/* ==========================================================================
   Fifty Adopters — companion site stylesheet
   Palette locked with the book cover and Field Manual PDFs.
   ========================================================================== */

@import url('https://fonts.googleapis.com/css2?family=Source+Serif+4:ital,opsz,wght@0,8..60,400;0,8..60,600;0,8..60,700;1,8..60,400&family=Inter:wght@400;500;700&family=JetBrains+Mono:wght@400;600&display=swap');

:root {
  /* Interior palette (locked) */
  --paper:      #F4F1E9;
  --paper-alt:  #EAE4D0;   /* ghost */
  --ink:        #1E1B15;
  --muted:      #3A362C;
  --line:       #B9B096;

  /* Accents (locked) */
  --teal:       #0E5A61;
  --teal-hover: #0A464C;
  --rust:       #C6541F;

  /* Type */
  --serif: 'Source Serif 4', Georgia, 'Times New Roman', serif;
  --sans:  'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', system-ui, sans-serif;
  --mono:  'JetBrains Mono', ui-monospace, Menlo, Consolas, monospace;

  /* Scale */
  --measure: 62ch;

  /* Spacing (8pt grid) */
  --s-1: 0.5rem;
  --s-2: 1rem;
  --s-3: 1.5rem;
  --s-4: 2rem;
  --s-5: 3rem;
  --s-6: 4rem;
  --s-7: 6rem;
  --s-8: 8rem;
}

/* ---------- reset ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; text-size-adjust: 100%; }
body { margin: 0; }
img, svg { display: block; max-width: 100%; height: auto; }
a { color: var(--teal); text-decoration: underline; text-decoration-thickness: 1px; text-underline-offset: 2px; }
a:hover { color: var(--teal-hover); }
a:focus-visible { outline: 2px solid var(--teal); outline-offset: 2px; border-radius: 2px; }

/* ---------- page ---------- */
body {
  font-family: var(--sans);
  font-size: 17px;
  line-height: 1.6;
  color: var(--ink);
  background: var(--paper);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

.wrap {
  max-width: 68rem;
  margin: 0 auto;
  padding: 0 var(--s-3);
}

/* ---------- header ---------- */
.site-header {
  padding: var(--s-4) 0 var(--s-3);
  border-bottom: 1px solid var(--line);
}
.site-header .wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--s-3);
  flex-wrap: wrap;
}
.masthead {
  font-family: var(--mono);
  font-size: 0.75rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--teal);
  text-decoration: none;
}
.masthead:hover { color: var(--teal-hover); }
.site-nav { display: flex; gap: var(--s-3); flex-wrap: wrap; }
.site-nav a {
  font-family: var(--mono);
  font-size: 0.75rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--muted);
  text-decoration: none;
}
.site-nav a:hover, .site-nav a[aria-current="page"] { color: var(--ink); }

/* ---------- footer ---------- */
.site-footer {
  border-top: 1px solid var(--line);
  padding: var(--s-4) 0 var(--s-5);
  margin-top: var(--s-8);
  font-family: var(--mono);
  font-size: 0.75rem;
  letter-spacing: 0.06em;
  color: var(--muted);
}
.site-footer .wrap {
  display: flex;
  gap: var(--s-3);
  justify-content: space-between;
  flex-wrap: wrap;
}
.site-footer a { color: var(--muted); text-decoration: none; }
.site-footer a:hover { color: var(--ink); }

/* ---------- typography ---------- */
h1, h2, h3 {
  font-family: var(--serif);
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: -0.01em;
  color: var(--ink);
  margin: 0 0 var(--s-3);
}
h1 { font-size: clamp(2.25rem, 5vw + 1rem, 4.25rem); line-height: 1.02; letter-spacing: -0.02em; }
h2 { font-size: clamp(1.5rem, 2.4vw + 0.8rem, 2.25rem); margin-top: var(--s-5); }
h3 { font-size: 1.25rem; margin-top: var(--s-4); font-weight: 600; }

p { max-width: var(--measure); margin: 0 0 var(--s-3); }
p.lede { font-family: var(--serif); font-size: 1.375rem; line-height: 1.4; color: var(--muted); }

.eyebrow {
  font-family: var(--mono);
  font-size: 0.75rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--teal);
  margin: 0 0 var(--s-2);
  display: block;
}

hr.rule {
  border: 0;
  border-top: 1px solid var(--line);
  margin: var(--s-5) 0;
  max-width: var(--measure);
}

/* ---------- sections ---------- */
main { padding: var(--s-5) 0 var(--s-4); }

.hero {
  padding: var(--s-6) 0 var(--s-7);
  border-bottom: 1px solid var(--line);
}
.hero .kicker {
  font-family: var(--mono);
  font-size: 0.75rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--teal);
  margin: 0 0 var(--s-3);
}
.hero p { font-family: var(--serif); font-size: clamp(1.125rem, 1vw + 0.9rem, 1.375rem); line-height: 1.45; color: var(--muted); max-width: 42rem; }

/* Cover image on Home */
.hero-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--s-5);
  align-items: center;
}
@media (min-width: 780px) {
  .hero-grid { grid-template-columns: 1.35fr 1fr; }
}
.hero-cover {
  max-width: 20rem;
  margin: 0 auto;
  box-shadow: 0 30px 60px -20px rgba(30, 27, 21, 0.35), 0 12px 20px -12px rgba(30, 27, 21, 0.25);
  border-radius: 2px;
}

/* ---------- buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.85rem 1.25rem;
  font-family: var(--sans);
  font-size: 0.9375rem;
  font-weight: 500;
  text-decoration: none;
  border-radius: 2px;
  transition: background 0.15s ease, color 0.15s ease, border-color 0.15s ease;
}
.btn-primary {
  background: var(--teal);
  color: var(--paper);
  border: 1px solid var(--teal);
}
.btn-primary:hover { background: var(--teal-hover); border-color: var(--teal-hover); color: var(--paper); }
.btn-secondary {
  background: transparent;
  color: var(--ink);
  border: 1px solid var(--ink);
}
.btn-secondary:hover { background: var(--ink); color: var(--paper); }

.btn-row {
  display: flex;
  flex-wrap: wrap;
  gap: var(--s-2);
  margin-top: var(--s-4);
}

/* ---------- cards ---------- */
.card-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--s-3);
}
@media (min-width: 720px) {
  .card-grid.two { grid-template-columns: 1fr 1fr; }
}
@media (min-width: 900px) {
  .card-grid.three { grid-template-columns: 1fr 1fr 1fr; }
}

.card {
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 2px;
  padding: var(--s-4);
}
.card h3 { margin-top: 0; }
.card .meta {
  font-family: var(--mono);
  font-size: 0.75rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--muted);
  margin: 0 0 var(--s-2);
}

/* ---------- sample chapter ---------- */
.chapter {
  font-family: var(--serif);
  font-size: 1.0625rem;
  line-height: 1.65;
  color: var(--ink);
}
.chapter h1 { font-family: var(--serif); }
.chapter h2 { font-family: var(--serif); font-weight: 700; }
.chapter p { font-family: var(--serif); max-width: var(--measure); }
.chapter ul { max-width: var(--measure); padding-left: 1.25rem; }
.chapter ul li { margin-bottom: 0.5rem; }
.chapter em { font-style: italic; }

/* Wee-nugget artefact block */
.artefact {
  font-family: var(--mono);
  font-size: 0.75rem;
  line-height: 1.55;
  background: #FAF8F0;
  border: 1px solid var(--line);
  padding: var(--s-3);
  margin: var(--s-4) 0;
  white-space: pre;
  overflow-x: auto;
  color: var(--ink);
  -webkit-overflow-scrolling: touch;
}
@media (max-width: 640px) {
  .artefact { font-size: 0.625rem; padding: var(--s-2); }
}

/* Chapter-1 receipts callout */
.receipt {
  border-left: 3px solid var(--rust);
  padding: var(--s-2) var(--s-3);
  margin: var(--s-3) 0;
  background: rgba(198, 84, 31, 0.05);
  max-width: var(--measure);
}
.receipt .tag {
  font-family: var(--mono);
  font-size: 0.7rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--rust);
  display: block;
  margin-bottom: var(--s-1);
}

/* ---------- utilities ---------- */
.skip-link {
  position: absolute; left: -9999px; top: auto;
  padding: 0.5rem 1rem; background: var(--ink); color: var(--paper);
  z-index: 100;
}
.skip-link:focus { left: 1rem; top: 1rem; }

.sr-only {
  position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0, 0, 0, 0); white-space: nowrap; border: 0;
}