/* ============================================================
   Sentient Snake — light landing page
   White background, navy accent, connected-nodes background to
   suggest a swarm of agents.
   ============================================================ */

:root {
  --bg-0: #ffffff;
  --bg-1: #fafafa;
  --bg-2: #f5f5f7;
  --bg-3: #ececef;

  --line: #e5e7eb;
  --line-soft: #efefef;

  --t-1: #0f172a;
  --t-2: #404040;
  --t-3: #6b7280;
  --t-4: #9ca3af;

  --accent: #1e40af;
  --accent-soft: rgba(30, 64, 175, 0.06);
  --accent-line: rgba(30, 64, 175, 0.25);

  --sans: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --mono: 'JetBrains Mono', ui-monospace, SFMono-Regular, Menlo, monospace;

  --max-w: 1200px;
  --gutter: 48px;
  --section-py: 120px;
  --r-sm: 6px;
  --r-md: 12px;
  --r-lg: 18px;
  --ease: cubic-bezier(.4, 0, .2, 1);
}

* { box-sizing: border-box; }

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  background: var(--bg-0);
  color: var(--t-1);
  font-family: var(--sans);
  font-size: 17px;
  line-height: 1.6;
  font-feature-settings: "ss01", "cv01", "cv11";
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

.container {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 var(--gutter);
  position: relative;
  z-index: 1;
}

.accent { color: var(--accent); }

/* ============================================================
   ANIMATED VECTOR-FIELD BACKGROUND
   Canvas placed behind the hero. Fades into white as you scroll.
   ============================================================ */
.bg-network {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 1100px;
  z-index: 0;
  pointer-events: none;
  display: block;
  mask-image: linear-gradient(to bottom, rgba(0,0,0,1) 0%, rgba(0,0,0,1) 55%, rgba(0,0,0,0) 100%);
  -webkit-mask-image: linear-gradient(to bottom, rgba(0,0,0,1) 0%, rgba(0,0,0,1) 55%, rgba(0,0,0,0) 100%);
}

/* ============================================================
   HEADER
   ============================================================ */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: saturate(140%) blur(10px);
  -webkit-backdrop-filter: saturate(140%) blur(10px);
  border-bottom: 1px solid var(--line-soft);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.logo {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--mono);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.12em;
  color: var(--t-1);
}
.logo-mark {
  display: inline-block;
  color: var(--accent);
  transform: translateY(-1px);
}

.nav {
  display: flex;
  align-items: center;
  gap: 28px;
}
.nav-link {
  font-size: 14px;
  color: var(--t-3);
  transition: color .2s var(--ease);
}
.nav-link:hover { color: var(--t-1); }

/* ============================================================
   BUTTONS
   ============================================================ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 9px 18px;
  border-radius: 999px;
  font-family: var(--sans);
  font-weight: 500;
  font-size: 14px;
  border: 1px solid transparent;
  cursor: pointer;
  transition: all .2s var(--ease);
  white-space: nowrap;
}
.btn-lg {
  padding: 14px 24px;
  font-size: 15px;
}

.btn-primary {
  background: var(--t-1);
  color: #ffffff;
  border-color: var(--t-1);
}
.btn-primary:hover {
  background: var(--accent);
  border-color: var(--accent);
}

.btn-ghost {
  color: var(--t-1);
  border-color: var(--line);
  background: var(--bg-0);
}
.btn-ghost:hover {
  border-color: var(--t-1);
  color: var(--t-1);
}

/* ============================================================
   HERO
   ============================================================ */
.hero {
  position: relative;
  padding: 120px 0 90px;
}

.eyebrow {
  font-family: var(--mono);
  text-transform: uppercase;
  letter-spacing: 0.18em;
  font-size: 12px;
  color: var(--t-3);
  margin: 0 0 24px;
}

.hero-title {
  font-size: clamp(40px, 6.4vw, 84px);
  font-weight: 600;
  line-height: 1.05;
  letter-spacing: -0.025em;
  margin: 0 0 28px;
  max-width: 1100px;
  color: var(--t-1);
}

.hero-sub {
  font-size: clamp(17px, 1.6vw, 21px);
  line-height: 1.55;
  color: var(--t-2);
  max-width: 720px;
  margin: 0 0 36px;
}

.hero-ctas {
  display: flex;
  gap: 14px;
  flex-wrap: wrap;
  margin-bottom: 80px;
}

/* ============================================================
   ANCHORS GRID (inside hero)
   ============================================================ */
.anchors-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  background: rgba(255,255,255,0.7);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
}
.anchors-grid-3 {
  grid-template-columns: repeat(3, 1fr);
}
.anchor {
  padding: 28px 24px;
  border-right: 1px solid var(--line);
}
.anchor:last-child { border-right: none; }

.anchor-label {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--accent);
  margin: 0 0 12px;
}
.anchor p:not(.anchor-label) {
  font-size: 14px;
  color: var(--t-2);
  line-height: 1.55;
  margin: 0;
}

/* ============================================================
   SECTIONS
   ============================================================ */
.section {
  padding: var(--section-py) 0;
  position: relative;
  z-index: 1;
  background: var(--bg-0);
}
.section-alt {
  background: var(--bg-1);
}

.section-eyebrow {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--accent);
  margin: 0 0 22px;
}

.section-title {
  font-size: clamp(32px, 4.4vw, 56px);
  font-weight: 600;
  line-height: 1.1;
  letter-spacing: -0.02em;
  margin: 0 0 36px;
  max-width: 980px;
  color: var(--t-1);
}

.section-lede {
  font-size: clamp(17px, 1.5vw, 20px);
  color: var(--t-2);
  line-height: 1.6;
  max-width: 840px;
  margin: 0 0 56px;
}

.section-body {
  font-size: clamp(16px, 1.4vw, 18px);
  color: var(--t-2);
  line-height: 1.7;
  max-width: 840px;
  margin: 0 0 24px;
}

.section-tail {
  margin-top: 56px;
  font-size: 17px;
  color: var(--t-2);
  line-height: 1.6;
  max-width: 840px;
}

/* ============================================================
   CARDS
   ============================================================ */
.grid-2 {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
}

.card {
  background: var(--bg-0);
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  padding: 32px;
  transition: border-color .2s var(--ease), transform .3s var(--ease), box-shadow .3s var(--ease);
}
.card:hover {
  border-color: var(--accent-line);
  transform: translateY(-2px);
  box-shadow: 0 12px 28px -16px rgba(30, 64, 175, 0.18);
}
.section-alt .card { background: var(--bg-0); }

.card-eyebrow {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--accent);
  margin: 0 0 16px;
}
.card-body {
  font-size: 16px;
  color: var(--t-2);
  line-height: 1.6;
  margin: 0;
}

/* ============================================================
   GRAPH FRAME
   ============================================================ */
.graph-frame {
  background: var(--bg-0);
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  padding: 32px;
  margin: 16px auto 0;
  max-width: 960px;
  box-shadow: 0 1px 3px rgba(0,0,0,0.04);
}
.graph-frame svg {
  width: 100%;
  height: auto;
  display: block;
}
.g-eyebrow {
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.18em;
  fill: var(--t-4);
  text-transform: uppercase;
}
.g-lbl {
  font-family: var(--sans);
  font-size: 13px;
  font-weight: 500;
  fill: var(--t-1);
}
.g-sub {
  font-family: var(--mono);
  font-size: 11px;
  fill: var(--t-3);
}
.g-flow {
  font-family: var(--mono);
  font-size: 11px;
  fill: var(--t-3);
  font-style: italic;
}

/* ============================================================
   FOOTER
   ============================================================ */
.site-footer {
  background: var(--bg-1);
  border-top: 1px solid var(--line);
  padding: 80px 0 40px;
  position: relative;
  z-index: 1;
}
.footer-inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 40px;
  padding-bottom: 60px;
  border-bottom: 1px solid var(--line);
}
.footer-block {}
.footer-label {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--t-3);
  margin: 0 0 16px;
}
.footer-mail {
  font-family: var(--sans);
  font-size: 22px;
  font-weight: 500;
  color: var(--t-1);
  border-bottom: 1px solid var(--accent);
  transition: color .2s var(--ease);
}
.footer-mail:hover { color: var(--accent); }
.footer-text {
  margin: 0;
  font-size: 15px;
  color: var(--t-2);
  line-height: 1.55;
}
.footer-bottom {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-top: 32px;
  font-size: 13px;
  color: var(--t-4);
}
.footer-bottom .mono {
  font-family: var(--mono);
}

/* ============================================================
   RESPONSIVE
   ============================================================ */
@media (max-width: 900px) {
  :root {
    --gutter: 24px;
    --section-py: 80px;
  }
  .nav-link { display: none; }
  .nav { gap: 12px; }

  .anchors-grid {
    grid-template-columns: 1fr 1fr;
  }
  .anchor:nth-child(2n) { border-right: none; }
  .anchor:nth-child(-n+2) { border-bottom: 1px solid var(--line); }

  .grid-2 {
    grid-template-columns: 1fr;
  }

  .footer-inner {
    grid-template-columns: 1fr;
  }
  .footer-bottom {
    flex-direction: column;
    gap: 8px;
    text-align: center;
  }
}

@media (max-width: 560px) {
  .hero { padding: 60px 0 40px; }
  .anchors-grid { grid-template-columns: 1fr; }
  .anchor { border-right: none !important; border-bottom: 1px solid var(--line); }
  .anchor:last-child { border-bottom: none; }
  .graph-frame { padding: 16px; }
}