/* Agent Sentry landing page (P3P-5b). Dark theme, system fonts, zero external assets. */

:root {
  --bg: #0b0e14;
  --bg-raised: #121826;
  --bg-card: #151c2c;
  --border: #243049;
  --text: #e6ebf4;
  --text-dim: #9aa7bd;
  --accent: #4f8cff;
  --accent-strong: #2f6fe8;
  --accent-soft: rgba(79, 140, 255, 0.12);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family:
    -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif,
    "Apple Color Emoji", "Segoe UI Emoji";
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

.container {
  max-width: 1040px;
  margin: 0 auto;
  padding: 0 24px;
}

a {
  color: var(--accent);
  text-decoration: none;
}

/* ---- nav -------------------------------------------------------------- */

.nav {
  position: sticky;
  top: 0;
  background: rgba(11, 14, 20, 0.9);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
  z-index: 10;
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 60px;
}

.brand {
  font-weight: 700;
  letter-spacing: 0.01em;
}

.brand-mark {
  color: var(--accent);
  margin-right: 4px;
}

.brand-by {
  font-weight: 400;
  color: var(--text-dim);
  font-size: 0.85em;
  margin-left: 4px;
}

/* ---- buttons ---------------------------------------------------------- */

.btn {
  display: inline-block;
  padding: 12px 22px;
  border-radius: 8px;
  border: 1px solid var(--border);
  color: var(--text);
  font-weight: 600;
  transition: background 0.15s ease, border-color 0.15s ease;
}

.btn-small {
  padding: 7px 14px;
  font-size: 0.9em;
}

.btn-primary {
  background: var(--accent-strong);
  border-color: var(--accent-strong);
  color: #fff;
}

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

.btn-ghost:hover,
.btn-small:hover {
  border-color: var(--accent);
  background: var(--accent-soft);
}

.cta-row {
  display: flex;
  gap: 14px;
  flex-wrap: wrap;
}

/* ---- hero ------------------------------------------------------------- */

.hero {
  padding: 110px 0 90px;
  background:
    radial-gradient(900px 420px at 75% -10%, rgba(79, 140, 255, 0.16), transparent 70%),
    radial-gradient(600px 320px at 10% 0%, rgba(47, 111, 232, 0.1), transparent 70%);
}

.eyebrow {
  color: var(--accent);
  font-weight: 600;
  font-size: 0.85em;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  margin: 0 0 14px;
}

.hero h1 {
  font-size: clamp(2rem, 5vw, 3.2rem);
  line-height: 1.15;
  margin: 0 0 20px;
  max-width: 18em;
}

.lede {
  color: var(--text-dim);
  font-size: 1.15em;
  max-width: 44em;
  margin: 0 0 32px;
}

/* ---- features --------------------------------------------------------- */

.features {
  padding: 30px 0 70px;
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 26px 24px;
}

.card h2 {
  margin: 0 0 12px;
  font-size: 1.2em;
}

.card p {
  margin: 0;
  color: var(--text-dim);
}

.card-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 30px;
  height: 30px;
  border-radius: 8px;
  background: var(--accent-soft);
  color: var(--accent);
  margin-right: 8px;
  font-size: 0.95em;
}

/* ---- how it works ----------------------------------------------------- */

.how {
  padding: 60px 0;
  background: var(--bg-raised);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}

.section-title {
  text-align: center;
  margin: 0 0 36px;
  font-size: 1.8em;
}

.flow {
  display: flex;
  align-items: stretch;
  gap: 16px;
}

.flow-step {
  flex: 1;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 20px;
}

.flow-step-gate {
  border-color: var(--accent);
  box-shadow: 0 0 0 1px var(--accent), 0 0 28px rgba(79, 140, 255, 0.18);
}

.flow-label {
  display: block;
  color: var(--accent);
  font-size: 0.75em;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: 6px;
}

.flow-step strong {
  display: block;
  margin-bottom: 6px;
}

.flow-step p {
  margin: 0;
  color: var(--text-dim);
  font-size: 0.95em;
}

.flow-arrow {
  align-self: center;
  color: var(--accent);
  font-size: 1.6em;
}

/* ---- closing CTA & footer --------------------------------------------- */

.closing {
  padding: 90px 0;
  text-align: center;
}

.closing h2 {
  font-size: 1.9em;
  margin: 0 0 12px;
}

.closing p {
  color: var(--text-dim);
  margin: 0 0 28px;
}

.closing .cta-row {
  justify-content: center;
}

.footer {
  border-top: 1px solid var(--border);
  padding: 26px 0;
  color: var(--text-dim);
  font-size: 0.9em;
}

.footer-inner {
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 10px;
}

/* ---- responsive -------------------------------------------------------- */

@media (max-width: 800px) {
  .grid-3 {
    grid-template-columns: 1fr;
  }

  .flow {
    flex-direction: column;
  }

  .flow-arrow {
    transform: rotate(90deg);
  }

  .hero {
    padding: 70px 0 60px;
  }
}