/*
 * PSIM public colour and document trim v9.
 * Additive companion to the immutable v3 site system and v4 chart system.
 * The restrained security-document blue remains limited to identity, navigation,
 * fine rules and evidence details; paper, white and ink remain dominant.
 */

:root {
  --blue-steel: #6f8798;
}

/* A persistent two-pixel signature without changing header geometry. */
.site-header::before {
  content: "";
  position: absolute;
  inset: 0 0 auto;
  height: 2px;
  background: var(--blue-dark);
  pointer-events: none;
}

/* Colour existing document rules; do not create additional card chrome. */
.fact-list {
  border-top: 2px solid var(--blue-dark);
}

.research-figure {
  border-top: 3px solid var(--blue-dark);
}

.metric-band,
.capacity-panel,
.contact-form {
  border-top-color: var(--blue-dark);
}

.data-table th {
  background: var(--blue-soft);
}

/* Breadcrumbs remain compact, but each link meets the 24px pointer target floor. */
.breadcrumbs a {
  min-height: 24px;
  display: inline-flex;
  align-items: center;
}

/* Keep the complete homepage decision set inside a common 1280×720 first view. */
@media (min-width: 1061px) and (max-width: 1300px) and (max-height: 800px) {
  .home-hero {
    grid-template-columns: minmax(0, .92fr) minmax(420px, 1.08fr);
    gap: clamp(36px, 5vw, 64px);
    padding-block: 48px 56px;
  }

  .home-hero h1 {
    margin-bottom: 20px;
    font-size: clamp(58px, 6.4vw, 82px);
  }

  .home-hero .actions {
    margin-top: 24px;
  }
}

/* Keep the visitor footer compact enough to scan on a phone. */
@media (max-width: 540px) {
  .site-footer .footer-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    column-gap: 18px;
  }

  .site-footer .footer-brand {
    grid-column: 1 / -1;
  }
}

/*
 * Public documents should remain legible when printed or saved to PDF. Navigation
 * and conversion controls are omitted; evidence, figures and tables remain intact.
 */
@page {
  margin: 16mm;
}

@media print {
  :root {
    --paper: #ffffff;
    --white: #ffffff;
    --ink: #111820;
    --copy: #25313a;
    --muted: #4c5962;
    --quiet: #5d6870;
    --line: #c7ccd0;
    --line-strong: #7a8389;
  }

  html,
  body,
  main,
  .section,
  .section--white,
  .section--ink,
  .page-hero,
  .home-hero,
  .research-figure,
  .plain-card,
  .proof-card,
  .route-row,
  .metric-band,
  .capacity-panel,
  .contact-form {
    background: #ffffff !important;
    color: var(--ink) !important;
  }

  .site-header,
  .site-footer,
  .actions {
    display: none !important;
  }

  .site-shell {
    width: 100%;
    max-width: none;
    padding-inline: 0;
  }

  .section,
  .page-hero,
  .home-hero {
    min-height: 0;
    padding-block: 18px;
  }

  .section--ink :is(h1, h2, h3, p, strong, span, small),
  .statement :is(h1, h2, h3, p, strong, span, small) {
    color: inherit !important;
  }

  h1,
  h2,
  h3,
  .section-head,
  .figure-head,
  figcaption {
    break-after: avoid;
    page-break-after: avoid;
  }

  article,
  figure,
  table,
  tr,
  .plain-card,
  .proof-card,
  .process-row,
  .route-row,
  .metric-band,
  .capacity-panel,
  .statement {
    break-inside: avoid;
    page-break-inside: avoid;
  }

  p,
  li {
    orphans: 3;
    widows: 3;
  }

  .research-figure,
  .table-wrap,
  .data-table {
    width: 100%;
    max-width: none;
    overflow: visible;
  }

  .chart-stage {
    min-height: 260px;
    overflow: visible;
  }

  .chart-stage svg {
    width: 100%;
    height: auto;
    max-height: none;
  }

  .data-table {
    border-collapse: collapse;
    font-size: 10pt;
  }

  .data-table thead {
    display: table-header-group;
  }

  a[href] {
    color: inherit;
    text-decoration: underline;
  }
}

@media (forced-colors: active) {
  .site-header::before {
    background: CanvasText;
  }
}

/* What is PSIM? /briefing — staged, learner-controlled guide. */
body[data-page-id="briefing"] {
  --guide-blue: #173f5b;
  --guide-blue-soft: #e5edf1;
  --guide-warm: #ebe5da;
  --guide-green: #355f52;
}

body[data-page-id="briefing"] section[id] {
  scroll-margin-top: 150px;
}

.guide-page {
  overflow: clip;
}

.guide-column {
  max-width: 1040px;
  margin-inline: auto;
}

.guide-hero {
  min-height: 680px;
  padding-block: clamp(72px, 9vw, 128px);
  display: grid;
  grid-template-columns: minmax(0, 1.25fr) minmax(300px, .55fr);
  gap: clamp(56px, 8vw, 120px);
  align-items: center;
}

.guide-hero-copy h1 {
  max-width: 900px;
  margin: 18px 0 28px;
  color: var(--ink);
  font: 400 clamp(58px, 6.8vw, 100px)/.93 var(--serif);
  letter-spacing: -.055em;
}

.guide-hero-copy .lead {
  max-width: 790px;
  margin: 0;
  color: var(--copy);
  font-size: clamp(18px, 1.45vw, 22px);
  line-height: 1.62;
}

.guide-welcome {
  max-width: 720px;
  margin: 28px 0 0;
  padding-left: 18px;
  border-left: 2px solid var(--guide-blue);
  color: var(--muted);
  font-size: 14px;
  line-height: 1.7;
}

.status-note {
  padding: 28px 0 0 28px;
  border-top: 3px solid var(--guide-blue);
  border-left: 1px solid var(--line);
}

.status-note dl {
  margin: 20px 0 0;
}

.status-note dl div {
  padding: 15px 0;
  border-top: 1px solid var(--line);
}

.status-note dt {
  margin-bottom: 4px;
  color: var(--quiet);
  font: 700 9px/1.4 var(--mono);
  letter-spacing: .1em;
  text-transform: uppercase;
}

.status-note dd {
  margin: 0;
  color: var(--ink);
  font-size: 13px;
  line-height: 1.55;
}

.path-picker {
  margin-bottom: 0;
  border-top: 2px solid var(--guide-blue);
  border-bottom: 1px solid var(--line);
}

.path-picker a {
  min-height: 98px;
  display: grid;
  grid-template-columns: 110px minmax(190px, .7fr) minmax(260px, 1fr);
  gap: 24px;
  align-items: center;
  border-top: 1px solid var(--line);
  color: inherit;
  text-decoration: none;
}

.path-picker a:first-child {
  border-top: 0;
}

.path-picker a:hover {
  background: var(--white);
}

.path-picker a:focus-visible {
  outline: 3px solid var(--guide-blue);
  outline-offset: 3px;
}

.path-picker span,
.level-tag {
  color: var(--guide-blue);
  font: 700 10px/1.4 var(--mono);
  letter-spacing: .1em;
  text-transform: uppercase;
}

.path-picker strong {
  font: 500 24px/1.2 var(--serif);
}

.path-picker small {
  color: var(--muted);
  font-size: 12px;
}

.guide-nav {
  position: sticky;
  z-index: 18;
  top: 73px;
  border-bottom: 1px solid var(--line);
  background: rgba(245, 244, 239, .96);
}

.guide-nav .site-shell {
  min-height: 52px;
  display: flex;
  align-items: center;
  gap: 28px;
  overflow-x: auto;
  scrollbar-width: none;
}

.guide-nav .site-shell::-webkit-scrollbar {
  display: none;
}

.guide-nav span {
  color: var(--quiet);
  font: 700 9px var(--mono);
  letter-spacing: .1em;
  text-transform: uppercase;
  white-space: nowrap;
}

.guide-nav a {
  min-height: 44px;
  display: inline-flex;
  align-items: center;
  color: var(--copy);
  font-size: 11px;
  text-decoration: none;
  white-space: nowrap;
}

.guide-nav a:hover {
  color: var(--guide-blue);
}

.guide-level {
  padding-block: clamp(82px, 10vw, 144px);
}

.level-header {
  max-width: 820px;
  margin-bottom: 58px;
}

.level-header h2 {
  margin: 16px 0 20px;
  color: var(--ink);
  font: 400 clamp(44px, 5vw, 72px)/1.01 var(--serif);
  letter-spacing: -.045em;
}

.level-header p {
  max-width: 760px;
  margin: 0;
  color: var(--muted);
  font-size: 16px;
  line-height: 1.7;
}

.story-example {
  display: grid;
  grid-template-columns: minmax(0, 1.15fr) minmax(280px, .75fr);
  border-top: 3px solid var(--guide-blue);
  border-bottom: 1px solid var(--line);
  background: var(--paper);
}

.story-main,
.story-questions {
  padding: clamp(30px, 4vw, 52px);
}

.story-main {
  border-left: 1px solid var(--line);
}

.story-main h3 {
  margin: 14px 0 22px;
  font: 500 clamp(32px, 3.4vw, 48px)/1.05 var(--serif);
  letter-spacing: -.03em;
}

.story-main p {
  max-width: 650px;
  margin: 0 0 16px;
  color: var(--copy);
  font-size: 16px;
  line-height: 1.72;
}

.story-questions {
  color: var(--ink);
  background: var(--guide-blue-soft);
}

.story-questions > p {
  margin: 0 0 18px;
  font: 500 24px/1.2 var(--serif);
}

.story-questions ol {
  margin: 0;
  padding-left: 22px;
}

.story-questions li {
  padding: 8px 0 8px 5px;
  line-height: 1.55;
}

.plain-answer {
  max-width: 880px;
  margin: clamp(62px, 8vw, 96px) auto;
  color: var(--ink);
  font: 400 clamp(34px, 4.4vw, 60px)/1.12 var(--serif);
  letter-spacing: -.035em;
  text-align: center;
}

.word-list {
  border-top: 2px solid var(--guide-blue);
}

.word-list article {
  padding: 27px 0;
  display: grid;
  grid-template-columns: minmax(170px, .45fr) minmax(0, 1fr);
  gap: 36px;
  border-bottom: 1px solid var(--line);
}

.word-list h3 {
  margin: 0;
  font: 500 25px/1.2 var(--serif);
}

.word-list p {
  max-width: 700px;
  margin: 0;
  color: var(--muted);
  line-height: 1.7;
}

.remember-this {
  margin: 54px 0 22px;
  padding: 28px 32px;
  display: grid;
  grid-template-columns: 150px 1fr;
  gap: 30px;
  color: var(--ink);
  background: var(--guide-warm);
  border-left: 4px solid var(--guide-blue);
}

.remember-this span {
  padding-top: 4px;
  font: 700 9px var(--mono);
  letter-spacing: .1em;
  text-transform: uppercase;
}

.remember-this p {
  margin: 0;
  font: 500 20px/1.45 var(--serif);
}

.knowledge-check {
  border-top: 1px solid var(--line-strong);
  border-bottom: 1px solid var(--line);
}

.knowledge-check summary,
.technical-note summary,
.glossary-drawer summary {
  list-style: none;
  cursor: pointer;
}

.knowledge-check summary::-webkit-details-marker,
.technical-note summary::-webkit-details-marker,
.glossary-drawer summary::-webkit-details-marker {
  display: none;
}

.knowledge-check summary {
  min-height: 70px;
  padding: 18px 56px 18px 0;
  display: flex;
  align-items: center;
  position: relative;
  color: var(--ink);
  font-weight: 700;
}

.knowledge-check summary::after,
.glossary-drawer summary::after {
  content: "+";
  position: absolute;
  right: 14px;
  color: var(--guide-blue);
  font: 400 28px/1 var(--serif);
}

.knowledge-check[open] summary::after,
.glossary-drawer[open] summary::after {
  content: "−";
}

.knowledge-check > div {
  padding: 0 56px 24px 0;
}

.knowledge-check > div p {
  max-width: 790px;
  margin: 0;
  color: var(--muted);
  line-height: 1.7;
}

.level-next {
  margin: 52px 0 0;
  text-align: right;
}

.level-next a {
  min-height: 44px;
  display: inline-flex;
  align-items: center;
  gap: 12px;
  color: var(--guide-blue);
  font-weight: 700;
  text-decoration: none;
}

.method-steps {
  margin: 0;
  padding: 0;
  list-style: none;
  border-top: 3px solid var(--guide-blue);
}

.method-steps li {
  min-height: 150px;
  padding: 30px 0;
  display: grid;
  grid-template-columns: 100px 1fr;
  gap: 28px;
  border-bottom: 1px solid var(--line);
}

.method-steps li > span {
  color: var(--guide-blue);
  font: 700 11px var(--mono);
  letter-spacing: .08em;
}

.method-steps h3 {
  margin: -5px 0 10px;
  font: 500 clamp(27px, 3vw, 38px)/1.15 var(--serif);
}

.method-steps p {
  max-width: 740px;
  margin: 0;
  color: var(--muted);
  font-size: 15px;
  line-height: 1.72;
}

.worked-case {
  margin: clamp(72px, 9vw, 116px) 0 30px;
  padding: clamp(34px, 5vw, 64px);
  border-top: 3px solid var(--guide-blue);
  background: var(--white);
}

.worked-case > div:first-child {
  max-width: 780px;
}

.worked-case h3,
.evidence-guide h3 {
  margin: 14px 0 18px;
  font: 500 clamp(34px, 4vw, 54px)/1.05 var(--serif);
  letter-spacing: -.035em;
}

.worked-case > div:first-child p {
  margin: 0;
  color: var(--muted);
  font-size: 16px;
  line-height: 1.7;
}

.neutral-figure {
  margin-top: 42px;
  display: grid;
  grid-template-columns: 1fr minmax(150px, .46fr) 1fr;
  border: 1px solid var(--line);
}

.neutral-side,
.neutral-middle {
  min-height: 230px;
  padding: 28px;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.neutral-side small {
  color: var(--quiet);
  font: 700 9px var(--mono);
  letter-spacing: .08em;
  text-transform: uppercase;
}

.neutral-side strong {
  margin: 18px 0 8px;
  font: 500 24px/1.2 var(--serif);
}

.neutral-side span {
  color: var(--muted);
}

.neutral-side b {
  margin-top: 26px;
  color: var(--guide-green);
  font: 500 36px/1 var(--serif);
}

.neutral-side--short b {
  color: #7b4f48;
}

.neutral-middle {
  align-items: center;
  border-inline: 1px solid #b8c8d1;
  background: var(--guide-blue-soft);
  text-align: center;
}

.neutral-middle span,
.neutral-middle small {
  color: var(--quiet);
  font: 700 8px var(--mono);
  letter-spacing: .08em;
  text-transform: uppercase;
}

.neutral-middle strong {
  margin: 14px 0 10px;
  color: var(--guide-blue);
  font: 500 44px/1 var(--serif);
}

.number-example {
  padding-top: 30px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 34px;
}

.number-example p {
  margin: 0;
  color: var(--muted);
  line-height: 1.72;
}

.evidence-guide {
  margin-top: clamp(76px, 9vw, 118px);
}

.evidence-guide header {
  max-width: 800px;
  margin-bottom: 34px;
}

.evidence-rows {
  border-top: 3px solid var(--guide-blue);
}

.evidence-rows > div {
  min-height: 140px;
  padding: 28px 0;
  display: grid;
  grid-template-columns: 180px 1fr;
  gap: 34px;
  border-bottom: 1px solid var(--line);
}

.evidence-rows > div > span {
  color: var(--guide-blue);
  font: 500 28px/1.2 var(--serif);
}

.evidence-rows strong {
  display: block;
  margin-bottom: 8px;
  font-size: 15px;
}

.evidence-rows p {
  max-width: 680px;
  margin: 0;
  color: var(--muted);
  line-height: 1.7;
}

.category-note {
  margin: 24px 0 0;
  padding: 24px 28px;
  background: var(--guide-warm);
  color: var(--copy);
  line-height: 1.7;
}

.technical-stack {
  border-top: 3px solid var(--guide-blue);
}

.technical-note {
  border-bottom: 1px solid var(--line);
}

.technical-note summary {
  min-height: 112px;
  padding: 24px 64px 24px 0;
  display: grid;
  grid-template-columns: 70px 1fr;
  gap: 4px 24px;
  align-content: center;
  position: relative;
}

.technical-note summary::after {
  content: "+";
  position: absolute;
  top: calc(50% - 17px);
  right: 14px;
  color: var(--guide-blue);
  font: 400 34px/1 var(--serif);
}

.technical-note[open] summary::after {
  content: "−";
}

.technical-note summary > span {
  grid-row: 1 / 3;
  padding-top: 5px;
  color: var(--guide-blue);
  font: 700 10px var(--mono);
  letter-spacing: .08em;
}

.technical-note summary strong {
  color: var(--ink);
  font: 500 clamp(23px, 2.6vw, 32px)/1.2 var(--serif);
}

.technical-note summary small {
  color: var(--muted);
  font-size: 11px;
}

.technical-note summary:hover strong,
.technical-note summary:focus-visible strong {
  color: var(--guide-blue);
}

.technical-note summary:focus-visible,
.knowledge-check summary:focus-visible,
.glossary-drawer summary:focus-visible {
  outline: 3px solid var(--guide-blue);
  outline-offset: 3px;
}

.technical-body {
  padding: 6px 0 50px 94px;
}

.technical-body > p {
  max-width: 780px;
  margin: 0 0 20px;
  color: var(--copy);
  font-size: 15px;
  line-height: 1.75;
}

.technical-body code {
  padding: 2px 5px;
  background: var(--guide-blue-soft);
  font: 500 .95em var(--mono);
}

.check-panel {
  max-width: 820px;
  margin: 28px 0;
  padding: 26px 30px;
  border-left: 3px solid var(--guide-blue);
  background: var(--paper);
}

.check-panel h3 {
  margin: 0 0 12px;
  font: 600 13px var(--sans);
}

.check-panel ul {
  margin: 0;
  padding-left: 19px;
  color: var(--muted);
}

.check-panel li {
  padding: 4px 0;
  line-height: 1.6;
}

.check-panel p {
  margin: 0;
  color: var(--muted);
  line-height: 1.7;
}

.failure-line {
  padding-top: 18px;
  border-top: 1px solid var(--line);
}

.fold-diagram {
  max-width: 820px;
  margin: 32px 0;
  display: grid;
  gap: 9px;
}

.fold-diagram > div {
  min-height: 42px;
  display: grid;
  grid-template-columns: 72px repeat(5, 1fr);
  gap: 5px;
}

.fold-diagram span {
  display: flex;
  align-items: center;
  color: var(--quiet);
  font: 700 9px var(--mono);
  text-transform: uppercase;
}

.fold-diagram b {
  display: grid;
  place-items: center;
  font: 700 9px var(--mono);
  letter-spacing: .06em;
  text-transform: uppercase;
}

.fold-diagram .train {
  grid-column: 2 / 4;
  color: var(--copy);
  background: #dfe1df;
}

.fold-diagram .train--two {
  grid-column: 2 / 5;
}

.fold-diagram .train--three {
  grid-column: 2 / 6;
}

.fold-diagram .test {
  color: #fff;
  background: var(--guide-blue);
}

.equation-grid {
  max-width: 820px;
  margin: 32px 0;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  border-top: 2px solid var(--guide-blue);
  border-left: 1px solid var(--line);
}

.equation-grid > div {
  min-height: 190px;
  padding: 25px;
  border-right: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.equation-grid span {
  color: var(--quiet);
  font: 700 9px var(--mono);
  letter-spacing: .07em;
  text-transform: uppercase;
}

.equation-grid code {
  margin: 24px 0 18px;
  padding: 0;
  display: block;
  color: var(--guide-blue);
  background: transparent;
  font: 500 27px/1.1 var(--serif);
}

.equation-grid p {
  margin: 0;
  color: var(--muted);
  font-size: 12px;
  line-height: 1.6;
}

.cost-equation {
  max-width: 820px !important;
  margin: 10px 0 34px !important;
  padding: 28px;
  display: flex;
  flex-wrap: wrap;
  gap: 10px 16px;
  align-items: baseline;
  background: var(--guide-blue-soft);
}

.cost-equation span {
  color: var(--ink);
  font: 500 18px/1.4 var(--serif);
}

.cost-equation b {
  color: var(--guide-blue);
}

.public-case-facts {
  max-width: 840px;
  margin: 0 0 28px;
  border-top: 2px solid var(--guide-blue);
}

.public-case-facts div {
  padding: 20px 0;
  display: grid;
  grid-template-columns: 170px 1fr;
  gap: 28px;
  border-bottom: 1px solid var(--line);
}

.public-case-facts dt {
  color: var(--ink);
  font-weight: 700;
}

.public-case-facts dd {
  margin: 0;
  color: var(--muted);
  line-height: 1.65;
}

.glossary-drawer {
  margin-top: 54px;
  border-top: 2px solid var(--guide-blue);
  border-bottom: 1px solid var(--line);
}

.glossary-drawer summary {
  min-height: 82px;
  padding: 20px 56px 20px 0;
  display: flex;
  align-items: center;
  position: relative;
  font: 500 27px/1.2 var(--serif);
}

.glossary-drawer .word-list {
  margin-bottom: 26px;
  border-top-width: 1px;
}

.today-balance {
  display: grid;
  grid-template-columns: 1fr 1fr;
  border-top: 3px solid var(--guide-blue);
  border-left: 1px solid var(--line);
}

.today-balance article {
  padding: clamp(30px, 4vw, 50px);
  border-right: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  background: var(--white);
}

.today-balance article:last-child {
  background: var(--guide-warm);
}

.today-balance h3 {
  margin: 15px 0 22px;
  font: 500 clamp(27px, 3vw, 38px)/1.15 var(--serif);
}

.today-balance ul {
  margin: 0;
  padding-left: 18px;
  color: var(--muted);
}

.today-balance li {
  padding: 6px 0;
  line-height: 1.62;
}

.why-positive {
  max-width: 900px;
  margin: 48px 0 0;
  color: var(--ink);
  font: 400 clamp(27px, 3.3vw, 42px)/1.28 var(--serif);
  letter-spacing: -.02em;
}

.guide-close {
  padding-block: clamp(86px, 11vw, 148px);
}

.guide-close header {
  max-width: 800px;
  margin-bottom: 44px;
}

.guide-close header h2 {
  margin: 15px 0 0;
  color: #fff;
  font: 400 clamp(40px, 4.7vw, 66px)/1.04 var(--serif);
  letter-spacing: -.04em;
}

.technical-stack--dark {
  border-top-color: #8ba2b1;
}

.technical-stack--dark .knowledge-check {
  border-color: rgba(255, 255, 255, .2);
}

.technical-stack--dark .knowledge-check summary {
  color: #fff;
}

.technical-stack--dark .knowledge-check summary::after {
  color: #a9becb;
}

.technical-stack--dark .knowledge-check > div p {
  color: #c0cbd1;
}

.guide-close .route-list {
  margin-top: 70px;
  border-top-color: #8ba2b1;
}

.guide-close .route-row {
  color: #fff;
  background: transparent;
  border-color: rgba(255, 255, 255, .2);
}

.guide-close .route-row:hover {
  background: rgba(255, 255, 255, .05);
}

.guide-close .route-main span,
.guide-close .route-state,
.guide-close .route-index {
  color: #aebcc4;
}

.guide-final-line {
  max-width: 820px;
  margin: 78px 0 0;
  color: #fff;
  font: 400 clamp(31px, 3.8vw, 50px)/1.2 var(--serif);
  letter-spacing: -.025em;
}

.guide-disclosure {
  margin: 28px 0 0;
  color: #9eacb4;
  font-size: 11px;
}

@media (max-width: 900px) {
  .guide-hero {
    min-height: 0;
    grid-template-columns: 1fr;
  }

  .status-note {
    max-width: 620px;
  }

  .story-example,
  .today-balance {
    grid-template-columns: 1fr;
  }

  .story-main {
    border-right: 1px solid var(--line);
  }

  .neutral-figure {
    grid-template-columns: 1fr 1fr;
  }

  .neutral-middle {
    grid-column: 1 / -1;
    grid-row: 2;
    min-height: 150px;
    border: 0;
    border-top: 1px solid #b8c8d1;
  }

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

  .equation-grid > div {
    min-height: 0;
  }
}

@media (max-width: 680px) {
  body[data-page-id="briefing"] section[id] {
    scroll-margin-top: 92px;
  }

  .guide-hero {
    padding-block: 56px 72px;
    gap: 44px;
  }

  .guide-hero-copy h1 {
    font-size: clamp(46px, 13vw, 66px);
  }

  .status-note {
    padding-left: 20px;
  }

  .path-picker a {
    padding-block: 22px;
    grid-template-columns: 78px 1fr;
    gap: 8px 18px;
  }

  .path-picker small {
    grid-column: 2;
  }

  .guide-nav {
    top: 62px;
  }

  .guide-nav .site-shell {
    gap: 22px;
  }

  .guide-level {
    padding-block: 78px;
  }

  .level-header {
    margin-bottom: 42px;
  }

  .story-main,
  .story-questions,
  .worked-case {
    padding: 28px 22px;
  }

  .word-list article,
  .evidence-rows > div,
  .public-case-facts div {
    grid-template-columns: 1fr;
    gap: 10px;
  }

  .remember-this {
    padding: 25px 22px;
    grid-template-columns: 1fr;
    gap: 12px;
  }

  .method-steps li {
    grid-template-columns: 46px 1fr;
    gap: 16px;
  }

  .neutral-figure,
  .number-example {
    grid-template-columns: 1fr;
  }

  .neutral-middle {
    grid-column: auto;
    grid-row: auto;
    min-height: 140px;
    border-top: 1px solid #b8c8d1;
    border-bottom: 1px solid #b8c8d1;
  }

  .neutral-side {
    min-height: 190px;
  }

  .technical-note summary {
    min-height: 102px;
    padding-right: 48px;
    grid-template-columns: 36px 1fr;
    gap: 4px 10px;
  }

  .technical-note summary::after {
    right: 4px;
  }

  .technical-body {
    padding: 4px 0 38px 46px;
  }

  .fold-diagram > div {
    grid-template-columns: 50px repeat(5, 1fr);
  }

  .cost-equation {
    padding: 22px;
  }

  .today-balance article {
    padding: 28px 22px;
  }
}

@media print {
  .guide-nav,
  .path-picker,
  .level-next {
    display: none !important;
  }

  .guide-hero {
    min-height: 0;
    padding-block: 24px;
  }

  .guide-level,
  .guide-close {
    padding-block: 28px;
  }

  details > :not(summary) {
    display: block !important;
  }

  .technical-note,
  .knowledge-check,
  .worked-case,
  .story-example,
  .today-balance article {
    break-inside: avoid;
    page-break-inside: avoid;
  }
}

@media (forced-colors: active) {
  .guide-nav {
    background: Canvas;
  }

  .story-questions,
  .remember-this,
  .category-note,
  .neutral-middle,
  .check-panel,
  .today-balance article:last-child {
    background: Canvas;
  }
}

/* September draft: compact introductions and a quieter reading hierarchy. */
@media screen {
  .home-hero {
    min-height: 0;
    grid-template-columns: minmax(0, 1.12fr) minmax(340px, .88fr);
    gap: clamp(40px, 6vw, 88px);
    padding-block: clamp(48px, 6vw, 84px);
  }

  .home-hero h1 {
    max-width: 760px;
    font-size: clamp(48px, 5.8vw, 78px);
    line-height: 1.02;
    letter-spacing: -.045em;
  }

  .home-hero .lead { font-size: 18px; line-height: 1.65; }
  .home-hero .actions { margin-top: 24px; }
  .hero-note { max-width: 54ch; margin: 18px 0 0; color: var(--muted); font-size: 16px; }

  .page-hero {
    min-height: 0;
    padding-block: clamp(42px, 5vw, 72px) clamp(44px, 5vw, 72px);
    gap: clamp(32px, 6vw, 84px);
    align-items: center;
  }
  .page-hero h1 { font-size: clamp(42px, 5vw, 66px); line-height: 1.06; letter-spacing: -.04em; }
  .page-hero .lead { font-size: 17px; }
  .page-hero .fact-list { margin-block: 0; }
  main section[id] { scroll-margin-top: 96px; }
  .section { padding-block: clamp(48px, 6vw, 84px); }
  .section-head { margin-bottom: 36px; gap: 48px; }
  .section-head h2 {
    font-size: clamp(28px, 2.8vw, 36px);
    line-height: 1.18;
    letter-spacing: -.025em;
  }
  .split-copy h2, .statement h2 { font-size: clamp(25px, 2.3vw, 30px); line-height: 1.22; letter-spacing: -.02em; }
  .contact-copy h2 { font: 600 22px/1.35 var(--sans); letter-spacing: 0; }
  .capacity-head h2 { font: 600 clamp(22px, 2vw, 26px)/1.35 var(--sans); letter-spacing: -.015em; }
  .plain-card h3, .proof-card h3, .process-row h3, .split-copy h3 { font: 600 18px/1.4 var(--sans); letter-spacing: 0; }
  .section--compact { padding-block: 36px; }

  .research-note { padding: 28px 30px; border-top: 2px solid var(--blue-dark); background: var(--white); }
  .research-note h2 { margin: 15px 0 24px; color: var(--ink); font: 600 24px/1.3 var(--sans); letter-spacing: -.015em; }
  .research-note-facts { margin: 0; }
  .research-note-facts div { padding: 15px 0; border-top: 1px solid var(--line); }
  .research-note-facts dt { color: var(--ink); font-size: 14px; font-weight: 700; }
  .research-note-facts dd { margin: 4px 0 0; color: var(--muted); font-size: 14px; line-height: 1.55; }
  .research-note > .text-link { margin-top: 12px; justify-content: flex-start; font-size: 13px; }
  .button-primary, .button-link, .text-link { gap: 12px; }
  .button-primary:focus-visible, .button-link:focus-visible, .text-link:focus-visible,
  .route-row:focus-visible, .footer-col a:focus-visible {
    outline: 2px solid var(--blue); outline-offset: 4px;
  }
  .section--ink :is(.button-primary, .button-link, .text-link):focus-visible { outline-color: var(--white); }

  .research-preview { display: grid; grid-template-columns: minmax(0, .8fr) minmax(0, 1.2fr); align-items: center; gap: clamp(36px, 6vw, 84px); }
  .research-preview-copy h2 { margin: 0 0 22px; color: var(--ink); font: 400 clamp(30px, 2.8vw, 38px)/1.2 var(--serif); letter-spacing: -.025em; }
  .research-preview-copy > p { max-width: 49ch; color: var(--muted); }
  .research-preview-copy .actions { gap: 10px 20px; margin-top: 22px; }
  .research-preview .chart-stage { min-height: 270px; }
  .research-preview .chart-stage svg, .research-preview .chart-empty { height: 270px; min-height: 270px; }

  .route-row { min-height: 96px; padding-block: 20px; grid-template-columns: 46px minmax(0, 1fr) minmax(140px, .25fr) 22px; gap: 20px; }
  .route-main span, .plain-card p, .proof-card p, .process-row p { font-size: 14px; line-height: 1.6; }
  .route-state, .fact-list dt, .field label { font-size: 12px; }
  .fact-list dd { font-size: 14px; }
  .plain-card, .proof-card { min-height: 0; padding: 26px; }
  .plain-card h3, .proof-card h3 { margin-top: 22px; }
  .plain-card > h3:first-child, .proof-card > h3:first-child { margin-top: 0; }
  .plain-card p + p, .proof-card p + p { margin-top: 14px; }
  .figure-head span, .figure-head small, .research-figure figcaption, .programme-note { font-size: 12px; line-height: 1.6; }
  .figure-meta small { font-size: 10px; letter-spacing: .025em; }
  .figure-meta div { padding-inline: 14px; }
  .footer-col a, .footer-col strong, .footer-brand p { font-size: 12px; }
  .footer-col a { min-height: 32px; }
  .footer-bottom { padding-inline: var(--gutter); font-size: 11px; }

  body[data-page-id="contact"] .page-hero { display: block; padding-block: 28px 38px; }
  body[data-page-id="contact"] .page-hero h1 { margin-block: 12px 16px; }
  body[data-page-id="contact"] .section { padding-top: 38px; }
  .contact-layout { gap: clamp(36px, 7vw, 90px); }
  .contact-copy .contact-followup { margin-top: 18px; }
  .contact-copy > .text-link { margin-top: 18px; }
  .contact-form .field { padding-block: 13px; }
  .contact-form textarea { min-height: 130px; }
  .contact-form .programme-note { font-size: 11px; }

  body[data-page-id="partnerships"] details { border-block: 1px solid var(--line); padding-block: 20px; }
  body[data-page-id="partnerships"] details > summary { cursor: pointer; color: var(--blue-dark); font-weight: 700; }
  body[data-page-id="partnerships"] details > summary:focus-visible { outline: 2px solid var(--blue); outline-offset: 4px; }
  .guide-hero { min-height: 0; padding-block: clamp(48px, 6vw, 84px); }
  .guide-hero-copy h1 { font-size: clamp(44px, 5vw, 68px); line-height: 1.06; }
  .level-header h2, .guide-close header h2 { font-size: clamp(30px, 3vw, 40px); line-height: 1.16; }
  .guide-level { padding-block: clamp(48px, 6vw, 84px); }
}

@media screen and (max-width: 1060px) {
  .home-hero { grid-template-columns: minmax(0, 1.05fr) minmax(300px, .95fr); gap: 32px; }
  .home-hero h1 { font-size: clamp(44px, 5.8vw, 60px); }
  .research-note { padding: 24px; }
  .research-preview { grid-template-columns: 1fr 1.2fr; gap: 32px; }
}

@media screen and (max-width: 790px) {
  .home-hero, .research-preview { grid-template-columns: 1fr; }
  .home-hero { padding-block: 40px 44px; gap: 34px; }
  .home-hero h1 { max-width: 620px; font-size: clamp(43px, 9vw, 60px); }
  .home-hero .lead { font-size: 17px; }
  .hero-note { font-size: 15px; }
  .page-hero { padding-block: 32px 42px; gap: 28px; }
  .page-hero h1 { font-size: clamp(39px, 9vw, 56px); }
  .section { padding-block: 44px; }
  .section-head { gap: 20px; margin-bottom: 28px; }
  .research-note { padding: 24px; }
  .research-note h2 { font-size: 23px; }
  .route-row { grid-template-columns: 28px minmax(0, 1fr) 18px; gap: 14px; }
  .route-state { grid-column: 2; font-size: 10px; }
  .route-arrow { grid-column: 3; grid-row: 1 / 3; }
  .route-main strong { font-size: 24px; }
  .contact-layout { grid-template-columns: 1fr; gap: 28px; }
  .contact-copy h2 { font-size: 22px; }
  .contact-copy .contact-followup { margin-top: 12px; }
  .footer-bottom { padding-inline: 18px; }
}

@media screen and (max-width: 540px) {
  .research-note > .text-link { display: flex; line-height: 1.5; }
  .home-hero .actions { gap: 8px 20px; }
  .home-hero .button-primary { padding-inline: 16px; }
  .figure-meta { grid-template-columns: repeat(3, minmax(0, 1fr)); }
  .figure-meta div { min-height: 0; padding: 12px 10px; border-right: 1px solid var(--line); border-bottom: 0; }
  .figure-meta div:last-child { border-right: 0; }
  .figure-meta small { font-size: 10px; letter-spacing: 0; }
  .figure-meta strong { font-size: 20px; }
  .research-preview .chart-stage { min-height: 0; }
  .research-preview .chart-stage svg { min-height: 0; height: auto; }
}