:root {
  --ink: #1a1a17;
  --ink-soft: #3d3d36;
  --ink-mute: #6b6b62;
  --ink-faint: #a8a89e;
  --paper: #f6f3ec;
  --paper-warm: #efeae0;
  --paper-deep: #e8e2d4;
  --rule: #d8d2c2;
  --rule-soft: #e8e2d4;
  --accent: #2d5d5e;
  --accent-soft: #3d7375;
  --accent-tint: #d4dfdf;
  --serif: 'Fraunces', Georgia, serif;
  --sans: 'Geist', -apple-system, system-ui, sans-serif;
  --mono: 'Geist Mono', 'SF Mono', monospace;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; scroll-padding-top: 80px; }

body {
  font-family: var(--sans);
  color: var(--ink);
  background: var(--paper);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  line-height: 1.55;
}

/* Subtle grain overlay */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 999;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 200 200' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='2' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='0.4'/%3E%3C/svg%3E");
  opacity: 0.05;
  mix-blend-mode: multiply;
}

/* --- Nav (shared across all pages) --- */
.site-nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 28px 56px;
  border-bottom: 1px solid var(--rule);
  position: sticky;
  top: 0;
  background: var(--paper);
  z-index: 100;
}
.logo {
  font-family: var(--serif);
  font-size: 22px;
  font-weight: 500;
  letter-spacing: -0.01em;
  color: var(--ink);
  text-decoration: none;
}
.logo span { color: var(--accent); }

.site-nav-links {
  display: flex;
  gap: 36px;
  align-items: center;
  font-size: 14px;
}
.site-nav-links a {
  color: var(--ink-soft);
  text-decoration: none;
  transition: color 0.2s;
}
.site-nav-links a:hover { color: var(--ink); }
.site-nav-links a.current {
  color: var(--ink);
  font-weight: 500;
}

/* --- Buttons --- */
.btn {
  font-family: var(--sans);
  font-size: 14px;
  font-weight: 500;
  padding: 10px 20px;
  border-radius: 6px;
  border: 1px solid transparent;
  cursor: pointer;
  text-decoration: none;
  display: inline-block;
  transition: all 0.18s;
}
.btn-primary { background: var(--ink); color: var(--paper); }
.btn-primary:hover { background: var(--accent); }
.btn-ghost { color: var(--ink); border-color: var(--rule); }
.btn-ghost:hover { border-color: var(--ink); }

/* --- Page header (shared layout for inner pages) --- */
.page-header {
  padding: 90px 56px 72px;
  max-width: 1240px;
  margin: 0 auto;
}
.page-eyebrow {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 24px;
  display: flex;
  align-items: center;
  gap: 12px;
}
.page-eyebrow::before {
  content: "";
  width: 32px;
  height: 1px;
  background: var(--accent);
}
.page-title {
  font-family: var(--serif);
  font-size: clamp(40px, 5vw, 64px);
  line-height: 1.05;
  font-weight: 400;
  letter-spacing: -0.025em;
  color: var(--ink);
  margin-bottom: 24px;
  max-width: 920px;
}
.page-title em { font-style: italic; font-weight: 300; color: var(--accent); }
.page-lede {
  font-size: 19px;
  color: var(--ink-soft);
  line-height: 1.55;
  max-width: 680px;
}

/* --- Content sections --- */
.section {
  padding: 64px 56px;
  max-width: 1240px;
  margin: 0 auto;
  border-top: 1px solid var(--rule);
}
.section-eyebrow {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--ink-mute);
  margin-bottom: 18px;
}
.section-title {
  font-family: var(--serif);
  font-size: 38px;
  font-weight: 400;
  line-height: 1.1;
  letter-spacing: -0.02em;
  margin-bottom: 40px;
  max-width: 780px;
}
.section-title em { font-style: italic; font-weight: 300; color: var(--accent); }

.section-prose {
  font-size: 17px;
  color: var(--ink-soft);
  line-height: 1.7;
  max-width: 680px;
  margin-bottom: 18px;
}
.section-prose strong { color: var(--ink); font-weight: 500; }

/* --- Steps grid --- */
.steps {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0;
  border-top: 1px solid var(--rule);
  margin-top: 24px;
}
.step {
  padding: 36px 36px 36px 0;
  border-right: 1px solid var(--rule);
}
.step:nth-child(2) { padding-left: 36px; }
.step:last-child { border-right: none; padding-left: 36px; }
.step-num {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--accent);
  margin-bottom: 18px;
}
.step-title {
  font-family: var(--serif);
  font-size: 26px;
  font-weight: 500;
  line-height: 1.15;
  letter-spacing: -0.015em;
  margin-bottom: 14px;
}
.step-body {
  font-size: 14.5px;
  color: var(--ink-soft);
  line-height: 1.6;
}

/* --- Survey list --- */
.survey-list { margin-top: 8px; }
.survey-item {
  display: grid;
  grid-template-columns: 56px 1fr;
  gap: 24px;
  padding: 28px 0;
  border-top: 1px solid var(--rule);
}
.survey-item:last-child { border-bottom: 1px solid var(--rule); }
.survey-num {
  font-family: var(--serif);
  font-size: 30px;
  font-style: italic;
  font-weight: 300;
  color: var(--accent);
  line-height: 1;
}
.survey-content { padding-top: 4px; }
.survey-name {
  font-family: var(--serif);
  font-size: 22px;
  font-weight: 500;
  letter-spacing: -0.01em;
  margin-bottom: 8px;
  line-height: 1.3;
}
.survey-when {
  font-family: var(--sans);
  font-size: 13px;
  font-weight: 400;
  font-style: normal;
  color: var(--ink-mute);
  letter-spacing: 0;
}
.survey-desc {
  font-size: 15.5px;
  color: var(--ink-soft);
  line-height: 1.6;
  max-width: 680px;
}

/* --- AI cards grid --- */
.ai-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1px;
  background: var(--rule);
  border: 1px solid var(--rule);
  margin-top: 8px;
}
.ai-card {
  background: var(--paper);
  padding: 32px 32px 36px;
}
.ai-card-num {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--accent);
  margin-bottom: 14px;
}
.ai-card-title {
  font-family: var(--serif);
  font-size: 22px;
  font-weight: 500;
  letter-spacing: -0.01em;
  line-height: 1.25;
  margin-bottom: 12px;
}
.ai-card-body {
  font-size: 14.5px;
  color: var(--ink-soft);
  line-height: 1.6;
}

/* --- Timeline --- */
.timeline {
  margin-top: 8px;
  border-top: 1px solid var(--rule);
}
.timeline-row {
  display: grid;
  grid-template-columns: 140px 1fr;
  gap: 32px;
  padding: 22px 0;
  border-bottom: 1px solid var(--rule);
  align-items: baseline;
}
.timeline-when {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent);
  padding-top: 2px;
}
.timeline-what {
  font-family: var(--serif);
  font-size: 17px;
  font-style: italic;
  font-weight: 300;
  line-height: 1.55;
  color: var(--ink);
  max-width: 720px;
}

/* --- Pull quote (inverted) --- */
.pullquote {
  padding: 96px 56px;
  background: var(--ink);
  color: var(--paper);
}
.pullquote-inner {
  max-width: 1000px;
  margin: 0 auto;
  text-align: center;
}
.pullquote-mark {
  font-family: var(--serif);
  font-size: 72px;
  line-height: 0.5;
  color: var(--accent-soft);
  margin-bottom: 18px;
}
.pullquote q {
  font-family: var(--serif);
  font-size: clamp(22px, 2.6vw, 32px);
  font-style: italic;
  font-weight: 300;
  line-height: 1.3;
  letter-spacing: -0.015em;
  quotes: none;
}
.pullquote-attr {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--ink-faint);
  margin-top: 28px;
}

/* --- Audience cards (For Instructors page) --- */
.audience-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1px;
  background: var(--rule);
  border: 1px solid var(--rule);
  margin-top: 8px;
}
.audience-card {
  background: var(--paper);
  padding: 36px 32px;
}
.audience-card-eyebrow {
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 14px;
}
.audience-card h3 {
  font-family: var(--serif);
  font-size: 24px;
  font-weight: 500;
  line-height: 1.2;
  letter-spacing: -0.01em;
  margin-bottom: 12px;
}
.audience-card p {
  font-size: 15px;
  color: var(--ink-soft);
  line-height: 1.6;
}

/* --- Numbers strip --- */
.numbers {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0;
  border-top: 1px solid var(--rule);
  margin-top: 24px;
}
.number-cell {
  padding: 32px 32px 32px 0;
  border-right: 1px solid var(--rule);
}
.number-cell:nth-child(2) { padding-left: 32px; }
.number-cell:last-child { border-right: none; padding-left: 32px; }
.number-value {
  font-family: var(--serif);
  font-size: 56px;
  font-weight: 400;
  line-height: 1;
  letter-spacing: -0.025em;
  color: var(--ink);
  margin-bottom: 12px;
}
.number-value em { font-style: italic; font-weight: 300; color: var(--accent); }
.number-label {
  font-size: 14px;
  color: var(--ink-soft);
  line-height: 1.5;
  max-width: 320px;
}

/* --- CTA strip --- */
.cta-strip {
  padding: 96px 56px;
  text-align: center;
  background: var(--paper-warm);
  border-top: 1px solid var(--rule);
  border-bottom: 1px solid var(--rule);
}
.cta-eyebrow {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 18px;
}
.cta-title {
  font-family: var(--serif);
  font-size: clamp(28px, 3.5vw, 42px);
  font-weight: 400;
  letter-spacing: -0.02em;
  line-height: 1.15;
  margin-bottom: 18px;
  max-width: 760px;
  margin-left: auto;
  margin-right: auto;
}
.cta-title em { font-style: italic; color: var(--accent); }
.cta-sub {
  font-size: 16px;
  color: var(--ink-mute);
  margin-bottom: 32px;
}

/* --- Footer --- */
.site-footer {
  padding: 36px 56px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--ink-mute);
  text-transform: uppercase;
  border-top: 1px solid var(--rule);
}

/* --- Hero (homepage only) --- */
.hero {
  padding: 96px 56px 80px;
  max-width: 1240px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1.1fr 1fr;
  gap: 72px;
  align-items: center;
}
.hero h1 {
  font-family: var(--serif);
  font-size: clamp(40px, 5vw, 68px);
  line-height: 1.05;
  font-weight: 400;
  letter-spacing: -0.025em;
  color: var(--ink);
  margin-bottom: 26px;
}
.hero h1 em { font-style: italic; font-weight: 300; color: var(--accent); }
.hero p.lede {
  font-size: 19px;
  color: var(--ink-soft);
  line-height: 1.55;
  margin-bottom: 36px;
  max-width: 520px;
}
.hero-cta {
  display: flex;
  gap: 14px;
  align-items: center;
  margin-bottom: 28px;
  flex-wrap: wrap;
}
.hero-cta .btn { padding: 14px 26px; font-size: 15px; }
.hero-meta {
  font-family: var(--mono);
  font-size: 12px;
  color: var(--ink-mute);
  letter-spacing: 0.02em;
}
.hero-meta strong { color: var(--ink); font-weight: 500; }

.hero-visual {
  position: relative;
  aspect-ratio: 4 / 5;
  background: var(--paper-warm);
  border: 1px solid var(--rule);
  padding: 36px 32px;
  box-shadow: 0 30px 60px -30px rgba(26,26,23,0.18), 0 1px 0 rgba(255,255,255,0.5) inset;
  transform: rotate(-1.2deg);
}
.doc-meta {
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ink-mute);
  margin-bottom: 18px;
  display: flex;
  justify-content: space-between;
}
.doc-title {
  font-family: var(--serif);
  font-size: 26px;
  line-height: 1.15;
  font-weight: 500;
  letter-spacing: -0.01em;
  margin-bottom: 24px;
}
.doc-title em { font-style: italic; font-weight: 300; }
.doc-rule { height: 1px; background: var(--rule); margin: 18px 0; }
.doc-section-label {
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 10px;
}
.doc-stat {
  display: flex;
  justify-content: space-between;
  padding: 6px 0;
  font-size: 13px;
  color: var(--ink-soft);
  border-bottom: 1px dotted var(--rule);
}
.doc-stat:last-child { border-bottom: none; }
.doc-stat .num {
  font-family: var(--serif);
  font-size: 15px;
  color: var(--ink);
  font-weight: 500;
}
.doc-quote {
  font-family: var(--serif);
  font-style: italic;
  font-size: 14px;
  line-height: 1.5;
  color: var(--ink-soft);
  padding: 12px 0 4px;
  border-left: 2px solid var(--accent);
  padding-left: 14px;
  margin-top: 14px;
}
.doc-quote .attr {
  display: block;
  font-style: normal;
  font-family: var(--mono);
  font-size: 10px;
  color: var(--ink-mute);
  margin-top: 6px;
  letter-spacing: 0.04em;
}

/* --- Trust strip --- */
.trust-strip {
  border-top: 1px solid var(--rule);
  border-bottom: 1px solid var(--rule);
  padding: 24px 56px;
  background: var(--paper-warm);
}
.trust-content {
  max-width: 1240px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 40px;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ink-mute);
}
.trust-platforms {
  display: flex;
  gap: 36px;
  font-family: var(--serif);
  font-size: 18px;
  font-weight: 500;
  text-transform: none;
  letter-spacing: -0.01em;
  color: var(--ink-soft);
}

/* --- Responsive --- */
@media (max-width: 980px) {
  .site-nav {
    padding: 16px 20px;
    flex-wrap: wrap;
    gap: 12px;
  }
  .site-nav-links {
    gap: 18px;
    font-size: 13px;
    flex-wrap: wrap;
  }

  .hero {
    grid-template-columns: 1fr;
    gap: 40px;
    padding: 48px 20px 56px;
  }
  .hero h1 { font-size: 38px; }
  .hero p.lede { font-size: 17px; }
  .hero-cta .btn { width: 100%; text-align: center; }
  .hero-visual { transform: none; padding: 28px 22px; }
  .doc-title { font-size: 22px; }

  .trust-strip { padding: 20px; }
  .trust-content { flex-direction: column; gap: 16px; text-align: center; }
  .trust-platforms { gap: 22px; font-size: 16px; flex-wrap: wrap; justify-content: center; }

  .page-header { padding: 56px 20px 40px; }
  .page-title { font-size: 36px; }
  .page-lede { font-size: 16.5px; }

  .section { padding: 48px 20px; }
  .section-title { font-size: 28px; }

  .steps { grid-template-columns: 1fr; }
  .step {
    padding: 24px 0 !important;
    border-right: none;
    border-bottom: 1px solid var(--rule);
  }
  .step:last-child { border-bottom: none; }

  .survey-item { grid-template-columns: 36px 1fr; gap: 14px; padding: 20px 0; }
  .survey-num { font-size: 22px; }
  .survey-name { font-size: 18px; }
  .survey-when { display: block; margin-top: 4px; }
  .survey-desc { font-size: 14.5px; }

  .ai-grid, .audience-grid { grid-template-columns: 1fr; }
  .ai-card, .audience-card { padding: 24px 22px 28px; }
  .ai-card-title, .audience-card h3 { font-size: 19px; }

  .timeline-row { grid-template-columns: 1fr; gap: 6px; padding: 18px 0; }
  .timeline-what { font-size: 15.5px; }

  .numbers { grid-template-columns: 1fr; }
  .number-cell {
    padding: 22px 0 !important;
    border-right: none;
    border-bottom: 1px solid var(--rule);
  }
  .number-cell:last-child { border-bottom: none; }
  .number-value { font-size: 42px; }

  .pullquote { padding: 56px 20px; }
  .pullquote q { font-size: 20px; line-height: 1.35; }

  .cta-strip { padding: 56px 20px; }

  .site-footer {
    padding: 24px 20px;
    flex-direction: column;
    gap: 10px;
    text-align: center;
  }
}