/* Modern Monochrome Premium Aesthetics for 飞鸟机场 */
:root {
  --bg-dark: #09090b;
  --bg-card: #121215;
  --bg-card-hover: #1a1a1f;
  --border-color: rgba(255, 255, 255, 0.1);
  --border-light: rgba(255, 255, 255, 0.18);
  --text-main: #f4f4f5;
  --text-muted: #a1a1aa;
  --text-sub: #71717a;
  --accent-white: #ffffff;
  --accent-glow: rgba(255, 255, 255, 0.15);
  --green-online: #10b981;
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'PingFang SC', 'Microsoft YaHei', sans-serif;
  --container-max: 1200px;
}

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

html {
  scroll-behavior: smooth;
  font-family: var(--font-family);
  background-color: var(--bg-dark);
  color: var(--text-main);
  line-height: 1.6;
}

body {
  overflow-x: hidden;
  position: relative;
  min-height: 100vh;
}

/* Background Canvas */
#bg-canvas {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  z-index: 0;
  pointer-events: none;
  opacity: 0.6;
}

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

/* Top Announcement Banner */
.top-banner {
  background: linear-gradient(90deg, #18181b 0%, #27272a 50%, #18181b 100%);
  border-bottom: 1px solid var(--border-color);
  padding: 8px 16px;
  text-align: center;
  font-size: 0.88rem;
  color: var(--text-muted);
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 12px;
}

.top-banner strong {
  color: var(--accent-white);
  background: rgba(255, 255, 255, 0.1);
  padding: 2px 8px;
  border-radius: 4px;
  font-weight: 600;
}

.top-banner a {
  color: var(--accent-white);
  text-decoration: underline;
  cursor: pointer;
}

/* Navbar */
.navbar {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(9, 9, 11, 0.85);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border-color);
  padding: 16px 0;
}

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

.logo {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  color: var(--text-main);
  font-size: 1.35rem;
  font-weight: 800;
  letter-spacing: -0.02em;
}

.logo-icon {
  width: 36px;
  height: 36px;
  background: #ffffff;
  color: #000000;
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  font-weight: 900;
}

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

.nav-links a {
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.95rem;
  font-weight: 500;
  transition: color 0.2s ease;
}

.nav-links a:hover {
  color: var(--accent-white);
}

.btn-primary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  background: #ffffff;
  color: #000000;
  font-weight: 700;
  padding: 12px 26px;
  border-radius: 30px;
  text-decoration: none;
  border: none;
  cursor: pointer;
  box-shadow: 0 4px 20px rgba(255, 255, 255, 0.15);
  transition: all 0.25s cubic-bezier(0.16, 1, 0.3, 1);
  font-size: 0.95rem;
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 30px rgba(255, 255, 255, 0.3);
  background: #f4f4f5;
}

.btn-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  background: rgba(255, 255, 255, 0.06);
  color: var(--text-main);
  font-weight: 600;
  padding: 12px 24px;
  border-radius: 30px;
  text-decoration: none;
  border: 1px solid var(--border-color);
  cursor: pointer;
  transition: all 0.2s ease;
  font-size: 0.95rem;
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.12);
  border-color: var(--border-light);
  color: var(--accent-white);
}

/* Hero Section */
.hero {
  padding: 100px 24px 80px;
  text-align: center;
  max-width: 960px;
  margin: 0 auto;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 16px;
  border-radius: 20px;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--border-color);
  color: var(--text-muted);
  font-size: 0.88rem;
  margin-bottom: 28px;
}

.badge-dot {
  width: 8px;
  height: 8px;
  background-color: var(--green-online);
  border-radius: 50%;
  box-shadow: 0 0 10px var(--green-online);
}

.hero-title {
  font-size: 3.6rem;
  font-weight: 900;
  line-height: 1.15;
  letter-spacing: -0.03em;
  margin-bottom: 24px;
  background: linear-gradient(180deg, #ffffff 0%, #a1a1aa 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-desc {
  font-size: 1.2rem;
  color: var(--text-muted);
  max-width: 760px;
  margin: 0 auto 40px;
  line-height: 1.7;
}

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

.hero-stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  margin-top: 60px;
  padding: 30px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
}

.stat-item h3 {
  font-size: 2rem;
  font-weight: 800;
  color: var(--accent-white);
}

.stat-item p {
  font-size: 0.9rem;
  color: var(--text-sub);
  margin-top: 4px;
}

/* General Section Styling */
.section {
  padding: 90px 24px;
  max-width: var(--container-max);
  margin: 0 auto;
}

.section-header {
  text-align: center;
  margin-bottom: 60px;
}

.section-tag {
  color: var(--text-sub);
  font-size: 0.85rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: 12px;
  display: block;
}

.section-title {
  font-size: 2.4rem;
  font-weight: 800;
  color: var(--accent-white);
  letter-spacing: -0.02em;
}

.section-desc {
  color: var(--text-muted);
  font-size: 1.05rem;
  margin-top: 12px;
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

/* Node Latency & Status Board */
.node-board {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 32px;
  box-shadow: 0 10px 40px rgba(0, 0, 0, 0.4);
}

.node-board-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 24px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--border-color);
  flex-wrap: wrap;
  gap: 16px;
}

.ping-btn {
  background: rgba(255, 255, 255, 0.08);
  color: var(--text-main);
  border: 1px solid var(--border-color);
  padding: 8px 18px;
  border-radius: 20px;
  font-size: 0.85rem;
  cursor: pointer;
  transition: all 0.2s ease;
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.ping-btn:hover {
  background: rgba(255, 255, 255, 0.15);
  color: var(--accent-white);
}

.nodes-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 16px;
}

.node-card {
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 20px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  transition: transform 0.2s ease, border-color 0.2s ease;
}

.node-card:hover {
  transform: translateY(-2px);
  border-color: var(--border-light);
}

.node-info {
  display: flex;
  align-items: center;
  gap: 12px;
}

.node-flag {
  font-size: 1.5rem;
}

.node-name {
  font-weight: 700;
  font-size: 0.98rem;
  color: var(--accent-white);
}

.node-tag {
  font-size: 0.75rem;
  color: var(--text-sub);
  background: rgba(255, 255, 255, 0.05);
  padding: 2px 6px;
  border-radius: 4px;
}

.node-status {
  text-align: right;
}

.ping-value {
  font-size: 1.1rem;
  font-weight: 800;
  color: var(--green-online);
}

.status-badge {
  font-size: 0.75rem;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  gap: 4px;
  justify-content: flex-end;
}

/* Core Advantages Grid */
.advantages-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 24px;
}

.adv-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 36px 30px;
  transition: all 0.3s ease;
}

.adv-card:hover {
  background: var(--bg-card-hover);
  border-color: var(--border-light);
  transform: translateY(-4px);
}

.adv-icon {
  width: 52px;
  height: 52px;
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid var(--border-color);
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  margin-bottom: 20px;
  color: var(--accent-white);
}

.adv-card h3 {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 12px;
  color: var(--accent-white);
}

.adv-card p {
  color: var(--text-muted);
  font-size: 0.95rem;
  line-height: 1.6;
}

/* Pricing Plans Section */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 28px;
  align-items: stretch;
}

.price-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 40px 32px;
  display: flex;
  flex-direction: column;
  position: relative;
  transition: all 0.3s ease;
}

.price-card.featured {
  border-color: #ffffff;
  box-shadow: 0 0 30px rgba(255, 255, 255, 0.12);
  background: linear-gradient(180deg, #18181c 0%, #101014 100%);
}

.featured-tag {
  position: absolute;
  top: -14px;
  right: 32px;
  background: #ffffff;
  color: #000000;
  font-size: 0.78rem;
  font-weight: 800;
  padding: 4px 14px;
  border-radius: 20px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.price-title {
  font-size: 1.4rem;
  font-weight: 800;
  color: var(--accent-white);
}

.price-desc {
  color: var(--text-sub);
  font-size: 0.88rem;
  margin-top: 6px;
}

.price-amount {
  margin: 28px 0;
  display: flex;
  align-items: baseline;
  gap: 4px;
}

.price-currency {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--accent-white);
}

.price-number {
  font-size: 3.2rem;
  font-weight: 900;
  color: var(--accent-white);
  letter-spacing: -0.03em;
}

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

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

.price-features li {
  color: var(--text-muted);
  font-size: 0.95rem;
  margin-bottom: 14px;
  display: flex;
  align-items: center;
  gap: 10px;
}

.price-features li::before {
  content: "✓";
  color: var(--accent-white);
  font-weight: 800;
}

/* FAQ Accordion */
.faq-container {
  max-width: 800px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.faq-item {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: border-color 0.2s ease;
}

.faq-item:hover {
  border-color: var(--border-light);
}

.faq-question {
  padding: 22px 28px;
  font-weight: 700;
  font-size: 1.05rem;
  color: var(--accent-white);
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  user-select: none;
}

.faq-icon {
  font-size: 1.2rem;
  transition: transform 0.3s ease;
  color: var(--text-sub);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.35s ease, padding 0.35s ease;
  padding: 0 28px;
  color: var(--text-muted);
  font-size: 0.98rem;
  line-height: 1.7;
}

.faq-item.active .faq-answer {
  max-height: 300px;
  padding: 0 28px 22px;
}

.faq-item.active .faq-icon {
  transform: rotate(45deg);
  color: var(--accent-white);
}

/* Knowledge Base / Articles Grid */
.articles-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(340px, 1fr));
  gap: 24px;
}

.article-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 30px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  text-decoration: none;
  transition: all 0.3s ease;
}

.article-card:hover {
  background: var(--bg-card-hover);
  border-color: var(--border-light);
  transform: translateY(-4px);
}

.article-meta {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 16px;
  font-size: 0.82rem;
}

.article-cat {
  background: rgba(255, 255, 255, 0.08);
  color: var(--text-main);
  padding: 3px 10px;
  border-radius: 12px;
  font-weight: 600;
}

.article-date {
  color: var(--text-sub);
}

.article-title {
  font-size: 1.18rem;
  font-weight: 700;
  color: var(--accent-white);
  line-height: 1.4;
  margin-bottom: 12px;
}

.article-summary {
  color: var(--text-muted);
  font-size: 0.9rem;
  line-height: 1.6;
  margin-bottom: 20px;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.article-link-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: var(--accent-white);
  font-weight: 600;
  font-size: 0.88rem;
  margin-top: auto;
}

/* Reviews Section */
.reviews-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 24px;
}

.review-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 30px;
}

.review-header {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 16px;
}

.avatar-placeholder {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.1);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  color: var(--accent-white);
  font-size: 1.1rem;
}

.user-info h4 {
  font-size: 1rem;
  font-weight: 700;
  color: var(--accent-white);
}

.user-info p {
  font-size: 0.78rem;
  color: var(--text-sub);
}

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

.review-text {
  color: var(--text-muted);
  font-size: 0.92rem;
  line-height: 1.6;
}

/* Footer */
.footer {
  border-top: 1px solid var(--border-color);
  padding: 60px 24px 40px;
  background: #050507;
  color: var(--text-sub);
  font-size: 0.9rem;
}

.footer-container {
  max-width: var(--container-max);
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 24px;
}

.footer-links {
  display: flex;
  gap: 24px;
  list-style: none;
}

.footer-links a {
  color: var(--text-muted);
  text-decoration: none;
  transition: color 0.2s ease;
}

.footer-links a:hover {
  color: var(--accent-white);
}

/* Article Detail Page Specifics */
.article-detail-container {
  max-width: 860px;
  margin: 60px auto;
  padding: 0 24px;
}

.article-header {
  margin-bottom: 40px;
  padding-bottom: 24px;
  border-bottom: 1px solid var(--border-color);
}

.article-header h1 {
  font-size: 2.4rem;
  font-weight: 900;
  color: var(--accent-white);
  line-height: 1.25;
  margin-top: 16px;
  margin-bottom: 16px;
}

.article-body {
  color: #d4d4d8;
  font-size: 1.05rem;
  line-height: 1.8;
}

.article-body h2 {
  font-size: 1.6rem;
  color: var(--accent-white);
  margin: 40px 0 16px;
  padding-bottom: 8px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.article-body h3 {
  font-size: 1.3rem;
  color: var(--accent-white);
  margin: 28px 0 12px;
}

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

.article-body ul, .article-body ol {
  margin-bottom: 24px;
  padding-left: 24px;
}

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

.back-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: var(--text-muted);
  text-decoration: none;
  margin-bottom: 24px;
  font-weight: 600;
  transition: color 0.2s ease;
}

.back-btn:hover {
  color: var(--accent-white);
}

.article-cta-box {
  background: linear-gradient(180deg, #18181c 0%, #0c0c0e 100%);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  padding: 40px;
  text-align: center;
  margin-top: 60px;
}

.article-cta-box h3 {
  font-size: 1.6rem;
  color: var(--accent-white);
  margin-bottom: 12px;
}

.article-cta-box p {
  color: var(--text-muted);
  margin-bottom: 24px;
}

/* Responsive Media Queries */
@media (max-width: 900px) {
  .hero-title {
    font-size: 2.5rem;
  }
  .hero-stats {
    grid-template-columns: repeat(2, 1fr);
  }
  .nav-links {
    display: none; /* simple mobile nav */
  }
  .section-title {
    font-size: 1.8rem;
  }
  .pricing-grid {
    grid-template-columns: 1fr;
  }
}