:root {
  --bg: #f6f8fc;
  --surface: #ffffff;
  --surface-strong: #edf4ff;
  --ink: #0d1117;
  --muted: #475569;
  --line: #dce3ee;
  --accent: #0f62fe;
  --accent-soft: #d6e5ff;
  --success: #0c6e31;
  --warning: #b35a14;
  --shadow: 0 18px 55px rgba(13, 17, 23, 0.1);
  --radius: 8px;
  --sans:
    "DM Sans", ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont,
    "Segoe UI", sans-serif;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
}

body {
  background: var(--bg);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

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

.grain {
  display: none;
}

.container {
  width: min(1120px, calc(100% - 40px));
  margin: 0 auto;
}

.container-narrow {
  width: min(780px, calc(100% - 40px));
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  border-bottom: 1px solid rgba(220, 227, 238, 0.88);
  background: rgba(246, 248, 252, 0.92);
  backdrop-filter: blur(16px);
}

.nav {
  min-height: 72px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 28px;
}

.brand {
  display: inline-flex;
  align-items: center;
  flex: 0 0 auto;
}

.brand-logo {
  width: 184px;
  height: 40px;
  display: block;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 26px;
  color: var(--muted);
  font-size: 14px;
  font-weight: 600;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 18px;
  border-radius: var(--radius);
  border: 1px solid transparent;
  font-weight: 700;
  line-height: 1;
}

.btn-primary {
  color: #ffffff;
  background: var(--accent);
  transition:
    color 0.25s ease,
    background-color 0.25s ease,
    border-color 0.25s ease,
    box-shadow 0.25s ease;
}

.btn-primary:hover {
  color: #ffffff;
  background: #002670;
  border-color: #002670;
  box-shadow: 0 4px 12px rgba(0, 38, 112, 0.3);
}

.btn-secondary {
  background: #ffffff;
  color: var(--ink);
  border-color: var(--line);
}

.btn-secondary:hover {
  background: var(--bg);
}

.hero {
  padding: 88px 0 76px;
  overflow: hidden;
}

.hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(340px, 0.95fr);
  gap: 56px;
  align-items: center;
}

.eyebrow {
  color: var(--accent);
  font-size: 12px;
  font-weight: 800;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  margin-bottom: 16px;
}

.hero h1,
.section-head h2,
.prose-header h1 {
  max-width: 720px;
  font-size: clamp(40px, 6vw, 72px);
  line-height: 1;
  letter-spacing: 0;
}

.hero-sub {
  max-width: 620px;
  margin: 24px 0 30px;
  color: var(--muted);
  font-size: clamp(17px, 2vw, 20px);
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.network-panel {
  min-height: 430px;
  padding: 22px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background:
    linear-gradient(
      180deg,
      rgba(255, 255, 255, 0.96),
      rgba(237, 244, 255, 0.96)
    ),
    radial-gradient(circle at 20% 20%, rgba(15, 98, 254, 0.18), transparent 34%);
  box-shadow: var(--shadow);
}

.panel-top {
  display: flex;
  justify-content: space-between;
  align-items: center;
  color: var(--muted);
  font-size: 14px;
  font-weight: 700;
}

.panel-top strong {
  color: var(--success);
  font-size: 24px;
}

.mesh-map {
  position: relative;
  height: 260px;
  margin: 20px 0;
  border-radius: var(--radius);
  border: 1px solid var(--line);
  background-image:
    linear-gradient(rgba(75, 85, 99, 0.08) 1px, transparent 1px),
    linear-gradient(90deg, rgba(75, 85, 99, 0.08) 1px, transparent 1px);
  background-size: 32px 32px;
}

.mesh-map::before,
.mesh-map::after {
  content: "";
  position: absolute;
  inset: 50% 16%;
  height: 2px;
  background: linear-gradient(90deg, transparent, var(--accent), transparent);
}

.mesh-map::after {
  transform: rotate(58deg);
}

.node {
  position: absolute;
  width: 18px;
  height: 18px;
  border: 4px solid #ffffff;
  border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 0 5px rgba(15, 98, 254, 0.16);
}

.node-core {
  left: 48%;
  top: 46%;
  width: 28px;
  height: 28px;
  background: var(--accent);
}

.node-a {
  left: 16%;
  top: 20%;
}
.node-b {
  right: 18%;
  top: 24%;
}
.node-c {
  left: 22%;
  bottom: 22%;
}
.node-d {
  right: 20%;
  bottom: 18%;
}

.signal-list {
  display: grid;
  gap: 10px;
}

.signal-list div {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 12px 14px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #ffffff;
  color: var(--muted);
  font-size: 14px;
  font-weight: 650;
}

.status {
  width: 10px;
  height: 10px;
  border-radius: 50%;
}

.status.ok {
  background: var(--success);
}
.status.warn {
  background: var(--warning);
}

.features {
  padding: 76px 0 104px;
  background: #ffffff;
  border-top: 1px solid var(--line);
}

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

.section-head h2 {
  font-size: clamp(32px, 4vw, 50px);
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 18px;
}

.feature-card {
  min-height: 250px;
  padding: 24px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  box-shadow: 0 1px 2px rgba(11, 18, 32, 0.04);
}

.feature-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  margin-bottom: 28px;
  border-radius: var(--radius);
  color: var(--accent);
  background: var(--surface-strong);
  font-size: 13px;
  font-weight: 900;
}

.feature-card h3 {
  margin-bottom: 10px;
  font-size: 20px;
  line-height: 1.25;
}

.feature-card p {
  color: var(--muted);
}

.site-footer {
  padding: 56px 0 26px;
  color: #c3ccd9;
  background: var(--ink);
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 38px;
  padding-bottom: 42px;
  border-bottom: 1px solid rgba(195, 204, 217, 0.18);
}

.footer-tag {
  max-width: 360px;
  margin-top: 18px;
  color: #97a3b6;
}

.site-footer h4 {
  margin-bottom: 14px;
  color: #ffffff;
  font-size: 13px;
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.site-footer ul {
  list-style: none;
}

.site-footer li {
  margin-bottom: 9px;
}

.site-footer a:hover {
  color: #7ca7ff;
}

.footer-base {
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
  padding-top: 22px;
  color: #97a3b6;
  font-size: 13px;
}

.prose {
  padding: 74px 0 100px;
}

.prose-header {
  margin-bottom: 42px;
  padding-bottom: 30px;
  border-bottom: 1px solid var(--line);
}

.prose-header h1 {
  margin-bottom: 18px;
  font-size: clamp(38px, 5vw, 58px);
}

.lede {
  max-width: 680px;
  color: var(--muted);
  font-size: 18px;
}

.prose-meta {
  margin-top: 16px;
  color: var(--muted);
  font-size: 13px;
  font-weight: 700;
}

.prose-body {
  color: var(--muted);
  font-size: 17px;
}

.prose-body h2 {
  margin: 34px 0 12px;
  color: var(--ink);
  font-size: 25px;
  line-height: 1.2;
}

.prose-body p {
  margin-bottom: 16px;
}

.prose-body strong {
  color: var(--ink);
}

@media (max-width: 920px) {
  .hero-grid,
  .footer-grid {
    grid-template-columns: 1fr;
  }

  .network-panel {
    min-height: 390px;
  }

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

@media (max-width: 640px) {
  .container,
  .container-narrow {
    width: min(100% - 32px, 1120px);
  }

  .nav {
    min-height: auto;
    padding: 14px 0;
    align-items: flex-start;
    flex-direction: column;
    gap: 12px;
  }

  .nav-links {
    width: 100%;
    justify-content: space-between;
    gap: 12px;
    font-size: 13px;
  }

  .brand-logo {
    width: 168px;
    height: auto;
  }

  .hero {
    padding: 54px 0 56px;
  }

  .hero-actions,
  .hero-actions .btn {
    width: 100%;
  }

  .feature-grid {
    grid-template-columns: 1fr;
  }

  .feature-card {
    min-height: auto;
  }

  .footer-base {
    flex-direction: column;
  }
}