/* ==========================================
   奈云 (NaiYun Cloud) - Orbital Space Elevator Design System
   Theme: 太空电梯与轨道碳缆风 (Orbital Space Elevator)
   Base Color: #060A13
   Accents: Laser Cyan (#00f2fe), Hyper Blue (#4facfe), Pure White (#ffffff)
   ========================================== */

:root {
  --bg-dark: #060A13;
  --bg-card: rgba(13, 23, 46, 0.7);
  --bg-card-hover: rgba(20, 36, 70, 0.85);
  --border-color: rgba(0, 242, 254, 0.2);
  --border-glow: rgba(0, 242, 254, 0.6);
  --text-main: #f0f6ff;
  --text-muted: #8fa0c0;
  --text-dim: #5c6b89;
  --laser-cyan: #00f2fe;
  --laser-blue: #4facfe;
  --accent-gold: #ffb703;
  --accent-green: #00f5d4;
  --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --container-width: 1200px;
  --radius-sm: 8px;
  --radius-md: 16px;
  --radius-lg: 24px;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
  background-color: var(--bg-dark);
  color: var(--text-main);
  font-family: var(--font-family);
  overflow-x: hidden;
  cursor: default;
}

body {
  position: relative;
  min-height: 100vh;
  line-height: 1.6;
  background: 
    radial-gradient(circle at 50% 0%, rgba(0, 242, 254, 0.08) 0%, transparent 50%),
    radial-gradient(circle at 100% 60%, rgba(79, 172, 254, 0.05) 0%, transparent 40%),
    #060A13;
  background-attachment: fixed;
}

/* Carbon nanotube grid background overlay */
body::before {
  content: "";
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  background-image: 
    linear-gradient(rgba(0, 242, 254, 0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(0, 242, 254, 0.03) 1px, transparent 1px);
  background-size: 40px 40px;
  pointer-events: none;
  z-index: 1;
}

/* Vertical Orbital Cable Line */
.orbital-cable {
  position: fixed;
  top: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 2px;
  height: 100vh;
  background: linear-gradient(180deg, 
    transparent 0%, 
    rgba(0, 242, 254, 0.15) 30%, 
    rgba(0, 242, 254, 0.4) 50%, 
    rgba(0, 242, 254, 0.15) 70%, 
    transparent 100%);
  pointer-events: none;
  z-index: 1;
}

.orbital-cable::after {
  content: "";
  position: absolute;
  top: 0;
  left: -2px;
  width: 6px;
  height: 120px;
  background: linear-gradient(180deg, transparent, var(--laser-cyan), transparent);
  animation: elevatorScan 8s infinite linear;
}

@keyframes elevatorScan {
  0% { top: -120px; }
  100% { top: 100vh; }
}

/* Custom Cursor Tailwing Canvas */
#cursor-canvas {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  pointer-events: none;
  z-index: 99999;
}

/* Typography & General Utility */
a {
  color: var(--laser-cyan);
  text-decoration: none;
  transition: all 0.3s ease;
}

a:hover {
  color: #ffffff;
  text-shadow: 0 0 10px var(--laser-cyan);
}

.container {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 24px;
  position: relative;
  z-index: 2;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 14px 32px;
  font-size: 1rem;
  font-weight: 700;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
  text-transform: uppercase;
  letter-spacing: 1px;
  position: relative;
  overflow: hidden;
  border: none;
}

.btn-primary {
  background: linear-gradient(135deg, var(--laser-cyan), var(--laser-blue));
  color: #060A13;
  box-shadow: 0 0 20px rgba(0, 242, 254, 0.4);
}

.btn-primary:hover {
  transform: translateY(-2px) scale(1.02);
  box-shadow: 0 0 35px rgba(0, 242, 254, 0.8);
  color: #000;
}

.btn-outline {
  background: rgba(13, 23, 46, 0.8);
  color: var(--text-main);
  border: 1px solid var(--border-color);
  backdrop-filter: blur(10px);
}

.btn-outline:hover {
  border-color: var(--laser-cyan);
  box-shadow: 0 0 20px rgba(0, 242, 254, 0.3);
  color: #ffffff;
}

.badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 14px;
  border-radius: 50px;
  font-size: 0.85rem;
  background: rgba(0, 242, 254, 0.1);
  border: 1px solid rgba(0, 242, 254, 0.3);
  color: var(--laser-cyan);
  letter-spacing: 0.5px;
  margin-bottom: 20px;
}

.badge-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background-color: var(--accent-green);
  box-shadow: 0 0 10px var(--accent-green);
  animation: pulseDot 2s infinite;
}

@keyframes pulseDot {
  0% { opacity: 0.4; }
  50% { opacity: 1; }
  100% { opacity: 0.4; }
}

/* Header & Nav */
header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 1000;
  background: rgba(6, 10, 19, 0.85);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid rgba(0, 242, 254, 0.15);
  transition: all 0.3s ease;
}

.nav-wrapper {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 80px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 1.5rem;
  font-weight: 800;
  color: #ffffff;
  letter-spacing: 1px;
}

.logo-icon {
  width: 36px;
  height: 36px;
  background: linear-gradient(135deg, var(--laser-cyan), var(--laser-blue));
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #060A13;
  font-weight: 900;
  font-size: 1.2rem;
  box-shadow: 0 0 15px rgba(0, 242, 254, 0.5);
}

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

.nav-links a {
  color: var(--text-muted);
  font-weight: 500;
  font-size: 0.95rem;
}

.nav-links a:hover {
  color: var(--laser-cyan);
}

.mobile-menu-btn {
  display: none;
  background: none;
  border: none;
  color: var(--text-main);
  font-size: 1.5rem;
  cursor: pointer;
}

/* Hero Section */
.hero {
  padding-top: 170px;
  padding-bottom: 100px;
  text-align: center;
  position: relative;
}

.hero-hud {
  display: inline-flex;
  align-items: center;
  gap: 20px;
  padding: 8px 20px;
  background: rgba(13, 23, 46, 0.8);
  border: 1px solid rgba(0, 242, 254, 0.3);
  border-radius: 30px;
  font-family: monospace;
  font-size: 0.85rem;
  color: var(--laser-cyan);
  margin-bottom: 30px;
  box-shadow: 0 0 20px rgba(0, 242, 254, 0.15);
}

.hero-hud span {
  display: flex;
  align-items: center;
  gap: 6px;
}

.hero h1 {
  font-size: 3.5rem;
  font-weight: 900;
  line-height: 1.15;
  margin-bottom: 24px;
  background: linear-gradient(180deg, #ffffff 0%, #a5c0ee 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  letter-spacing: -1px;
}

.hero h1 span.gradient-text {
  background: linear-gradient(135deg, var(--laser-cyan), var(--laser-blue));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-subtitle {
  font-size: 1.25rem;
  color: var(--text-muted);
  max-width: 760px;
  margin: 0 auto 40px auto;
  line-height: 1.7;
}

.hero-cta-group {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 20px;
  margin-bottom: 60px;
}

.hero-stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  max-width: 960px;
  margin: 0 auto;
}

.stat-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  padding: 24px;
  border-radius: var(--radius-md);
  backdrop-filter: blur(10px);
  position: relative;
  overflow: hidden;
  transition: all 0.3s ease;
}

.stat-card:hover {
  border-color: var(--laser-cyan);
  transform: translateY(-4px);
  box-shadow: 0 10px 30px rgba(0, 242, 254, 0.15);
}

.stat-value {
  font-size: 2.2rem;
  font-weight: 800;
  color: var(--laser-cyan);
  font-family: monospace;
  margin-bottom: 6px;
}

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

/* Elevator Window Card / Feature Grid */
.section-title-area {
  text-align: center;
  margin-bottom: 60px;
}

.section-title-area h2 {
  font-size: 2.5rem;
  font-weight: 800;
  color: #ffffff;
  margin-bottom: 16px;
}

.section-title-area p {
  color: var(--text-muted);
  font-size: 1.1rem;
  max-width: 640px;
  margin: 0 auto;
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 30px;
  margin-bottom: 100px;
}

.elevator-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 36px 28px;
  position: relative;
  overflow: hidden;
  backdrop-filter: blur(12px);
  transition: all 0.4s cubic-bezier(0.16, 1, 0.3, 1);
}

.elevator-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 4px;
  background: linear-gradient(90deg, transparent, var(--laser-cyan), transparent);
  opacity: 0;
  transition: opacity 0.3s ease;
}

.elevator-card:hover {
  border-color: var(--laser-cyan);
  background: var(--bg-card-hover);
  transform: translateY(-8px);
  box-shadow: 0 15px 40px rgba(0, 242, 254, 0.2);
}

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

.card-hud-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 24px;
  font-family: monospace;
  font-size: 0.8rem;
  color: var(--text-dim);
}

.card-icon {
  width: 56px;
  height: 56px;
  border-radius: 14px;
  background: rgba(0, 242, 254, 0.1);
  border: 1px solid rgba(0, 242, 254, 0.3);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.8rem;
  margin-bottom: 20px;
  color: var(--laser-cyan);
}

.elevator-card h3 {
  font-size: 1.4rem;
  color: #ffffff;
  margin-bottom: 12px;
}

.elevator-card p {
  color: var(--text-muted);
  font-size: 0.98rem;
  line-height: 1.6;
}

/* Ping Live Simulator */
.ping-simulator {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 40px;
  margin-bottom: 100px;
  backdrop-filter: blur(12px);
}

.ping-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 30px;
}

.ping-table {
  width: 100%;
  border-collapse: collapse;
}

.ping-table th, .ping-table td {
  padding: 16px 20px;
  text-align: left;
  border-bottom: 1px solid rgba(255, 255, 255, 0.06);
}

.ping-table th {
  color: var(--text-dim);
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 1px;
}

.ping-table td {
  font-size: 0.95rem;
  color: var(--text-main);
}

.status-indicator {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 4px 12px;
  border-radius: 20px;
  font-size: 0.8rem;
  font-family: monospace;
  background: rgba(0, 245, 212, 0.1);
  color: var(--accent-green);
  border: 1px solid rgba(0, 245, 212, 0.3);
}

/* Pricing Section */
.pricing-section {
  padding: 60px 0 100px 0;
}

.pricing-toggle-wrapper {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  margin-bottom: 50px;
}

.pricing-toggle-btn {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  padding: 8px 24px;
  border-radius: 30px;
  color: var(--text-muted);
  cursor: pointer;
  font-weight: 600;
  transition: all 0.3s ease;
}

.pricing-toggle-btn.active {
  background: linear-gradient(135deg, var(--laser-cyan), var(--laser-blue));
  color: #060A13;
  border-color: transparent;
  box-shadow: 0 0 15px rgba(0, 242, 254, 0.4);
}

.pricing-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 30px;
}

.price-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 40px 32px;
  position: relative;
  display: flex;
  flex-direction: column;
  backdrop-filter: blur(12px);
  transition: all 0.4s ease;
}

.price-card.popular {
  border-color: var(--laser-cyan);
  background: rgba(16, 32, 64, 0.9);
  box-shadow: 0 0 35px rgba(0, 242, 254, 0.25);
  transform: scale(1.03);
}

.popular-tag {
  position: absolute;
  top: -14px;
  right: 32px;
  background: linear-gradient(135deg, var(--laser-cyan), var(--laser-blue));
  color: #060A13;
  font-size: 0.75rem;
  font-weight: 800;
  padding: 4px 16px;
  border-radius: 20px;
  text-transform: uppercase;
  letter-spacing: 1px;
}

.price-card h3 {
  font-size: 1.5rem;
  color: #ffffff;
  margin-bottom: 12px;
}

.price-amount {
  font-size: 3rem;
  font-weight: 900;
  color: var(--laser-cyan);
  font-family: monospace;
  margin-bottom: 20px;
}

.price-amount span {
  font-size: 1rem;
  color: var(--text-muted);
  font-family: var(--font-family);
  font-weight: 400;
}

.price-features {
  list-style: none;
  margin-bottom: 36px;
  flex: 1;
}

.price-features li {
  display: flex;
  align-items: center;
  gap: 12px;
  color: var(--text-muted);
  margin-bottom: 14px;
  font-size: 0.95rem;
}

.price-features li span.icon {
  color: var(--accent-green);
  font-weight: 900;
}

/* SEO Articles / Knowledge Section */
.articles-section {
  padding: 60px 0 100px 0;
}

.article-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 30px;
}

.article-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 28px;
  backdrop-filter: blur(10px);
  display: flex;
  flex-direction: column;
  transition: all 0.3s ease;
}

.article-card:hover {
  border-color: var(--laser-cyan);
  transform: translateY(-5px);
  box-shadow: 0 10px 30px rgba(0, 242, 254, 0.15);
}

.article-tag {
  font-size: 0.8rem;
  color: var(--laser-cyan);
  font-family: monospace;
  margin-bottom: 12px;
}

.article-card h3 {
  font-size: 1.2rem;
  color: #ffffff;
  margin-bottom: 14px;
  line-height: 1.4;
}

.article-card p {
  font-size: 0.9rem;
  color: var(--text-muted);
  margin-bottom: 20px;
  flex: 1;
  line-height: 1.6;
}

.article-link {
  font-size: 0.9rem;
  font-weight: 700;
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

/* User Reviews Section */
.reviews-section {
  padding: 60px 0 100px 0;
}

.reviews-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 30px;
}

.review-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 30px;
  backdrop-filter: blur(10px);
}

.stars {
  color: var(--accent-gold);
  margin-bottom: 16px;
  font-size: 1.1rem;
}

.review-text {
  color: var(--text-main);
  font-size: 0.95rem;
  line-height: 1.6;
  margin-bottom: 20px;
}

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

.avatar {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--laser-cyan), var(--laser-blue));
  display: flex;
  align-items: center;
  justify-content: center;
  color: #060A13;
  font-weight: 800;
}

.reviewer-info h4 {
  color: #ffffff;
  font-size: 0.95rem;
}

.reviewer-info p {
  color: var(--text-dim);
  font-size: 0.8rem;
}

/* FAQ Section */
.faq-section {
  padding: 60px 0 100px 0;
}

.faq-list {
  max-width: 840px;
  margin: 0 auto;
}

.faq-item {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  margin-bottom: 16px;
  overflow: hidden;
  transition: border-color 0.3s ease;
}

.faq-question {
  padding: 24px 30px;
  font-size: 1.1rem;
  font-weight: 700;
  color: #ffffff;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: space-between;
  user-select: none;
}

.faq-question::after {
  content: "+";
  font-size: 1.5rem;
  color: var(--laser-cyan);
  transition: transform 0.3s ease;
}

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

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.4s ease, padding 0.4s ease;
  padding: 0 30px;
  color: var(--text-muted);
  font-size: 0.95rem;
  line-height: 1.7;
}

.faq-item.active .faq-answer {
  max-height: 300px;
  padding: 0 30px 24px 30px;
}

/* Footer & Core Task 2: PBN Links Injection Area */
footer {
  background: #03060c;
  border-top: 1px solid rgba(0, 242, 254, 0.15);
  padding: 60px 0 40px 0;
  text-align: center;
  position: relative;
  z-index: 10;
}

.footer-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 24px;
}

.footer-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.3rem;
  font-weight: 800;
  color: #ffffff;
}

.footer-nav {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 24px;
  list-style: none;
}

.footer-nav a {
  color: var(--text-muted);
  font-size: 0.9rem;
}

/* PBN Precise Links Injection Zone */
.pbn-links-zone {
  margin-top: 30px;
  padding-top: 24px;
  border-top: 1px solid rgba(255, 255, 255, 0.05);
  width: 100%;
  max-width: 900px;
}

.pbn-title {
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 1.5px;
  color: var(--text-dim);
  margin-bottom: 12px;
}

.pbn-links-list {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 12px 18px;
  list-style: none;
}

.pbn-links-list a {
  font-size: 0.78rem;
  color: var(--text-dim);
  transition: color 0.2s ease;
}

.pbn-links-list a:hover {
  color: var(--laser-cyan);
  text-shadow: none;
}

.copyright {
  font-size: 0.8rem;
  color: var(--text-dim);
  margin-top: 20px;
}

/* Article Page Specific Layouts */
.article-page {
  padding-top: 140px;
  padding-bottom: 100px;
}

.article-container {
  max-width: 800px;
  margin: 0 auto;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 50px 40px;
  backdrop-filter: blur(12px);
}

.article-header {
  margin-bottom: 40px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
  padding-bottom: 24px;
}

.article-header h1 {
  font-size: 2.2rem;
  color: #ffffff;
  margin-bottom: 16px;
  line-height: 1.3;
}

.article-meta {
  display: flex;
  gap: 20px;
  color: var(--text-dim);
  font-size: 0.85rem;
  font-family: monospace;
}

.article-body {
  color: var(--text-main);
  font-size: 1.05rem;
  line-height: 1.8;
}

.article-body h2 {
  font-size: 1.5rem;
  color: var(--laser-cyan);
  margin: 32px 0 16px 0;
  border-left: 4px solid var(--laser-cyan);
  padding-left: 12px;
}

.article-body h3 {
  font-size: 1.25rem;
  color: #ffffff;
  margin: 24px 0 12px 0;
}

.article-body p {
  margin-bottom: 20px;
  color: var(--text-muted);
}

.article-body ul, .article-body ol {
  margin: 0 0 24px 24px;
  color: var(--text-muted);
}

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

.article-body strong {
  color: #ffffff;
}

.article-cta-box {
  background: linear-gradient(135deg, rgba(0, 242, 254, 0.1), rgba(79, 172, 254, 0.1));
  border: 1px solid var(--laser-cyan);
  border-radius: var(--radius-md);
  padding: 30px;
  margin: 40px 0;
  text-align: center;
}

.article-cta-box h3 {
  color: #ffffff;
  margin-bottom: 12px;
}

.article-cta-box p {
  color: var(--text-muted);
  margin-bottom: 20px;
}

/* Mobile Responsiveness */
@media (max-width: 992px) {
  .hero h1 { font-size: 2.8rem; }
  .features-grid, .pricing-grid, .article-grid, .reviews-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .hero-stats { grid-template-columns: repeat(2, 1fr); }
  .price-card.popular { transform: none; }
}

@media (max-width: 768px) {
  .nav-links {
    display: none;
    position: absolute;
    top: 80px;
    left: 0;
    width: 100%;
    background: #060A13;
    flex-direction: column;
    padding: 30px;
    border-bottom: 1px solid var(--border-color);
  }
  .nav-links.active { display: flex; }
  .mobile-menu-btn { display: block; }
  .hero { padding-top: 130px; }
  .hero h1 { font-size: 2.2rem; }
  .hero-subtitle { font-size: 1rem; }
  .features-grid, .pricing-grid, .article-grid, .reviews-grid, .hero-stats {
    grid-template-columns: 1fr;
  }
  .hero-cta-group { flex-direction: column; width: 100%; }
  .btn { width: 100%; }
  .article-container { padding: 30px 20px; }
  .ping-simulator { padding: 20px; }
  .ping-table { font-size: 0.85rem; }
}