/* ==========================================================================
   传送门云机场官网 - 全新独家 Cyber Portal 深色极光视觉样式
   Domain: chuansongmen.sbs
   Theme: Deep Cyber Navy (#0a0f1d) + Neon Cyan (#06b6d4) + Electric Purple (#8b5cf6)
   ========================================================================== */

:root {
  --primary-color: #06b6d4;
  --primary-hover: #0891b2;
  --primary-glow: rgba(6, 182, 212, 0.4);
  --accent-color: #a855f7;
  --accent-hover: #9333ea;
  --accent-glow: rgba(168, 85, 247, 0.4);
  --emerald-accent: #10b981;
  --bg-dark: #0a0f1d;
  --bg-card: #131b2e;
  --bg-card-hover: #1c273e;
  --bg-header: rgba(10, 15, 29, 0.88);
  --border-color: rgba(255, 255, 255, 0.08);
  --border-glow: rgba(6, 182, 212, 0.25);
  --text-dark: #f8fafc;
  --text-muted: #94a3b8;
  --text-light: #64748b;
  --shadow-sm: 0 4px 12px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 10px 30px rgba(0, 0, 0, 0.5);
  --shadow-glow: 0 0 25px rgba(6, 182, 212, 0.25);
  --radius-sm: 10px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* Reset & Base */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  font-family: "Plus Jakarta Sans", "Inter", system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  color: var(--text-dark);
  background-color: var(--bg-dark);
  line-height: 1.6;
}

body {
  overflow-x: hidden;
  background-color: var(--bg-dark);
  background-image: 
    radial-gradient(circle at 15% 20%, rgba(6, 182, 212, 0.12) 0%, transparent 45%),
    radial-gradient(circle at 85% 70%, rgba(168, 85, 247, 0.12) 0%, transparent 45%);
  background-attachment: fixed;
}

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

a:hover {
  color: #38bdf8;
}

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

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

/* Utility Classes */
.text-center { text-align: center; }
.text-primary { color: var(--primary-color); }
.gradient-text {
  background: linear-gradient(135deg, #38bdf8 0%, #a855f7 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.section-title {
  font-size: 2.2rem;
  font-weight: 800;
  color: #ffffff;
  margin-bottom: 14px;
  text-align: center;
  letter-spacing: -0.5px;
}

.section-subtitle {
  font-size: 1.05rem;
  color: var(--text-muted);
  text-align: center;
  max-width: 680px;
  margin: 0 auto 52px auto;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 13px 26px;
  font-size: 0.95rem;
  font-weight: 700;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: var(--transition);
  border: 1px solid transparent;
  white-space: nowrap;
}

.btn-primary {
  background: linear-gradient(135deg, var(--primary-color) 0%, #2563eb 100%);
  color: #ffffff !important;
  border-color: transparent;
  box-shadow: 0 4px 20px var(--primary-glow);
}

.btn-primary:hover {
  background: linear-gradient(135deg, #0284c7 0%, #1d4ed8 100%);
  transform: translateY(-2px);
  box-shadow: 0 8px 25px rgba(6, 182, 212, 0.5);
  color: #ffffff !important;
}

.btn-outline {
  background-color: rgba(255, 255, 255, 0.05);
  color: #38bdf8 !important;
  border: 1px solid rgba(56, 189, 248, 0.3);
  backdrop-filter: blur(8px);
}

.btn-outline:hover {
  background-color: rgba(56, 189, 248, 0.15);
  border-color: #38bdf8;
  color: #ffffff !important;
  transform: translateY(-2px);
}

/* Required Button: 机场推荐 */
.btn-recommend {
  background: linear-gradient(135deg, #10b981 0%, #059669 100%);
  color: #ffffff !important;
  font-weight: 700;
  box-shadow: 0 4px 16px rgba(16, 185, 129, 0.4);
}

.btn-recommend:hover {
  background: linear-gradient(135deg, #059669 0%, #047857 100%);
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(16, 185, 129, 0.55);
}

/* Header & Nav */
.header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background-color: var(--bg-header);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border-color);
  padding: 16px 0;
}

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

.brand-logo-wrap {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 1.35rem;
  font-weight: 800;
  color: #ffffff;
}

.brand-logo-img {
  width: 40px;
  height: 40px;
  object-fit: contain;
  border-radius: 10px;
  box-shadow: 0 0 12px rgba(6, 182, 212, 0.4);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 28px;
  list-style: none;
}

.nav-links a {
  font-weight: 600;
  color: var(--text-muted);
  font-size: 0.95rem;
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--primary-color);
  text-shadow: 0 0 10px var(--primary-glow);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 12px;
}

.mobile-toggle {
  display: none;
  background: none;
  border: none;
  font-size: 1.5rem;
  cursor: pointer;
  color: #ffffff;
}

/* Hero Section */
.hero-section {
  padding: 90px 0 70px 0;
  position: relative;
  overflow: hidden;
}

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

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 16px;
  background: rgba(6, 182, 212, 0.12);
  border: 1px solid rgba(6, 182, 212, 0.3);
  color: #38bdf8;
  font-size: 0.85rem;
  font-weight: 700;
  border-radius: 30px;
  margin-bottom: 24px;
}

.hero-title {
  font-size: 2.9rem;
  font-weight: 800;
  color: #ffffff;
  line-height: 1.25;
  margin-bottom: 22px;
  letter-spacing: -0.8px;
}

.hero-desc {
  font-size: 1.05rem;
  color: var(--text-muted);
  line-height: 1.8;
  margin-bottom: 36px;
}

.hero-buttons {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-bottom: 44px;
}

.hero-stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  padding-top: 24px;
  border-top: 1px solid var(--border-color);
}

.stat-item h4 {
  font-size: 1.7rem;
  font-weight: 800;
  color: #38bdf8;
  text-shadow: 0 0 12px var(--primary-glow);
}

.stat-item p {
  font-size: 0.85rem;
  color: var(--text-muted);
}

.hero-illustration {
  display: flex;
  justify-content: center;
  align-items: center;
}

.hero-card-img {
  width: 100%;
  max-width: 500px;
  height: auto;
  filter: drop-shadow(0 0 30px rgba(6, 182, 212, 0.25));
}

/* Feature / Advantages Section */
.advantages-section {
  padding: 90px 0;
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.feature-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  padding: 34px 26px;
  border-radius: var(--radius-md);
  transition: var(--transition);
  backdrop-filter: blur(10px);
}

.feature-card:hover {
  transform: translateY(-6px);
  border-color: var(--border-glow);
  box-shadow: var(--shadow-glow);
  background-color: var(--bg-card-hover);
}

.feature-icon {
  font-size: 2.6rem;
  margin-bottom: 18px;
}

.feature-card h3 {
  font-size: 1.25rem;
  font-weight: 700;
  color: #ffffff;
  margin-bottom: 12px;
}

.feature-card p {
  font-size: 0.95rem;
  color: var(--text-muted);
  line-height: 1.65;
}

/* Pricing Section */
.pricing-section {
  padding: 90px 0;
}

.pricing-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

.pricing-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 38px 24px;
  display: flex;
  flex-direction: column;
  position: relative;
  transition: var(--transition);
}

.pricing-card:hover {
  transform: translateY(-6px);
  border-color: rgba(6, 182, 212, 0.4);
  box-shadow: var(--shadow-md);
}

.pricing-card.featured {
  border: 2px solid var(--primary-color);
  box-shadow: 0 0 30px rgba(6, 182, 212, 0.3);
  background: linear-gradient(180deg, rgba(6, 182, 212, 0.08) 0%, var(--bg-card) 100%);
}

.pricing-badge {
  position: absolute;
  top: -14px;
  right: 20px;
  background: linear-gradient(135deg, var(--primary-color) 0%, var(--accent-color) 100%);
  color: #ffffff;
  font-size: 0.75rem;
  font-weight: 800;
  padding: 4px 14px;
  border-radius: 20px;
  box-shadow: 0 4px 12px rgba(6, 182, 212, 0.4);
}

.pricing-card h3 {
  font-size: 1.3rem;
  font-weight: 800;
  color: #ffffff;
  margin-bottom: 12px;
}

.pricing-card .price {
  font-size: 2.3rem;
  font-weight: 800;
  color: #38bdf8;
  margin-bottom: 8px;
  text-shadow: 0 0 10px var(--primary-glow);
}

.pricing-card .price span {
  font-size: 0.9rem;
  font-weight: 400;
  color: var(--text-muted);
}

.pricing-features {
  list-style: none;
  margin: 24px 0 32px 0;
  flex-grow: 1;
}

.pricing-features li {
  font-size: 0.9rem;
  color: #cbd5e1;
  margin-bottom: 12px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.pricing-features li::before {
  content: "✓";
  color: var(--emerald-accent);
  font-weight: bold;
}

/* Articles Showcase Section */
.articles-section {
  padding: 90px 0;
}

.articles-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}

.article-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 28px;
  display: flex;
  flex-direction: column;
  transition: var(--transition);
}

.article-card:hover {
  transform: translateY(-6px);
  border-color: var(--border-glow);
  box-shadow: var(--shadow-glow);
}

.article-tag {
  display: inline-block;
  align-self: flex-start;
  padding: 4px 12px;
  background-color: rgba(6, 182, 212, 0.15);
  color: #38bdf8;
  font-size: 0.75rem;
  font-weight: 700;
  border-radius: 6px;
  border: 1px solid rgba(6, 182, 212, 0.3);
  margin-bottom: 14px;
}

.article-card h3 {
  font-size: 1.15rem;
  font-weight: 700;
  line-height: 1.5;
  margin-bottom: 12px;
}

.article-card h3 a {
  color: #ffffff;
}

.article-card h3 a:hover {
  color: var(--primary-color);
}

.article-card p {
  font-size: 0.9rem;
  color: var(--text-muted);
  line-height: 1.65;
  margin-bottom: 20px;
  flex-grow: 1;
}

.article-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.8rem;
  color: var(--text-light);
  border-top: 1px solid var(--border-color);
  padding-top: 14px;
}

/* User Reviews Section */
.reviews-section {
  padding: 90px 0;
}

.reviews-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.review-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 28px;
  transition: var(--transition);
}

.review-card:hover {
  transform: translateY(-4px);
  border-color: rgba(168, 85, 247, 0.4);
  box-shadow: 0 0 20px rgba(168, 85, 247, 0.2);
}

.review-header {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 14px;
}

.review-avatar {
  width: 46px;
  height: 46px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--primary-color) 0%, var(--accent-color) 100%);
  color: #ffffff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  font-size: 1.1rem;
  box-shadow: 0 0 10px var(--primary-glow);
}

.review-user-info h4 {
  font-size: 0.95rem;
  font-weight: 700;
  color: #ffffff;
}

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

.review-stars {
  color: #f59e0b;
  font-size: 0.9rem;
  margin-bottom: 12px;
}

.review-content {
  font-size: 0.9rem;
  color: #cbd5e1;
  line-height: 1.65;
}

/* Interactive FAQ Section */
.faq-section {
  padding: 90px 0;
}

.faq-accordion {
  max-width: 840px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

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

.faq-question {
  width: 100%;
  padding: 20px 24px;
  background: none;
  border: none;
  text-align: left;
  font-size: 1.05rem;
  font-weight: 700;
  color: #ffffff;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.faq-question::after {
  content: "+";
  font-size: 1.4rem;
  color: var(--primary-color);
  transition: var(--transition);
}

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

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease-out, padding 0.3s ease;
  padding: 0 24px;
  background-color: rgba(10, 15, 29, 0.6);
}

.faq-item.active .faq-answer {
  max-height: 300px;
  padding: 16px 24px 24px 24px;
  border-top: 1px solid var(--border-color);
}

.faq-answer p {
  font-size: 0.95rem;
  color: var(--text-muted);
  line-height: 1.7;
}

/* Article Page Layout */
.article-page {
  padding: 60px 0 90px 0;
}

.article-container {
  display: grid;
  grid-template-columns: 2.8fr 1.2fr;
  gap: 36px;
}

.article-main {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 42px;
  box-shadow: var(--shadow-md);
}

.article-header {
  margin-bottom: 32px;
  padding-bottom: 24px;
  border-bottom: 1px solid var(--border-color);
}

.article-title {
  font-size: 2.2rem;
  font-weight: 800;
  color: #ffffff;
  line-height: 1.3;
  margin-bottom: 16px;
}

.article-body-content {
  font-size: 1.05rem;
  color: #cbd5e1;
  line-height: 1.85;
}

.article-body-content h2 {
  font-size: 1.5rem;
  font-weight: 700;
  color: #ffffff;
  margin: 38px 0 18px 0;
  padding-bottom: 8px;
  border-bottom: 2px solid rgba(6, 182, 212, 0.3);
}

.article-body-content h3 {
  font-size: 1.25rem;
  font-weight: 700;
  color: #38bdf8;
  margin: 26px 0 14px 0;
}

.article-body-content p {
  margin-bottom: 18px;
}

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

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

.article-callout {
  background: rgba(6, 182, 212, 0.1);
  border-left: 4px solid var(--primary-color);
  padding: 20px 24px;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  margin: 28px 0;
  border-top: 1px solid rgba(6, 182, 212, 0.2);
  border-right: 1px solid rgba(6, 182, 212, 0.2);
  border-bottom: 1px solid rgba(6, 182, 212, 0.2);
}

.article-callout p {
  margin: 0;
  font-weight: 600;
  color: #38bdf8;
}

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

.sidebar-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 26px;
}

.sidebar-card h4 {
  font-size: 1.1rem;
  font-weight: 700;
  color: #ffffff;
  margin-bottom: 16px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--border-color);
}

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

.sidebar-list li {
  margin-bottom: 12px;
}

.sidebar-list a {
  font-size: 0.9rem;
  color: #cbd5e1;
  line-height: 1.5;
  display: block;
}

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

/* Footer Section & PBN Links (Core Task 2) */
.site-footer {
  background-color: #060913;
  color: #94a3b8;
  padding: 70px 0 30px 0;
  border-top: 1px solid var(--border-color);
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px;
  margin-bottom: 50px;
}

.footer-brand h3 {
  font-size: 1.4rem;
  color: #ffffff;
  margin-bottom: 16px;
  font-weight: 800;
}

.footer-brand p {
  font-size: 0.9rem;
  line-height: 1.7;
  color: #94a3b8;
}

.footer-col h4 {
  font-size: 1.05rem;
  color: #ffffff;
  margin-bottom: 20px;
  font-weight: 700;
}

.footer-col ul {
  list-style: none;
}

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

.footer-col a {
  color: #94a3b8;
  font-size: 0.9rem;
}

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

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  padding-top: 30px;
  text-align: center;
  font-size: 0.85rem;
}

.footer-bottom p {
  margin-bottom: 12px;
  color: #64748b;
}

/* Core Task 2: PBN Links Styling */
.friendly-links-area {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  font-size: 0.82rem;
  color: #64748b;
  margin-top: 8px;
}

.friendly-links-title {
  color: #475569;
}

.friendly-links-area a {
  color: #64748b;
  text-decoration: none;
  transition: var(--transition);
}

.friendly-links-area a:hover {
  color: #38bdf8;
  text-decoration: underline;
}

/* Responsive Layout */
@media (max-width: 1024px) {
  .hero-title { font-size: 2.3rem; }
  .features-grid, .reviews-grid, .articles-grid { grid-template-columns: repeat(2, 1fr); }
  .pricing-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .article-container { grid-template-columns: 1fr; }
}

@media (max-width: 768px) {
  .hero-grid { grid-template-columns: 1fr; }
  .features-grid, .reviews-grid, .articles-grid, .pricing-grid { grid-template-columns: 1fr; }
  .nav-links { display: none; }
  .mobile-toggle { display: block; }
  .footer-grid { grid-template-columns: 1fr; }
  .hero-stats { grid-template-columns: 1fr; gap: 12px; }
  .article-main { padding: 24px; }
}