:root {
  --ink: #202728;
  --ink-soft: #343c3d;
  --panel: rgba(255, 255, 255, 0.94);
  --panel-dark: rgba(28, 32, 31, 0.78);
  --line: rgba(244, 119, 0, 0.3);
  --line-soft: rgba(255, 255, 255, 0.14);
  --teal: #2f6f68;
  --cyan: #8da5aa;
  --amber: #f47700;
  --amber-soft: #fff2e8;
  --amber-line: #f4a35f;
  --olive: #7f8d73;
  --paper: #f7f5f1;
  --muted: #69706e;
  --white: #ffffff;
  --shadow: 0 22px 56px rgba(48, 42, 34, 0.12);
  --radius: 8px;
  font-family: "Inter", "Noto Sans SC", "Microsoft YaHei", system-ui, sans-serif;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background:
    linear-gradient(180deg, #fbfaf7 0%, var(--paper) 100%);
  letter-spacing: 0;
  overflow-x: hidden;
}

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

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

.site-shell {
  min-height: 100vh;
  overflow: hidden;
}

.nav {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 40;
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 72px;
  padding: 14px clamp(18px, 5vw, 72px);
  color: var(--white);
  background: linear-gradient(180deg, rgba(24, 29, 29, 0.86), rgba(24, 29, 29, 0.4) 72%, transparent);
  backdrop-filter: blur(12px);
}

.brand {
  display: grid;
  gap: 2px;
  min-width: 210px;
}

.brand strong {
  font-size: 18px;
  line-height: 1.15;
  font-weight: 700;
}

.brand span {
  font-size: 11px;
  color: rgba(255, 255, 255, 0.68);
  text-transform: uppercase;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: clamp(12px, 2vw, 28px);
  font-size: 14px;
  color: rgba(255, 255, 255, 0.78);
}

.nav-links a {
  position: relative;
  padding: 10px 0;
}

.nav-links a::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 5px;
  width: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--amber), var(--amber-line));
  transition: width 220ms ease;
}

.nav-links a:hover::after,
body[data-page="home"] .nav-links a[href="index.html"]::after,
body[data-page="strategy"] .nav-links a[href="strategy.html"]::after,
body[data-page="ecosystem"] .nav-links a[href="ecosystem.html"]::after,
body[data-page="zone"] .nav-links a[href="aviation-zone.html"]::after,
body[data-page="cooperation"] .nav-links a[href="cooperation.html"]::after {
  width: 100%;
}

.menu-toggle {
  display: none;
  width: 42px;
  height: 42px;
  border: 1px solid rgba(255, 255, 255, 0.22);
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.08);
  color: var(--white);
  cursor: pointer;
}

.hero {
  position: relative;
  min-height: 96vh;
  display: grid;
  align-items: end;
  padding: 116px clamp(20px, 6vw, 88px) 56px;
  color: var(--white);
  isolation: isolate;
}

.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -3;
  background: var(--hero-image) center / cover no-repeat;
  transform: scale(1.02);
  animation: slowDrift 18s ease-in-out infinite alternate;
}

.hero::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -2;
  background:
    linear-gradient(90deg, rgba(22, 27, 27, 0.94), rgba(31, 35, 34, 0.72) 48%, rgba(54, 48, 40, 0.36)),
    linear-gradient(180deg, rgba(23, 28, 28, 0.48), rgba(23, 28, 28, 0.92));
}

.hero-grid {
  position: absolute;
  inset: 0;
  z-index: -1;
  opacity: 0.36;
  background-image:
    linear-gradient(rgba(244, 119, 0, 0.09) 1px, transparent 1px),
    linear-gradient(90deg, rgba(244, 119, 0, 0.08) 1px, transparent 1px);
  background-size: 84px 84px;
  mask-image: linear-gradient(180deg, transparent, #000 20%, #000 78%, transparent);
}

.hero-content {
  width: min(100%, 980px);
  max-width: 980px;
  min-width: 0;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 20px;
  color: var(--amber-line);
  font-size: 13px;
  text-transform: uppercase;
}

.eyebrow::before {
  content: "";
  width: 42px;
  height: 1px;
  background: var(--amber);
}

h1,
h2,
h3,
p {
  margin-top: 0;
}

h1 {
  max-width: 900px;
  margin-bottom: 24px;
  font-size: clamp(42px, 8vw, 92px);
  line-height: 0.98;
  font-weight: 760;
  overflow-wrap: anywhere;
  word-break: break-all;
  line-break: anywhere;
}

.hero-lede {
  width: 100%;
  max-width: 720px;
  margin-bottom: 34px;
  color: rgba(255, 255, 255, 0.82);
  font-size: clamp(17px, 2.2vw, 22px);
  line-height: 1.8;
  overflow-wrap: anywhere;
  word-break: break-all;
}

.hero-actions,
.section-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 0 20px;
  border: 1px solid rgba(255, 255, 255, 0.2);
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.1);
  color: var(--white);
  font-weight: 650;
  transition: transform 180ms ease, border-color 180ms ease, background 180ms ease;
}

.btn.primary {
  border-color: transparent;
  background: linear-gradient(135deg, var(--amber), #ff9b38);
  color: #21130a;
}

.btn.dark {
  color: var(--ink);
  border-color: rgba(7, 19, 22, 0.16);
  background: var(--white);
}

.btn:hover {
  transform: translateY(-2px);
  border-color: rgba(244, 119, 0, 0.72);
}

.metrics-strip {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  margin-top: 64px;
  border: 1px solid rgba(255, 255, 255, 0.16);
  background: rgba(30, 34, 33, 0.54);
  backdrop-filter: blur(16px);
}

.metric {
  padding: 22px;
  border-right: 1px solid rgba(255, 255, 255, 0.12);
}

.metric:last-child {
  border-right: 0;
}

.metric strong {
  display: block;
  margin-bottom: 8px;
  color: var(--white);
  font-size: clamp(24px, 4vw, 38px);
}

.metric span {
  color: rgba(255, 255, 255, 0.66);
  font-size: 13px;
}

.section {
  position: relative;
  padding: clamp(72px, 9vw, 128px) clamp(20px, 6vw, 88px);
}

.section.dark {
  color: var(--white);
  background:
    linear-gradient(135deg, rgba(32, 39, 40, 0.96), rgba(55, 49, 41, 0.95)),
    radial-gradient(circle at 18% 18%, rgba(244, 119, 0, 0.18), transparent 34%);
}

.section-head {
  display: grid;
  grid-template-columns: minmax(0, 0.82fr) minmax(260px, 0.45fr);
  gap: clamp(28px, 6vw, 72px);
  align-items: end;
  margin-bottom: clamp(36px, 5vw, 64px);
}

.section-head h2 {
  margin-bottom: 0;
  font-size: clamp(30px, 5vw, 58px);
  line-height: 1.12;
}

.section-head p,
.lead {
  color: var(--muted);
  font-size: 17px;
  line-height: 1.8;
}

.dark .section-head p,
.dark .lead {
  color: rgba(255, 255, 255, 0.68);
}

.cards {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
}

.card {
  position: relative;
  min-height: 230px;
  padding: 28px;
  border: 1px solid rgba(69, 61, 49, 0.1);
  border-radius: var(--radius);
  background: var(--panel);
  box-shadow: var(--shadow);
  overflow: hidden;
}

.dark .card {
  border-color: rgba(255, 255, 255, 0.12);
  background: rgba(255, 255, 255, 0.06);
  box-shadow: none;
}

.card::before {
  content: "";
  position: absolute;
  inset: 0 auto auto 0;
  width: 3px;
  height: 100%;
  background: linear-gradient(180deg, var(--amber), var(--amber-line));
}

.card small {
  display: block;
  margin-bottom: 24px;
  color: var(--amber);
  font-weight: 700;
}

.card h3 {
  margin-bottom: 14px;
  font-size: 22px;
}

.card p {
  margin-bottom: 0;
  color: var(--muted);
  line-height: 1.75;
}

.dark .card p {
  color: rgba(255, 255, 255, 0.7);
}

.split {
  display: grid;
  grid-template-columns: minmax(0, 0.92fr) minmax(320px, 0.72fr);
  gap: clamp(28px, 6vw, 72px);
  align-items: center;
}

.media-panel {
  position: relative;
  min-height: 470px;
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
}

.media-panel img {
  width: 100%;
  height: 100%;
  min-height: 470px;
  object-fit: cover;
}

.media-panel::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(0deg, rgba(4, 16, 19, 0.62), transparent 56%);
}

.caption-panel {
  position: absolute;
  left: 22px;
  right: 22px;
  bottom: 22px;
  z-index: 1;
  padding: 20px;
  border: 1px solid rgba(255, 255, 255, 0.18);
  border-radius: var(--radius);
  background: rgba(5, 20, 24, 0.68);
  color: var(--white);
  backdrop-filter: blur(12px);
}

.caption-panel strong {
  display: block;
  margin-bottom: 8px;
  font-size: 18px;
}

.caption-panel span {
  color: rgba(255, 255, 255, 0.68);
  line-height: 1.6;
}

.feature-list {
  display: grid;
  gap: 16px;
}

.feature-row {
  display: grid;
  grid-template-columns: 52px minmax(0, 1fr);
  gap: 18px;
  align-items: start;
  padding: 18px;
  border: 1px solid rgba(69, 61, 49, 0.1);
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.7);
}

.dark .feature-row {
  border-color: rgba(255, 255, 255, 0.12);
  background: rgba(255, 255, 255, 0.06);
}

.num {
  display: grid;
  place-items: center;
  width: 52px;
  height: 52px;
  border-radius: 50%;
  color: #041316;
  background: linear-gradient(135deg, var(--amber), #ffb066);
  font-weight: 800;
}

.feature-row h3 {
  margin-bottom: 6px;
  font-size: 19px;
}

.feature-row p {
  margin-bottom: 0;
  color: var(--muted);
  line-height: 1.7;
}

.dark .feature-row p {
  color: rgba(255, 255, 255, 0.68);
}

.network {
  position: relative;
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 16px;
  margin-top: 26px;
}

.node {
  position: relative;
  min-height: 150px;
  padding: 20px;
  border: 1px solid rgba(244, 119, 0, 0.26);
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.075);
}

.node::after {
  content: "";
  position: absolute;
  top: 34px;
  right: -17px;
  width: 16px;
  height: 1px;
  background: var(--line);
}

.node:last-child::after {
  display: none;
}

.node strong {
  display: block;
  margin-bottom: 12px;
  color: #ffb066;
}

.node span {
  color: rgba(255, 255, 255, 0.68);
  font-size: 14px;
  line-height: 1.65;
}

.timeline {
  display: grid;
  grid-template-columns: repeat(6, minmax(0, 1fr));
  gap: 0;
  border: 1px solid rgba(69, 61, 49, 0.12);
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--white);
  box-shadow: var(--shadow);
}

.step {
  min-height: 220px;
  padding: 24px;
  border-right: 1px solid rgba(69, 61, 49, 0.1);
}

.step:last-child {
  border-right: 0;
}

.step strong {
  display: block;
  margin-bottom: 22px;
  color: var(--amber);
  font-size: 28px;
}

.step h3 {
  font-size: 19px;
}

.step p {
  color: var(--muted);
  line-height: 1.7;
}

.cta-band {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 24px;
  align-items: center;
  padding: clamp(34px, 6vw, 64px);
  color: var(--white);
  background:
    linear-gradient(135deg, rgba(22, 27, 27, 0.94), rgba(58, 43, 29, 0.76)),
    url("assets/images/drone-city-flight.jpg") center 48% / cover no-repeat;
  overflow: hidden;
}

.cta-band::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background:
    linear-gradient(90deg, rgba(244, 119, 0, 0.18) 1px, transparent 1px),
    linear-gradient(rgba(255, 255, 255, 0.08) 1px, transparent 1px);
  background-size: 72px 72px;
  opacity: 0.34;
  mask-image: linear-gradient(90deg, #000, transparent 76%);
}

.cta-band > * {
  position: relative;
  z-index: 1;
}

.cta-band h2 {
  margin-bottom: 12px;
  font-size: clamp(28px, 4vw, 48px);
}

.cta-band p {
  margin-bottom: 0;
  max-width: 760px;
  color: rgba(255, 255, 255, 0.72);
  line-height: 1.8;
}

.footer {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 20px;
  padding: 34px clamp(20px, 6vw, 88px);
  color: rgba(255, 255, 255, 0.68);
  background: #1d2425;
}

.footer strong {
  display: block;
  color: var(--white);
  margin-bottom: 6px;
}

.reveal {
  opacity: 0;
  transform: translateY(22px);
  transition: opacity 700ms ease, transform 700ms ease;
}

.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

@keyframes slowDrift {
  from {
    transform: scale(1.02) translate3d(0, 0, 0);
  }
  to {
    transform: scale(1.08) translate3d(-1.5%, 1%, 0);
  }
}

@media (max-width: 980px) {
  .menu-toggle {
    display: block;
  }

  .nav-links {
    position: absolute;
    left: 18px;
    right: 18px;
    top: 70px;
    display: none;
    flex-direction: column;
    align-items: stretch;
    padding: 16px;
    border: 1px solid rgba(255, 255, 255, 0.16);
    border-radius: var(--radius);
    background: rgba(5, 18, 21, 0.94);
  }

  .nav.open .nav-links {
    display: flex;
  }

  .section-head,
  .split,
  .cta-band,
  .footer {
    grid-template-columns: 1fr;
  }

  .cards,
  .metrics-strip,
  .network,
  .timeline {
    grid-template-columns: 1fr 1fr;
  }

  .node::after {
    display: none;
  }
}

@media (max-width: 640px) {
  .brand {
    min-width: 0;
  }

  .hero {
    min-height: 92vh;
  }

  .hero-content {
    width: calc(100vw - 58px);
    max-width: calc(100vw - 58px);
  }

  h1 {
    max-width: 300px;
    font-size: clamp(32px, 10vw, 40px);
    line-height: 1.06;
  }

  .hero-lede {
    max-width: 310px;
    font-size: 16px;
  }

  .cards,
  .metrics-strip,
  .network,
  .timeline {
    grid-template-columns: 1fr;
  }

  .metric,
  .step {
    border-right: 0;
    border-bottom: 1px solid rgba(7, 19, 22, 0.1);
  }

  .media-panel,
  .media-panel img {
    min-height: 340px;
  }
}