md);
  border-color: var(--primary-light);
}

/* Glass Card - 浅色版本 */
.glass-card {
  background: var(--bg-white);
  border: 1px solid var(--border-color);
  border-radius: var(--border-radius-lg);
  padding: 32px;
  box-shadow: var(--card-shadow);
  transition: var(--transition);
}

.glass-card:hover {
  box-shadow: var(--card-shadow-md);
  transform: translateY(-2px);
  border-color: rgba(37, 99, 235, 0.3);
}

/* Section */
.section {
  padding: 80px 0;
  position: relative;
}

.section:nth-child(even) {
  background: var(--bg-light);
}

.section-title {
  font-size: 2rem;
  font-weight: 700;
  text-align: center;
  margin-bottom: 16px;
  color: var(--text-primary);
}

.section-subtitle {
  text-align: center;
  color: var(--text-secondary);
  font-size: 1.1rem;
  margin-bottom: 48px;
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

/* Navigation */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  padding: 0;
  border-bottom: 1px solid var(--border-color);
  transition: var(--transition);
}

.nav.scrolled {
  box-shadow: var(--card-shadow);
}

.nav-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 24px;
  height: 64px;
}

.nav-logo {
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--text-primary);
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: 8px;
}

.nav-links {
  display: flex;
  gap: 8px;
  list-style: none;
}

.nav-links a {
  color: var(--text-secondary);
  text-decoration: none;
  font-weight: 500;
  font-size: 0.95rem;
  padding: 8px 16px;
  border-radius: 8px;
  transition: var(--transition);
}

.nav-links a:hover {
  color: var(--primary);
  background: var(--primary-bg);
}

.nav-links a.active {
  color: var(--primary);
  background: var(--primary-bg);
}

/* Mobile Menu Toggle */
.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  padding: 5px;
}

.nav-toggle span {
  width: 24px;
  height: 2px;
  background: var(--text-primary);
  border-radius: 2px;
  transition: var(--transition);
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 28px;
  border-radius: 10px;
  font-weight: 600;
  font-size: 0.95rem;
  text-decoration: none;
  transition: var(--transition);
  cursor: pointer;
  border: none;
  gap: 8px;
}

.btn-primary {
  background: var(--gradient-primary);
  color: white;
  box-shadow: 0 2px 8px rgba(37, 99, 235, 0.25);
}

.btn-primary:hover {
  transform: translateY(-1px);
  box-shadow: 0 4px 16px rgba(37, 99, 235, 0.35);
}

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

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

.btn-large {
  padding: 14px 36px;
  font-size: 1rem;
  border-radius: 12px;
}

/* Grid */
.grid {
  display: grid;
  gap: 24px;
}

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

.grid-3 {
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
}

.grid-4 {
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
}

/* Hero Section */
.hero {
  padding-top: 120px;
  padding-bottom: 80px;
  text-align: center;
  position: relative;
  overflow: hidden;
  background: var(--gradient-hero);
}

.hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: 
    radial-gradient(ellipse 60% 40% at 50% 0%, rgba(37, 99, 235, 0.08), transparent),
    radial-gradient(ellipse 40% 30% at 80% 50%, rgba(6, 182, 212, 0.05), transparent);
  pointer-events: none;
}

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

.hero h1 {
  font-size: 3rem;
  font-weight: 800;
  margin-bottom: 20px;
  line-height: 1.2;
  color: var(--text-primary);
}

.hero p {
  font-size: 1.15rem;
  margin-bottom: 36px;
  color: var(--text-secondary);
  max-width: 640px;
  margin-left: auto;
  margin-right: auto;
  line-height: 1.8;
}

.hero-buttons {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
}

/* Hero Illustration */
.hero-illustration {
  max-width: 500px;
  margin: 50px auto 0;
  animation: floatSlow 6s ease-in-out infinite;
}

@keyframes floatSlow {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-10px); }
}

/* Stats */
.stats-item {
  text-align: center;
  padding: 24px;
}

.stats-number {
  font-size: 2.5rem;
  font-weight: 800;
  color: var(--primary);
}

.stats-label {
  font-size: 0.95rem;
  color: var(--text-secondary);
  margin-top: 8px;
}

/* Feature Card */
.feature-card {
  text-align: center;
  padding: 36px 24px;
}

.feature-icon {
  font-size: 2rem;
  margin-bottom: 16px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 64px;
  height: 64px;
  background: var(--primary-bg);
  border-radius: 16px;
}

.feature-title {
  font-size: 1.15rem;
  margin-bottom: 10px;
  font-weight: 600;
  color: var(--text-primary);
}

.feature-desc {
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.7;
}

/* Comparison Table */
.comparison-table {
  overflow-x: auto;
  border-radius: var(--border-radius);
  border: 1px solid var(--border-color);
}

.comparison-table table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
  background: var(--bg-white);
}

.comparison-table th,
.comparison-table td {
  padding: 16px 20px;
}

.comparison-table thead {
  background: var(--bg-light);
}

.comparison-table thead tr {
  border-bottom: 1px solid var(--border-color);
}

.comparison-table tbody tr {
  border-bottom: 1px solid var(--border-light);
  transition: var(--transition);
}

.comparison-table tbody tr:hover {
  background: var(--bg-light);
}

.comparison-table th {
  font-weight: 600;
  font-size: 0.95rem;
  color: var(--text-primary);
}

.comparison-table td {
  color: var(--text-secondary);
}

/* Transport Types */
.transport-type {
  display: flex;
  align-items: flex-start;
  gap: 16px;
  padding: 24px;
}

.transport-icon {
  font-size: 1.8rem;
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 48px;
  height: 48px;
  background: var(--primary-bg);
  border-radius: 12px;
}

.transport-content h3 {
  font-size: 1.1rem;
  margin-bottom: 6px;
  color: var(--text-primary);
}

.transport-content p {
  color: var(--text-secondary);
  font-size: 0.95rem;
}

/* Contact Form */
.contact-form {
  max-width: 560px;
  margin: 0 auto;
}

.form-group {
  margin-bottom: 20px;
}

.form-group label {
  display: block;
  margin-bottom: 8px;
  font-weight: 500;
  color: var(--text-primary);
  font-size: 0.95rem;
}

.form-group input,
.form-group textarea,
.form-group select {
  width: 100%;
  padding: 12px 16px;
  border: 1px solid var(--border-color);
  border-radius: 10px;
  background: var(--bg-white);
  color: var(--text-primary);
  font-size: 1rem;
  transition: var(--transition);
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.form-group input::placeholder,
.form-group textarea::placeholder {
  color: var(--text-muted);
}

.form-group textarea {
  min-height: 120px;
  resize: vertical;
}

/* Contact Info */
.contact-info {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.contact-item {
  display: flex;
  align-items: center;
  gap: 14px;
}

.contact-item-icon {
  width: 48px;
  height: 48px;
  background: var(--primary-bg);
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  flex-shrink: 0;
}

.contact-item-content h4 {
  font-size: 0.9rem;
  margin-bottom: 2px;
  color: var(--text-muted);
  font-weight: 500;
}

.contact-item-content p {
  color: var(--text-primary);
  font-size: 0.95rem;
}

/* Footer */
.footer {
  background: var(--text-primary);
  padding: 60px 0 30px;
  margin-top: 80px;
}

.footer-content {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 40px;
  margin-bottom: 40px;
}

.footer-section h4 {
  margin-bottom: 20px;
  font-size: 1rem;
  font-weight: 600;
  color: white;
}

.footer-section p {
  color: rgba(255, 255, 255, 0.6);
  font-size: 0.95rem;
  margin-bottom: 8px;
}

.footer-section a {
  color: rgba(255, 255, 255, 0.6);
  text-decoration: none;
  display: block;
  margin-bottom: 12px;
  transition: var(--transition);
  font-size: 0.95rem;
}

.footer-section a:hover {
  color: white;
}

.footer-bottom {
  text-align: center;
  padding-top: 30px;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  color: rgba(255, 255, 255, 0.4);
  font-size: 0.9rem;
}

/* Animations */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.animate-in {
  animation: fadeInUp 0.5s ease forwards;
}

/* Benefits List */
.benefits-list {
  list-style: none;
  padding: 0;
}

.benefits-list li {
  padding: 12px 0;
  display: flex;
  align-items: center;
  gap: 12px;
  border-bottom: 1px solid var(--border-light);
  color: var(--text-secondary);
}

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

.benefits-list li::before {
  content: '✓';
  display: flex;
  align-items: center;
  justify-content: center;
  width: 20px;
  height: 20px;
  background: var(--primary);
  border-radius: 50%;
  font-size: 0.7rem;
  color: white;
  flex-shrink: 0;
}

/* Page Header */
.page-header {
  padding-top: 120px;
  padding-bottom: 50px;
  text-align: center;
  background: var(--gradient-hero);
  position: relative;
}

.page-header h1 {
  font-size: 2.5rem;
  font-weight: 700;
  margin-bottom: 12px;
  color: var(--text-primary);
}

.page-header p {
  font-size: 1.1rem;
  color: var(--text-secondary);
}

/* Article Content */
.article-content {
  color: var(--text-primary);
}

.article-content h2 {
  color: var(--text-primary);
  margin-top: 40px;
}

.article-content h3 {
  color: var(--text-primary);
}

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

.article-content ul,
.article-content ol {
  color: var(--text-secondary);
}

.article-content a {
  color: var(--primary);
  text-decoration: none;
}

.article-content a:hover {
  text-decoration: underline;
}

.article-content blockquote {
  border-left: 4px solid var(--primary);
  padding: 20px 24px;
  margin: 30px 0;
  background: var(--bg-light);
  border-radius: 0 var(--border-radius) var(--border-radius) 0;
}

.article-content blockquote p {
  margin: 0;
}

/* Highlight Box */
.highlight-box {
  background: var(--primary-bg);
  border: 1px solid rgba(37, 99, 235, 0.2);
  border-radius: var(--border-radius);
  padding: 20px;
}

/* Responsive */
@media (max-width: 768px) {
  .nav-links {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: white;
    flex-direction: column;
    padding: 16px;
    gap: 8px;
    border-bottom: 1px solid var(--border-color);
    box-shadow: var(--card-shadow);
  }
  
  .nav-links.active {
    display: flex;
  }
  
  .nav-toggle {
    display: flex;
  }
  
  .hero {
    padding-top: 100px;
    padding-bottom: 60px;
  }
  
  .hero h1 {
    font-size: 2rem;
  }
  
  .hero p {
    font-size: 1rem;
  }
  
  .section-title {
    font-size: 1.6rem;
  }
  
  .section {
    padding: 50px 0;
  }
  
  .glass-card {
    padding: 24px;
  }
  
  .stats-number {
    font-size: 2rem;
  }
  
  .footer-content {
    grid-template-columns: 1fr;
    text-align: center;
  }
  
  .hero-illustration {
    max-width: 280px;
  }
  
  .page-header {
    padding-top: 100px;
    padding-bottom: 40px;
  }
  
  .page-header h1 {
    font-size: 1.8rem;
  }
  
  .page-header p {
    font-size: 1rem;
  }
  
  /* Grid 响应式 */
  .grid-2,
  .grid-3,
  .grid-4 {
    grid-template-columns: 1fr;
  }
  
  /* 联系页面 2x2 网格 */
  .contact-info[style*="grid-template-columns: repeat(2, 1fr)"] {
    grid-template-columns: 1fr !important;
  }
  
  /* 文章内容表格 */
  .article-content table {
    font-size: 0.85rem;
  }
  
  .article-content th,
  .article-content td {
    padding: 10px 12px;
  }
  
  /* 按钮组 */
  .hero-buttons {
    flex-direction: column;
    align-items: stretch;
  }
  
  .btn-large {
    padding: 12px 24px;
    font-size: 0.95rem;
  }
  
  /* 新闻卡片 */
  .glass-card[style*="overflow: hidden"] img {
    max-width: 100%;
    height: auto;
  }
  
  /* 统计数据网格 */
  .grid-4 {
    grid-template-columns: repeat(2, 1fr);
  }
  
  /* 联系信息网格 */
  .contact-info {
    display: flex !important;
    flex-direction: column;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 16px;
  }
  
  .hero {
    padding-top: 80px;
    padding-bottom: 40px;
  }
  
  .hero h1 {
    font-size: 1.6rem;
    line-height: 1.3;
  }
  
  .hero p {
    font-size: 0.95rem;
  }
  
  .section-title {
    font-size: 1.4rem;
  }
  
  .section {
    padding: 40px 0;
  }
  
  .glass-card {
    padding: 20px;
  }
  
  .btn {
    padding: 10px 20px;
    font-size: 0.9rem;
  }
  
  .page-header h1 {
    font-size: 1.5rem;
  }
  
  .stats-number {
    font-size: 1.6rem;
  }
  
  .stats-label {
    font-size: 0.85rem;
  }
  
  /* 统计数据网格 - 单列 */
  .grid-4 {
    grid-template-columns: 1fr;
  }
  
  /* 功能卡片 */
  .feature-card {
    padding: 24px 16px;
  }
  
  .feature-icon {
    width: 48px;
    height: 48px;
    font-size: 1.5rem;
  }
  
  /* 文章标题 */
  .article-content h2 {
    font-size: 1.25rem;
    margin-top: 30px;
  }
  
  .article-content h3 {
    font-size: 1.1rem;
  }
  
  /* 表格滚动 */
  .article-content > div[style*="overflow-x: auto"] {
    margin-left: -16px;
    margin-right: -16px;
    padding: 0 16px;
  }
  
  /* 引用块 */
  .article-content blockquote {
    padding: 16px 20px;
    margin: 20px 0;
  }
  
  /* Footer */
  .footer {
    padding: 40px 0 20px;
  }
  
  .footer-section h4 {
    font-size: 1rem;
    margin-bottom: 15px;
  }
  
  .footer-bottom {
    padding-top: 20px;
    font-size: 0.85rem;
  }
}