:root {
  color-scheme: light;
  --ink: #12212f;
  --muted: #5d6c7d;
  --line: #d9e3ec;
  --soft: #f3f7fb;
  --panel: #ffffff;
  --green: #218c59;
  --green-dark: #12633f;
  --blue: #1f6f9f;
  --orange: #f37a3d;
  --shadow: 0 22px 60px rgba(25, 42, 61, 0.12);
  font-family: Inter, "Microsoft YaHei", "PingFang SC", system-ui, sans-serif;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: #fbfdff;
  color: var(--ink);
  letter-spacing: 0;
}

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

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 24px;
  padding: 14px clamp(18px, 4vw, 56px);
  border-bottom: 1px solid rgba(217, 227, 236, 0.86);
  background: rgba(251, 253, 255, 0.92);
  backdrop-filter: blur(16px);
}

.brand {
  display: inline-flex;
  align-items: center;
}

.brand img {
  display: block;
  width: 102px;
  height: auto;
}

nav {
  display: flex;
  justify-content: center;
  gap: clamp(14px, 3vw, 32px);
  color: var(--muted);
  font-size: 15px;
}

nav a:hover,
.login-link:hover {
  color: var(--green-dark);
}

.login-link,
.primary-action,
.secondary-action {
  display: inline-flex;
  min-height: 44px;
  align-items: center;
  justify-content: center;
  border-radius: 8px;
  font-weight: 700;
  line-height: 1;
  white-space: nowrap;
}

.login-link {
  min-width: 82px;
  border: 1px solid var(--line);
  background: var(--panel);
  box-shadow: 0 6px 18px rgba(25, 42, 61, 0.07);
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1.02fr) minmax(330px, 0.78fr);
  gap: clamp(32px, 6vw, 72px);
  align-items: center;
  min-height: calc(100vh - 73px);
  padding: clamp(54px, 8vw, 96px) clamp(18px, 5vw, 72px) 64px;
  background:
    radial-gradient(circle at 8% 18%, rgba(31, 111, 159, 0.12), transparent 30%),
    linear-gradient(135deg, #fbfdff 0%, #eef6f1 48%, #fff7f1 100%);
}

.hero-copy {
  max-width: 760px;
}

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

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

h1 {
  max-width: 720px;
  margin-bottom: 22px;
  font-size: clamp(38px, 6vw, 76px);
  line-height: 1.04;
  letter-spacing: 0;
}

.hero-text {
  max-width: 660px;
  margin-bottom: 30px;
  color: #3f5061;
  font-size: clamp(17px, 2vw, 21px);
  line-height: 1.75;
}

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

.primary-action {
  min-width: 152px;
  padding: 0 22px;
  background: var(--ink);
  color: #fff;
  box-shadow: 0 14px 32px rgba(18, 33, 47, 0.22);
}

.primary-action:hover {
  background: #223345;
}

.secondary-action {
  min-width: 142px;
  padding: 0 20px;
  border: 1px solid #c8d8e5;
  background: rgba(255, 255, 255, 0.72);
  color: #263849;
}

.network-panel {
  position: relative;
  display: grid;
  gap: 16px;
  padding: clamp(18px, 3vw, 28px);
  border: 1px solid rgba(207, 221, 232, 0.9);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.78);
  box-shadow: var(--shadow);
}

.signal-card {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: 58px 1fr;
  gap: 4px 16px;
  align-items: center;
  min-height: 104px;
  padding: 18px;
  border: 1px solid #d8e4ee;
  border-radius: 8px;
  background: #fff;
}

.signal-card span {
  grid-row: span 2;
  display: inline-flex;
  width: 58px;
  height: 58px;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  background: #e9f5ef;
  color: var(--green-dark);
  font-weight: 800;
}

.signal-card strong {
  font-size: 19px;
}

.signal-card small {
  color: var(--muted);
  font-size: 14px;
  line-height: 1.5;
}

.signal-card.active {
  border-color: rgba(33, 140, 89, 0.38);
}

.signal-card.dark {
  background: var(--ink);
  color: #fff;
}

.signal-card.dark span {
  background: rgba(255, 255, 255, 0.13);
  color: #fff;
}

.signal-card.dark small {
  color: #c9d6e2;
}

.signal-path {
  width: 72%;
  height: 2px;
  margin: -2px auto;
  background: linear-gradient(90deg, var(--green), var(--blue), var(--orange));
  opacity: 0.5;
}

.signal-path.reverse {
  background: linear-gradient(90deg, var(--orange), var(--blue), var(--green));
}

.section {
  padding: 82px clamp(18px, 5vw, 72px);
}

.section-heading {
  max-width: 760px;
  margin-bottom: 34px;
}

.section-heading h2,
.access-band h2 {
  margin-bottom: 14px;
  font-size: clamp(28px, 4vw, 44px);
  line-height: 1.16;
}

.section-heading p:not(.eyebrow),
.access-band p {
  color: var(--muted);
  font-size: 17px;
  line-height: 1.75;
}

.route-grid,
.assurance-grid {
  display: grid;
  gap: 18px;
}

.route-grid {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.route-grid article,
.assurance-grid article {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--panel);
  box-shadow: 0 12px 36px rgba(25, 42, 61, 0.08);
}

.route-grid article {
  min-height: 246px;
  padding: 28px;
}

.tag {
  display: inline-flex;
  margin-bottom: 22px;
  padding: 7px 11px;
  border: 1px solid #cae0d4;
  border-radius: 999px;
  background: #eef8f3;
  color: var(--green-dark);
  font-size: 13px;
  font-weight: 800;
}

.route-grid h3,
.assurance-grid h3 {
  margin-bottom: 12px;
  font-size: 23px;
}

.route-grid p,
.assurance-grid p {
  color: var(--muted);
  line-height: 1.75;
}

.assurance {
  background: var(--soft);
}

.assurance-grid {
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.assurance-grid article {
  min-height: 260px;
  padding: 24px;
}

.metric {
  display: block;
  margin-bottom: 30px;
  color: var(--blue);
  font-size: 34px;
  font-weight: 800;
}

.access-band {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 24px;
  align-items: center;
  margin: 82px clamp(18px, 5vw, 72px);
  padding: clamp(28px, 5vw, 44px);
  border-radius: 8px;
  background:
    linear-gradient(135deg, rgba(18, 33, 47, 0.95), rgba(24, 75, 86, 0.94)),
    #12212f;
  color: #fff;
}

.access-band .eyebrow {
  color: #8de0b6;
}

.access-band p {
  margin-bottom: 0;
  color: #d9e6ef;
}

.access-band .primary-action {
  background: #fff;
  color: var(--ink);
  box-shadow: none;
}

footer {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 14px;
  padding: 28px clamp(18px, 5vw, 72px);
  border-top: 1px solid var(--line);
  color: var(--muted);
}

footer span:first-child {
  color: var(--ink);
  font-weight: 800;
}

@media (max-width: 980px) {
  .hero,
  .access-band {
    grid-template-columns: 1fr;
  }

  .hero {
    min-height: auto;
  }

  .network-panel {
    max-width: 620px;
  }

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

@media (max-width: 680px) {
  .site-header {
    grid-template-columns: 1fr auto;
    gap: 12px;
  }

  nav {
    grid-column: 1 / -1;
    grid-row: 2;
    justify-content: flex-start;
    overflow-x: auto;
    padding-bottom: 2px;
  }

  .hero {
    padding-top: 40px;
  }

  h1 {
    font-size: 38px;
  }

  .hero-actions,
  .access-band {
    align-items: stretch;
  }

  .primary-action,
  .secondary-action {
    width: 100%;
  }

  .route-grid,
  .assurance-grid {
    grid-template-columns: 1fr;
  }

  .signal-card {
    grid-template-columns: 48px 1fr;
    padding: 16px;
  }

  .signal-card span {
    width: 48px;
    height: 48px;
  }
}