/* ==========================================================================
   Skylinx 机场官网 — 折纸艺术与维度展开风 (Origami & Multi-Dimensional Unfold)
   Visual Tone: #EFEFED warm architectural paper + AO soft shadows + pastel facets
   ========================================================================== */

:root {
  --bg-paper: #EFEFED;
  --bg-paper-deep: #E6E6E2;
  --surface-white: #FFFFFF;
  --surface-ivory: #F8F7F3;
  --pastel-blue: #E4ECF2;
  --pastel-blush: #EFE3DC;
  --pastel-sage: #E1EBE5;
  --pastel-lilac: #EAE4F0;

  --ink-primary: #1C1D20;
  --ink-secondary: #53565C;
  --ink-muted: #84878E;
  --accent-indigo: #466380;
  --accent-coral: #C66A52;
  --accent-mint: #3B7D62;

  --crease-line: rgba(28, 29, 32, 0.09);
  --crease-strong: rgba(28, 29, 32, 0.16);

  --ao-sm: 0 2px 6px rgba(20, 22, 26, 0.04), 0 10px 22px rgba(20, 22, 26, 0.05);
  --ao-md: 0 6px 16px rgba(20, 22, 26, 0.05), 0 22px 46px rgba(20, 22, 26, 0.08);
  --ao-lg: 0 14px 32px rgba(20, 22, 26, 0.07), 0 40px 80px rgba(20, 22, 26, 0.12);

  --radius-sm: 10px;
  --radius-md: 18px;
  --radius-lg: 26px;

  --font-sans: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --font-mono: "JetBrains Mono", "SFMono-Regular", Consolas, "Liberation Mono", monospace;

  --container-max: 1200px;
  --nav-height: 72px;
  --ease-fold: cubic-bezier(0.22, 1, 0.36, 1);
}

*, *::before, *::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  background-color: var(--bg-paper);
  color: var(--ink-primary);
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
}

body {
  margin: 0;
  font-family: var(--font-sans);
  line-height: 1.7;
  background-color: var(--bg-paper);
  color: var(--ink-primary);
  overflow-x: hidden;
  position: relative;
}

/* Subtle paper grain & architectural draft grid */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
  background-image:
    linear-gradient(to right, rgba(28, 29, 32, 0.024) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(28, 29, 32, 0.024) 1px, transparent 1px);
  background-size: 64px 64px;
}

#origami-canvas {
  position: fixed;
  inset: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: 0;
}

main, header, footer, section {
  position: relative;
  z-index: 1;
}

a {
  color: inherit;
  text-decoration: none;
}

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

.container {
  width: min(100% - 40px, var(--container-max));
  margin-inline: auto;
}

.mono {
  font-family: var(--font-mono);
}

/* ==========================================================================
   Top Navigation Bar
   ========================================================================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--nav-height);
  background: rgba(239, 239, 237, 0.82);
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
  border-bottom: 1px solid var(--crease-line);
  transition: box-shadow 0.3s var(--ease-fold), background 0.3s ease;
}

.site-header.scrolled {
  background: rgba(248, 247, 243, 0.92);
  box-shadow: var(--ao-sm);
}

.nav-inner {
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 11px;
  font-weight: 700;
  letter-spacing: -0.02em;
  font-size: 1.05rem;
  flex-shrink: 0;
}

.brand-mark {
  width: 34px;
  height: 34px;
  display: grid;
  place-items: center;
  background: var(--surface-white);
  border: 1px solid var(--crease-line);
  border-radius: 10px;
  box-shadow: var(--ao-sm);
}

.brand-sub {
  font-size: 0.72rem;
  font-weight: 500;
  color: var(--ink-muted);
  letter-spacing: 0.06em;
  display: block;
  line-height: 1.1;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 6px;
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav-links a {
  display: inline-flex;
  align-items: center;
  padding: 7px 12px;
  font-size: 0.88rem;
  font-weight: 500;
  color: var(--ink-secondary);
  border-radius: 8px;
  transition: color 0.2s ease, background 0.2s ease, transform 0.2s ease;
  white-space: nowrap;
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--ink-primary);
  background: rgba(255, 255, 255, 0.75);
}

.nav-links a.nav-kb-link {
  color: var(--accent-indigo);
  background: rgba(228, 236, 242, 0.7);
  border: 1px solid rgba(70, 99, 128, 0.14);
}

.nav-links a.nav-kb-link:hover {
  background: var(--pastel-blue);
}

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

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 11px 22px;
  border-radius: 12px;
  font-size: 0.92rem;
  font-weight: 600;
  cursor: pointer;
  border: 1px solid transparent;
  transition: transform 0.25s var(--ease-fold), box-shadow 0.25s var(--ease-fold), background 0.25s ease;
}

.btn:hover {
  transform: translateY(-2px);
}

.btn-primary {
  background: var(--ink-primary);
  color: var(--surface-white);
  box-shadow: var(--ao-sm);
}

.btn-primary:hover {
  background: #2C2E33;
  box-shadow: var(--ao-md);
}

.btn-paper {
  background: var(--surface-white);
  color: var(--ink-primary);
  border-color: var(--crease-strong);
  box-shadow: var(--ao-sm);
}

.btn-paper:hover {
  background: var(--surface-ivory);
  box-shadow: var(--ao-md);
}

.btn-sm {
  padding: 8px 16px;
  font-size: 0.85rem;
  border-radius: 10px;
}

.nav-toggle {
  display: none;
  width: 40px;
  height: 40px;
  border-radius: 10px;
  background: var(--surface-white);
  border: 1px solid var(--crease-line);
  box-shadow: var(--ao-sm);
  align-items: center;
  justify-content: center;
  cursor: pointer;
}

/* ==========================================================================
   Hero Section — Compact Folded White Paper Airplane at Center
   ========================================================================== */
.hero {
  padding: 52px 0 64px;
  min-height: calc(100vh - var(--nav-height));
  display: flex;
  flex-direction: column;
  justify-content: center;
  position: relative;
}

.hero-layout {
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  align-items: center;
  gap: 48px;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 14px;
  background: var(--surface-white);
  border: 1px solid var(--crease-line);
  border-radius: 999px;
  box-shadow: var(--ao-sm);
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--accent-indigo);
  margin-bottom: 22px;
}

.hero-badge .dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--accent-mint);
  box-shadow: 0 0 0 4px rgba(59, 125, 98, 0.16);
}

.hero-title {
  font-size: clamp(2.1rem, 4.1vw, 3.35rem);
  line-height: 1.18;
  letter-spacing: -0.03em;
  margin: 0 0 20px;
  font-weight: 700;
}

.hero-title .accent-underline {
  position: relative;
  display: inline-block;
  z-index: 1;
}

.hero-title .accent-underline::after {
  content: "";
  position: absolute;
  left: -2px;
  right: -2px;
  bottom: 4px;
  height: 12px;
  background: var(--pastel-blush);
  z-index: -1;
  transform: skewX(-8deg);
}

.hero-manifesto {
  font-size: 1.12rem;
  color: var(--ink-primary);
  font-weight: 600;
  padding: 14px 18px;
  background: linear-gradient(135deg, rgba(255,255,255,0.92), rgba(248,247,243,0.85));
  border-left: 3px solid var(--accent-coral);
  border-radius: 0 14px 14px 0;
  box-shadow: var(--ao-sm);
  margin: 0 0 18px;
}

.hero-desc {
  font-size: 1rem;
  color: var(--ink-secondary);
  margin: 0 0 28px;
  max-width: 560px;
}

.hero-highlights {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 30px;
}

.highlight-chip {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 7px 13px;
  background: var(--surface-white);
  border: 1px solid var(--crease-line);
  border-radius: 10px;
  font-size: 0.83rem;
  font-weight: 500;
  color: var(--ink-secondary);
  box-shadow: var(--ao-sm);
}

.hero-cta-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 14px;
}

.hero-metrics {
  margin-top: 30px;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 14px;
  max-width: 520px;
}

.metric-fold {
  background: var(--surface-white);
  border: 1px solid var(--crease-line);
  border-radius: 14px;
  padding: 14px 16px;
  box-shadow: var(--ao-sm);
  position: relative;
}

.metric-fold::after {
  content: "";
  position: absolute;
  top: 0;
  right: 0;
  width: 14px;
  height: 14px;
  background: linear-gradient(225deg, var(--bg-paper) 50%, rgba(28, 29, 32, 0.06) 50%);
  border-bottom-left-radius: 4px;
}

.metric-value {
  font-family: var(--font-mono);
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--ink-primary);
  display: block;
}

.metric-label {
  font-size: 0.78rem;
  color: var(--ink-muted);
}

/* 3D Compact White Paper Airplane Centerpiece */
.hero-origami-stage {
  position: relative;
  height: 440px;
  display: grid;
  place-items: center;
  perspective: 1200px;
}

.origami-pedestal {
  position: relative;
  width: 340px;
  height: 340px;
  display: grid;
  place-items: center;
  transform-style: preserve-3d;
}

.pedestal-ring {
  position: absolute;
  width: 310px;
  height: 310px;
  border-radius: 50%;
  border: 1px dashed var(--crease-strong);
  transform: rotateX(68deg) translateZ(-70px);
  pointer-events: none;
}

.pedestal-shadow {
  position: absolute;
  width: 220px;
  height: 90px;
  border-radius: 50%;
  background: radial-gradient(ellipse at center, rgba(24, 26, 30, 0.16) 0%, rgba(24, 26, 30, 0.04) 55%, transparent 75%);
  transform: translateY(118px) rotateX(72deg);
  filter: blur(8px);
  transition: transform 0.2s ease;
}

.paper-plane-3d {
  width: 270px;
  height: 270px;
  position: relative;
  transform-style: preserve-3d;
  animation: planeHover 5.6s ease-in-out infinite;
  transition: transform 0.18s ease-out;
  cursor: grab;
}

@keyframes planeHover {
  0%, 100% { transform: translateY(0px) rotateX(18deg) rotateY(-22deg) rotateZ(-6deg); }
  50% { transform: translateY(-14px) rotateX(22deg) rotateY(-14deg) rotateZ(-3deg); }
}

.plane-svg {
  width: 100%;
  height: 100%;
  filter: drop-shadow(0 28px 34px rgba(24, 26, 30, 0.13)) drop-shadow(0 6px 12px rgba(24, 26, 30, 0.06));
  overflow: visible;
}

.plane-caption {
  position: absolute;
  bottom: 12px;
  left: 50%;
  transform: translateX(-50%);
  background: rgba(255, 255, 255, 0.88);
  border: 1px solid var(--crease-line);
  border-radius: 999px;
  padding: 6px 14px;
  font-size: 0.78rem;
  color: var(--ink-secondary);
  box-shadow: var(--ao-sm);
  white-space: nowrap;
}

/* ==========================================================================
   Section Common Headers
   ========================================================================== */
.section {
  padding: 88px 0;
}

.section-header {
  max-width: 700px;
  margin-bottom: 44px;
}

.section-header.centered {
  margin-inline: auto;
  text-align: center;
}

.section-kicker {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--accent-indigo);
  background: var(--surface-white);
  border: 1px solid var(--crease-line);
  padding: 5px 12px;
  border-radius: 999px;
  margin-bottom: 14px;
  box-shadow: var(--ao-sm);
}

.section-title {
  font-size: clamp(1.7rem, 3vw, 2.35rem);
  line-height: 1.24;
  letter-spacing: -0.02em;
  margin: 0 0 14px;
}

.section-subtitle {
  font-size: 1rem;
  color: var(--ink-secondary);
  margin: 0;
}

/* ==========================================================================
   Section 1: Scroll-Driven 3D Origami Multi-Dimensional Unfold
   ========================================================================== */
.unfold-section {
  padding: 96px 0;
  position: relative;
}

.unfold-controls {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 10px;
  margin-bottom: 34px;
}

.unfold-tab {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 18px;
  border-radius: 12px;
  background: var(--surface-white);
  border: 1px solid var(--crease-line);
  box-shadow: var(--ao-sm);
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--ink-secondary);
  cursor: pointer;
  transition: all 0.25s var(--ease-fold);
}

.unfold-tab.active {
  background: var(--ink-primary);
  color: var(--surface-white);
  box-shadow: var(--ao-md);
}

.unfold-progress-track {
  max-width: 560px;
  height: 6px;
  margin: 0 auto 38px;
  background: rgba(28, 29, 32, 0.08);
  border-radius: 999px;
  overflow: hidden;
}

.unfold-progress-bar {
  height: 100%;
  width: 33%;
  background: linear-gradient(90deg, var(--accent-indigo), var(--accent-coral));
  border-radius: 999px;
  transition: width 0.2s ease-out;
}

.unfold-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  perspective: 1400px;
}

.origami-facet-card {
  position: relative;
  background: var(--surface-white);
  border: 1px solid var(--crease-line);
  border-radius: var(--radius-lg);
  padding: 30px 26px;
  box-shadow: var(--ao-md);
  transform-style: preserve-3d;
  transition: transform 0.65s var(--ease-fold), box-shadow 0.4s ease, opacity 0.5s ease;
  overflow: hidden;
}

.origami-facet-card[data-facet="nodes"] {
  background: linear-gradient(155deg, #FFFFFF 0%, var(--pastel-blue) 140%);
  transform: rotateY(calc((1 - var(--unfold-1, 1)) * -24deg)) rotateX(calc((1 - var(--unfold-1, 1)) * 14deg)) translateY(calc((1 - var(--unfold-1, 1)) * 28px));
}

.origami-facet-card[data-facet="protocols"] {
  background: linear-gradient(155deg, #FFFFFF 0%, var(--pastel-blush) 140%);
  transform: rotateX(calc((1 - var(--unfold-2, 1)) * 22deg)) translateY(calc((1 - var(--unfold-2, 1)) * 34px));
}

.origami-facet-card[data-facet="tunnel"] {
  background: linear-gradient(155deg, #FFFFFF 0%, var(--pastel-sage) 140%);
  transform: rotateY(calc((1 - var(--unfold-3, 1)) * 24deg)) rotateX(calc((1 - var(--unfold-3, 1)) * 14deg)) translateY(calc((1 - var(--unfold-3, 1)) * 28px));
}

.origami-facet-card.focused {
  box-shadow: var(--ao-lg);
  border-color: rgba(70, 99, 128, 0.28);
}

/* Folded corner crease */
.origami-facet-card::before {
  content: "";
  position: absolute;
  top: 0;
  right: 0;
  width: 34px;
  height: 34px;
  background: linear-gradient(225deg, var(--bg-paper) 48%, rgba(28, 29, 32, 0.08) 50%, rgba(255,255,255,0.9) 52%);
  box-shadow: -3px 3px 8px rgba(24, 26, 30, 0.06);
}

.facet-index {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  font-weight: 700;
  color: var(--accent-indigo);
  letter-spacing: 0.08em;
  margin-bottom: 10px;
}

.origami-facet-card h3 {
  margin: 0 0 10px;
  font-size: 1.3rem;
}

.origami-facet-card p {
  margin: 0 0 18px;
  font-size: 0.93rem;
  color: var(--ink-secondary);
}

.facet-specs {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 10px;
  border-top: 1px dashed var(--crease-strong);
  padding-top: 16px;
}

.facet-specs li {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.87rem;
  color: var(--ink-primary);
}

.facet-specs .tag {
  font-family: var(--font-mono);
  font-size: 0.76rem;
  padding: 3px 9px;
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.85);
  border: 1px solid var(--crease-line);
  color: var(--ink-secondary);
}

/* ==========================================================================
   Section 3: Node Latency & Status Matrix
   ========================================================================== */
.node-toolbar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 24px;
}

.region-filters {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.filter-btn {
  padding: 8px 15px;
  border-radius: 10px;
  background: var(--surface-white);
  border: 1px solid var(--crease-line);
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--ink-secondary);
  cursor: pointer;
  box-shadow: var(--ao-sm);
  transition: all 0.2s ease;
}

.filter-btn.active,
.filter-btn:hover {
  background: var(--ink-primary);
  color: var(--surface-white);
}

.node-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(270px, 1fr));
  gap: 18px;
}

.node-card {
  background: var(--surface-white);
  border: 1px solid var(--crease-line);
  border-radius: var(--radius-md);
  padding: 20px;
  box-shadow: var(--ao-sm);
  transition: transform 0.28s var(--ease-fold), box-shadow 0.28s ease;
  position: relative;
}

.node-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--ao-md);
}

.node-card-top {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 10px;
  margin-bottom: 12px;
}

.node-name {
  font-weight: 700;
  font-size: 1rem;
  margin: 0 0 3px;
}

.node-route {
  font-size: 0.78rem;
  color: var(--ink-muted);
}

.latency-pill {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  font-weight: 700;
  padding: 4px 10px;
  border-radius: 999px;
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.latency-pill.fast {
  background: var(--pastel-sage);
  color: #265D47;
}

.latency-pill.medium {
  background: var(--pastel-blue);
  color: #2E4F72;
}

.latency-pill .pulse {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: currentColor;
}

.node-bars {
  margin: 12px 0;
}

.node-bar-label {
  display: flex;
  justify-content: space-between;
  font-size: 0.76rem;
  color: var(--ink-muted);
  margin-bottom: 5px;
}

.node-bar-track {
  height: 6px;
  border-radius: 999px;
  background: var(--bg-paper);
  overflow: hidden;
}

.node-bar-fill {
  height: 100%;
  border-radius: 999px;
  background: linear-gradient(90deg, var(--accent-indigo), var(--accent-mint));
  transition: width 0.5s var(--ease-fold);
}

.node-badges {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-top: 12px;
}

.node-badge {
  font-size: 0.73rem;
  padding: 3px 8px;
  border-radius: 6px;
  background: var(--surface-ivory);
  border: 1px solid var(--crease-line);
  color: var(--ink-secondary);
}

/* ==========================================================================
   Section 4A: Pricing Section (Origami Ticket Plans)
   ========================================================================== */
.billing-switch-wrap {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  margin-bottom: 34px;
}

.billing-pill {
  display: inline-flex;
  background: var(--surface-white);
  border: 1px solid var(--crease-line);
  border-radius: 14px;
  padding: 5px;
  box-shadow: var(--ao-sm);
}

.billing-btn {
  padding: 8px 18px;
  border: none;
  border-radius: 10px;
  background: transparent;
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--ink-secondary);
  cursor: pointer;
  transition: all 0.2s ease;
}

.billing-btn.active {
  background: var(--ink-primary);
  color: var(--surface-white);
}

.pricing-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.plan-card {
  background: var(--surface-white);
  border: 1px solid var(--crease-line);
  border-radius: var(--radius-lg);
  padding: 28px 22px;
  box-shadow: var(--ao-sm);
  display: flex;
  flex-direction: column;
  position: relative;
  transition: transform 0.3s var(--ease-fold), box-shadow 0.3s ease;
}

.plan-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--ao-md);
}

.plan-card.featured {
  background: linear-gradient(180deg, #FFFFFF 0%, var(--pastel-ivory, #FAF8F4) 100%);
  border: 1.5px solid var(--ink-primary);
  box-shadow: var(--ao-md);
}

.plan-ribbon {
  position: absolute;
  top: 16px;
  right: 16px;
  font-size: 0.72rem;
  font-weight: 700;
  padding: 4px 10px;
  border-radius: 999px;
  background: var(--pastel-blush);
  color: var(--accent-coral);
}

.plan-tier {
  font-size: 0.8rem;
  font-family: var(--font-mono);
  color: var(--ink-muted);
  margin-bottom: 6px;
}

.plan-name {
  font-size: 1.25rem;
  font-weight: 700;
  margin: 0 0 12px;
}

.plan-price-row {
  display: flex;
  align-items: baseline;
  gap: 4px;
  margin-bottom: 8px;
}

.plan-currency {
  font-size: 1rem;
  font-weight: 700;
}

.plan-amount {
  font-family: var(--font-mono);
  font-size: 2.1rem;
  font-weight: 700;
  letter-spacing: -0.03em;
}

.plan-period {
  font-size: 0.85rem;
  color: var(--ink-muted);
}

.plan-summary {
  font-size: 0.86rem;
  color: var(--ink-secondary);
  margin: 0 0 18px;
  padding-bottom: 16px;
  border-bottom: 1px dashed var(--crease-strong);
}

.plan-features {
  list-style: none;
  margin: 0 0 24px;
  padding: 0;
  display: grid;
  gap: 10px;
  flex: 1;
}

.plan-features li {
  display: flex;
  align-items: flex-start;
  gap: 8px;
  font-size: 0.86rem;
  color: var(--ink-primary);
}

.plan-features li::before {
  content: "◆";
  color: var(--accent-indigo);
  font-size: 0.65rem;
  margin-top: 5px;
  flex-shrink: 0;
}

/* ==========================================================================
   Section 4B: Core Advantages (化繁为简工程美学)
   ========================================================================== */
.advantages-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 22px;
}

.adv-card {
  background: var(--surface-white);
  border: 1px solid var(--crease-line);
  border-radius: var(--radius-md);
  padding: 26px 24px;
  box-shadow: var(--ao-sm);
  position: relative;
  overflow: hidden;
  transition: transform 0.28s var(--ease-fold), box-shadow 0.28s ease;
}

.adv-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--ao-md);
}

.adv-card.pastel-1 { background: linear-gradient(160deg, #FFFFFF 20%, var(--pastel-blue) 140%); }
.adv-card.pastel-2 { background: linear-gradient(160deg, #FFFFFF 20%, var(--pastel-blush) 140%); }
.adv-card.pastel-3 { background: linear-gradient(160deg, #FFFFFF 20%, var(--pastel-sage) 140%); }
.adv-card.pastel-4 { background: linear-gradient(160deg, #FFFFFF 20%, var(--pastel-lilac) 140%); }

.adv-icon {
  width: 44px;
  height: 44px;
  border-radius: 12px;
  background: var(--surface-ivory);
  border: 1px solid var(--crease-line);
  display: grid;
  place-items: center;
  margin-bottom: 16px;
  color: var(--ink-primary);
}

.adv-card h3 {
  font-size: 1.12rem;
  margin: 0 0 8px;
}

.adv-card p {
  font-size: 0.9rem;
  color: var(--ink-secondary);
  margin: 0;
}

/* ==========================================================================
   Section 5: FAQ Accordion & Internal Jump to Standalone Knowledge Base
   ========================================================================== */
.faq-layout {
  display: grid;
  grid-template-columns: 0.9fr 1.1fr;
  gap: 40px;
  align-items: start;
}

.kb-redirect-card {
  margin-top: 24px;
  background: linear-gradient(145deg, #FFFFFF 0%, var(--pastel-blue) 125%);
  border: 1px solid rgba(70, 99, 128, 0.2);
  border-radius: var(--radius-md);
  padding: 24px;
  box-shadow: var(--ao-sm);
}

.kb-redirect-card h3 {
  margin: 0 0 8px;
  font-size: 1.12rem;
}

.kb-redirect-card p {
  margin: 0 0 16px;
  font-size: 0.9rem;
  color: var(--ink-secondary);
}

.faq-list {
  display: grid;
  gap: 12px;
}

.faq-item {
  background: var(--surface-white);
  border: 1px solid var(--crease-line);
  border-radius: 16px;
  box-shadow: var(--ao-sm);
  overflow: hidden;
}

.faq-question {
  width: 100%;
  text-align: left;
  padding: 18px 22px;
  background: transparent;
  border: none;
  font-family: inherit;
  font-size: 0.98rem;
  font-weight: 600;
  color: var(--ink-primary);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  cursor: pointer;
}

.faq-toggle-icon {
  width: 24px;
  height: 24px;
  border-radius: 50%;
  background: var(--bg-paper);
  display: grid;
  place-items: center;
  flex-shrink: 0;
  font-family: var(--font-mono);
  transition: transform 0.25s ease;
}

.faq-item.open .faq-toggle-icon {
  transform: rotate(45deg);
  background: var(--ink-primary);
  color: var(--surface-white);
}

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

.faq-answer-inner {
  padding: 0 22px 18px;
  font-size: 0.91rem;
  color: var(--ink-secondary);
  border-top: 1px dashed var(--crease-line);
  padding-top: 14px;
}

/* ==========================================================================
   Section 6: User Reviews (文创 / UI-UX / 跨境极客评价)
   ========================================================================== */
.reviews-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.review-card {
  background: var(--surface-white);
  border: 1px solid var(--crease-line);
  border-radius: var(--radius-md);
  padding: 24px;
  box-shadow: var(--ao-sm);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 18px;
}

.review-stars {
  font-size: 0.85rem;
  color: var(--accent-coral);
  letter-spacing: 0.1em;
  margin-bottom: 10px;
}

.review-quote {
  font-size: 0.93rem;
  color: var(--ink-primary);
  margin: 0;
}

.review-author {
  display: flex;
  align-items: center;
  gap: 12px;
  padding-top: 14px;
  border-top: 1px dashed var(--crease-line);
}

.review-avatar {
  width: 40px;
  height: 40px;
  border-radius: 12px;
  background: var(--pastel-blue);
  display: grid;
  place-items: center;
  font-weight: 700;
  color: var(--accent-indigo);
  flex-shrink: 0;
}

.review-name {
  font-weight: 700;
  font-size: 0.92rem;
}

.review-role {
  font-size: 0.78rem;
  color: var(--ink-muted);
}

/* ==========================================================================
   Bottom Boarding Pass Reassembly Card (登机凭证卡片)
   ========================================================================== */
.boarding-section {
  padding: 80px 0 100px;
}

.boarding-stage {
  position: relative;
  max-width: 960px;
  margin-inline: auto;
}

.origami-shards {
  display: flex;
  justify-content: center;
  gap: 16px;
  margin-bottom: 18px;
  pointer-events: none;
}

.shard {
  width: 56px;
  height: 36px;
  background: var(--surface-white);
  border: 1px solid var(--crease-line);
  box-shadow: var(--ao-sm);
  clip-path: polygon(0 100%, 50% 0, 100% 100%);
  transition: transform 0.8s var(--ease-fold), opacity 0.8s ease;
}

.shard.s1 { background: var(--pastel-blue); transform: translate(-60px, -30px) rotate(-28deg); opacity: 0.5; }
.shard.s2 { background: var(--surface-white); transform: translate(-20px, -48px) rotate(14deg); opacity: 0.5; }
.shard.s3 { background: var(--pastel-blush); transform: translate(20px, -44px) rotate(-18deg); opacity: 0.5; }
.shard.s4 { background: var(--pastel-sage); transform: translate(60px, -28px) rotate(32deg); opacity: 0.5; }

.boarding-stage.assembled .shard {
  transform: translate(0, 18px) rotate(0deg) scale(0.82);
  opacity: 0.95;
}

.boarding-pass {
  display: grid;
  grid-template-columns: 1.5fr 0.72fr;
  background: var(--surface-white);
  border: 1px solid var(--crease-strong);
  border-radius: 24px;
  box-shadow: var(--ao-lg);
  overflow: hidden;
  transform: translateY(24px) scale(0.97);
  transition: transform 0.8s var(--ease-fold), box-shadow 0.8s ease;
}

.boarding-stage.assembled .boarding-pass {
  transform: translateY(0) scale(1);
}

.boarding-main {
  padding: 34px 36px;
  position: relative;
  border-right: 2px dashed var(--crease-strong);
}

.boarding-main::before,
.boarding-main::after {
  content: "";
  position: absolute;
  right: -13px;
  width: 24px;
  height: 24px;
  border-radius: 50%;
  background: var(--bg-paper);
  border: 1px solid var(--crease-line);
}

.boarding-main::before { top: -12px; }
.boarding-main::after { bottom: -12px; }

.boarding-top {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 24px;
}

.boarding-carrier {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 0.88rem;
  letter-spacing: 0.08em;
  color: var(--accent-indigo);
}

.boarding-class {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  padding: 4px 10px;
  border-radius: 8px;
  background: var(--pastel-blue);
  color: var(--ink-primary);
}

.boarding-route {
  display: flex;
  align-items: center;
  gap: 20px;
  margin-bottom: 24px;
}

.airport-code {
  font-family: var(--font-mono);
  font-size: 2.1rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.1;
}

.airport-city {
  font-size: 0.8rem;
  color: var(--ink-muted);
}

.route-line {
  flex: 1;
  height: 2px;
  border-top: 2px dashed var(--crease-strong);
  position: relative;
}

.route-line::after {
  content: "✈";
  position: absolute;
  top: -13px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--surface-white);
  padding: 0 8px;
  color: var(--accent-coral);
  font-size: 1rem;
}

.boarding-meta-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 14px;
  padding-top: 18px;
  border-top: 1px solid var(--crease-line);
}

.boarding-meta-label {
  font-size: 0.72rem;
  color: var(--ink-muted);
  text-transform: uppercase;
  font-family: var(--font-mono);
}

.boarding-meta-val {
  font-family: var(--font-mono);
  font-size: 0.92rem;
  font-weight: 700;
}

.boarding-stub {
  padding: 34px 28px;
  background: linear-gradient(170deg, var(--surface-ivory) 0%, var(--pastel-blue) 160%);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 18px;
}

.stub-title {
  font-size: 1.05rem;
  font-weight: 700;
  margin: 0 0 6px;
}

.stub-desc {
  font-size: 0.84rem;
  color: var(--ink-secondary);
  margin: 0;
}

.barcode-strip {
  height: 36px;
  background: repeating-linear-gradient(
    90deg,
    var(--ink-primary) 0 2px,
    transparent 2px 5px,
    var(--ink-primary) 5px 8px,
    transparent 8px 10px,
    var(--ink-primary) 10px 11px,
    transparent 11px 15px
  );
  opacity: 0.78;
  border-radius: 4px;
}

/* ==========================================================================
   Footer (Clean — NO sitemap.xml or robots.txt references on landing page)
   ========================================================================== */
.site-footer {
  border-top: 1px solid var(--crease-line);
  background: rgba(248, 247, 243, 0.7);
  padding: 46px 0 34px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr;
  gap: 32px;
  margin-bottom: 28px;
}

.footer-links {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 8px;
  font-size: 0.88rem;
  color: var(--ink-secondary);
}

.footer-links a:hover {
  color: var(--ink-primary);
}

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 12px;
  padding-top: 20px;
  border-top: 1px dashed var(--crease-line);
  font-size: 0.82rem;
  color: var(--ink-muted);
}

/* ==========================================================================
   Standalone Knowledge Base & Article Styles (kb/*.html)
   ========================================================================== */
.kb-hero {
  padding: 64px 0 38px;
}

.kb-filter-bar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 28px;
}

.kb-search {
  padding: 10px 16px;
  border-radius: 12px;
  border: 1px solid var(--crease-strong);
  background: var(--surface-white);
  font-family: inherit;
  font-size: 0.9rem;
  min-width: 260px;
  box-shadow: var(--ao-sm);
}

.kb-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 22px;
  padding-bottom: 84px;
}

.kb-card {
  background: var(--surface-white);
  border: 1px solid var(--crease-line);
  border-radius: var(--radius-md);
  padding: 24px;
  box-shadow: var(--ao-sm);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 14px;
  transition: transform 0.25s var(--ease-fold), box-shadow 0.25s ease;
}

.kb-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--ao-md);
}

.kb-card-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.78rem;
  color: var(--ink-muted);
}

.kb-cat-tag {
  padding: 3px 9px;
  border-radius: 8px;
  background: var(--pastel-blue);
  color: var(--accent-indigo);
  font-weight: 600;
}

.kb-card h2 {
  font-size: 1.08rem;
  line-height: 1.4;
  margin: 0;
}

.kb-card p {
  font-size: 0.87rem;
  color: var(--ink-secondary);
  margin: 0;
}

.kb-keywords {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.kb-kw {
  font-size: 0.73rem;
  padding: 2px 8px;
  border-radius: 6px;
  background: var(--surface-ivory);
  border: 1px solid var(--crease-line);
  color: var(--ink-secondary);
}

/* Article Detail Page */
.article-wrap {
  padding: 46px 0 88px;
  display: grid;
  grid-template-columns: minmax(0, 1fr) 310px;
  gap: 34px;
  align-items: start;
}

.article-paper {
  background: var(--surface-white);
  border: 1px solid var(--crease-line);
  border-radius: var(--radius-lg);
  padding: 44px 48px;
  box-shadow: var(--ao-md);
}

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  font-size: 0.83rem;
  color: var(--ink-muted);
  margin-bottom: 18px;
}

.breadcrumb a:hover {
  color: var(--ink-primary);
}

.article-header h1 {
  font-size: clamp(1.65rem, 2.8vw, 2.2rem);
  line-height: 1.3;
  margin: 0 0 16px;
}

.article-meta-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  font-size: 0.84rem;
  color: var(--ink-muted);
  padding-bottom: 20px;
  margin-bottom: 28px;
  border-bottom: 1px dashed var(--crease-strong);
}

.article-content h2 {
  font-size: 1.32rem;
  margin: 34px 0 12px;
  padding-left: 12px;
  border-left: 3px solid var(--accent-indigo);
}

.article-content h3 {
  font-size: 1.08rem;
  margin: 22px 0 10px;
}

.article-content p {
  margin: 0 0 16px;
  color: #2A2C30;
  line-height: 1.85;
}

.article-content ul, .article-content ol {
  margin: 0 0 18px;
  padding-left: 22px;
  color: #2A2C30;
}

.article-content li {
  margin-bottom: 8px;
  line-height: 1.75;
}

.article-callout {
  background: var(--surface-ivory);
  border: 1px solid var(--crease-line);
  border-left: 3px solid var(--accent-coral);
  border-radius: 12px;
  padding: 16px 20px;
  margin: 22px 0;
  font-size: 0.93rem;
}

.article-sidebar {
  position: sticky;
  top: 94px;
  display: grid;
  gap: 20px;
}

.sidebar-card {
  background: var(--surface-white);
  border: 1px solid var(--crease-line);
  border-radius: var(--radius-md);
  padding: 22px;
  box-shadow: var(--ao-sm);
}

.sidebar-card h3 {
  font-size: 0.98rem;
  margin: 0 0 12px;
}

.toc-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 8px;
  font-size: 0.85rem;
  color: var(--ink-secondary);
}

.toc-list a:hover {
  color: var(--ink-primary);
}

/* ==========================================================================
   Responsive Breakpoints
   ========================================================================== */
@media (max-width: 1024px) {
  .hero-layout,
  .faq-layout,
  .article-wrap {
    grid-template-columns: 1fr;
  }
  .pricing-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .unfold-grid,
  .advantages-grid,
  .reviews-grid,
  .kb-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .boarding-pass {
    grid-template-columns: 1fr;
  }
  .boarding-main {
    border-right: none;
    border-bottom: 2px dashed var(--crease-strong);
  }
  .boarding-main::before, .boarding-main::after {
    display: none;
  }
}

@media (max-width: 860px) {
  .nav-links {
    display: none;
    position: absolute;
    top: var(--nav-height);
    left: 0;
    right: 0;
    background: rgba(248, 247, 243, 0.98);
    border-bottom: 1px solid var(--crease-line);
    padding: 16px 20px;
    flex-direction: column;
    align-items: stretch;
    box-shadow: var(--ao-md);
  }
  .nav-links.open {
    display: flex;
  }
  .nav-toggle {
    display: inline-flex;
  }
}

@media (max-width: 640px) {
  .pricing-grid,
  .unfold-grid,
  .advantages-grid,
  .reviews-grid,
  .kb-grid,
  .footer-grid {
    grid-template-columns: 1fr;
  }
  .hero-metrics {
    grid-template-columns: 1fr;
  }
  .article-paper {
    padding: 26px 20px;
  }
  .hero-origami-stage {
    height: 340px;
  }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
}