:root {
  --ink: #16201d;
  --muted: #5c6863;
  --line: #dce5e0;
  --paper: #f6f8f5;
  --white: #ffffff;
  --green: #0c8a52;
  --green-deep: #075738;
  --cyan: #16a7b6;
  --amber: #d99a22;
  --red: #c44738;
  --graphite: #222827;
  --shadow: 0 18px 50px rgba(20, 33, 29, 0.16);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: "Microsoft YaHei", "PingFang SC", "Segoe UI", Arial, sans-serif;
  line-height: 1.6;
}

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

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

.site-header {
  position: fixed;
  z-index: 20;
  top: 0;
  left: 0;
  right: 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 28px;
  padding: 18px 42px;
  color: var(--white);
  transition: background 180ms ease, box-shadow 180ms ease, color 180ms ease;
}

.site-header.is-scrolled {
  color: var(--ink);
  background: rgba(255, 255, 255, 0.94);
  box-shadow: 0 10px 30px rgba(22, 32, 29, 0.08);
  backdrop-filter: blur(14px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  min-width: 168px;
}

.brand-mark {
  display: grid;
  width: 42px;
  height: 42px;
  place-items: center;
  border-radius: 8px;
  background: var(--green);
  color: var(--white);
  font-weight: 800;
}

.brand strong,
.brand small {
  display: block;
}

.brand small {
  color: currentColor;
  font-size: 12px;
  opacity: 0.76;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 26px;
  font-size: 14px;
}

.site-nav a {
  position: relative;
  padding: 6px 0;
}

.site-nav a::after {
  position: absolute;
  left: 0;
  bottom: 0;
  width: 0;
  height: 2px;
  background: var(--green);
  content: "";
  transition: width 180ms ease;
}

.site-nav a:hover::after {
  width: 100%;
}

.hero {
  position: relative;
  min-height: 88vh;
  overflow: hidden;
  color: var(--white);
  background: var(--graphite);
}

.hero-media,
.hero-shade {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
}

.hero-media {
  object-fit: cover;
}

.hero-shade {
  background: rgba(0, 0, 0, 0.42);
}

.hero-content {
  position: relative;
  z-index: 2;
  max-width: 760px;
  padding: 154px 42px 190px;
}

.eyebrow {
  margin: 0 0 12px;
  color: var(--green);
  font-size: 13px;
  font-weight: 800;
  letter-spacing: 0;
  text-transform: uppercase;
}

.hero .eyebrow {
  color: #8ef0b9;
}

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

h1 {
  margin-bottom: 18px;
  font-size: 76px;
  line-height: 1;
  letter-spacing: 0;
}

h2 {
  margin-bottom: 18px;
  font-size: 42px;
  line-height: 1.16;
  letter-spacing: 0;
}

h3 {
  margin-bottom: 10px;
  font-size: 21px;
  line-height: 1.28;
  letter-spacing: 0;
}

.hero-copy {
  max-width: 650px;
  margin-bottom: 30px;
  font-size: 21px;
  color: rgba(255, 255, 255, 0.9);
}

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

.primary-action,
.secondary-action {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 46px;
  padding: 0 20px;
  border-radius: 8px;
  font-weight: 800;
}

.primary-action {
  background: var(--green);
  color: var(--white);
}

.secondary-action {
  border: 1px solid rgba(255, 255, 255, 0.62);
  color: var(--white);
}

.site-header.is-scrolled + main .secondary-action {
  color: var(--white);
}

.hero-metrics {
  position: absolute;
  z-index: 3;
  right: 42px;
  bottom: 28px;
  display: grid;
  width: min(610px, calc(100% - 84px));
  grid-template-columns: repeat(3, minmax(0, 1fr));
  border: 1px solid rgba(255, 255, 255, 0.24);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.12);
  backdrop-filter: blur(18px);
}

.hero-metrics article {
  min-height: 104px;
  padding: 20px;
  border-right: 1px solid rgba(255, 255, 255, 0.18);
}

.hero-metrics article:last-child {
  border-right: 0;
}

.hero-metrics strong {
  display: block;
  font-size: 32px;
  line-height: 1;
}

.hero-metrics span {
  display: block;
  margin-top: 10px;
  color: rgba(255, 255, 255, 0.78);
  font-size: 14px;
}

.section {
  width: min(1180px, calc(100% - 56px));
  margin: 0 auto;
  padding: 88px 0;
}

.intro {
  display: grid;
  grid-template-columns: minmax(260px, 0.92fr) minmax(320px, 1.08fr);
  gap: 58px;
  align-items: start;
}

.section-heading {
  max-width: 760px;
}

.section-heading.compact {
  max-width: 620px;
}

.lead {
  margin: 0;
  color: var(--muted);
  font-size: 24px;
}

.capability-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 16px;
}

.capability {
  min-height: 286px;
  padding: 26px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--white);
  box-shadow: 0 8px 26px rgba(22, 32, 29, 0.05);
}

.capability:nth-child(2) {
  border-top: 4px solid var(--cyan);
}

.capability:nth-child(3) {
  border-top: 4px solid var(--amber);
}

.capability:nth-child(4) {
  border-top: 4px solid var(--red);
}

.capability-index {
  display: inline-block;
  margin-bottom: 28px;
  color: var(--green);
  font-size: 14px;
  font-weight: 900;
}

.capability p,
.region-detail p,
.timeline p,
.capability p {
  color: var(--muted);
}

.network {
  width: 100%;
  padding: 92px max(28px, calc((100% - 1180px) / 2));
  background: #eaf0ea;
}

.network-layout {
  display: grid;
  grid-template-columns: 300px minmax(0, 1fr);
  gap: 28px;
  align-items: stretch;
}

.region-panel {
  display: grid;
  gap: 10px;
  align-content: start;
}

.region-tab {
  min-height: 58px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--white);
  color: var(--ink);
  cursor: pointer;
  font: inherit;
  font-weight: 800;
  text-align: left;
  padding: 0 18px;
}

.region-tab.is-active {
  border-color: var(--green);
  background: var(--green);
  color: var(--white);
}

.region-detail {
  min-height: 330px;
  padding: 36px;
  border-radius: 8px;
  background: var(--white);
  box-shadow: var(--shadow);
}

.region-kicker {
  color: var(--green);
  font-weight: 900;
}

.city-cloud {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 28px;
}

.city-cloud span {
  min-height: 36px;
  padding: 6px 12px;
  border: 1px solid var(--line);
  border-radius: 8px;
  color: var(--graphite);
  background: #f7faf8;
  font-weight: 700;
}

.timeline {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
  margin: 26px 0 0;
  padding: 0;
  list-style: none;
}

.timeline li {
  min-height: 260px;
  padding: 28px;
  border-radius: 8px;
  color: var(--white);
  background: var(--graphite);
}

.timeline li:nth-child(2) {
  background: var(--green-deep);
}

.timeline li:nth-child(3) {
  background: #674819;
}

.timeline time {
  display: block;
  margin-bottom: 52px;
  color: #9ee7bd;
  font-size: 15px;
  font-weight: 900;
}

.timeline p {
  color: rgba(255, 255, 255, 0.78);
}

.closing {
  width: 100%;
  margin-top: 24px;
  padding: 92px max(28px, calc((100% - 980px) / 2));
  color: var(--white);
  background: var(--green-deep);
}

.closing .eyebrow {
  color: #9ee7bd;
}

.closing h2 {
  max-width: 850px;
}

@media (max-width: 980px) {
  .site-header {
    padding: 14px 22px;
  }

  .site-nav {
    gap: 14px;
    font-size: 13px;
  }

  h1 {
    font-size: 58px;
  }

  h2 {
    font-size: 34px;
  }

  .hero-content {
    padding: 132px 28px 220px;
  }

  .hero-metrics {
    left: 28px;
    right: 28px;
    width: auto;
  }

  .intro,
  .network-layout {
    grid-template-columns: 1fr;
  }

  .capability-grid,
  .timeline {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 680px) {
  .site-header {
    align-items: flex-start;
    flex-direction: column;
    gap: 8px;
  }

  .site-nav {
    width: 100%;
    justify-content: space-between;
    gap: 8px;
  }

  .site-nav a {
    font-size: 12px;
  }

  .hero {
    min-height: 92vh;
  }

  .hero-media {
    object-position: 58% center;
  }

  .hero-content {
    padding: 156px 22px 250px;
  }

  h1 {
    font-size: 44px;
  }

  h2 {
    font-size: 28px;
  }

  .hero-copy,
  .lead {
    font-size: 18px;
  }

  .hero-metrics {
    grid-template-columns: 1fr;
    left: 22px;
    right: 22px;
    bottom: 18px;
  }

  .hero-metrics article {
    min-height: auto;
    padding: 14px 16px;
    border-right: 0;
    border-bottom: 1px solid rgba(255, 255, 255, 0.18);
  }

  .hero-metrics article:last-child {
    border-bottom: 0;
  }

  .section {
    width: min(100% - 32px, 1180px);
    padding: 64px 0;
  }

  .capability-grid,
  .timeline {
    grid-template-columns: 1fr;
  }

  .network,
  .closing {
    padding-left: 16px;
    padding-right: 16px;
  }

  .region-detail {
    padding: 24px;
  }
}