/* =========================================================
   CHAI LABS — Design System + Layout
   ========================================================= */

/* ===== Color Tokens (from user) ===== */
:root {
  /* Base */
  --clr-dark-a0: #000000;
  --clr-light-a0: #ffffff;

  /* Primary */
  --clr-primary-a0: #bd6657;
  --clr-primary-a10: #c67768;
  --clr-primary-a20: #cf877a;
  --clr-primary-a30: #d7988c;
  --clr-primary-a40: #dfa99e;
  --clr-primary-a50: #e6bab1;

  /* Surface */
  --clr-surface-a0: #121212;
  --clr-surface-a10: #282828;
  --clr-surface-a20: #3f3f3f;
  --clr-surface-a30: #575757;
  --clr-surface-a40: #717171;
  --clr-surface-a50: #8b8b8b;

  /* Tonal Surface */
  --clr-surface-tonal-a0: #221a19;
  --clr-surface-tonal-a10: #372f2e;
  --clr-surface-tonal-a20: #4d4544;
  --clr-surface-tonal-a30: #645d5c;
  --clr-surface-tonal-a40: #7c7675;
  --clr-surface-tonal-a50: #95908f;

  /* Semantic */
  --clr-success-a0: #22946e;
  --clr-warning-a0: #a87a2a;
  --clr-danger-a0: #9c2121;
  --clr-info-a0: #21498a;

  /* ===== Semantic Mappings ===== */
  --bg-page: var(--clr-surface-a0);
  --bg-surface: var(--clr-surface-a10);
  --bg-card: var(--clr-surface-tonal-a0);

  --text-primary: var(--clr-light-a0);
  --text-muted: var(--clr-surface-a50);

  --border-subtle: rgba(255,255,255,0.08);

  --accent: var(--clr-primary-a0);
  --accent-soft: var(--clr-primary-a30);

  --shadow-lg: 0 18px 40px rgba(0,0,0,0.55);
  --shadow-md: 0 10px 22px rgba(0,0,0,0.45);

  --radius-sm: 12px;
  --radius-md: 18px;
  --radius-lg: 24px;
}

/* ===== Base ===== */
* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Arial;
  background: var(--bg-page);
  color: var(--text-primary);
  line-height: 1.5;
}

a {
  color: var(--clr-primary-a40);
  text-decoration: none;
}

a:hover {
  color: var(--clr-primary-a50);
}

.container {
  max-width: 1120px;
  margin: 0 auto;
  padding: 0 20px;
}

.muted {
  color: var(--text-muted);
}

/* ===== Navigation ===== */
.nav {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(18,18,18,0.85);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--border-subtle);
}

.nav__inner {
  display: flex;
  align-items: center;
  gap: 18px;
  padding: 14px 0;
}

.brand {
  display: flex;
  gap: 10px;
  font-weight: 800;
  color: var(--text-primary);
}

.brand__mark {
  width: 28px;
  height: 28px;
  border-radius: 10px;
  background: linear-gradient(
    135deg,
    var(--clr-primary-a0),
    var(--clr-primary-a30)
  );
}

.nav__links a {
  margin-left: 14px;
  font-weight: 600;
  opacity: 0.85;
}

.nav__links a:hover {
  opacity: 1;
}

.nav__cta {
  margin-left: auto;
  display: flex;
  gap: 10px;
}

/* ===== Buttons ===== */
.btn {
  padding: 10px 16px;
  border-radius: 999px;
  font-weight: 700;
  border: 1px solid var(--clr-primary-a0);
  background: var(--clr-primary-a0);
  color: var(--clr-light-a0);
  box-shadow: var(--shadow-md);
}

.btn:hover {
  background: var(--clr-primary-a10);
}

.btn--ghost {
  background: transparent;
  color: var(--clr-primary-a40);
  border: 1px solid var(--border-subtle);
}

.btn--ghost:hover {
  background: var(--clr-surface-a10);
}

.btn--lg {
  padding: 12px 20px;
  font-size: 16px;
}

/* ===== Hero ===== */
.hero {
  padding: 72px 0 32px;
  position: relative;
}

.hero::before {
  content: "";
  position: absolute;
  inset: -120px;
  background:
    radial-gradient(circle at 20% 20%, rgba(189,102,87,0.25), transparent 60%),
    radial-gradient(circle at 80% 30%, rgba(214,152,140,0.20), transparent 60%);
  filter: blur(20px);
  pointer-events: none;
}

.hero__grid {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 32px;
  align-items: center;
  position: relative;
}

h1 {
  font-size: 52px;
  line-height: 1.05;
  letter-spacing: -0.03em;
  margin: 16px 0 12px;
}

.lead {
  font-size: 18px;
  color: var(--text-muted);
  max-width: 60ch;
}

.hero__actions {
  display: flex;
  gap: 14px;
  margin-top: 20px;
  flex-wrap: wrap;
}

/* ===== Cards ===== */
.cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  margin-top: 24px;
}

.card {
  background: var(--bg-card);
  border-radius: var(--radius-md);
  padding: 20px;
  border: 1px solid var(--border-subtle);
  box-shadow: var(--shadow-md);
}

.card h3 {
  margin-top: 0;
}

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

/* ===== Sections ===== */
.section {
  padding: 64px 0;
}

.section--alt {
  background: linear-gradient(
    180deg,
    var(--clr-surface-tonal-a0),
    var(--clr-surface-a0)
  );
  border-top: 1px solid var(--border-subtle);
  border-bottom: 1px solid var(--border-subtle);
}

/* ===== CTA ===== */
.cta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  background: linear-gradient(
    135deg,
    var(--clr-surface-tonal-a0),
    var(--clr-surface-tonal-a20)
  );
  padding: 24px;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-subtle);
  box-shadow: var(--shadow-lg);
}

/* ===== Footer ===== */
.footer {
  border-top: 1px solid var(--border-subtle);
  padding: 40px 0 20px;
  margin-top: 40px;
}

.footer a {
  display: block;
  margin: 8px 0;
  color: var(--text-muted);
}

.footer a:hover {
  color: var(--clr-primary-a40);
}

/* ===== Utility Example ===== */
.bg-primary {
  color: var(--clr-primary-a50);
  background-color: var(--clr-surface-a0);
}

/* ===== Responsive ===== */
@media (max-width: 980px) {
  .hero__grid {
    grid-template-columns: 1fr;
  }

  h1 {
    font-size: 40px;
  }

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

  .nav__links {
    display: none;
  }
}