/* Atlas Compendium — Apple-style trust site
   Colour scheme: Apple white/light-grey alternating, near-black ink, blue accent links
   2026-05-09 */

*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }

:root {
  /* Apple palette */
  --bg-white: #ffffff;
  --bg-grey: #f5f5f7;
  --bg-dark: #000000;
  --ink: #1d1d1f;
  --ink-soft: #424245;
  --muted: #6e6e73;
  --line: #d2d2d7;
  --accent: #0066cc;        /* Apple link blue */
  --accent-hover: #0077ed;

  /* Type */
  --sans: -apple-system, BlinkMacSystemFont, 'SF Pro Display', 'SF Pro Text', 'Helvetica Neue', Helvetica, Arial, sans-serif;

  --max: 980px;
  --max-wide: 1440px;
  --gutter: clamp(22px, 4vw, 44px);
}

html { scroll-behavior: smooth; }

body {
  font-family: var(--sans);
  font-size: 17px;
  line-height: 1.47;
  color: var(--ink);
  background: var(--bg-white);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  letter-spacing: -0.022em;
}

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

/* ─────────────── Apple Nav ─────────────── */

.nav {
  position: sticky;
  top: 0;
  height: 44px;
  background: rgba(0, 0, 0, 0.8);
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  z-index: 9999;
}

.nav-inner {
  max-width: var(--max-wide);
  margin: 0 auto;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 0 var(--gutter);
}

.nav-list {
  display: flex;
  gap: clamp(20px, 3.5vw, 44px);
  list-style: none;
  align-items: center;
}

.nav-list a {
  color: rgba(255,255,255,0.85);
  font-size: 12px;
  font-weight: 400;
  letter-spacing: -0.01em;
  transition: color 0.15s;
  text-decoration: none;
}

.nav-list a:hover { color: #fff; }

.nav-brand {
  font-weight: 600;
  font-size: 13px;
  letter-spacing: -0.01em;
}

.nav-brand a { color: rgba(255,255,255,0.92); }
.nav-brand a:hover { color: #fff; }

/* ─────────────── Section frame ─────────────── */

.section {
  position: relative;
  text-align: center;
  padding: clamp(60px, 6vw, 90px) var(--gutter) 0;
  overflow: hidden;
}

.section.has-tail { padding-bottom: 0; }
.section.full-pad { padding-bottom: clamp(60px, 6vw, 90px); }

.section--white { background: var(--bg-white); }
.section--grey  { background: var(--bg-grey); }
.section--dark  { background: var(--bg-dark); color: #f5f5f7; }
.section--dark .section-eyebrow { color: rgba(255,255,255,0.6); }
.section--dark h1, .section--dark h2 { color: #f5f5f7; }
.section--dark .lead { color: rgba(255,255,255,0.85); }

.section-inner {
  max-width: var(--max);
  margin: 0 auto;
}

.section-inner-wide {
  max-width: var(--max-wide);
  margin: 0 auto;
}

/* ─────────────── Type ─────────────── */

h1, h2, h3, h4 {
  font-family: var(--sans);
  font-weight: 600;
  letter-spacing: -0.025em;
  line-height: 1.05;
  color: var(--ink);
}

.eyebrow,
.section-eyebrow {
  font-size: 14px;
  font-weight: 600;
  letter-spacing: -0.01em;
  color: var(--muted);
  margin-bottom: 8px;
  text-transform: none;
}

h1.headline {
  font-size: clamp(40px, 6.4vw, 80px);
  font-weight: 600;
  letter-spacing: -0.04em;
  line-height: 1.05;
  margin-bottom: 8px;
}

h2.headline {
  font-size: clamp(36px, 5.6vw, 64px);
  font-weight: 600;
  letter-spacing: -0.035em;
  line-height: 1.0625;
  margin-bottom: 8px;
}

h3.subhead {
  font-size: clamp(20px, 2.4vw, 28px);
  font-weight: 500;
  letter-spacing: -0.022em;
  line-height: 1.14;
  margin-bottom: 20px;
}

p.lead {
  font-size: clamp(19px, 2vw, 24px);
  line-height: 1.21;
  font-weight: 400;
  letter-spacing: -0.022em;
  color: var(--ink-soft);
  margin-bottom: 28px;
}

p {
  font-size: 17px;
  line-height: 1.47;
  color: var(--ink-soft);
}

/* ─────────────── CTA links (Apple style) ─────────────── */

.cta-row {
  display: flex;
  gap: 32px;
  justify-content: center;
  align-items: center;
  flex-wrap: wrap;
  margin-top: 8px;
}

.cta {
  font-size: 17px;
  font-weight: 400;
  color: var(--accent);
  text-decoration: none;
  letter-spacing: -0.022em;
  transition: color 0.15s;
}

.cta:hover { color: var(--accent-hover); text-decoration: underline; }

.cta::after {
  content: ' ›';
  display: inline;
  font-weight: 400;
}

.section--dark .cta { color: #2997ff; }
.section--dark .cta:hover { color: #429eff; }

/* ─────────────── Hero panel ─────────────── */

.hero {
  padding: clamp(60px, 6vw, 90px) var(--gutter) clamp(60px, 6vw, 90px);
  text-align: center;
  background: var(--bg-white);
}

.hero h1 { margin-bottom: 8px; }
.hero p.lead { margin: 0 auto 28px; max-width: 720px; }

/* ─────────────── Visual / image area ─────────────── */

.visual {
  margin: clamp(40px, 5vw, 60px) auto 0;
  position: relative;
}

.visual img,
.visual .placeholder {
  display: block;
  margin: 0 auto;
  max-width: 100%;
  height: auto;
}

.visual .placeholder {
  width: 100%;
  max-width: 1000px;
  aspect-ratio: 16 / 10;
  border-radius: 18px;
  background: linear-gradient(135deg, #f5f5f7 0%, #e8e8ed 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--muted);
  font-size: 14px;
  letter-spacing: -0.01em;
}

/* Half panels — Apple two-up grid */

.duo {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  max-width: var(--max-wide);
  margin: 0 auto;
  padding: 16px var(--gutter);
}

.duo-card {
  background: var(--bg-grey);
  border-radius: 18px;
  padding: clamp(40px, 5vw, 64px) clamp(24px, 4vw, 56px) clamp(32px, 4vw, 48px);
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  min-height: 580px;
}

.duo-card.dark { background: var(--bg-dark); color: #f5f5f7; }
.duo-card.dark h2 { color: #f5f5f7; }
.duo-card.dark p { color: rgba(255,255,255,0.78); }

.duo-card h2 {
  font-size: clamp(28px, 3.4vw, 40px);
  font-weight: 600;
  letter-spacing: -0.025em;
  line-height: 1.1;
  margin-bottom: 8px;
}

.duo-card p.sub {
  font-size: clamp(17px, 1.6vw, 21px);
  font-weight: 400;
  margin-bottom: 18px;
  color: var(--ink-soft);
  letter-spacing: -0.022em;
}

.duo-card .visual { margin-top: auto; padding-top: 24px; }
.duo-card .visual .placeholder { aspect-ratio: 4/3; }

@media (max-width: 760px) {
  .duo { grid-template-columns: 1fr; }
  .duo-card { min-height: 480px; }
}

/* ─────────────── Tile grid (atlases) ─────────────── */

.tiles {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
  max-width: var(--max-wide);
  margin: 16px auto;
  padding: 0 var(--gutter);
}

.tile {
  position: relative;
  background: var(--bg-grey);
  border-radius: 18px;
  padding: 56px 40px 40px;
  text-align: center;
  min-height: 520px;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  transition: transform 0.25s ease;
  text-decoration: none;
  color: inherit;
}

.tile:hover { transform: translateY(-2px); text-decoration: none; }

.tile .tile-eyebrow {
  font-size: 13px;
  font-weight: 600;
  color: var(--muted);
  margin-bottom: 8px;
  letter-spacing: -0.01em;
}

.tile h3 {
  font-size: clamp(28px, 3.2vw, 40px);
  font-weight: 600;
  letter-spacing: -0.03em;
  line-height: 1.05;
  margin-bottom: 12px;
  color: var(--ink);
}

.tile p {
  font-size: 17px;
  line-height: 1.4;
  color: var(--ink-soft);
  max-width: 320px;
  margin: 0 auto 20px;
}

.tile .tile-cta {
  color: var(--accent);
  font-size: 15px;
  font-weight: 400;
  margin-bottom: auto;
}

.tile .tile-cta::after { content: ' ›'; }

.tile .tile-visual {
  margin-top: auto;
  width: 100%;
  aspect-ratio: 16/10;
  border-radius: 12px;
  background-size: cover;
  background-position: center;
  background-color: #e8e8ed;
}

.tile.dark { background: var(--bg-dark); color: #f5f5f7; }
.tile.dark h3 { color: #f5f5f7; }
.tile.dark p { color: rgba(255,255,255,0.78); }

@media (max-width: 760px) {
  .tiles { grid-template-columns: 1fr; }
  .tile { min-height: 440px; }
}

/* ─────────────── Stat / methodology row ─────────────── */

.stat-row {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 32px;
  max-width: var(--max);
  margin: clamp(40px, 5vw, 60px) auto 0;
  padding: 0 var(--gutter);
}

.stat .num {
  display: block;
  font-size: clamp(40px, 4.5vw, 60px);
  font-weight: 600;
  letter-spacing: -0.03em;
  line-height: 1;
  margin-bottom: 8px;
  color: var(--ink);
}

.stat .lbl {
  display: block;
  font-size: 14px;
  font-weight: 400;
  color: var(--muted);
  letter-spacing: -0.01em;
}

.section--dark .stat .num { color: #f5f5f7; }
.section--dark .stat .lbl { color: rgba(255,255,255,0.65); }

@media (max-width: 760px) {
  .stat-row { grid-template-columns: repeat(2, 1fr); gap: 32px 16px; }
}

/* ─────────────── Methodology pillars ─────────────── */

.pillars {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: clamp(24px, 4vw, 56px);
  max-width: var(--max);
  margin: clamp(40px, 5vw, 60px) auto 0;
  padding: 0 var(--gutter);
  text-align: left;
}

.pillar h3 {
  font-size: 21px;
  font-weight: 600;
  letter-spacing: -0.022em;
  margin-bottom: 8px;
  color: var(--ink);
}

.pillar p {
  font-size: 15px;
  line-height: 1.47;
  color: var(--ink-soft);
}

.section--dark .pillar h3 { color: #f5f5f7; }
.section--dark .pillar p { color: rgba(255,255,255,0.78); }

@media (max-width: 760px) {
  .pillars { grid-template-columns: 1fr; gap: 32px; text-align: center; }
}

/* ─────────────── Footer (Apple style) ─────────────── */

.footer {
  background: var(--bg-grey);
  font-size: 12px;
  color: var(--muted);
  padding: 16px var(--gutter) 20px;
}

.footer-inner {
  max-width: var(--max-wide);
  margin: 0 auto;
}

.footer-disc {
  border-bottom: 1px solid var(--line);
  padding-bottom: 16px;
  margin-bottom: 16px;
  line-height: 1.5;
  font-size: 11px;
}

.footer-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 32px;
  border-bottom: 1px solid var(--line);
  padding-bottom: 16px;
  margin-bottom: 16px;
}

.footer-grid h5 {
  font-size: 12px;
  font-weight: 600;
  color: var(--ink);
  margin-bottom: 8px;
  letter-spacing: -0.01em;
}

.footer-grid ul { list-style: none; }
.footer-grid li { margin-bottom: 6px; line-height: 1.5; }

.footer-grid a {
  color: var(--muted);
  font-size: 12px;
  text-decoration: none;
}

.footer-grid a:hover { color: var(--ink); text-decoration: underline; }

.footer-bottom {
  display: flex;
  justify-content: space-between;
  font-size: 12px;
  color: var(--muted);
  flex-wrap: wrap;
  gap: 12px;
  letter-spacing: -0.01em;
}

@media (max-width: 760px) {
  .footer-grid { grid-template-columns: 1fr 1fr; }
}

/* ─────────────── Page templates ─────────────── */

.page-hero {
  text-align: center;
  padding: clamp(80px, 9vw, 120px) var(--gutter) clamp(40px, 5vw, 60px);
  background: var(--bg-white);
}

.page-hero h1 {
  font-size: clamp(40px, 5.5vw, 72px);
  font-weight: 600;
  letter-spacing: -0.035em;
  margin-bottom: 16px;
}

.page-hero p {
  font-size: clamp(18px, 1.8vw, 22px);
  color: var(--ink-soft);
  max-width: 720px;
  margin: 0 auto;
  letter-spacing: -0.022em;
}

.prose {
  max-width: 720px;
  margin: 0 auto;
  padding: clamp(40px, 6vw, 80px) var(--gutter) clamp(60px, 8vw, 100px);
  text-align: left;
}

.prose h2 {
  font-size: 28px;
  font-weight: 600;
  margin: 48px 0 12px;
  letter-spacing: -0.025em;
  color: var(--ink);
}

.prose h2:first-child { margin-top: 0; }

.prose h3 {
  font-size: 19px;
  font-weight: 600;
  margin: 28px 0 8px;
  color: var(--ink);
  letter-spacing: -0.022em;
}

.prose p {
  font-size: 17px;
  line-height: 1.55;
  margin-bottom: 16px;
  color: var(--ink-soft);
}

.prose ul, .prose ol {
  margin: 0 0 16px 24px;
  color: var(--ink-soft);
}

.prose li { margin-bottom: 6px; line-height: 1.5; }

.prose a { color: var(--accent); text-decoration: none; }
.prose a:hover { text-decoration: underline; }

.prose strong { color: var(--ink); font-weight: 600; }