/* ==========================================================================
   永连 (yonglian.cfd) - 极速科学上网与全球加速 | 核心全局CSS定义
   风格：暗黑宇宙粒子风（Particle Mesh Network & Glassmorphism）
   ========================================================================== */

:root {
  --bg-dark: #070913;
  --bg-card: rgba(18, 22, 41, 0.75);
  --bg-card-hover: rgba(28, 34, 62, 0.9);
  --border-color: rgba(0, 242, 254, 0.2);
  --border-hover: rgba(0, 242, 254, 0.5);
  
  --primary-cyan: #00f2fe;
  --primary-blue: #4facfe;
  --primary-purple: #7f00ff;
  --accent-neon: #00ffcc;
  --accent-pink: #ff007f;
  
  --text-main: #f0f4f8;
  --text-muted: #94a3b8;
  --text-dim: #64748b;
  
  --font-family: 'PingFang SC', 'Microsoft YaHei', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --max-width: 1240px;
  --radius-sm: 8px;
  --radius-md: 16px;
  --radius-lg: 24px;
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
  background-color: var(--bg-dark);
}

body {
  font-family: var(--font-family);
  background-color: var(--bg-dark);
  color: var(--text-main);
  line-height: 1.6;
  overflow-x: hidden;
  position: relative;
  min-height: 100vh;
}

/* Particle Canvas Background */
#particle-canvas {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  z-index: -1;
  pointer-events: none;
}

/* Glassmorphism Containers */
.glass-panel {
  background: var(--bg-card);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  box-shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.4);
  transition: transform 0.3s ease, border-color 0.3s ease, box-shadow 0.3s ease;
}

.glass-panel:hover {
  border-color: var(--border-hover);
  box-shadow: 0 12px 40px 0 rgba(0, 242, 254, 0.25);
}

/* Container */
.container {
  width: 90%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 15px;
}

/* Typography Helpers */
.gradient-text {
  background: linear-gradient(135deg, var(--primary-cyan) 0%, var(--primary-blue) 50%, var(--primary-purple) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  display: inline-block;
}

.section-title {
  font-size: 2.25rem;
  font-weight: 800;
  text-align: center;
  margin-bottom: 0.75rem;
  letter-spacing: -0.5px;
  color: #ffffff;
}

.section-subtitle {
  text-align: center;
  color: var(--text-muted);
  font-size: 1.05rem;
  margin-bottom: 3rem;
  max-width: 680px;
  margin-left: auto;
  margin-right: auto;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.85rem 1.85rem;
  font-size: 1rem;
  font-weight: 700;
  border-radius: var(--radius-md);
  text-decoration: none;
  cursor: pointer;
  transition: all 0.3s ease;
  border: none;
  outline: none;
}

.btn-primary {
  background: linear-gradient(135deg, var(--primary-cyan), var(--primary-blue));
  color: #050b14 !important;
  box-shadow: 0 4px 20px rgba(0, 242, 254, 0.4);
}

.btn-primary:hover {
  transform: translateY(-3px) scale(1.02);
  box-shadow: 0 8px 30px rgba(0, 242, 254, 0.6);
  color: #000000 !important;
}

.btn-secondary {
  background: rgba(255, 255, 255, 0.08);
  color: var(--text-main) !important;
  border: 1px solid rgba(255, 255, 255, 0.2);
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.15);
  border-color: var(--primary-cyan);
  color: var(--primary-cyan) !important;
  transform: translateY(-2px);
}

/* Navbar */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  padding: 1rem 0;
  background: rgba(7, 9, 19, 0.85);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid rgba(0, 242, 254, 0.2);
}

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

.brand-logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  text-decoration: none;
}

.brand-icon {
  width: 42px;
  height: 42px;
  background: linear-gradient(135deg, var(--primary-cyan), var(--primary-purple));
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.4rem;
  font-weight: 900;
  color: #fff;
  box-shadow: 0 0 15px rgba(0, 242, 254, 0.5);
}

.brand-name {
  font-size: 1.4rem;
  font-weight: 800;
  color: #fff;
  letter-spacing: 1px;
}

.brand-domain {
  font-size: 0.75rem;
  background: rgba(0, 242, 254, 0.15);
  color: var(--primary-cyan);
  padding: 2px 8px;
  border-radius: 20px;
  border: 1px solid rgba(0, 242, 254, 0.3);
  margin-left: 4px;
}

/* Nav links formatting fix */
.nav-links {
  display: flex;
  list-style: none !important;
  margin: 0;
  padding: 0;
  gap: 1.8rem;
  align-items: center;
}

.nav-links li {
  list-style: none !important;
  margin: 0;
  padding: 0;
}

.nav-links li a {
  color: var(--text-muted);
  text-decoration: none;
  font-weight: 600;
  font-size: 0.95rem;
  transition: color 0.2s ease;
}

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

.mobile-toggle {
  display: none;
  background: transparent;
  border: 1px solid rgba(0, 242, 254, 0.3);
  color: var(--primary-cyan);
  font-size: 1.6rem;
  padding: 4px 10px;
  border-radius: 8px;
  cursor: pointer;
}

/* Hero Section */
.hero {
  padding: 9rem 0 5rem;
  text-align: center;
  position: relative;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.4rem 1.2rem;
  background: rgba(0, 242, 254, 0.08);
  border: 1px solid rgba(0, 242, 254, 0.3);
  border-radius: 50px;
  font-size: 0.88rem;
  color: var(--primary-cyan);
  margin-bottom: 1.5rem;
  animation: pulseGlow 3s infinite alternate;
}

@keyframes pulseGlow {
  0% { box-shadow: 0 0 5px rgba(0, 242, 254, 0.2); }
  100% { box-shadow: 0 0 20px rgba(0, 242, 254, 0.6); }
}

.hero-title {
  font-size: 3.5rem;
  font-weight: 900;
  line-height: 1.2;
  margin-bottom: 1.5rem;
  letter-spacing: -1px;
  color: #ffffff;
}

.hero-desc {
  font-size: 1.25rem;
  color: var(--text-muted);
  max-width: 800px;
  margin: 0 auto 2.5rem;
  line-height: 1.7;
}

.hero-keywords {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.6rem;
  margin-bottom: 2.5rem;
}

.kw-tag {
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid rgba(255, 255, 255, 0.12);
  padding: 0.4rem 1rem;
  border-radius: 20px;
  font-size: 0.88rem;
  color: #cbd5e1;
  text-decoration: none;
  transition: all 0.2s ease;
}

.kw-tag:hover {
  border-color: var(--primary-cyan);
  color: var(--primary-cyan);
  background: rgba(0, 242, 254, 0.12);
  transform: translateY(-2px);
}

.hero-actions {
  display: flex;
  gap: 1.25rem;
  justify-content: center;
  align-items: center;
  margin-bottom: 3.5rem;
}

/* Feature Highlights Grid */
.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 1.75rem;
  margin: 4rem 0;
}

.feature-card {
  padding: 2rem;
  text-align: left;
}

.feature-icon {
  width: 56px;
  height: 56px;
  border-radius: 16px;
  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: 1.25rem;
  color: var(--primary-cyan);
}

.feature-card h3 {
  font-size: 1.3rem;
  margin-bottom: 0.75rem;
  font-weight: 700;
  color: #ffffff;
}

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

/* Pricing Section */
.pricing-section {
  padding: 5rem 0;
}

.pricing-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 2rem;
  align-items: stretch;
}

.pricing-card {
  padding: 2.5rem 2rem;
  display: flex;
  flex-direction: column;
  position: relative;
}

.pricing-card.popular {
  border-color: var(--primary-cyan);
  box-shadow: 0 0 35px rgba(0, 242, 254, 0.3);
}

.popular-badge {
  position: absolute;
  top: -14px;
  right: 24px;
  background: linear-gradient(135deg, var(--primary-cyan), var(--primary-purple));
  color: #fff;
  padding: 4px 14px;
  border-radius: 20px;
  font-size: 0.78rem;
  font-weight: 800;
  letter-spacing: 0.5px;
}

.plan-name {
  font-size: 1.35rem;
  font-weight: 800;
  margin-bottom: 0.5rem;
  color: #ffffff;
}

.plan-price {
  font-size: 2.75rem;
  font-weight: 900;
  color: var(--primary-cyan);
  margin-bottom: 1.5rem;
  display: flex;
  align-items: baseline;
  gap: 0.3rem;
}

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

.plan-features {
  list-style: none !important;
  padding: 0;
  margin: 0 0 2rem 0;
  flex-grow: 1;
}

.plan-features li {
  list-style: none !important;
  padding: 0.6rem 0;
  border-bottom: 1px solid rgba(255, 255, 255, 0.05);
  font-size: 0.95rem;
  color: #cbd5e1;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

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

/* Nodes & Latency Board */
.node-board {
  margin: 5rem 0;
  padding: 2.5rem;
}

.node-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1.25rem;
  margin-top: 2rem;
}

.node-item {
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: var(--radius-sm);
  padding: 1.2rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.node-info {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

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

.node-name {
  font-weight: 700;
  font-size: 0.95rem;
  color: #ffffff;
}

.node-ping {
  color: var(--accent-neon);
  font-family: monospace;
  font-size: 0.9rem;
  font-weight: 700;
  background: rgba(0, 255, 204, 0.1);
  padding: 2px 8px;
  border-radius: 4px;
}

/* Airport Comparison Table Section */
.comparison-section {
  padding: 5rem 0;
}

.table-responsive {
  overflow-x: auto;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
}

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

.compare-table th, .compare-table td {
  padding: 1.1rem 1.25rem;
  border-bottom: 1px solid rgba(255, 255, 255, 0.06);
  color: #cbd5e1;
}

.compare-table th {
  background: rgba(0, 242, 254, 0.08);
  color: var(--primary-cyan);
  font-weight: 800;
  font-size: 1rem;
}

.compare-table tr:hover {
  background: rgba(255, 255, 255, 0.03);
}

.compare-table .featured-row {
  background: rgba(0, 242, 254, 0.07);
}

.status-badge-green {
  color: #10b981;
  background: rgba(16, 185, 129, 0.15);
  padding: 4px 10px;
  border-radius: 20px;
  font-size: 0.85rem;
  font-weight: bold;
}

/* Articles Matrix Section */
.articles-section {
  padding: 5rem 0;
}

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

.article-card {
  padding: 2rem;
  display: flex;
  flex-direction: column;
}

.article-tag {
  color: var(--primary-cyan);
  font-size: 0.85rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: 0.5rem;
}

.article-title {
  font-size: 1.25rem;
  font-weight: 800;
  margin-bottom: 0.75rem;
  line-height: 1.4;
  color: #ffffff;
}

.article-title a {
  color: #ffffff;
  text-decoration: none;
  transition: color 0.2s;
}

.article-title a:hover {
  color: var(--primary-cyan);
}

.article-excerpt {
  color: var(--text-muted);
  font-size: 0.92rem;
  line-height: 1.6;
  margin-bottom: 1.5rem;
  flex-grow: 1;
}

.article-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.82rem;
  color: var(--text-dim);
  border-top: 1px solid rgba(255, 255, 255, 0.05);
  padding-top: 1rem;
}

/* Testimonials / User Reviews Section */
.reviews-section {
  padding: 5rem 0;
}

.reviews-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 1.75rem;
}

.review-card {
  padding: 1.75rem;
}

.review-user {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-bottom: 1rem;
}

.avatar {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--primary-cyan), var(--primary-purple));
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: bold;
  color: #fff;
  font-size: 1.2rem;
}

.user-meta h4 {
  font-size: 1rem;
  font-weight: 700;
  color: #ffffff;
}

.user-meta span {
  font-size: 0.8rem;
  color: var(--text-muted);
}

.stars {
  color: #fbbf24;
  margin-bottom: 0.75rem;
  font-size: 1.1rem;
}

.review-text {
  color: #cbd5e1;
  font-size: 0.95rem;
  line-height: 1.6;
}

/* FAQ Accordion Section */
.faq-section {
  padding: 5rem 0;
}

.faq-accordion {
  max-width: 850px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.faq-item {
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: var(--radius-md);
  background: var(--bg-card);
  overflow: hidden;
  transition: border-color 0.2s;
}

.faq-question {
  width: 100%;
  padding: 1.4rem 1.75rem;
  text-align: left;
  background: transparent;
  border: none;
  color: #ffffff;
  font-size: 1.1rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: space-between;
  cursor: pointer;
}

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

.faq-item.active .faq-question::after {
  transform: rotate(45deg);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.35s ease, padding 0.35s ease;
  padding: 0 1.75rem;
  color: var(--text-muted);
  font-size: 0.98rem;
  line-height: 1.7;
}

.faq-item.active .faq-answer {
  max-height: 500px;
  padding: 0 1.75rem 1.5rem 1.75rem;
}

/* Article Detail Page Layout Styling */
.article-container {
  padding: 8rem 0 5rem;
  max-width: 900px;
  margin: 0 auto;
}

.article-header {
  margin-bottom: 3rem;
  text-align: center;
}

.article-header h1 {
  font-size: 2.5rem;
  font-weight: 900;
  line-height: 1.3;
  margin-bottom: 1.25rem;
  color: #ffffff;
}

.article-content {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 3rem 2.5rem;
  line-height: 1.8;
  font-size: 1.05rem;
  color: #e2e8f0;
}

.article-content h2 {
  font-size: 1.75rem;
  color: var(--primary-cyan);
  margin: 2.25rem 0 1rem;
  padding-bottom: 0.4rem;
  border-bottom: 1px solid rgba(0, 242, 254, 0.2);
}

.article-content h3 {
  font-size: 1.35rem;
  color: #ffffff;
  margin: 1.75rem 0 0.8rem;
}

.article-content p {
  margin-bottom: 1.25rem;
  color: #cbd5e1;
}

.article-content ul, .article-content ol {
  margin-bottom: 1.25rem;
  padding-left: 1.5rem;
  color: #cbd5e1;
}

.article-content li {
  margin-bottom: 0.5rem;
}

.article-cta-box {
  background: linear-gradient(135deg, rgba(0, 242, 254, 0.1), rgba(127, 0, 255, 0.15));
  border: 1px solid var(--primary-cyan);
  border-radius: var(--radius-md);
  padding: 2rem;
  text-align: center;
  margin: 3rem 0;
}

.article-cta-box h3 {
  font-size: 1.5rem;
  margin-bottom: 0.75rem;
  color: #ffffff;
}

/* ==========================================================================
   【核心任务 2】页脚 PBN 权重精准输血管道 专属CSS
   ========================================================================== */

footer.pbn-footer {
  background: #04050a;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  padding: 3.5rem 0 2rem;
  color: var(--text-dim);
  font-size: 0.85rem;
  line-height: 1.6;
}

.pbn-footer-container {
  display: flex;
  flex-direction: column;
  gap: 2rem;
}

.pbn-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 2rem;
}

.pbn-col h4 {
  color: var(--text-muted);
  font-size: 0.92rem;
  font-weight: 700;
  margin-bottom: 1rem;
  letter-spacing: 0.5px;
}

.pbn-col ul {
  list-style: none !important;
  padding: 0;
  margin: 0;
}

.pbn-col ul li {
  list-style: none !important;
  margin-bottom: 0.45rem;
}

.pbn-col ul li a {
  color: var(--text-dim);
  text-decoration: none;
  transition: color 0.2s;
  font-size: 0.82rem;
}

.pbn-col ul li a:hover {
  color: var(--primary-cyan);
}

.pbn-keywords-cloud {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  padding: 1rem 0;
  border-top: 1px solid rgba(255, 255, 255, 0.05);
  border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

.pbn-keywords-cloud a {
  color: #475569;
  text-decoration: none;
  font-size: 0.78rem;
  transition: color 0.2s;
}

.pbn-keywords-cloud a:hover {
  color: var(--primary-cyan);
}

.pbn-bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  font-size: 0.78rem;
  color: #475569;
}

.pbn-bottom a {
  color: #64748b;
  text-decoration: none;
}

.pbn-bottom a:hover {
  color: var(--text-muted);
}

/* Responsive Media Queries */
@media (max-width: 992px) {
  .hero-title {
    font-size: 2.75rem;
  }
  .nav-links {
    display: none;
  }
  .mobile-toggle {
    display: block;
  }
  .nav-links.mobile-open {
    display: flex !important;
    flex-direction: column;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: rgba(7, 9, 19, 0.95);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    padding: 1.5rem;
    border-bottom: 1px solid var(--border-color);
  }
}

@media (max-width: 640px) {
  .hero-title {
    font-size: 2.1rem;
  }
  .hero-desc {
    font-size: 1rem;
  }
  .hero-actions {
    flex-direction: column;
    width: 100%;
  }
  .btn {
    width: 100%;
  }
  .section-title {
    font-size: 1.75rem;
  }
  .article-content {
    padding: 1.5rem 1.25rem;
  }
}