/* ---------- Design tokens ---------- */
:root {
  --paper: #FBFAF6;
  --paper-raised: #FFFFFF;
  --ink: #17181C;
  --ink-soft: #4A4C56;
  --ink-faint: #7D7F8C;
  --line: #E4E2D9;
  --line-strong: #D2CFC2;
  --accent: #4F3CC9;
  --accent-ink: #FFFFFF;
  --accent-soft: #EFEBFF;
  --accent-soft-line: #D9D1FF;
  --serif: Georgia, "Iowan Old Style", "Palatino Linotype", "URW Palladio", Palatino, serif;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Inter, Roboto, "Helvetica Neue", Arial, sans-serif;
  --mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace;
  --max: 760px;
  --max-wide: 980px;
  --radius: 10px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --paper: #131319;
    --paper-raised: #1B1B23;
    --ink: #F1F0EC;
    --ink-soft: #C7C6D1;
    --ink-faint: #8C8B98;
    --line: #2C2C36;
    --line-strong: #3A3A46;
    --accent: #9C8CFF;
    --accent-ink: #16131F;
    --accent-soft: #241F3D;
    --accent-soft-line: #3C3466;
  }
}
:root[data-theme="dark"] {
  --paper: #131319; --paper-raised: #1B1B23; --ink: #F1F0EC; --ink-soft: #C7C6D1; --ink-faint: #8C8B98;
  --line: #2C2C36; --line-strong: #3A3A46; --accent: #9C8CFF; --accent-ink: #16131F;
  --accent-soft: #241F3D; --accent-soft-line: #3C3466;
}
:root[data-theme="light"] {
  --paper: #FBFAF6; --paper-raised: #FFFFFF; --ink: #17181C; --ink-soft: #4A4C56; --ink-faint: #7D7F8C;
  --line: #E4E2D9; --line-strong: #D2CFC2; --accent: #4F3CC9; --accent-ink: #FFFFFF;
  --accent-soft: #EFEBFF; --accent-soft-line: #D9D1FF;
}

/* ---------- Reset-ish ---------- */
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 17px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}
@media (max-width: 640px) { body { font-size: 16px; } }

img, svg { max-width: 100%; }

.skip-link {
  position: absolute; left: -999px; top: 0; z-index: 200;
  background: var(--accent); color: var(--accent-ink);
  padding: 0.75em 1.25em; border-radius: 0 0 8px 0; font-weight: 600;
}
.skip-link:focus { left: 0; }

a { color: var(--accent); text-decoration-thickness: 1.5px; text-underline-offset: 2px; }
a:hover { text-decoration-thickness: 2px; }

/* ---------- Header / TOC ---------- */
.site-header {
  position: sticky; top: 0; z-index: 100;
  background: color-mix(in srgb, var(--paper) 88%, transparent);
  backdrop-filter: saturate(140%) blur(10px);
  border-bottom: 1px solid var(--line);
}
.header-inner {
  max-width: var(--max-wide); margin: 0 auto;
  display: flex; align-items: center; justify-content: space-between;
  padding: 0.85rem 1.25rem;
}
.brand { font-family: var(--serif); font-weight: 700; font-size: 1.05rem; color: var(--ink); text-decoration: none; letter-spacing: -0.01em; }
.brand-sub { font-family: var(--sans); font-weight: 400; font-size: 0.85rem; color: var(--ink-faint); }
.brand:hover { text-decoration: none; }

.toc-toggle {
  display: inline-flex; align-items: center; gap: 0.4rem;
  background: var(--paper-raised); color: var(--ink);
  border: 1px solid var(--line-strong); border-radius: 999px;
  padding: 0.45rem 0.9rem; font-size: 0.85rem; font-weight: 600;
  font-family: var(--sans); cursor: pointer;
}
.toc-toggle:hover { border-color: var(--accent); color: var(--accent); }
.toc-toggle svg { transition: transform 0.2s ease; }
.toc-toggle[aria-expanded="true"] svg { transform: rotate(180deg); }

.progress-track { height: 2px; background: transparent; }
.progress-fill { height: 100%; width: 0%; background: var(--accent); transition: width 0.1s linear; }

.toc-panel {
  max-height: 0; overflow: hidden;
  background: var(--paper-raised);
  border-bottom: 1px solid transparent;
  transition: max-height 0.28s ease, border-color 0.28s ease;
}
.toc-panel.open { max-height: 760px; border-bottom-color: var(--line); }
.toc-panel ol {
  list-style: none; margin: 0 auto; padding: 1rem 1.25rem 1.5rem;
  max-width: var(--max-wide);
  display: grid; grid-template-columns: repeat(2, 1fr); gap: 0.35rem 1.5rem;
}
@media (max-width: 640px) { .toc-panel ol { grid-template-columns: 1fr; } }
.toc-panel a {
  display: block; padding: 0.35rem 0; color: var(--ink-soft); text-decoration: none;
  font-size: 0.93rem; border-bottom: 1px solid var(--line);
}
.toc-panel a:hover { color: var(--accent); }
.toc-panel a.active { color: var(--accent); font-weight: 700; }

/* ---------- Layout ---------- */
main { max-width: var(--max); margin: 0 auto; padding: 0 1.25rem 4rem; }
section { padding-top: 3.2rem; scroll-margin-top: 5.5rem; }
section#executive-summary { padding-top: 2.4rem; }

.hero { padding-top: 3.5rem; padding-bottom: 1rem; }
.eyebrow {
  font-family: var(--mono); font-size: 0.78rem; letter-spacing: 0.04em;
  color: var(--accent); text-transform: uppercase; margin: 0 0 1rem;
}
h1 {
  font-family: var(--serif); font-weight: 700; letter-spacing: -0.015em;
  font-size: clamp(2rem, 4.4vw, 2.9rem); line-height: 1.12; margin: 0 0 1.1rem;
}
.lede { font-size: 1.18rem; color: var(--ink-soft); max-width: 62ch; margin: 0 0 1.5rem; }
.hero-meta {
  display: flex; flex-wrap: wrap; gap: 0.6rem 1.2rem;
  font-size: 0.85rem; color: var(--ink-faint);
  border-top: 1px solid var(--line); padding-top: 1.1rem;
}
.hero-byline {
  margin: 1.1rem 0 0; font-size: 0.92rem; color: var(--ink-soft);
  line-height: 1.5;
}
.hero-byline a { font-weight: 600; }

/* ---------- Stat band ---------- */
.stat-section { padding-top: 2.4rem; }
.stat-band {
  display: grid; grid-template-columns: repeat(2, 1fr); gap: 1px;
  background: var(--line); border: 1px solid var(--line);
  border-radius: var(--radius); overflow: hidden;
}
@media (max-width: 620px) { .stat-band { grid-template-columns: 1fr; } }
.stat { background: var(--paper-raised); padding: 1.25rem 1.3rem; }
.stat-num {
  display: block; font-family: var(--serif); font-weight: 700;
  font-size: clamp(1.7rem, 4vw, 2.15rem); line-height: 1.05;
  color: var(--accent); letter-spacing: -0.02em; margin-bottom: 0.45rem;
}
.stat-desc { display: block; font-size: 0.88rem; color: var(--ink-soft); line-height: 1.5; }
.stat-src, .cite {
  display: inline-block; font-family: var(--mono); font-size: 0.72rem;
  color: var(--ink-faint); text-decoration: none;
  border-bottom: 1px dotted var(--line-strong); white-space: nowrap;
}
.stat-src { margin-top: 0.15rem; }
.cite { margin-left: 0.15rem; }
.stat-src:hover, .cite:hover { color: var(--accent); border-bottom-color: var(--accent); }

h2 {
  font-family: var(--serif); font-weight: 700; letter-spacing: -0.01em;
  font-size: clamp(1.5rem, 3vw, 1.85rem); line-height: 1.2;
  margin: 0 0 1.1rem; padding-bottom: 0.6rem; border-bottom: 2px solid var(--ink);
}
h3 {
  font-family: var(--sans); font-weight: 700; font-size: 1.15rem;
  color: var(--ink); margin: 2.1rem 0 0.7rem;
}
h4 { font-size: 1rem; margin: 1.4rem 0 0.5rem; }

p { margin: 0 0 1.05rem; color: var(--ink); }
section p { color: var(--ink-soft); }
ul, ol { color: var(--ink-soft); padding-left: 1.3rem; margin: 0 0 1.1rem; }
li { margin-bottom: 0.45rem; }
li strong, p strong, dd strong { color: var(--ink); }

/* ---------- Executive summary box ---------- */
.summary-box {
  background: var(--accent-soft);
  border: 1px solid var(--accent-soft-line);
  border-radius: var(--radius);
  padding: 1.6rem 1.7rem;
}
.summary-box p { color: var(--ink); }
.summary-lead-in { font-weight: 700; margin-bottom: 0.7rem; }
.summary-points { padding-left: 1.1rem; margin-bottom: 0; }
.summary-points li { margin-bottom: 0.7rem; }
.summary-points li:last-child { margin-bottom: 0; }
.summary-note {
  margin: 1.2rem 0 0; padding-top: 0.9rem; border-top: 1px solid var(--accent-soft-line);
  font-size: 0.9rem; color: var(--ink-soft) !important; font-style: italic;
}

/* ---------- Inline notes & leads ---------- */
.text-note {
  font-size: 0.92rem; border-left: 2px solid var(--line-strong);
  padding-left: 0.9rem; margin: 1.2rem 0 1.3rem; color: var(--ink-faint);
}
.section-lead { font-size: 1.02rem; }

/* ---------- Tables ---------- */
.table-wrap { overflow-x: auto; margin: 0.5rem 0 1.4rem; -webkit-overflow-scrolling: touch; }
table {
  width: 100%; min-width: 460px; border-collapse: collapse;
  margin: 0; font-size: 0.93rem;
}
caption { text-align: left; font-size: 0.85rem; color: var(--ink-faint); margin-bottom: 0.4rem; }
th, td { text-align: left; padding: 0.65rem 0.8rem; vertical-align: top; border-bottom: 1px solid var(--line); }
thead th { border-bottom: 2px solid var(--ink); font-family: var(--mono); font-size: 0.75rem; text-transform: uppercase; letter-spacing: 0.03em; color: var(--ink-faint); }
.landscape-table td:first-child, .def-table td:first-child { width: 22%; }
.adoption-table td:first-child { width: 20%; }
.adoption-table td:last-child { width: 18%; white-space: nowrap; font-family: var(--mono); font-size: 0.82rem; }
.decision-table td:first-child { width: 24%; }
.metrics-table td:first-child { width: 30%; }
td { color: var(--ink-soft); }
td strong { color: var(--ink); }
.route-note {
  display: inline-block; margin-top: 0.25rem; font-family: var(--mono);
  font-size: 0.68rem; text-transform: uppercase; letter-spacing: 0.04em; color: var(--accent);
}

/* ---------- Case study callouts ---------- */
.case-study {
  background: var(--paper-raised); border: 1px solid var(--line);
  border-left: 3px solid var(--accent); border-radius: 0 var(--radius) var(--radius) 0;
  padding: 1.3rem 1.4rem; margin: 1.3rem 0 1.6rem;
}
.case-label {
  font-family: var(--mono); font-size: 0.72rem; text-transform: uppercase;
  letter-spacing: 0.04em; color: var(--accent); margin: 0 0 0.6rem; font-weight: 700;
}
.case-study p:last-child { margin-bottom: 0; color: var(--ink-soft); }
.case-warning { border-left-color: #C2410C; }
.case-warning .case-label { color: #C2410C; }
@media (prefers-color-scheme: dark) {
  .case-warning { border-left-color: #F97316; }
  .case-warning .case-label { color: #F97316; }
}
:root[data-theme="dark"] .case-warning { border-left-color: #F97316; }
:root[data-theme="dark"] .case-warning .case-label { color: #F97316; }
:root[data-theme="light"] .case-warning { border-left-color: #C2410C; }
:root[data-theme="light"] .case-warning .case-label { color: #C2410C; }

/* ---------- Sources ---------- */
.source-list { list-style: none; padding: 0; margin: 1.6rem 0 0; }
.source-list li {
  padding: 1rem 0; border-bottom: 1px solid var(--line);
  display: grid; grid-template-columns: 210px 1fr; gap: 1.2rem;
}
.source-list li:first-child { padding-top: 0; }
@media (max-width: 640px) {
  .source-list li { grid-template-columns: 1fr; gap: 0.35rem; }
}
.source-org { font-weight: 700; color: var(--ink); font-size: 0.9rem; line-height: 1.45; }
.source-detail { color: var(--ink-soft); font-size: 0.9rem; line-height: 1.6; }
.source-detail a {
  display: inline-block; font-family: var(--mono); font-size: 0.78rem;
  margin-top: 0.3rem;
}
.source-caveat {
  margin-top: 1.8rem; padding: 1.1rem 1.2rem;
  background: var(--paper-raised); border: 1px solid var(--line);
  border-radius: var(--radius);
  font-size: 0.88rem; color: var(--ink-faint) !important; line-height: 1.6;
}

/* ---------- FAQ / Glossary ---------- */
.faq-list { margin: 0; }
.faq-item { border-bottom: 1px solid var(--line); padding: 1.1rem 0; }
.faq-item:first-child { padding-top: 0; }
.faq-item dt { font-weight: 700; color: var(--ink); margin-bottom: 0.45rem; font-size: 1.02rem; }
.faq-item dd { margin: 0; color: var(--ink-soft); }

.glossary-list { display: grid; gap: 0.9rem; margin: 0; }
.glossary-list > div { display: grid; grid-template-columns: 170px 1fr; gap: 1rem; padding-bottom: 0.9rem; border-bottom: 1px solid var(--line); }
.glossary-list dt { font-family: var(--mono); font-weight: 700; font-size: 0.88rem; color: var(--accent); }
.glossary-list dd { margin: 0; color: var(--ink-soft); }
@media (max-width: 560px) {
  .glossary-list > div { grid-template-columns: 1fr; gap: 0.25rem; }
}

/* ---------- Footer ---------- */
.site-footer {
  max-width: var(--max); margin: 2rem auto 0; padding: 1.6rem 1.25rem 3rem;
  border-top: 1px solid var(--line);
  display: flex; justify-content: space-between; align-items: flex-start; gap: 1.5rem;
  color: var(--ink-faint); font-size: 0.85rem;
}
.footer-text { max-width: 52ch; }
.site-footer p { margin: 0 0 0.5rem; color: var(--ink-faint); font-size: 0.85rem; }
.site-footer p:last-child { margin-bottom: 0; }
.footer-org { font-weight: 700; color: var(--ink) !important; }
.footer-author a { font-weight: 600; }
.footer-meta { font-size: 0.8rem !important; line-height: 1.55; }
.back-to-top {
  background: var(--paper-raised); color: var(--ink);
  border: 1px solid var(--line-strong); border-radius: 999px;
  padding: 0.5rem 1rem; font-size: 0.85rem; font-weight: 600; cursor: pointer;
  font-family: var(--sans); white-space: nowrap;
}
.back-to-top:hover { border-color: var(--accent); color: var(--accent); }

@media (max-width: 560px) {
  .site-footer { flex-direction: column; align-items: flex-start; }
}