/* ==========================================================================
   一元机场 品牌全局样式系统 (Design System)
   风格：圆润、现代、极简、高保真
   ========================================================================== */

:root {
  /* 颜色 Token */
  --bg-main: #f8fafc;
  --bg-gradient: linear-gradient(135deg, #f8fafc 0%, #f1f5f9 100%);
  --bg-card: #ffffff;
  
  --color-primary-base: #334155; /* 低饱和灰蓝 */
  --color-heading: #0f172a;
  --color-body: #475569;
  --color-muted: #64748b;
  --color-light-muted: #94a3b8;
  --color-border: #e2e8f0;
  
  /* 渐变与品牌高亮 */
  --brand-gradient: linear-gradient(135deg, #6366f1 0%, #8b5cf6 100%);
  --brand-gradient-hover: linear-gradient(135deg, #4f46e5 0%, #7c3aed 100%);
  --brand-color: #6366f1;
  --brand-color-accent: #8b5cf6;
  
  /* 阴影 Token */
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.04);
  --shadow-md: 0 10px 30px -5px rgba(0, 0, 0, 0.05), 0 4px 12px -2px rgba(0, 0, 0, 0.03);
  --shadow-lg: 0 20px 40px -10px rgba(99, 102, 241, 0.12), 0 8px 16px -4px rgba(0, 0, 0, 0.04);
  --shadow-inset: inset 0 2px 4px 0 rgba(0, 0, 0, 0.06);

  /* 布局与圆角 */
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 20px;
  --radius-full: 9999px;
  
  --max-width: 1200px;
  --header-height: 72px;
  --transition-fast: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-normal: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* 基础重置 */
*, *::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: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  background: var(--bg-main);
  background-image: var(--bg-gradient);
  background-attachment: fixed;
  color: var(--color-body);
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  overflow-x: hidden;
}

/* 标题样式：粗圆现代风格 */
h1, h2, h3, h4, h5, h6 {
  color: var(--color-heading);
  font-weight: 700;
  line-height: 1.25;
  letter-spacing: -0.02em;
}

h1 {
  font-size: clamp(2.2rem, 5vw, 3.4rem);
  font-weight: 800;
}

h2 {
  font-size: clamp(1.75rem, 3.5vw, 2.4rem);
}

h3 {
  font-size: clamp(1.25rem, 2.5vw, 1.5rem);
}

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

a:hover {
  color: #4f46e5;
}

img, svg {
  max-width: 100%;
  height: auto;
  vertical-align: middle;
}

/* 键盘焦点 */
a:focus-visible, button:focus-visible {
  outline: 3px solid #a5b4fc;
  outline-offset: 3px;
  border-radius: var(--radius-sm);
}

/* Container */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

/* 统一按钮设计 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 28px;
  font-size: 1.05rem;
  font-weight: 600;
  border-radius: var(--radius-full);
  transition: all var(--transition-fast);
  cursor: pointer;
  border: none;
  min-height: 48px;
  text-decoration: none;
  white-space: nowrap;
}

.btn-primary {
  background: var(--brand-gradient);
  color: #ffffff !important;
  box-shadow: 0 4px 14px rgba(99, 102, 241, 0.35);
}

.btn-primary:hover {
  background: var(--brand-gradient-hover);
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(99, 102, 241, 0.45);
}

.btn-primary:active {
  transform: translateY(0);
}

.btn-secondary {
  background: #ffffff;
  color: var(--color-primary-base) !important;
  border: 1px solid var(--color-border);
  box-shadow: var(--shadow-sm);
}

.btn-secondary:hover {
  background: #f8fafc;
  border-color: #cbd5e1;
  color: var(--color-heading) !important;
  transform: translateY(-2px);
}

.btn-sm {
  padding: 8px 18px;
  font-size: 0.9rem;
  min-height: 38px;
}

/* 页眉 Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--header-height);
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid rgba(226, 232, 240, 0.8);
  transition: all var(--transition-fast);
}

.header-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

.brand-logo {
  display: flex;
  align-items: center;
  gap: 10px;
}

.brand-logo img {
  height: 38px;
  width: auto;
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 32px;
  list-style: none;
}

.nav-link {
  color: var(--color-primary-base);
  font-weight: 600;
  font-size: 0.98rem;
  padding: 6px 0;
  position: relative;
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--brand-gradient);
  transition: width var(--transition-fast);
  border-radius: 2px;
}

.nav-link:hover::after,
.nav-link.active::after {
  width: 100%;
}

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

.mobile-menu-btn {
  display: none;
  background: none;
  border: none;
  font-size: 1.5rem;
  color: var(--color-heading);
  cursor: pointer;
  padding: 8px;
}

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

.section-tag {
  display: inline-block;
  padding: 6px 16px;
  background: #e0e7ff;
  color: #4338ca;
  font-weight: 700;
  font-size: 0.85rem;
  border-radius: var(--radius-full);
  margin-bottom: 16px;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.section-header {
  text-align: center;
  max-width: 680px;
  margin: 0 auto 56px auto;
}

.section-header p {
  color: var(--color-muted);
  font-size: 1.1rem;
  margin-top: 12px;
}

/* Hero Section */
.hero-section {
  padding: 60px 0 90px 0;
  overflow: hidden;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: center;
}

.hero-content {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
}

.hero-title {
  margin-bottom: 20px;
}

.hero-title .highlight {
  background: var(--brand-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-desc {
  font-size: 1.2rem;
  color: var(--color-body);
  margin-bottom: 32px;
  line-height: 1.7;
}

.hero-cta {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  margin-bottom: 36px;
}

.hero-badges {
  display: flex;
  align-items: center;
  gap: 20px;
  font-size: 0.9rem;
  color: var(--color-muted);
}

.badge-item {
  display: flex;
  align-items: center;
  gap: 6px;
}

.badge-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: #10b981;
}

.hero-visual {
  position: relative;
  width: 100%;
  display: flex;
  justify-content: center;
}

/* 核心优势 Cards */
.advantages-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
}

.card {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  padding: 36px 30px;
  box-shadow: var(--shadow-md);
  border: 1px solid var(--color-border);
  transition: all var(--transition-normal);
  display: flex;
  flex-direction: column;
}

.card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-lg);
  border-color: #cbd5e1;
}

.advantage-icon {
  width: 60px;
  height: 60px;
  border-radius: var(--radius-md);
  background: #e0e7ff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.8rem;
  margin-bottom: 24px;
}

.card h3 {
  margin-bottom: 12px;
}

.card p {
  color: var(--color-muted);
  font-size: 0.98rem;
  line-height: 1.65;
}

/* 流媒体与 AI 支持 */
.services-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: 24px;
}

.service-item {
  background: var(--bg-card);
  border-radius: var(--radius-md);
  padding: 24px 16px;
  text-align: center;
  border: 1px solid var(--color-border);
  box-shadow: var(--shadow-sm);
  transition: transform var(--transition-fast);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
}

.service-item:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}

.service-item img {
  width: 48px;
  height: 48px;
}

.service-item span {
  font-weight: 700;
  color: var(--color-heading);
  font-size: 0.95rem;
}

.service-item small {
  color: var(--color-light-muted);
  font-size: 0.8rem;
}

.service-disclaimer {
  text-align: center;
  margin-top: 32px;
  color: var(--color-muted);
  font-size: 0.88rem;
  background: #f1f5f9;
  padding: 12px 24px;
  border-radius: var(--radius-full);
  display: inline-block;
}

/* 套餐对比 Table & Cards */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
  align-items: stretch;
}

.pricing-card {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  padding: 40px 32px;
  box-shadow: var(--shadow-md);
  border: 1px solid var(--color-border);
  display: flex;
  flex-direction: column;
  position: relative;
  transition: all var(--transition-normal);
}

.pricing-card.featured {
  border: 2px solid var(--brand-color);
  box-shadow: var(--shadow-lg);
}

.featured-badge {
  position: absolute;
  top: -14px;
  right: 24px;
  background: var(--brand-gradient);
  color: #ffffff;
  padding: 4px 16px;
  border-radius: var(--radius-full);
  font-size: 0.8rem;
  font-weight: 700;
}

.pricing-header h3 {
  font-size: 1.4rem;
  margin-bottom: 8px;
}

.pricing-price {
  margin: 20px 0;
  display: flex;
  align-items: baseline;
  gap: 4px;
}

.pricing-price .amount {
  font-size: 2.5rem;
  font-weight: 800;
  color: var(--color-heading);
}

.pricing-price .cycle {
  color: var(--color-muted);
  font-size: 0.95rem;
}

.pricing-features {
  list-style: none;
  margin: 24px 0 36px 0;
  flex-grow: 1;
}

.pricing-features li {
  padding: 10px 0;
  border-bottom: 1px stroke var(--color-border);
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 0.95rem;
  color: var(--color-body);
}

.pricing-features li::before {
  content: '✓';
  color: var(--brand-color);
  font-weight: bold;
}

.pricing-note {
  font-size: 0.85rem;
  color: var(--color-light-muted);
  text-align: center;
  margin-top: 16px;
}

/* FAQ 问答 */
.faq-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 20px;
  max-width: 860px;
  margin: 0 auto;
}

.faq-item {
  background: var(--bg-card);
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
}

.faq-question {
  padding: 24px;
  width: 100%;
  text-align: left;
  background: none;
  border: none;
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--color-heading);
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.faq-question::after {
  content: '+';
  font-size: 1.4rem;
  color: var(--brand-color);
  transition: transform var(--transition-fast);
}

.faq-item.active .faq-question::after {
  content: '−';
}

.faq-answer {
  padding: 0 24px 24px 24px;
  color: var(--color-muted);
  font-size: 0.98rem;
  line-height: 1.7;
  display: none;
}

.faq-item.active .faq-answer {
  display: block;
}

/* 页脚 Footer */
.site-footer {
  background: #0f172a;
  color: #94a3b8;
  padding: 60px 0 40px 0;
  margin-top: auto;
}

.footer-container {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 32px;
  text-align: center;
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 12px;
  color: #ffffff;
  font-size: 1.3rem;
  font-weight: 800;
}

.footer-links {
  display: flex;
  gap: 32px;
  list-style: none;
  flex-wrap: wrap;
  justify-content: center;
}

.footer-link {
  color: #cbd5e1;
  font-size: 0.98rem;
  font-weight: 500;
}

.footer-link:hover {
  color: #ffffff;
}

.footer-copyright {
  font-size: 0.88rem;
  color: #64748b;
  border-top: 1px solid #1e293b;
  width: 100%;
  padding-top: 24px;
}

/* 右侧浮动章节导航箭头 (Floating Chapter Arrows) */
.chapter-nav-widget {
  position: fixed;
  right: 24px;
  bottom: 100px;
  z-index: 99;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.chapter-btn {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.9);
  backdrop-filter: blur(8px);
  border: 1px solid var(--color-border);
  color: var(--color-heading);
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-md);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.chapter-btn:hover:not(:disabled) {
  background: var(--brand-color);
  color: #ffffff;
  transform: scale(1.08);
}

.chapter-btn:disabled {
  opacity: 0.35;
  cursor: not-allowed;
  box-shadow: none;
}

/* 文章样式 Article Page Styling */
.article-container {
  max-width: 840px;
  margin: 40px auto 80px auto;
  background: #ffffff;
  padding: 48px 40px;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  border: 1px solid var(--color-border);
}

.article-header {
  margin-bottom: 36px;
  padding-bottom: 24px;
  border-bottom: 1px solid var(--color-border);
}

.article-meta {
  display: flex;
  gap: 16px;
  color: var(--color-muted);
  font-size: 0.9rem;
  margin-top: 12px;
}

.article-body {
  font-size: 1.08rem;
  line-height: 1.8;
  color: var(--color-primary-base);
}

.article-body h2 {
  margin: 36px 0 18px 0;
  font-size: 1.5rem;
}

.article-body h3 {
  margin: 28px 0 14px 0;
  font-size: 1.25rem;
}

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

.article-body ul, .article-body ol {
  margin: 0 0 20px 24px;
}

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

.article-body blockquote {
  border-left: 4px solid var(--brand-color);
  background: #f8fafc;
  padding: 16px 20px;
  margin: 24px 0;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  color: var(--color-muted);
  font-style: italic;
}

/* 响应式适配 Responsive */
@media (max-width: 992px) {
  .hero-grid {
    grid-template-columns: 1fr;
    text-align: center;
  }
  
  .hero-content {
    align-items: center;
  }
  
  .advantages-grid, .pricing-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 768px) {
  :root {
    --header-height: 64px;
  }

  .nav-menu {
    position: fixed;
    top: var(--header-height);
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.98);
    backdrop-filter: blur(12px);
    flex-direction: column;
    padding: 24px;
    gap: 20px;
    border-bottom: 1px solid var(--color-border);
    transform: translateY(-150%);
    transition: transform var(--transition-normal);
  }

  .nav-menu.open {
    transform: translateY(0);
    box-shadow: var(--shadow-lg);
  }

  .mobile-menu-btn {
    display: block;
  }

  .hero-cta {
    justify-content: center;
    width: 100%;
  }

  .btn {
    width: 100%;
  }

  .chapter-nav-widget {
    right: 12px;
    bottom: 24px;
  }
  
  .chapter-btn {
    width: 38px;
    height: 38px;
  }

  .article-container {
    padding: 24px 18px;
  }
}

/* Prefers reduced motion */
@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}