/* ==========================================================================
   极速VPN (Jisu VPN) - 全场景智能专线网络样式表
   Design Language: Modern Industrial + Component Architecture + Data Visuals
   Palette: Warm White (#F6F4EE), Block Blue (#2563EB), Function Yellow (#F59E0B), 
            Status Green (#10B981), Graphite Black (#1E293B), Border Slate (#CBD5E1)
   ========================================================================== */

:root {
  --bg-warm-white: #F6F4EE;
  --bg-card: #FFFFFF;
  --bg-card-subtle: #F0EDE4;
  --bg-dark: #121824;
  --bg-dark-card: #1A2234;

  --color-primary: #2563EB;
  --color-primary-dark: #1D4ED8;
  --color-primary-light: #DBEAFE;
  
  --color-accent-yellow: #D97706;
  --color-accent-yellow-light: #FEF3C7;
  
  --color-status-green: #059669;
  --color-status-green-light: #D1FAE5;
  
  --color-status-red: #DC2626;
  --color-status-red-light: #FEE2E2;
  
  --color-graphite: #0F172A;
  --color-text-body: #334155;
  --color-text-muted: #64748B;
  --color-border: #DDE2EB;
  --color-border-dark: #334155;

  --shadow-sm: 0 1px 2px 0 rgba(15, 23, 42, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(15, 23, 42, 0.08), 0 2px 4px -2px rgba(15, 23, 42, 0.05);
  --shadow-lg: 0 10px 15px -3px rgba(15, 23, 42, 0.08), 0 4px 6px -4px rgba(15, 23, 42, 0.05);
  --shadow-block: 4px 4px 0px #0F172A;
  --shadow-block-sm: 2px 2px 0px #0F172A;
  --shadow-block-hover: 6px 6px 0px #0F172A;

  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --radius-full: 9999px;

  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-mono: "JetBrains Mono", SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", monospace;
  
  --transition-fast: 0.15s ease;
  --transition-normal: 0.25s cubic-bezier(0.16, 1, 0.3, 1);
  --transition-smooth: 0.4s cubic-bezier(0.16, 1, 0.3, 1);
}

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

html {
  font-family: var(--font-sans);
  background-color: var(--bg-warm-white);
  color: var(--color-graphite);
  line-height: 1.6;
  scroll-behavior: smooth;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  overflow-x: hidden;
  background-image: 
    radial-gradient(#CBD5E1 0.75px, transparent 0.75px), 
    linear-gradient(to right, rgba(226, 232, 240, 0.3) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(226, 232, 240, 0.3) 1px, transparent 1px);
  background-size: 24px 24px, 120px 120px, 120px 120px;
  background-position: 0 0, 0 0, 0 0;
}

img, svg {
  display: block;
  max-width: 100%;
}

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

a:hover {
  color: var(--color-primary-dark);
}

ul, ol {
  list-style: none;
}

button, input, select, textarea {
  font-family: inherit;
  font-size: inherit;
}

/* Container */
.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

.container-narrow {
  max-width: 860px;
}

/* Header & Navigation */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(246, 244, 238, 0.88);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 2px solid var(--color-graphite);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
  gap: 16px;
}

.brand-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 800;
  font-size: 1.25rem;
  color: var(--color-graphite);
  text-decoration: none;
  white-space: nowrap;
  flex-shrink: 0;
}

.brand-icon {
  width: 38px;
  height: 38px;
  background: var(--color-primary);
  border: 2px solid var(--color-graphite);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-block-sm);
  transition: transform var(--transition-fast);
  flex-shrink: 0;
}

.brand-logo:hover .brand-icon {
  transform: translateY(-2px) rotate(2deg);
}

.brand-icon svg {
  width: 20px;
  height: 20px;
  fill: #FFFFFF;
}

.brand-badge {
  font-size: 0.72rem;
  font-family: var(--font-mono);
  background: var(--color-accent-yellow-light);
  color: #92400E;
  padding: 2px 8px;
  border-radius: var(--radius-full);
  border: 1px solid #F59E0B;
  font-weight: 700;
  letter-spacing: 0.5px;
  white-space: nowrap;
  flex-shrink: 0;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 10px;
}

.nav-link {
  font-weight: 700;
  color: var(--color-text-body);
  font-size: 0.88rem;
  padding: 6px 8px;
  border-radius: var(--radius-sm);
  transition: all var(--transition-fast);
  position: relative;
  white-space: nowrap;
  flex-shrink: 0;
}

.nav-link:hover, .nav-link.active {
  color: var(--color-primary);
  background: rgba(37, 99, 235, 0.08);
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
}

/* Buttons - Modular Block Aesthetics */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-weight: 700;
  font-size: 0.92rem;
  padding: 9px 18px;
  border-radius: var(--radius-md);
  border: 2px solid var(--color-graphite);
  cursor: pointer;
  transition: all var(--transition-fast);
  text-decoration: none;
  line-height: 1.2;
  white-space: nowrap;
  flex-shrink: 0;
}

.btn-primary {
  background: var(--color-primary);
  color: #FFFFFF;
  box-shadow: var(--shadow-block);
}
  box-shadow: var(--shadow-block);
}

.btn-primary:hover {
  background: var(--color-primary-dark);
  color: #FFFFFF;
  transform: translate(-2px, -2px);
  box-shadow: var(--shadow-block-hover);
}

.btn-primary:active {
  transform: translate(2px, 2px);
  box-shadow: 0 0 0 transparent;
}

.btn-outline {
  background: #FFFFFF;
  color: var(--color-graphite);
  box-shadow: var(--shadow-block-sm);
}

.btn-outline:hover {
  background: #F8FAFC;
  transform: translate(-1px, -1px);
  box-shadow: var(--shadow-block);
}

.btn-yellow {
  background: #F59E0B;
  color: var(--color-graphite);
  box-shadow: var(--shadow-block);
}

.btn-yellow:hover {
  background: #D97706;
  color: #FFFFFF;
  transform: translate(-2px, -2px);
  box-shadow: var(--shadow-block-hover);
}

.btn-lg {
  padding: 14px 28px;
  font-size: 1.05rem;
}

.btn-sm {
  padding: 6px 14px;
  font-size: 0.85rem;
}

/* Mobile Nav Toggle */
.mobile-nav-toggle {
  display: none;
  background: #FFFFFF;
  border: 2px solid var(--color-graphite);
  border-radius: var(--radius-sm);
  padding: 8px;
  cursor: pointer;
  box-shadow: var(--shadow-block-sm);
}

@media (max-width: 1080px) {
  .mobile-nav-toggle {
    display: flex;
    align-items: center;
    justify-content: center;
  }

  .site-nav {
    display: none;
    position: absolute;
    top: 72px;
    left: 0;
    right: 0;
    background: #FAF9F5;
    border-bottom: 3px solid var(--color-graphite);
    box-shadow: 0 10px 15px -3px rgba(0,0,0,0.1);
    flex-direction: column;
    padding: 20px 24px;
    gap: 8px;
    z-index: 99;
  }

  .site-nav.mobile-open {
    display: flex;
  }

  .nav-link {
    width: 100%;
    padding: 10px 14px;
    font-size: 1rem;
  }
}

/* Hero Section */
.hero-section {
  padding: 60px 0 80px;
  position: relative;
  overflow: hidden;
}

.hero-pill-tag {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: #FFFFFF;
  border: 2px solid var(--color-graphite);
  padding: 6px 14px;
  border-radius: var(--radius-full);
  font-size: 0.85rem;
  font-weight: 700;
  box-shadow: var(--shadow-block-sm);
  margin-bottom: 24px;
}

.hero-pill-dot {
  width: 10px;
  height: 10px;
  background: var(--color-status-green);
  border-radius: 50%;
  display: inline-block;
  box-shadow: 0 0 0 3px rgba(16, 185, 129, 0.25);
  animation: pulse-dot 2s infinite;
}

@keyframes pulse-dot {
  0% { transform: scale(0.95); box-shadow: 0 0 0 0 rgba(16, 185, 129, 0.7); }
  70% { transform: scale(1); box-shadow: 0 0 0 6px rgba(16, 185, 129, 0); }
  100% { transform: scale(0.95); box-shadow: 0 0 0 0 rgba(16, 185, 129, 0); }
}

.hero-title {
  font-size: 3.25rem;
  line-height: 1.15;
  font-weight: 900;
  letter-spacing: -0.02em;
  color: var(--color-graphite);
  margin-bottom: 20px;
}

.hero-title .highlight {
  color: var(--color-primary);
  position: relative;
  display: inline-block;
}

.hero-title .highlight::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 6px;
  width: 100%;
  height: 12px;
  background: var(--color-accent-yellow-light);
  border-bottom: 3px solid #F59E0B;
  z-index: -1;
}

.hero-subtitle {
  font-size: 1.18rem;
  color: var(--color-text-body);
  max-width: 680px;
  margin-bottom: 36px;
  line-height: 1.68;
}

.hero-cta-group {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  align-items: center;
  margin-bottom: 40px;
}

.hero-guarantee {
  display: flex;
  align-items: center;
  gap: 20px;
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--color-text-muted);
}

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

/* ==========================================================================
   MODULAR BUILDING BLOCKS VISUALIZER (Interactive Pipeline)
   ========================================================================== */
.modular-visualizer-container {
  margin-top: 50px;
  background: #FFFFFF;
  border: 3px solid var(--color-graphite);
  border-radius: var(--radius-xl);
  padding: 32px;
  box-shadow: var(--shadow-block);
  position: relative;
}

.visualizer-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 16px;
  padding-bottom: 24px;
  border-bottom: 2px dashed #CBD5E1;
  margin-bottom: 28px;
}

.visualizer-title-area h3 {
  font-size: 1.25rem;
  font-weight: 800;
  display: flex;
  align-items: center;
  gap: 8px;
}

.visualizer-title-area p {
  font-size: 0.88rem;
  color: var(--color-text-muted);
}

/* Scenario Mode Switcher */
.mode-switcher {
  display: flex;
  background: var(--bg-card-subtle);
  border: 2px solid var(--color-graphite);
  border-radius: var(--radius-md);
  padding: 4px;
  gap: 4px;
}

.mode-btn {
  padding: 8px 16px;
  font-size: 0.85rem;
  font-weight: 700;
  border-radius: var(--radius-sm);
  border: none;
  background: transparent;
  color: var(--color-text-body);
  cursor: pointer;
  transition: all var(--transition-fast);
  display: flex;
  align-items: center;
  gap: 6px;
}

.mode-btn:hover {
  background: rgba(255, 255, 255, 0.6);
}

.mode-btn.active {
  background: #FFFFFF;
  color: var(--color-primary);
  border: 1.5px solid var(--color-graphite);
  box-shadow: 2px 2px 0 var(--color-graphite);
}

/* Pipeline Track & Flow */
.pipeline-track {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  gap: 14px;
  position: relative;
  padding: 10px 0;
}

@media (max-width: 992px) {
  .pipeline-track {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 576px) {
  .pipeline-track {
    grid-template-columns: 1fr;
  }
}

.pipeline-module {
  background: #FAF9F5;
  border: 2px solid var(--color-graphite);
  border-radius: var(--radius-lg);
  padding: 18px 16px;
  display: flex;
  flex-direction: column;
  position: relative;
  transition: all var(--transition-normal);
  box-shadow: 3px 3px 0 rgba(15, 23, 42, 0.1);
}

.pipeline-module:hover {
  transform: translateY(-4px);
  box-shadow: 4px 6px 0 var(--color-graphite);
}

.pipeline-module.active-flow {
  background: #FFFFFF;
  border-color: var(--color-primary);
  box-shadow: 4px 4px 0 var(--color-primary);
}

.pipeline-module.highlight-swap {
  animation: module-snap 0.5s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

@keyframes module-snap {
  0% { transform: scale(0.9) translateY(8px); opacity: 0.7; }
  50% { transform: scale(1.04) translateY(-4px); }
  100% { transform: scale(1) translateY(0); opacity: 1; }
}

.module-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 12px;
}

.module-step-badge {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  font-weight: 800;
  padding: 2px 6px;
  background: #E2E8F0;
  border-radius: var(--radius-sm);
  color: var(--color-graphite);
  border: 1px solid #CBD5E1;
}

.module-icon {
  width: 34px;
  height: 34px;
  border-radius: var(--radius-sm);
  background: var(--color-primary-light);
  border: 1.5px solid var(--color-graphite);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
}

.module-title {
  font-size: 0.98rem;
  font-weight: 800;
  color: var(--color-graphite);
  margin-bottom: 4px;
}

.module-desc {
  font-size: 0.78rem;
  color: var(--color-text-muted);
  line-height: 1.4;
  margin-bottom: 12px;
  min-height: 34px;
}

.module-meta {
  margin-top: auto;
  padding-top: 10px;
  border-top: 1px dashed #CBD5E1;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 700;
}

.meta-val-badge {
  background: #ECFDF5;
  color: #065F46;
  padding: 2px 6px;
  border-radius: 4px;
  border: 1px solid #A7F3D0;
}

/* Real-time Status Footer in visualizer */
.visualizer-status-bar {
  margin-top: 24px;
  background: #0F172A;
  border-radius: var(--radius-md);
  padding: 16px 20px;
  color: #FFFFFF;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 16px;
  font-family: var(--font-mono);
  font-size: 0.85rem;
}

.status-indicator {
  display: flex;
  align-items: center;
  gap: 10px;
}

.status-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: #10B981;
  box-shadow: 0 0 10px #10B981;
}

.status-metrics {
  display: flex;
  gap: 20px;
  flex-wrap: wrap;
}

.metric-item span {
  color: #94A3B8;
  margin-right: 6px;
}

.metric-item b {
  color: #38BDF8;
}

/* Section Common Styling */
.section-padding {
  padding: 90px 0;
}

.section-head {
  text-align: center;
  max-width: 720px;
  margin: 0 auto 56px;
}

.section-tag {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  font-weight: 800;
  text-transform: uppercase;
  color: var(--color-primary);
  background: var(--color-primary-light);
  border: 1.5px solid var(--color-graphite);
  padding: 4px 12px;
  border-radius: var(--radius-full);
  margin-bottom: 14px;
  box-shadow: var(--shadow-block-sm);
}

.section-title {
  font-size: 2.35rem;
  font-weight: 900;
  color: var(--color-graphite);
  letter-spacing: -0.01em;
  line-height: 1.25;
  margin-bottom: 16px;
}

.section-desc {
  font-size: 1.05rem;
  color: var(--color-text-body);
  line-height: 1.6;
}

/* Feature Grid */
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

@media (max-width: 992px) {
  .features-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 640px) {
  .features-grid {
    grid-template-columns: 1fr;
  }
}

.feature-card {
  background: #FFFFFF;
  border: 2px solid var(--color-graphite);
  border-radius: var(--radius-xl);
  padding: 28px;
  box-shadow: var(--shadow-block);
  transition: all var(--transition-normal);
  display: flex;
  flex-direction: column;
}

.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-block-hover);
}

.feature-icon-box {
  width: 52px;
  height: 52px;
  border-radius: var(--radius-md);
  border: 2px solid var(--color-graphite);
  background: var(--color-accent-yellow-light);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  margin-bottom: 20px;
  box-shadow: var(--shadow-block-sm);
}

.feature-card:nth-child(2) .feature-icon-box {
  background: var(--color-primary-light);
}
.feature-card:nth-child(3) .feature-icon-box {
  background: var(--color-status-green-light);
}

.feature-title {
  font-size: 1.2rem;
  font-weight: 800;
  margin-bottom: 12px;
  color: var(--color-graphite);
}

.feature-text {
  font-size: 0.92rem;
  color: var(--color-text-body);
  line-height: 1.65;
  margin-bottom: 20px;
}

.feature-specs {
  margin-top: auto;
  background: #F8FAFC;
  border-radius: var(--radius-sm);
  padding: 10px 14px;
  font-size: 0.8rem;
  font-family: var(--font-mono);
  color: var(--color-text-muted);
  border: 1px solid #E2E8F0;
  display: flex;
  justify-content: space-between;
}

/* Pricing Section - Modular Bill of Materials Style */
.pricing-billing-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 14px;
  margin-bottom: 44px;
  font-weight: 700;
}

.toggle-switch {
  position: relative;
  width: 56px;
  height: 28px;
  background: #CBD5E1;
  border: 2px solid var(--color-graphite);
  border-radius: var(--radius-full);
  cursor: pointer;
  transition: background var(--transition-fast);
}

.toggle-switch.active {
  background: var(--color-primary);
}

.toggle-slider {
  position: absolute;
  top: 2px;
  left: 2px;
  width: 20px;
  height: 20px;
  background: #FFFFFF;
  border: 1.5px solid var(--color-graphite);
  border-radius: 50%;
  transition: transform var(--transition-fast);
}

.toggle-switch.active .toggle-slider {
  transform: translateX(28px);
}

.save-badge {
  background: #DC2626;
  color: #FFFFFF;
  font-size: 0.75rem;
  padding: 2px 8px;
  border-radius: var(--radius-full);
  font-weight: 800;
}

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

@media (max-width: 992px) {
  .pricing-grid {
    grid-template-columns: 1fr;
    max-width: 480px;
    margin: 0 auto;
  }
}

.pricing-card {
  background: #FFFFFF;
  border: 2px solid var(--color-graphite);
  border-radius: var(--radius-xl);
  padding: 36px 30px;
  display: flex;
  flex-direction: column;
  position: relative;
  box-shadow: var(--shadow-block);
  transition: transform var(--transition-normal);
}

.pricing-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-block-hover);
}

.pricing-card.featured {
  border: 3px solid var(--color-primary);
  box-shadow: 6px 6px 0 var(--color-primary);
  background: #FCFDFE;
}

.popular-badge {
  position: absolute;
  top: -14px;
  right: 24px;
  background: #F59E0B;
  color: #0F172A;
  font-size: 0.78rem;
  font-weight: 800;
  padding: 4px 14px;
  border-radius: var(--radius-full);
  border: 2px solid var(--color-graphite);
  box-shadow: 2px 2px 0 var(--color-graphite);
}

.pricing-plan-name {
  font-size: 1.35rem;
  font-weight: 900;
  margin-bottom: 6px;
  color: var(--color-graphite);
}

.pricing-plan-desc {
  font-size: 0.88rem;
  color: var(--color-text-muted);
  margin-bottom: 24px;
  min-height: 40px;
}

.pricing-price-area {
  display: flex;
  align-items: baseline;
  gap: 4px;
  margin-bottom: 24px;
  padding-bottom: 24px;
  border-bottom: 2px dashed #E2E8F0;
}

.price-currency {
  font-size: 1.4rem;
  font-weight: 800;
  color: var(--color-graphite);
}

.price-amount {
  font-size: 2.85rem;
  font-weight: 900;
  color: var(--color-graphite);
  line-height: 1;
}

.price-period {
  font-size: 0.9rem;
  color: var(--color-text-muted);
  font-weight: 600;
}

/* Modular Bill of Materials */
.modular-bom-title {
  font-size: 0.78rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  color: var(--color-text-muted);
  font-family: var(--font-mono);
  margin-bottom: 14px;
}

.bom-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-bottom: 32px;
}

.bom-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.9rem;
  color: var(--color-graphite);
}

.bom-item-name {
  display: flex;
  align-items: center;
  gap: 8px;
}

.bom-item-check {
  width: 18px;
  height: 18px;
  border-radius: 4px;
  background: #DCFCE7;
  border: 1.5px solid #16A34A;
  color: #16A34A;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.75rem;
  font-weight: 900;
}

.bom-tag {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  background: #F1F5F9;
  border: 1px solid #CBD5E1;
  padding: 2px 6px;
  border-radius: 4px;
  font-weight: 700;
  color: #475569;
}

.pricing-card .btn {
  width: 100%;
  margin-top: auto;
}

/* Audience / Use Cases Section */
.audience-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

@media (max-width: 992px) {
  .audience-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 576px) {
  .audience-grid {
    grid-template-columns: 1fr;
  }
}

.audience-card {
  background: #FFFFFF;
  border: 2px solid var(--color-graphite);
  border-radius: var(--radius-lg);
  padding: 24px;
  box-shadow: var(--shadow-block-sm);
  transition: all var(--transition-fast);
}

.audience-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-block);
  border-color: var(--color-primary);
}

.audience-card .audience-emoji {
  font-size: 2rem;
  margin-bottom: 14px;
}

.audience-card h4 {
  font-size: 1.15rem;
  font-weight: 800;
  margin-bottom: 8px;
}

.audience-card p {
  font-size: 0.88rem;
  color: var(--color-text-body);
  line-height: 1.6;
}

.audience-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-top: 14px;
}

.audience-tag {
  font-size: 0.72rem;
  font-family: var(--font-mono);
  background: #F1F5F9;
  padding: 2px 8px;
  border-radius: 4px;
  color: #475569;
}

/* ==========================================================================
   TUTORIAL / CLASH CONFIGURATION WORKFLOW
   ========================================================================== */
.tutorial-section {
  background: #FFFFFF;
  border-top: 3px solid var(--color-graphite);
  border-bottom: 3px solid var(--color-graphite);
}

.client-tabs {
  display: flex;
  justify-content: center;
  gap: 12px;
  margin-bottom: 36px;
  flex-wrap: wrap;
}

.client-tab-btn {
  background: #FAF9F5;
  border: 2px solid var(--color-graphite);
  padding: 10px 22px;
  border-radius: var(--radius-full);
  font-weight: 700;
  font-size: 0.92rem;
  cursor: pointer;
  transition: all var(--transition-fast);
  display: flex;
  align-items: center;
  gap: 8px;
}

.client-tab-btn.active {
  background: var(--color-primary);
  color: #FFFFFF;
  box-shadow: var(--shadow-block-sm);
}

.tutorial-steps-flow {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  margin-bottom: 40px;
}

@media (max-width: 992px) {
  .tutorial-steps-flow {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 576px) {
  .tutorial-steps-flow {
    grid-template-columns: 1fr;
  }
}

.step-card {
  background: #FAF9F5;
  border: 2px solid var(--color-graphite);
  border-radius: var(--radius-lg);
  padding: 24px;
  position: relative;
}

.step-number {
  width: 32px;
  height: 32px;
  background: var(--color-graphite);
  color: #FFFFFF;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 900;
  font-family: var(--font-mono);
  font-size: 0.9rem;
  margin-bottom: 16px;
}

.step-card h4 {
  font-size: 1.1rem;
  font-weight: 800;
  margin-bottom: 8px;
}

.step-card p {
  font-size: 0.86rem;
  color: var(--color-text-body);
  line-height: 1.55;
  margin-bottom: 14px;
}

.step-code-box {
  background: #0F172A;
  color: #38BDF8;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  padding: 10px 12px;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: space-between;
  overflow-x: auto;
}

/* Live Ping / Node Latency Simulator Tool */
.tool-box-card {
  background: #F0EDE4;
  border: 2px solid var(--color-graphite);
  border-radius: var(--radius-xl);
  padding: 30px;
  box-shadow: var(--shadow-block);
  margin-top: 40px;
}

.tool-box-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 20px;
  flex-wrap: wrap;
  gap: 12px;
}

.node-table {
  width: 100%;
  border-collapse: separate;
  border-spacing: 0;
  background: #FFFFFF;
  border: 2px solid var(--color-graphite);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.node-table th, .node-table td {
  padding: 12px 18px;
  text-align: left;
  font-size: 0.88rem;
}

.node-table th {
  background: #F8FAFC;
  border-bottom: 2px solid var(--color-graphite);
  font-weight: 800;
  font-family: var(--font-mono);
  font-size: 0.8rem;
}

.node-table tr:not(:last-child) td {
  border-bottom: 1px solid #E2E8F0;
}

.badge-tag {
  display: inline-block;
  padding: 2px 8px;
  border-radius: 4px;
  font-size: 0.75rem;
  font-weight: 700;
  font-family: var(--font-mono);
}

.badge-green {
  background: #DCFCE7;
  color: #166534;
  border: 1px solid #86EFAC;
}

.badge-blue {
  background: #DBEAFE;
  color: #1E40AF;
  border: 1px solid #93C5FD;
}

.badge-purple {
  background: #F3E8FF;
  color: #6B21A8;
  border: 1px solid #D8B4FE;
}

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

@media (max-width: 992px) {
  .reviews-grid {
    grid-template-columns: 1fr;
  }
}

.review-card {
  background: #FFFFFF;
  border: 2px solid var(--color-graphite);
  border-radius: var(--radius-xl);
  padding: 28px;
  box-shadow: var(--shadow-block);
  display: flex;
  flex-direction: column;
}

.review-stars {
  color: #F59E0B;
  font-size: 1.1rem;
  margin-bottom: 14px;
  letter-spacing: 2px;
}

.review-quote {
  font-size: 0.95rem;
  color: var(--color-text-body);
  line-height: 1.65;
  margin-bottom: 20px;
  font-style: italic;
}

.review-user {
  margin-top: auto;
  display: flex;
  align-items: center;
  gap: 12px;
}

.review-avatar {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  border: 2px solid var(--color-graphite);
  background: #E2E8F0;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  font-size: 1rem;
}

.review-user-name {
  font-weight: 800;
  font-size: 0.95rem;
}

.review-user-tag {
  font-size: 0.78rem;
  color: var(--color-text-muted);
}

/* FAQ Accordion */
.faq-list {
  max-width: 820px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.faq-item {
  background: #FFFFFF;
  border: 2px solid var(--color-graphite);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-block-sm);
  overflow: hidden;
  transition: all var(--transition-fast);
}

.faq-item:hover {
  box-shadow: var(--shadow-block);
}

.faq-question {
  width: 100%;
  text-align: left;
  padding: 20px 24px;
  background: transparent;
  border: none;
  font-size: 1.05rem;
  font-weight: 800;
  color: var(--color-graphite);
  display: flex;
  justify-content: space-between;
  align-items: center;
  cursor: pointer;
  gap: 16px;
}

.faq-icon {
  width: 28px;
  height: 28px;
  border-radius: 50%;
  background: #F1F5F9;
  border: 1.5px solid var(--color-graphite);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  transition: transform var(--transition-fast);
  flex-shrink: 0;
}

.faq-item.active .faq-icon {
  transform: rotate(45deg);
  background: var(--color-primary);
  color: #FFFFFF;
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.35s ease;
}

.faq-item.active .faq-answer {
  max-height: 500px;
}

.faq-answer-inner {
  padding: 0 24px 22px;
  color: var(--color-text-body);
  font-size: 0.95rem;
  line-height: 1.7;
  border-top: 1px dashed #E2E8F0;
  padding-top: 16px;
}

/* Article Cards & Directory */
.article-cards-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 26px;
}

@media (max-width: 992px) {
  .article-cards-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 640px) {
  .article-cards-grid {
    grid-template-columns: 1fr;
  }
}

.article-card {
  background: #FFFFFF;
  border: 2px solid var(--color-graphite);
  border-radius: var(--radius-xl);
  overflow: hidden;
  box-shadow: var(--shadow-block);
  display: flex;
  flex-direction: column;
  transition: all var(--transition-normal);
}

.article-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-block-hover);
}

.article-card-media {
  height: 180px;
  background: linear-gradient(135deg, #1E293B, #0F172A);
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  border-bottom: 2px solid var(--color-graphite);
  padding: 20px;
  overflow: hidden;
}

.article-card-icon {
  font-size: 3rem;
  filter: drop-shadow(0 4px 10px rgba(0,0,0,0.3));
}

.article-category-badge {
  position: absolute;
  top: 14px;
  left: 14px;
  background: #FFFFFF;
  color: var(--color-graphite);
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 800;
  padding: 3px 10px;
  border-radius: var(--radius-full);
  border: 1.5px solid var(--color-graphite);
}

.article-card-body {
  padding: 24px;
  display: flex;
  flex-direction: column;
  flex-grow: 1;
}

.article-meta {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 0.78rem;
  color: var(--color-text-muted);
  font-family: var(--font-mono);
  margin-bottom: 12px;
}

.article-card-title {
  font-size: 1.15rem;
  font-weight: 800;
  line-height: 1.4;
  margin-bottom: 10px;
  color: var(--color-graphite);
}

.article-card-title a {
  color: inherit;
}

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

.article-card-excerpt {
  font-size: 0.88rem;
  color: var(--color-text-body);
  line-height: 1.6;
  margin-bottom: 20px;
  flex-grow: 1;
}

.article-card-footer {
  margin-top: auto;
  padding-top: 14px;
  border-top: 1px solid #F1F5F9;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.read-more-link {
  font-weight: 700;
  font-size: 0.88rem;
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

/* Call-to-Action Banner */
.cta-banner-section {
  padding: 80px 0;
}

.cta-banner-box {
  background: #0F172A;
  border: 3px solid var(--color-graphite);
  border-radius: var(--radius-xl);
  padding: 60px 48px;
  color: #FFFFFF;
  box-shadow: var(--shadow-block);
  position: relative;
  overflow: hidden;
  text-align: center;
}

.cta-banner-box::before {
  content: "";
  position: absolute;
  top: -50px;
  right: -50px;
  width: 250px;
  height: 250px;
  background: radial-gradient(circle, rgba(37, 99, 235, 0.4) 0%, transparent 70%);
}

.cta-banner-title {
  font-size: 2.6rem;
  font-weight: 900;
  margin-bottom: 16px;
  line-height: 1.2;
}

.cta-banner-desc {
  font-size: 1.15rem;
  color: #94A3B8;
  max-width: 640px;
  margin: 0 auto 36px;
  line-height: 1.65;
}

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

/* Footer & Sitemap */
.site-footer {
  background: #181F2E;
  color: #E2E8F0;
  border-top: 3px solid var(--color-graphite);
  padding: 70px 0 30px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 48px;
  margin-bottom: 50px;
}

@media (max-width: 992px) {
  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 576px) {
  .footer-grid {
    grid-template-columns: 1fr;
  }
}

.footer-brand p {
  font-size: 0.9rem;
  color: #94A3B8;
  line-height: 1.65;
  margin: 16px 0 20px;
  max-width: 320px;
}

.footer-col h4 {
  font-size: 1rem;
  font-weight: 800;
  color: #FFFFFF;
  margin-bottom: 20px;
  letter-spacing: 0.5px;
}

.footer-links {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.footer-links a {
  color: #94A3B8;
  font-size: 0.88rem;
}

.footer-links a:hover {
  color: #FFFFFF;
  padding-left: 4px;
}

.footer-bottom {
  padding-top: 30px;
  border-top: 1px solid #334155;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 16px;
  font-size: 0.82rem;
  color: #64748B;
}

.footer-legal-links {
  display: flex;
  gap: 20px;
}

.footer-legal-links a {
  color: #94A3B8;
}

.footer-legal-links a:hover {
  color: #FFFFFF;
}

/* ==========================================================================
   ARTICLE / CONTENT PAGE STYLES (Rich Typography, Breadcrumbs, Author, FAQ)
   ========================================================================== */
.breadcrumbs-bar {
  padding: 18px 0;
  background: rgba(246, 244, 238, 0.6);
  border-bottom: 1px solid #E2E8F0;
  font-size: 0.86rem;
  font-family: var(--font-mono);
}

.breadcrumbs-list {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
}

.breadcrumb-sep {
  color: #94A3B8;
}

.article-hero {
  padding: 48px 0 36px;
}

.article-title-h1 {
  font-size: 2.5rem;
  font-weight: 900;
  line-height: 1.25;
  color: var(--color-graphite);
  margin-bottom: 20px;
  letter-spacing: -0.015em;
}

.article-meta-bar {
  display: flex;
  align-items: center;
  gap: 20px;
  flex-wrap: wrap;
  font-size: 0.88rem;
  color: var(--color-text-muted);
  font-family: var(--font-mono);
  padding-bottom: 24px;
  border-bottom: 2px dashed #CBD5E1;
  margin-bottom: 36px;
}

.article-body-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 300px;
  gap: 48px;
  align-items: start;
}

@media (max-width: 992px) {
  .article-body-layout {
    grid-template-columns: 1fr;
  }
}

.article-content {
  background: #FFFFFF;
  border: 2px solid var(--color-graphite);
  border-radius: var(--radius-xl);
  padding: 44px 40px;
  box-shadow: var(--shadow-block);
  font-size: 1.05rem;
  line-height: 1.8;
  color: #334155;
}

@media (max-width: 640px) {
  .article-content {
    padding: 26px 20px;
  }
}

.article-content h2 {
  font-size: 1.75rem;
  font-weight: 800;
  color: var(--color-graphite);
  margin: 40px 0 18px;
  padding-bottom: 10px;
  border-bottom: 2px solid #E2E8F0;
  display: flex;
  align-items: center;
  gap: 10px;
}

.article-content h2::before {
  content: "";
  display: inline-block;
  width: 8px;
  height: 24px;
  background: var(--color-primary);
  border-radius: 4px;
}

.article-content h3 {
  font-size: 1.35rem;
  font-weight: 800;
  color: var(--color-graphite);
  margin: 28px 0 14px;
}

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

.article-content ul, .article-content ol {
  margin: 16px 0 24px 20px;
}

.article-content ul {
  list-style-type: disc;
}

.article-content ol {
  list-style-type: decimal;
}

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

.article-content blockquote {
  background: #F8FAFC;
  border-left: 4px solid var(--color-primary);
  padding: 16px 20px;
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  margin: 24px 0;
  font-style: italic;
  color: #475569;
}

.article-content pre {
  background: #0F172A;
  color: #38BDF8;
  padding: 18px 20px;
  border-radius: var(--radius-md);
  font-family: var(--font-mono);
  font-size: 0.88rem;
  overflow-x: auto;
  margin: 24px 0;
  border: 1.5px solid var(--color-graphite);
}

.article-content code:not(pre code) {
  background: #F1F5F9;
  color: #DC2626;
  padding: 2px 6px;
  border-radius: 4px;
  font-family: var(--font-mono);
  font-size: 0.88em;
  border: 1px solid #E2E8F0;
}

.article-content table {
  width: 100%;
  border-collapse: collapse;
  margin: 28px 0;
  font-size: 0.95rem;
}

.article-content th, .article-content td {
  border: 1px solid #CBD5E1;
  padding: 12px 16px;
  text-align: left;
}

.article-content th {
  background: #F1F5F9;
  font-weight: 800;
  color: var(--color-graphite);
}

.article-content tr:nth-child(even) {
  background: #FAF9F5;
}

/* Sidebar in Article Page */
.article-sidebar {
  display: flex;
  flex-direction: column;
  gap: 24px;
  position: sticky;
  top: 96px;
}

.sidebar-card {
  background: #FFFFFF;
  border: 2px solid var(--color-graphite);
  border-radius: var(--radius-lg);
  padding: 24px;
  box-shadow: var(--shadow-block-sm);
}

.sidebar-card h4 {
  font-size: 1.05rem;
  font-weight: 800;
  margin-bottom: 16px;
  padding-bottom: 10px;
  border-bottom: 2px dashed #E2E8F0;
}

.sidebar-links {
  display: flex;
  flex-direction: column;
  gap: 12px;
  font-size: 0.88rem;
}

.sidebar-links a {
  color: var(--color-text-body);
  display: block;
  line-height: 1.45;
}

.sidebar-links a:hover {
  color: var(--color-primary);
  font-weight: 700;
}

.sidebar-cta-box {
  background: #FEF3C7;
  border: 2px solid var(--color-graphite);
  border-radius: var(--radius-lg);
  padding: 24px;
  text-align: center;
  box-shadow: var(--shadow-block-sm);
}

.sidebar-cta-box h4 {
  font-size: 1.15rem;
  font-weight: 800;
  margin-bottom: 10px;
}

.sidebar-cta-box p {
  font-size: 0.88rem;
  color: #78350F;
  margin-bottom: 16px;
}

/* Author Box */
.author-box {
  margin-top: 48px;
  padding: 24px;
  background: #FAF9F5;
  border: 2px solid var(--color-graphite);
  border-radius: var(--radius-lg);
  display: flex;
  gap: 20px;
  align-items: center;
}

.author-avatar {
  width: 60px;
  height: 60px;
  border-radius: 50%;
  background: var(--color-primary);
  color: #FFFFFF;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 900;
  font-size: 1.4rem;
  flex-shrink: 0;
  border: 2px solid var(--color-graphite);
}

.author-details h4 {
  font-size: 1.05rem;
  font-weight: 800;
  margin-bottom: 4px;
}

.author-details p {
  font-size: 0.86rem;
  color: var(--color-text-muted);
  margin-bottom: 0;
}

/* Related Articles Section */
.related-articles {
  margin-top: 48px;
  padding-top: 36px;
  border-top: 2px dashed #CBD5E1;
}

.related-articles h3 {
  font-size: 1.4rem;
  font-weight: 800;
  margin-bottom: 20px;
}

.related-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 18px;
}

@media (max-width: 640px) {
  .related-grid {
    grid-template-columns: 1fr;
  }
}

.related-item {
  background: #FFFFFF;
  border: 2px solid var(--color-graphite);
  border-radius: var(--radius-md);
  padding: 16px 20px;
  box-shadow: 2px 2px 0 var(--color-graphite);
  transition: all var(--transition-fast);
}

.related-item:hover {
  transform: translateY(-2px);
  box-shadow: 4px 4px 0 var(--color-graphite);
}

.related-item h5 {
  font-size: 0.95rem;
  font-weight: 800;
  margin-bottom: 6px;
}

.related-item p {
  font-size: 0.82rem;
  color: var(--color-text-muted);
  margin-bottom: 0;
}