/* PSIM: a quiet reading room for studies, results and working notes. */
:root {
  --paper: #f7f5f0;
  --white: #fdfcf9;
  --ink: #282c29;
  --copy: #424844;
  --muted: #5c645f;
  --quiet: #626b64;
  --line: #d9dcd3;
  --line-strong: #b6bdb2;
  --blue: #315a50;
  --blue-dark: #294e45;
  --blue-soft: #edf0e9;
  --accent: #315a50;
  --sans: "Segoe UI", Arial, sans-serif;
  --max: 1280px;
  --gutter: clamp(20px, 4vw, 56px);
}
@media screen {
  body { min-width: 0; background: var(--paper); font-family: var(--sans); font-size: 16px; line-height: 1.7; }
  .site-header { background: var(--paper); }
  .site-header::before { display: none; }
  .brand-mark { font-family: Georgia, serif; font-size: 25px; letter-spacing: .04em; }
  .brand-descriptor { border: 0; padding: 0; font-size: 12px; }
  .primary-nav { gap: 22px; }
  .nav-link { font-size: 14px; }
  .kicker, .route-state, .plain-card small, .proof-card small { font-weight: 500; letter-spacing: .01em; text-transform: none; font-size: 12px; }
  .home-hero { grid-template-columns: minmax(0, 1.45fr) minmax(270px, .75fr); gap: clamp(40px, 6vw, 80px); padding-block: 64px 68px; align-items: start; }
  .home-hero h1 { max-width: 660px; margin-block: 18px 24px; font-size: clamp(42px, 4.4vw, 56px); line-height: 1.1; letter-spacing: -.025em; font-weight: 400; }
  .home-hero .lead { max-width: 53ch; font-size: 18px; line-height: 1.75; }
  .hero-note { max-width: 55ch; font-size: 15px; }
  .author-line { margin: 24px 0 0; color: var(--muted); font-size: 13px; }
  .author-line a { color: var(--blue); text-decoration: underline; text-underline-offset: 4px; }
  .home-hero .actions { margin-top: 26px; }
  .research-note { padding: 10px 0 0 28px; border-top: 0; border-left: 1px solid var(--line-strong); background: transparent; }
  .research-note h2 { margin-block: 12px 18px; font: 400 27px/1.25 var(--serif); }
  .research-note-facts div { padding: 13px 0; }
  .research-note-facts dt { font-size: 13px; font-weight: 600; }
  .research-note-facts dd { font-size: 14px; }
  .button-primary { min-height: 46px; padding: 10px 18px; font-size: 14px; }
  .button-link, .text-link { min-height: 44px; font-size: 14px; }
  .section { padding-block: 52px; border-top: 1px solid var(--line); }
  .section--white { background: var(--white); }
  .section--compact { padding-block: 28px; }
  .section-head { margin-bottom: 28px; gap: 36px; align-items: start; }
  .section-head h2, .split-copy h2, .statement h2 { font: 400 clamp(26px, 2.7vw, 32px)/1.25 var(--serif); letter-spacing: -.015em; }
  .section-head p { font-size: 16px; max-width: 62ch; }
  .page-hero { padding-block: 40px 48px; gap: 52px; align-items: start; grid-template-columns: minmax(0, 1.3fr) minmax(260px, .6fr); }
  .page-hero h1 { margin-block: 16px 22px; font-size: clamp(36px, 4vw, 50px); line-height: 1.15; letter-spacing: -.02em; }
  .page-hero .lead { max-width: 58ch; font-size: 17px; line-height: 1.75; }
  .fact-list { border-top: 1px solid var(--line-strong); margin-block: 8px 0; }
  .fact-list dt { font-size: 12px; }
  .fact-list dd { font-size: 14px; font-weight: 500; }
  .route-row { grid-template-columns: 34px minmax(0, 1fr) minmax(120px, .25fr) 22px; gap: 18px; min-height: 100px; }
  .route-main strong { font-size: 25px; letter-spacing: -.01em; }
  .route-main span { font-size: 15px; }
  .route-state { font-size: 12px; }
  .proof-grid, .three-grid, .four-grid { border: 0; gap: 28px; }
  .plain-card, .proof-card { border: 0; border-top: 1px solid var(--line-strong); padding: 20px 0 0; background: transparent; }
  .plain-card h3, .proof-card h3 { margin: 12px 0; font-size: 18px; font-weight: 600; }
  .plain-card p, .proof-card p, .process-row p { font-size: 15px; line-height: 1.75; }
  .process-row { grid-template-columns: 34px minmax(180px, .55fr) minmax(0, 1fr); gap: 24px; min-height: 0; padding-block: 26px; }
  .process-row h3 { font-size: 18px; }
  .split-copy { gap: 48px; }
  .split-copy p { margin-top: 14px; font-size: 16px; }
  .research-preview { grid-template-columns: minmax(0, .72fr) minmax(0, 1.28fr); gap: 50px; }
  .research-preview-copy h2 { font-size: 30px; }
  .research-figure { background: transparent; border: 0; border-top: 1px solid var(--line-strong); }
  .figure-head { padding-inline: 0; }
  .research-figure figcaption { font-size: 12px; padding-inline: 0; }
  .figure-meta { border-bottom: 1px solid var(--line); }
  .notes-topics { display: block; border: 0; margin-top: 24px; }
  .notes-topic { display: grid; grid-template-columns: 155px minmax(0, .9fr) minmax(0, 1fr); gap: 30px; padding: 26px 0; border: 0; border-top: 1px solid var(--line); background: transparent; }
  .notes-topic h3 { margin: 0; font: 400 25px/1.3 var(--serif); }
  .notes-topic h3 a:hover { text-decoration: underline; text-underline-offset: 4px; }
  .notes-topic p { margin: 0; font-size: 15px; }
  .notes-topic .kicker { max-width: 145px; line-height: 1.6; }
  .notes-topic > .text-link { display: none; }
  .notes-related { padding-block: 34px; }
  .notes-related .split-copy { grid-template-columns: minmax(0, .65fr) minmax(0, 1fr); }
  .notes-related .kicker { display: none; }
  .notes-related h2 { font-size: 25px; }
  .notes-related p { margin-top: 0; font-size: 15px; }
  .section--ink { background: var(--paper); color: var(--ink); }
  .section--ink .statement :is(h2, p), .section--ink .statement .button-link { color: var(--copy); }
  .section--ink .statement .button-link { border-color: var(--line-strong); }
  .statement { gap: 40px; }
  .capacity-panel { border-top-width: 1px; }
  .capacity-facts small, .metric-band small { font-size: 12px; }
  .capacity-note { font-size: 14px; }
  .programme-note { font-size: 13px; }
  .contact-form :is(input, select, textarea) { font-size: 16px; background: var(--white); }
  .contact-form .programme-note { font-size: 13px; }
  .site-footer { background: var(--paper); padding-block: 36px 0; }
  .footer-col strong, .footer-col a, .footer-brand p { font-size: 13px; }
  .footer-col a { min-height: 36px; }
  .footer-col strong { text-transform: none; letter-spacing: 0; }
  .footer-bottom { font-size: 12px; }
  .guide-hero { gap: 50px; padding-block: 42px 54px; }
  .guide-hero-copy h1 { font-size: clamp(36px, 4vw, 50px); line-height: 1.15; }
  .guide-level { padding-block: 54px; }
  .level-header { margin-bottom: 30px; }
  .level-header h2, .guide-close header h2 { font-size: 32px; line-height: 1.25; }
  .story-main h3, .worked-case h3, .evidence-guide h3 { font-size: 29px; line-height: 1.3; }
  .plain-answer { font-size: 27px; text-align: left; max-width: 750px; margin-block: 36px; }
  .status-note { padding-left: 22px; border-top-width: 1px; }
  .why-positive, .guide-final-line { font-size: 25px; line-height: 1.5; }
  .guide-close { background: #293c35; }
  .research-questions { margin: 0; padding-left: 22px; max-width: 80ch; }
  .research-questions li { padding: 12px 0 12px 4px; }
  .research-questions strong { font-weight: 600; }
  .research-questions p { display: inline; margin: 0; }
  .next-tests { padding-left: 20px; margin: 14px 0; }
  .next-tests li { padding: 6px 0; }
  .research-byline { border-top: 1px solid var(--line); padding-block: 22px; font-size: 14px; }
  .journal, body:has(.prose) { background: var(--paper); }
  .header { background: var(--paper); }
  .notes-intro h1 { font-size: clamp(35px, 4vw, 48px); }
  .journal .wrap { width: min(1000px, calc(100% - 64px)); }
  .notes-kicker, .eyebrow { text-transform: none; letter-spacing: .01em; }
  .notes-scope.notes-disclaimer { border-left: 2px solid var(--line-strong); padding-left: 16px; }
  .header nav a { min-height: 44px; display: inline-flex; align-items: center; }
  .prose { font-size: 17px; }
  .prose :is(input, select, textarea) { font-size: 16px; }
  .prose button, .explorer-controls button { min-height: 44px; }
  body:has(.prose) .header .brand strong, .journal .header .brand strong { color: var(--ink); }
}
@media screen and (max-width: 1060px) {
  .home-hero { grid-template-columns: minmax(0, 1.2fr) minmax(260px, .8fr); gap: 36px; }
  .page-hero { gap: 32px; }
}
@media screen and (max-width: 790px) {
  .home-hero, .page-hero, .research-preview, .notes-related .split-copy { grid-template-columns: 1fr; }
  .home-hero { padding-block: 36px 42px; gap: 34px; }
  .home-hero h1 { font-size: clamp(36px, 8vw, 46px); max-width: 570px; }
  .home-hero .lead { font-size: 17px; }
  .research-note { padding: 20px 0 0; border-left: 0; border-top: 1px solid var(--line-strong); }
  .research-note-facts { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; }
  .research-note-facts div { border: 0; }
  .page-hero { padding-block: 30px 38px; gap: 26px; }
  .page-hero h1 { font-size: clamp(34px, 7.5vw, 43px); }
  .section { padding-block: 38px; }
  .section-head { gap: 16px; }
  .proof-grid, .three-grid, .four-grid { gap: 26px; }
  .process-row { grid-template-columns: 28px minmax(0, 1fr); gap: 12px 16px; }
  .process-row p { grid-column: 2; }
  .route-row { grid-template-columns: 24px minmax(0, 1fr) 18px; gap: 12px; }
  .route-state { grid-column: 2; font-size: 12px; }
  .route-main strong { font-size: 23px; }
  .notes-topic { grid-template-columns: 1fr; gap: 10px; padding-block: 24px; }
  .notes-topic .kicker { max-width: none; }
  .notes-topic h3 { font-size: 25px; }
  .notes-related .split-copy { gap: 14px; }
  .guide-hero { grid-template-columns: 1fr; gap: 28px; }
  .guide-level { padding-block: 40px; }
  .level-header h2 { font-size: 29px; }
  .footer-col a { min-height: 44px; }
}
@media screen and (max-width: 540px) {
  .research-note-facts { display: block; }
  .research-note-facts div { padding-block: 10px; border-top: 1px solid var(--line); }
  .home-hero h1 { font-size: 36px; }
  .page-hero h1 { font-size: 34px; }
  .home-hero .actions { align-items: flex-start; gap: 8px 18px; }
  .split-copy { gap: 30px; }
  .section-head h2, .split-copy h2, .statement h2 { font-size: 27px; }
  .guide-hero-copy h1 { font-size: 35px; }
  .journal .wrap { width: calc(100% - 40px); }
  .header .wrap { gap: 12px; }
  .header nav { gap: 18px; flex-wrap: wrap; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
}