/* Autonomous AI Orgs — AIAP / ZTAAO landing.
 * Discipline: black on white, one accent (#2563eb to match credexai.org + CALMVAULT site),
 * system fonts, mobile-first single column, no carousels, no GIFs, no marketing visuals.
 * Page weight target: under 25KB total deployable. */

:root {
  --accent: #2563eb;
  --ink: #0a0a0a;
  --ink-2: #404040;
  --rule: #e5e5e5;
  --pale: #f5f5f5;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: #ffffff;
  color: var(--ink);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  font-size: 17px;
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

main {
  max-width: 700px;
  margin: 0 auto;
  padding: 32px 24px 96px;
}

section { margin: 56px 0; }
section:first-of-type { margin-top: 8px; }

h1 {
  font-size: 36px;
  line-height: 1.18;
  font-weight: 700;
  letter-spacing: -0.02em;
  margin: 16px 0 24px;
}

h2 {
  font-size: 22px;
  font-weight: 600;
  letter-spacing: -0.01em;
  margin: 0 0 16px;
}

h3 {
  font-size: 17px;
  font-weight: 600;
  margin: 0 0 8px;
}

p { margin: 0 0 14px; color: var(--ink-2); }
p.kicker {
  text-transform: uppercase;
  letter-spacing: 0.08em;
  font-size: 12px;
  color: var(--accent);
  font-weight: 600;
  margin: 0;
}
p.sub {
  font-size: 19px;
  color: var(--ink);
  line-height: 1.45;
  margin: 0 0 20px;
}
p.meta {
  font-size: 13px;
  color: var(--ink-2);
  border-top: 1px solid var(--rule);
  padding-top: 16px;
  margin-top: 24px;
}
p.caption {
  font-size: 14px;
  color: var(--ink-2);
  margin: 0 0 16px;
}
p.footer-line {
  font-size: 13px;
  color: var(--ink-2);
  margin-top: 20px;
}

.hero {
  padding: 12px 0 8px;
  border-bottom: 1px solid var(--rule);
  margin-bottom: 56px;
}

.prose p { font-size: 16px; }
.prose em { font-style: italic; }

.invariants .grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
  margin-top: 16px;
}

.card {
  border: 1px solid var(--rule);
  border-radius: 8px;
  padding: 18px 18px 16px;
  background: #ffffff;
  position: relative;
}

.card .num {
  position: absolute;
  top: 14px;
  right: 16px;
  font-size: 11px;
  color: var(--accent);
  font-weight: 700;
  letter-spacing: 0.06em;
}

.card h3 { margin-right: 32px; }
.card p { font-size: 15px; margin: 0; }

.layered ul.layers {
  list-style: none;
  padding: 0;
  margin: 16px 0 0;
}
.layered ul.layers li {
  padding: 14px 0;
  border-bottom: 1px solid var(--rule);
  font-size: 15px;
  color: var(--ink-2);
}
.layered ul.layers li:last-child { border-bottom: 0; }
.layered ul.layers li strong { color: var(--ink); }

.rigor ul {
  padding-left: 18px;
  margin: 8px 0 12px;
}
.rigor ul li { margin-bottom: 8px; font-size: 15px; color: var(--ink-2); }
.rigor ul li strong { color: var(--ink); }

.credits p { font-size: 15px; }
.credits strong { color: var(--ink); }

code {
  font-family: "SF Mono", Menlo, Consolas, monospace;
  font-size: 13px;
  background: var(--pale);
  padding: 1px 6px;
  border-radius: 4px;
  color: var(--ink);
}

footer {
  border-top: 1px solid var(--rule);
  padding-top: 24px;
  margin-top: 56px;
}
footer p {
  font-size: 13px;
  color: var(--ink-2);
  margin: 0 0 6px;
}
footer p em { color: var(--ink); font-style: italic; }

@media (min-width: 640px) {
  h1 { font-size: 44px; }
  .invariants .grid {
    grid-template-columns: 1fr 1fr;
    gap: 18px;
  }
}

@media (min-width: 900px) {
  main { padding-top: 56px; }
  h1 { font-size: 52px; }
}