/* ==========================================================================
   影子机场 - 视觉规范与响应式样式表
   Visual Direction:
     - Split-screen Product Design
     - Palette:
         White: #FFFFFF
         Almost-Black: #20252A
         Warm Light Gray: #F1F0EC
         Restrained Coral: #D47E70
     - Headings: Heavy system sans-serif
     - Body: Lighter system sans-serif (17px)
     - Dashboard labels: Monospace
     - H1: 56px desktop / 36px mobile
     - One-time split-panel entrance & restrained coral hover cues
     - Reduced-motion support
     - No neon
   ========================================================================== */

:root {
  --color-white: #FFFFFF;
  --color-dark: #20252A;
  --color-dark-surface: #292F36;
  --color-dark-border: rgba(255, 255, 255, 0.1);
  --color-gray-bg: #F1F0EC;
  --color-gray-card: #FFFFFF;
  --color-gray-subtle: #E8E6E0;
  --color-coral: #D47E70;
  --color-coral-hover: #C26B5D;
  --color-coral-bg: rgba(212, 126, 112, 0.1);
  --color-text-primary: #20252A;
  --color-text-secondary: #575D65;
  --color-text-light: #F1F0EC;
  --color-text-light-muted: #A3A8B1;
  --color-border: #E2E0D8;
  --font-heading: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --font-body: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --font-mono: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, Courier, monospace;
  --max-width: 1280px;
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --transition-fast: 0.2s cubic-bezier(0.2, 0, 0, 1);
  --transition-normal: 0.35s cubic-bezier(0.2, 0, 0, 1);
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  background-color: var(--color-white);
  color: var(--color-text-primary);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-body);
  font-weight: 400;
  font-size: 17px;
  line-height: 1.68;
  color: var(--color-text-primary);
  background-color: var(--color-white);
  overflow-x: hidden;
}

/* Typography Hierarchy */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: 800;
  color: var(--color-dark);
  line-height: 1.25;
  letter-spacing: -0.02em;
}

h1 {
  font-size: 36px;
  line-height: 1.2;
}

@media (min-width: 1024px) {
  h1 {
    font-size: 56px;
    line-height: 1.15;
  }
}

h2 {
  font-size: 28px;
  line-height: 1.25;
  margin-bottom: 16px;
}

@media (min-width: 768px) {
  h2 {
    font-size: 38px;
  }
}

h3 {
  font-size: 20px;
  line-height: 1.35;
  margin-bottom: 10px;
}

@media (min-width: 768px) {
  h3 {
    font-size: 22px;
  }
}

p {
  margin-bottom: 16px;
  color: var(--color-text-secondary);
}

p:last-child {
  margin-bottom: 0;
}

a {
  color: inherit;
  text-decoration: none;
  transition: color var(--transition-fast), border-color var(--transition-fast);
}

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

.mono-tag {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

/* Accessibility & Utilities */
.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.skip-link {
  position: absolute;
  top: -100px;
  left: 20px;
  background: var(--color-coral);
  color: var(--color-white);
  padding: 12px 20px;
  z-index: 9999;
  font-weight: 700;
  transition: top var(--transition-fast);
}

.skip-link:focus {
  top: 20px;
}

.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

@media (min-width: 768px) {
  .container {
    padding: 0 40px;
  }
}

/* Header & Navigation */
.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background-color: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border);
  transition: background-color var(--transition-fast);
}

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

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

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

.nav-links a {
  font-size: 15px;
  font-weight: 600;
  color: var(--color-dark);
  position: relative;
  padding: 6px 0;
}

.nav-links a:hover,
.nav-links a:focus-visible {
  color: var(--color-coral);
}

.nav-links a::after {
  content: '';
  position: absolute;
  left: 0;
  bottom: 0;
  width: 0;
  height: 2px;
  background-color: var(--color-coral);
  transition: width var(--transition-fast);
}

.nav-links a:hover::after,
.nav-links a:focus-visible::after {
  width: 100%;
}

.header-actions {
  display: none;
  align-items: center;
  gap: 16px;
}

.mobile-toggle {
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  width: 44px;
  height: 44px;
  background: transparent;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  cursor: pointer;
  padding: 10px;
  gap: 5px;
}

.mobile-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background-color: var(--color-dark);
  transition: transform var(--transition-fast), opacity var(--transition-fast);
}

.mobile-toggle[aria-expanded="true"] span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.mobile-toggle[aria-expanded="true"] span:nth-child(2) {
  opacity: 0;
}

.mobile-toggle[aria-expanded="true"] span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

@media (min-width: 1024px) {
  .nav-links {
    display: flex;
  }
  .header-actions {
    display: flex;
  }
  .mobile-toggle {
    display: none;
  }
}

/* Mobile Nav Drawer */
.mobile-nav {
  display: none;
  position: fixed;
  top: 72px;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: var(--color-white);
  padding: 32px 24px;
  flex-direction: column;
  gap: 20px;
  border-top: 1px solid var(--color-border);
  z-index: 999;
  overflow-y: auto;
}

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

.mobile-nav a {
  font-size: 18px;
  font-weight: 700;
  color: var(--color-dark);
  padding: 12px 0;
  border-bottom: 1px solid var(--color-gray-subtle);
}

.mobile-nav a:hover {
  color: var(--color-coral);
}

/* Buttons & CTA Cues */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 24px;
  font-size: 15px;
  font-weight: 700;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--transition-fast);
  border: 1px solid transparent;
  white-space: nowrap;
}

.btn-primary {
  background-color: var(--color-coral);
  color: var(--color-white);
}

.btn-primary:hover,
.btn-primary:focus-visible {
  background-color: var(--color-coral-hover);
  transform: translateY(-1px);
}

.btn-secondary {
  background-color: transparent;
  color: var(--color-dark);
  border-color: var(--color-dark);
}

.btn-secondary:hover,
.btn-secondary:focus-visible {
  background-color: var(--color-dark);
  color: var(--color-white);
  transform: translateY(-1px);
}

.btn-dark {
  background-color: var(--color-dark);
  color: var(--color-white);
}

.btn-dark:hover,
.btn-dark:focus-visible {
  background-color: #333940;
}

.btn-outline-light {
  background-color: transparent;
  color: var(--color-white);
  border-color: rgba(255, 255, 255, 0.3);
}

.btn-outline-light:hover,
.btn-outline-light:focus-visible {
  border-color: var(--color-coral);
  color: var(--color-coral);
}

.btn-sm {
  padding: 8px 16px;
  font-size: 13px;
}

.btn-lg {
  padding: 16px 32px;
  font-size: 16px;
}

/* ==========================================================================
   Hero Section - Strong Split Screen
   Desktop: White Copy (Left) + Dark Visualization (Right)
   Mobile: Stack Cleanly
   Entrance: Split-panel entrance animation
   ========================================================================== */

.hero-split {
  display: flex;
  flex-direction: column;
  width: 100%;
  min-height: calc(100vh - 72px);
  position: relative;
  background-color: var(--color-white);
}

@media (min-width: 1024px) {
  .hero-split {
    flex-direction: row;
    min-height: 720px;
  }
}

.hero-copy-half {
  flex: 1;
  background-color: var(--color-white);
  padding: 48px 24px;
  display: flex;
  align-items: center;
  justify-content: center;
  animation: heroSlideInLeft 0.8s cubic-bezier(0.16, 1, 0.3, 1) forwards;
}

@media (min-width: 768px) {
  .hero-copy-half {
    padding: 72px 48px;
  }
}

@media (min-width: 1024px) {
  .hero-copy-half {
    padding: 80px 56px 80px 64px;
  }
}

.hero-copy-inner {
  max-width: 580px;
  width: 100%;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 14px;
  background-color: var(--color-gray-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  color: var(--color-dark);
  font-size: 13px;
  font-weight: 600;
  margin-bottom: 24px;
}

.hero-badge .badge-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background-color: var(--color-coral);
}

.hero-copy-inner h1 {
  margin-bottom: 20px;
  color: var(--color-dark);
}

.hero-desc {
  font-size: 17px;
  line-height: 1.7;
  color: var(--color-text-secondary);
  margin-bottom: 32px;
}

.hero-cta-group {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  margin-bottom: 36px;
}

.hero-specs-row {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  padding-top: 28px;
  border-top: 1px solid var(--color-gray-subtle);
}

.hero-spec-item {
  display: flex;
  flex-direction: column;
}

.hero-spec-label {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--color-text-secondary);
  margin-bottom: 4px;
}

.hero-spec-value {
  font-size: 16px;
  font-weight: 700;
  color: var(--color-dark);
}

/* Hero Dark Visualization Half */
.hero-visual-half {
  flex: 1;
  background-color: var(--color-dark);
  color: var(--color-text-light);
  padding: 48px 24px;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
  animation: heroSlideInRight 0.8s cubic-bezier(0.16, 1, 0.3, 1) forwards;
}

@media (min-width: 768px) {
  .hero-visual-half {
    padding: 72px 48px;
  }
}

@media (min-width: 1024px) {
  .hero-visual-half {
    padding: 80px 64px 80px 56px;
  }
}

/* Subtle background grid pattern on dark half */
.hero-visual-half::before {
  content: '';
  position: absolute;
  inset: 0;
  background-image: 
    linear-gradient(to right, rgba(255, 255, 255, 0.04) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(255, 255, 255, 0.04) 1px, transparent 1px);
  background-size: 32px 32px;
  pointer-events: none;
}

.dashboard-panel {
  position: relative;
  z-index: 2;
  width: 100%;
  max-width: 520px;
  background-color: var(--color-dark-surface);
  border: 1px solid var(--color-dark-border);
  border-radius: var(--radius-md);
  padding: 24px;
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.3);
}

.dashboard-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-bottom: 16px;
  margin-bottom: 20px;
  border-bottom: 1px solid var(--color-dark-border);
}

.dashboard-title {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
  color: var(--color-text-light);
  letter-spacing: 0.04em;
}

.dashboard-indicator {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background-color: var(--color-coral);
}

.dashboard-protocol {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--color-coral);
  padding: 2px 8px;
  border: 1px solid rgba(212, 126, 112, 0.3);
  border-radius: var(--radius-sm);
  background: rgba(212, 126, 112, 0.05);
}

/* Vertical Network Route Ladder (Strictly factual: NO fake live stats, NO fake pings) */
.route-ladder {
  display: flex;
  flex-direction: column;
  gap: 14px;
  position: relative;
}

.route-ladder::before {
  content: '';
  position: absolute;
  top: 24px;
  bottom: 24px;
  left: 20px;
  width: 2px;
  background-color: rgba(255, 255, 255, 0.15);
  z-index: 1;
}

.route-step {
  position: relative;
  z-index: 2;
  display: flex;
  align-items: flex-start;
  gap: 16px;
  padding: 12px 14px;
  background-color: rgba(255, 255, 255, 0.02);
  border: 1px solid rgba(255, 255, 255, 0.06);
  border-radius: var(--radius-sm);
  transition: border-color var(--transition-fast), background-color var(--transition-fast);
}

.route-step:hover {
  border-color: var(--color-coral);
  background-color: rgba(212, 126, 112, 0.04);
}

.step-node {
  width: 14px;
  height: 14px;
  border-radius: 50%;
  border: 2px solid var(--color-coral);
  background-color: var(--color-dark-surface);
  flex-shrink: 0;
  margin-top: 4px;
}

.step-content {
  flex: 1;
}

.step-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 4px;
}

.step-region {
  font-size: 14px;
  font-weight: 700;
  color: var(--color-text-light);
}

.step-tag {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--color-text-light-muted);
}

.step-desc {
  font-size: 13px;
  color: var(--color-text-light-muted);
  line-height: 1.4;
  margin: 0;
}

.dashboard-footer {
  margin-top: 20px;
  padding-top: 14px;
  border-top: 1px solid var(--color-dark-border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--color-text-light-muted);
}

/* Animations */
@keyframes heroSlideInLeft {
  from {
    opacity: 0;
    transform: translateX(-30px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

@keyframes heroSlideInRight {
  from {
    opacity: 0;
    transform: translateX(30px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

@media (prefers-reduced-motion: reduce) {
  .hero-copy-half,
  .hero-visual-half,
  * {
    animation: none !important;
    transition: none !important;
  }
}

/* ==========================================================================
   Section Compositions (Alternating Wide Text & Diagram)
   ========================================================================== */

.section-block {
  padding: 80px 0;
  border-bottom: 1px solid var(--color-gray-subtle);
}

@media (min-width: 1024px) {
  .section-block {
    padding: 104px 0;
  }
}

.section-block.bg-warm {
  background-color: var(--color-gray-bg);
}

.section-header {
  margin-bottom: 48px;
}

.section-header.text-center {
  text-align: center;
  max-width: 760px;
  margin-left: auto;
  margin-right: auto;
}

.section-tag {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  color: var(--color-coral);
  letter-spacing: 0.1em;
  margin-bottom: 8px;
}

.section-lead {
  font-size: 18px;
  color: var(--color-text-secondary);
  line-height: 1.6;
}

/* Alternating Grid Layout */
.alt-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 40px;
  align-items: center;
}

@media (min-width: 1024px) {
  .alt-grid {
    grid-template-columns: 1.1fr 0.9fr;
    gap: 64px;
  }
  .alt-grid.reverse {
    grid-template-columns: 0.9fr 1.1fr;
  }
  .alt-grid.reverse .alt-text {
    order: 2;
  }
  .alt-grid.reverse .alt-diagram {
    order: 1;
  }
}

.alt-text h3 {
  font-size: 24px;
  margin-bottom: 16px;
}

.alt-text p {
  margin-bottom: 20px;
}

.alt-features {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-top: 24px;
}

.alt-features li {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  font-size: 16px;
  color: var(--color-dark);
}

.alt-features li svg {
  flex-shrink: 0;
  margin-top: 4px;
  color: var(--color-coral);
}

/* Diagram Components (Clean, technical, no neon) */
.diagram-box {
  background-color: var(--color-dark);
  color: var(--color-text-light);
  border-radius: var(--radius-md);
  padding: 32px;
  border: 1px solid var(--color-dark-border);
  position: relative;
}

.diagram-box.light-theme {
  background-color: var(--color-white);
  color: var(--color-dark);
  border: 1px solid var(--color-border);
}

.diagram-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 24px;
  padding-bottom: 12px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.diagram-box.light-theme .diagram-header {
  border-bottom: 1px solid var(--color-border);
}

.diagram-title {
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.05em;
}

/* ==========================================================================
   Advantages Section - NOT Equal-Sized Cards (Asymmetrical Hierarchy)
   ========================================================================== */

.asymmetric-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 24px;
}

@media (min-width: 1024px) {
  .asymmetric-grid {
    grid-template-columns: 1.4fr 1fr;
  }
}

.adv-card {
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 36px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  transition: border-color var(--transition-fast), transform var(--transition-fast);
}

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

.adv-card-large {
  background-color: var(--color-dark);
  color: var(--color-text-light);
  border-color: var(--color-dark-surface);
}

.adv-card-large:hover {
  border-color: var(--color-coral);
}

.adv-card-large h3 {
  color: var(--color-white);
  font-size: 26px;
}

.adv-card-large p {
  color: var(--color-text-light-muted);
}

.adv-side-stack {
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.adv-card-small {
  padding: 28px;
}

.adv-num {
  font-family: var(--font-mono);
  font-size: 14px;
  font-weight: 700;
  color: var(--color-coral);
  margin-bottom: 12px;
}

/* Route Ladder Matrix in Global Nodes */
.node-grid-list {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
}

@media (min-width: 640px) {
  .node-grid-list {
    grid-template-columns: repeat(2, 1fr);
  }
}

.node-item {
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 18px 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  transition: border-color var(--transition-fast);
}

.node-item:hover {
  border-color: var(--color-coral);
}

.node-region-title {
  font-size: 16px;
  font-weight: 700;
  color: var(--color-dark);
  margin-bottom: 4px;
}

.node-usecase {
  font-size: 13px;
  color: var(--color-text-secondary);
}

.node-protocol-tag {
  font-family: var(--font-mono);
  font-size: 11px;
  padding: 4px 8px;
  background-color: var(--color-gray-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  color: var(--color-dark);
}

/* ==========================================================================
   AI & Streaming Explanatory Scenarios Grid
   Covering: ChatGPT, Claude, Gemini, Google AI Studio, Perplexity, Cursor,
             YouTube, Netflix, Disney+, Spotify, Twitch
   ========================================================================== */

.scenario-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 20px;
}

@media (min-width: 640px) {
  .scenario-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1024px) {
  .scenario-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.scenario-card {
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 24px;
  display: flex;
  flex-direction: column;
  transition: border-color var(--transition-fast), transform var(--transition-fast);
}

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

.scenario-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--color-coral);
  margin-bottom: 12px;
  font-weight: 700;
}

.scenario-card h4 {
  font-size: 18px;
  font-weight: 700;
  color: var(--color-dark);
  margin-bottom: 8px;
}

.scenario-card p {
  font-size: 14px;
  line-height: 1.6;
  color: var(--color-text-secondary);
  flex-grow: 1;
}

.scenario-target {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--color-text-secondary);
  padding-top: 12px;
  border-top: 1px solid var(--color-gray-subtle);
  margin-top: 14px;
}

/* ==========================================================================
   Pricing Section - Full-Width Matrix
   Strictly verified current package data / labeled editorial placeholders
   ========================================================================== */

.pricing-matrix-wrap {
  width: 100%;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  margin-top: 32px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background-color: var(--color-white);
}

.pricing-table {
  width: 100%;
  min-width: 780px;
  border-collapse: collapse;
  text-align: left;
}

.pricing-table th,
.pricing-table td {
  padding: 20px 24px;
  border-bottom: 1px solid var(--color-border);
  vertical-align: middle;
}

.pricing-table th {
  background-color: var(--color-gray-bg);
  font-family: var(--font-heading);
  font-size: 14px;
  font-weight: 800;
  color: var(--color-dark);
  letter-spacing: 0.02em;
}

.pricing-table tbody tr:last-child td {
  border-bottom: none;
}

.pricing-table tbody tr:hover {
  background-color: rgba(212, 126, 112, 0.02);
}

.pkg-name {
  font-size: 17px;
  font-weight: 800;
  color: var(--color-dark);
  display: block;
}

.pkg-desc {
  font-size: 13px;
  color: var(--color-text-secondary);
}

.pkg-price {
  font-size: 22px;
  font-weight: 800;
  color: var(--color-dark);
  font-family: var(--font-heading);
}

.pkg-price span {
  font-size: 13px;
  font-weight: 400;
  color: var(--color-text-secondary);
}

.editorial-tag {
  display: inline-block;
  font-size: 11px;
  font-family: var(--font-mono);
  background: var(--color-gray-bg);
  border: 1px solid var(--color-border);
  padding: 2px 6px;
  border-radius: var(--radius-sm);
  color: var(--color-text-secondary);
}

.pricing-notice {
  margin-top: 16px;
  font-size: 13px;
  color: var(--color-text-secondary);
  line-height: 1.5;
}

/* ==========================================================================
   Nine Article Cards - Compact Numbered Summaries
   Placed after pricing in 3 desktop / 2 tablet / 1 mobile columns
   ========================================================================== */

.articles-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 24px;
  margin-top: 36px;
}

@media (min-width: 640px) {
  .articles-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1024px) {
  .articles-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.article-card-compact {
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 28px;
  display: flex;
  flex-direction: column;
  transition: all var(--transition-fast);
  position: relative;
}

.article-card-compact:hover {
  border-color: var(--color-coral);
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(32, 37, 42, 0.05);
}

.article-num {
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
  color: var(--color-coral);
  margin-bottom: 12px;
}

.article-card-compact h3 {
  font-size: 18px;
  font-weight: 700;
  line-height: 1.4;
  margin-bottom: 10px;
  color: var(--color-dark);
}

.article-card-compact p {
  font-size: 14px;
  line-height: 1.6;
  color: var(--color-text-secondary);
  margin-bottom: 18px;
  flex-grow: 1;
}

.article-card-link {
  font-size: 14px;
  font-weight: 700;
  color: var(--color-dark);
  display: inline-flex;
  align-items: center;
  gap: 6px;
  transition: color var(--transition-fast);
}

.article-card-compact:hover .article-card-link {
  color: var(--color-coral);
}

/* ==========================================================================
   Testimonials - Clearly Labeled Sample Feedback
   No fake ratings or invented guarantees
   ========================================================================== */

.testimonials-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 24px;
  margin-top: 36px;
}

@media (min-width: 768px) {
  .testimonials-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.testimonial-card {
  background-color: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 28px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.testimonial-sample-tag {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--color-coral);
  background-color: var(--color-coral-bg);
  padding: 2px 8px;
  border-radius: var(--radius-sm);
  display: inline-block;
  align-self: flex-start;
  margin-bottom: 16px;
}

.testimonial-quote {
  font-size: 15px;
  line-height: 1.65;
  color: var(--color-dark);
  margin-bottom: 20px;
}

.testimonial-author {
  display: flex;
  flex-direction: column;
  border-top: 1px solid var(--color-gray-subtle);
  padding-top: 14px;
}

.author-role {
  font-size: 14px;
  font-weight: 700;
  color: var(--color-dark);
}

.author-scenario {
  font-size: 12px;
  color: var(--color-text-secondary);
}

/* ==========================================================================
   FAQ Section - Open List Accordion
   ========================================================================== */

.faq-list {
  display: flex;
  flex-direction: column;
  gap: 16px;
  max-width: 860px;
  margin: 0 auto;
}

.faq-item {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  background-color: var(--color-white);
  overflow: hidden;
  transition: border-color var(--transition-fast);
}

.faq-item:hover,
.faq-item[open] {
  border-color: var(--color-coral);
}

.faq-summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 20px 24px;
  font-size: 17px;
  font-weight: 700;
  color: var(--color-dark);
  cursor: pointer;
  list-style: none;
}

.faq-summary::-webkit-details-marker {
  display: none;
}

.faq-summary::after {
  content: '+';
  font-family: var(--font-mono);
  font-size: 20px;
  font-weight: 400;
  color: var(--color-coral);
  transition: transform var(--transition-fast);
}

.faq-item[open] .faq-summary::after {
  content: '−';
}

.faq-answer {
  padding: 0 24px 22px 24px;
  font-size: 15px;
  line-height: 1.7;
  color: var(--color-text-secondary);
  border-top: 1px solid var(--color-gray-subtle);
  padding-top: 16px;
}

/* ==========================================================================
   Footer
   Links to About, Terms, Privacy, Sitemap, Tutorial, and 3 external resources
   ========================================================================== */

.site-footer {
  background-color: var(--color-dark);
  color: var(--color-text-light);
  padding: 64px 0 32px 0;
  border-top: 1px solid var(--color-dark-border);
}

.footer-top {
  display: grid;
  grid-template-columns: 1fr;
  gap: 40px;
  margin-bottom: 48px;
}

@media (min-width: 768px) {
  .footer-top {
    grid-template-columns: 2fr 1fr 1fr 1.2fr;
  }
}

.footer-brand-desc {
  font-size: 14px;
  color: var(--color-text-light-muted);
  line-height: 1.6;
  margin-top: 14px;
  max-width: 320px;
}

.footer-col h5 {
  font-size: 14px;
  font-weight: 700;
  color: var(--color-white);
  letter-spacing: 0.05em;
  margin-bottom: 16px;
  text-transform: uppercase;
}

.footer-col ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.footer-col ul a {
  font-size: 14px;
  color: var(--color-text-light-muted);
}

.footer-col ul a:hover {
  color: var(--color-coral);
}

.footer-bottom {
  display: flex;
  flex-direction: column;
  gap: 16px;
  padding-top: 32px;
  border-top: 1px solid var(--color-dark-border);
  align-items: center;
  justify-content: space-between;
  font-size: 13px;
  color: var(--color-text-light-muted);
}

@media (min-width: 768px) {
  .footer-bottom {
    flex-direction: row;
  }
}

/* ==========================================================================
   Article Pages & Editorial Layout
   ========================================================================== */

.article-hero {
  background-color: var(--color-gray-bg);
  padding: 48px 0;
  border-bottom: 1px solid var(--color-border);
}

@media (min-width: 768px) {
  .article-hero {
    padding: 64px 0;
  }
}

.breadcrumb-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  font-size: 13px;
  font-family: var(--font-mono);
  color: var(--color-text-secondary);
  margin-bottom: 20px;
}

.breadcrumb-nav a:hover {
  color: var(--color-coral);
}

.breadcrumb-sep {
  color: var(--color-coral);
}

.article-container {
  max-width: 860px;
  margin: 0 auto;
  padding: 48px 24px;
}

@media (min-width: 768px) {
  .article-container {
    padding: 64px 24px;
  }
}

.article-body {
  font-size: 17px;
  line-height: 1.8;
  color: var(--color-dark);
}

.article-body h2 {
  font-size: 26px;
  margin-top: 48px;
  margin-bottom: 16px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--color-gray-subtle);
}

.article-body h3 {
  font-size: 20px;
  margin-top: 32px;
  margin-bottom: 12px;
}

.article-body p {
  margin-bottom: 20px;
  color: #333940;
}

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

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

.callout-box {
  background-color: var(--color-gray-bg);
  border-left: 4px solid var(--color-coral);
  padding: 20px 24px;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  margin: 28px 0;
}

.callout-box p:last-child {
  margin-bottom: 0;
}

.article-faq {
  margin-top: 56px;
  padding-top: 36px;
  border-top: 1px solid var(--color-border);
}

.related-articles {
  margin-top: 48px;
  padding: 32px;
  background-color: var(--color-gray-bg);
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border);
}

.related-articles h3 {
  margin-bottom: 16px;
}

.related-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
}

@media (min-width: 640px) {
  .related-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

.related-item {
  background-color: var(--color-white);
  padding: 16px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--color-border);
  transition: border-color var(--transition-fast);
}

.related-item:hover {
  border-color: var(--color-coral);
}

.related-item a {
  font-weight: 700;
  font-size: 15px;
  color: var(--color-dark);
}

.related-item a:hover {
  color: var(--color-coral);
}