/* 01. Design tokens */
:root {
  --carbon: #252a2c; --teal: #315f60; --green: #71806d; --orange: #c0744d;
  --violet: #756778; --gold: #b89b5e; --steel: #607b8a; --cool: #dde7e5;
  --green-wash: #e6ebe2; --violet-wash: #ece7ed; --orange-wash: #f1e4dc;
  --sand: #f6f1e7; --graphite: #3b4042; --muted: #767d7f; --white: #fff;
  --font-editorial: Georgia, Cambria, "Times New Roman", Times, serif;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", monospace;
  --fs-sm: .75rem; --fs-body: clamp(.96rem, .9rem + .2vw, 1.08rem); --fs-h3: clamp(1.2rem, 1rem + .5vw, 1.55rem);
  --fs-h2: clamp(2rem, 1.4rem + 2vw, 3.5rem); --fs-h1: clamp(2.8rem, 1.8rem + 4vw, 5.8rem);
  --space-1: .5rem; --space-2: 1rem; --space-3: 1.5rem; --space-4: 2rem; --space-5: 3rem; --space-6: clamp(4.5rem, 9vw, 8rem);
  --container: 1200px; --border: 1px solid rgba(37,42,44,.22); --radius: 10px;
  --shadow: 0 15px 36px rgba(37,42,44,.08); --transition: 220ms ease;
}

/* 02. Reset */
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: auto; }
body, h1, h2, h3, h4, p, ul, dl, dd { margin: 0; }
img, svg { display: block; max-width: 100%; }
button, input { font: inherit; }
button, summary { cursor: pointer; }
a { color: inherit; }

/* 03. Base */
body { background: var(--sand); color: var(--graphite); font: var(--fs-body)/1.65 var(--font-sans); }
.container { width: min(calc(100% - 2rem), var(--container)); margin-inline: auto; }
.section { padding-block: var(--space-6); }
section { scroll-margin-top: 6rem; }

/* 04. Accessibility */
.skip-link { position: fixed; z-index: 1000; top: .5rem; left: .5rem; padding: .75rem 1rem; background: var(--white); color: var(--carbon); transform: translateY(-150%); }
.skip-link:focus { transform: none; }
:focus-visible { outline: 3px solid var(--gold); outline-offset: 4px; }
.sr-only { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; }
[hidden] { display: none !important; }

/* 05. Typography */
h1, h2, h3 { color: var(--carbon); font-family: var(--font-editorial); line-height: 1.08; font-weight: 500; }
h1 { font-size: var(--fs-h1); letter-spacing: -.045em; }
h1 em { color: var(--teal); font-style: italic; }
h2 { max-width: 880px; font-size: var(--fs-h2); letter-spacing: -.025em; }
h3 { font-size: var(--fs-h3); }
.eyebrow, .micro, .category, .field, .orcid, .tags { font: 700 var(--fs-sm)/1.35 var(--font-mono); letter-spacing: .1em; text-transform: uppercase; }
.eyebrow { margin-bottom: 1.2rem; color: var(--teal); }
.lead, .intro { max-width: 760px; font-size: clamp(1.05rem, .95rem + .4vw, 1.25rem); }

/* 06. Layout */
.actions { display: flex; flex-wrap: wrap; gap: .8rem; margin-block: 2rem; }
.button { display: inline-flex; align-items: center; justify-content: center; min-height: 48px; padding: .7rem 1.15rem; border: 1px solid var(--carbon); border-radius: 3px; text-decoration: none; font-weight: 700; transition: var(--transition); }
.button:hover { transform: translateY(-2px); }
.button.primary { background: var(--carbon); color: var(--white); }
.button.secondary { background: transparent; }

/* 07. Header */
.site-header { position: sticky; z-index: 100; top: 0; border-bottom: var(--border); background: rgba(246,241,231,.97); }
.header-inner { min-height: 78px; display: flex; align-items: center; justify-content: space-between; gap: 1.5rem; }
.brand { flex: 0 0 245px; }
.brand img { width: 245px; }
#primary-navigation { display: flex; align-items: center; gap: clamp(.65rem, 1.4vw, 1.25rem); }
#primary-navigation a { font-size: .78rem; font-weight: 650; text-decoration: none; white-space: nowrap; }
#primary-navigation a:hover { color: var(--teal); }
#primary-navigation .nav-cta { padding: .55rem .8rem; border: 1px solid var(--carbon); }
.menu-toggle { display: none; width: 44px; height: 44px; border: 1px solid var(--carbon); background: transparent; }
.menu-toggle span { display: block; width: 21px; height: 2px; margin: 4px auto; background: var(--carbon); }

/* 08. Hero */
.hero { min-height: calc(100vh - 78px); padding-block: clamp(3rem, 8vw, 7rem); overflow: hidden; }
.hero-grid { display: grid; grid-template-columns: minmax(0, 1.1fr) minmax(430px, .9fr); gap: clamp(2rem, 6vw, 6rem); align-items: center; }
.hero-copy .lead { margin-top: 1.7rem; }
.micro { color: var(--muted); }

/* 09. Pivot Board */
.pivot-board { position: relative; min-height: 650px; }
.pivot-board::before, .pivot-board::after { content: ""; position: absolute; z-index: -1; left: 50%; top: 50%; height: 2px; width: 55%; background: var(--carbon); transform-origin: left; }
.pivot-board::before { transform: rotate(-34deg); }.pivot-board::after { transform: rotate(32deg); }
.board-module { position: absolute; width: min(75%, 330px); padding: 1.1rem 1.2rem; border: 1px solid currentColor; border-radius: var(--radius); background: var(--white); box-shadow: var(--shadow); }
.board-module > span { font: 700 .68rem var(--font-mono); letter-spacing: .12em; }
.board-module h2 { margin: .35rem 0 .8rem; font: 700 1rem var(--font-sans); }
.board-module dl { display: grid; grid-template-columns: 78px 1fr; gap: .25rem .5rem; font-size: .76rem; line-height: 1.4; }
.board-module dt { font-family: var(--font-mono); text-transform: uppercase; }.board-module dd { margin: 0; }
.module-a { top: 0; left: 0; color: var(--teal); }.module-b { top: 32%; right: 0; color: var(--violet); }.module-c { bottom: 3rem; left: 4%; color: var(--orange); }
.hinge { position: absolute; z-index: 2; left: 44%; top: 46%; width: 90px; aspect-ratio: 1; display: grid; place-items: center; border: 8px solid var(--gold); border-radius: 50%; background: var(--carbon); color: var(--white); box-shadow: 0 0 0 7px var(--sand); }
.hinge span { font: 700 .65rem var(--font-mono); letter-spacing: .12em; }
.board-note { position: absolute; right: 0; bottom: 0; max-width: 330px; padding-top: .7rem; border-top: var(--border); font-size: .75rem; }

/* 10. Pivot Units */
.profile-head::after { content: ""; width: 40px; height: 8px; border-left: 8px solid currentColor; border-right: 8px solid currentColor; background: var(--gold); transform: rotate(-12deg); }

/* 11. Concept band */
.concept-band { padding-block: 4rem; background: var(--carbon); color: var(--white); }
.concept-band .eyebrow { color: var(--gold); }.concept-band h2 { color: var(--white); }
.statements { display: grid; grid-template-columns: repeat(4, 1fr); margin-top: 3rem; border-top: 1px solid #596063; }
.statements p { padding: 1.2rem 1rem 0 0; border-right: 1px solid #596063; font-family: var(--font-editorial); font-size: 1.15rem; }

/* 12. Study scales */
.scales { display: grid; grid-template-columns: repeat(4, 1fr); gap: 1px; margin-top: 3.5rem; background: rgba(37,42,44,.2); }
.scale { min-height: 420px; padding: 1.5rem; background: var(--sand); border-top: 5px solid currentColor; }
.scale > span { font: 700 .72rem var(--font-mono); }.scale h3 { margin: 2.5rem 0 1.2rem; }.scale ul { padding: 1rem 0 0; list-style: none; }
.scale li { padding-block: .35rem; border-bottom: var(--border); font-size: .84rem; }.cell { color: var(--teal); }.learning { color: var(--violet); }.economy { color: var(--orange); }.systems { color: var(--steel); }
.scale p, .profile p, .transfer-panel p { color: var(--graphite); }

/* 13. Transfer questions */
.transfer { background: var(--white); }.transfer-panels { margin-top: 3rem; }
.transfer-panel { position: relative; width: 87%; margin-bottom: 2rem; padding: 2rem clamp(1.25rem, 4vw, 3.5rem); border: 1px solid currentColor; border-left: 8px solid; }
.transfer-panel:nth-child(even) { margin-left: auto; }.pivot-label { display: flex; justify-content: space-between; border-bottom: 1px solid currentColor; font: 700 .72rem var(--font-mono); }
.transfer-panel .field { margin: 1rem 0; color: currentColor; }.transfer-panel h3 { max-width: 780px; font-size: clamp(1.6rem, 1.2rem + 1vw, 2.5rem); }
.transfer-panel h4 { margin: 1.5rem 0 .2rem; font: 700 .72rem var(--font-mono); text-transform: uppercase; }.transfer-panel aside { margin-top: 1.5rem; padding: 1rem; background: rgba(37,42,44,.05); color: var(--graphite); font-size: .88rem; }

/* 14. Pivot Method */
.method-list { max-width: 980px; margin: 3.5rem auto; }.method-step { width: 78%; display: grid; grid-template-columns: 85px 1fr; gap: 1rem; margin-bottom: 1.2rem; padding: 1.5rem; border: var(--border); background: var(--white); }
.method-step:nth-child(even) { margin-left: auto; }.method-step > span { display: grid; place-items: center; width: 62px; aspect-ratio: 1; border: 8px solid var(--cool); border-radius: 50%; font: 700 .8rem var(--font-mono); }
.method-step div > p:first-child { color: var(--teal); font: 700 .72rem var(--font-mono); letter-spacing: .08em; }.method-step h3 { margin: .3rem 0 .5rem; }

/* 15. Systems checklist */
.checklist { padding: clamp(1.5rem, 4vw, 4rem); background: var(--teal); color: var(--white); }.checklist h2 { color: var(--white); }.checklist .eyebrow { color: var(--cool); }
.checklist ul { columns: 3; gap: 3rem; margin-top: 2rem; padding: 0; list-style: none; }.checklist li { break-inside: avoid; padding: .7rem 0 .7rem 1.4rem; border-bottom: 1px solid rgba(255,255,255,.25); position: relative; }
.checklist li::before { content: "◇"; position: absolute; left: 0; color: var(--gold); }

/* 16. Academic references */
.references { background: var(--green-wash); }.contact-note { max-width: 850px; margin: 2rem 0; padding: 1rem 1.2rem; border-left: 4px solid var(--gold); background: var(--white); }
.profiles { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1.25rem; margin-top: 3rem; }.profile { padding: 1.6rem; border-top: 5px solid currentColor; background: var(--white); box-shadow: var(--shadow); }
.profile.offset { transform: translateY(1.5rem); }.profile-head { display: flex; align-items: center; justify-content: space-between; color: currentColor; }
.avatar { display: grid; place-items: center; width: 54px; aspect-ratio: 1; border: 1px solid currentColor; font: 700 .85rem var(--font-mono); }.profile h3 { margin: 1.4rem 0 .4rem; }.profile p { margin-top: .85rem; font-size: .85rem; }
.profile .role { color: currentColor; font-weight: 700; }.profile .tags, .profile .orcid { color: var(--muted); font-size: .67rem; }.email { display: grid; gap: .5rem; margin-top: 1.2rem; padding-top: 1rem; border-top: var(--border); font-size: .78rem; }
.email > span:first-child, .reference-status { font: 700 .7rem var(--font-mono); text-transform: uppercase; }.copy-email { width: max-content; padding: .4rem .7rem; border: 1px solid currentColor; background: transparent; color: inherit; }

/* 17. Independence note */
.independence { margin-top: 5rem; padding: 2rem; border: 1px solid var(--gold); background: var(--sand); }.independence p:not(.eyebrow) { max-width: 920px; margin-top: 1rem; }

/* 18. Study notes */
.notes-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 1rem; }.study-note { background: var(--white); border: var(--border); }
.study-note summary { position: relative; padding: 1.5rem 3rem 1.5rem 1.5rem; list-style: none; }.study-note summary::-webkit-details-marker { display: none; }.study-note summary::after { content: "+"; position: absolute; right: 1.5rem; top: 1.4rem; font-size: 1.5rem; }.study-note details[open] summary::after { content: "−"; }
.study-note summary > span { color: var(--teal); font: 700 .68rem var(--font-mono); text-transform: uppercase; }.study-note h3 { margin: .7rem 0; }.study-note summary p { font-size: .88rem; }.study-note details > div { padding: 0 1.5rem 1.5rem; border-top: var(--border); }.study-note details > div p { margin-top: 1rem; }.study-note .tags { color: var(--muted); font-size: .67rem; }

/* 19. Search */
.search-box { display: grid; grid-template-columns: 1fr auto; gap: .5rem 1rem; margin-block: 2.5rem; padding: 1.2rem; border: 1px solid var(--carbon); background: var(--white); }.search-box label { grid-column: 1 / -1; font: 700 .78rem var(--font-mono); text-transform: uppercase; }.search-box > div { display: flex; }
.search-box input { width: min(100%, 650px); min-height: 48px; padding: .7rem; border: 1px solid var(--muted); background: var(--sand); }.search-box button { padding: .6rem 1rem; border: 1px solid var(--carbon); background: var(--carbon); color: var(--white); }.search-box > p { align-self: center; font-family: var(--font-mono); }.no-results { padding: 3rem; border: var(--border); text-align: center; }

/* 20. About */
.about { background: var(--violet-wash); }.about-grid { display: grid; grid-template-columns: 1.1fr .9fr; gap: clamp(2rem, 6vw, 6rem); }.about-grid > div:first-child > p:not(.eyebrow) { margin-top: 1.2rem; }.principles { display: grid; grid-template-columns: 1fr 1fr; gap: 1px; background: rgba(37,42,44,.2); }.principles article { padding: 1.4rem; background: var(--violet-wash); }.principles span { color: var(--violet); font: 700 .7rem var(--font-mono); }.principles h3 { margin: 1.2rem 0 .6rem; }

/* 21. Final CTA */
.final-cta { padding-block: var(--space-6); background: var(--teal); color: var(--white); }.final-cta h2 { color: var(--white); }.final-cta .eyebrow { color: var(--gold); }.final-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 4rem; align-items: center; }.button.light { background: var(--white); color: var(--carbon); }.button.outline { border-color: var(--white); color: var(--white); }
.final-mechanism { min-height: 430px; display: grid; grid-template-columns: 1fr 1fr; gap: 4rem; place-items: center; position: relative; }.final-mechanism span { width: 100%; padding: 1.4rem .5rem; border: 1px solid var(--white); color: var(--white); font: 700 .72rem var(--font-mono); text-align: center; }.final-mechanism span:nth-child(2), .final-mechanism span:nth-child(4) { transform: translateY(2rem); }.final-mechanism b { position: absolute; display: grid; place-items: center; width: 95px; aspect-ratio: 1; border-radius: 50%; background: var(--gold); color: var(--carbon); font: 700 .72rem var(--font-mono); }.final-mechanism::before, .final-mechanism::after { content: ""; position: absolute; width: 65%; height: 1px; background: rgba(255,255,255,.7); }.final-mechanism::before { transform: rotate(38deg); }.final-mechanism::after { transform: rotate(-38deg); }

/* 22. Footer */
footer { padding: 4rem 0 1.5rem; background: var(--carbon); color: var(--white); }.footer-grid { display: grid; grid-template-columns: 1fr 1.5fr auto; gap: 3rem; }.footer-grid img { width: 54px; filter: invert(1); }.footer-grid h2 { margin-top: 1rem; color: var(--white); font-size: 1.6rem; }.footer-grid p, .footer-grid small { color: #bec3c4; }.footer-grid nav { display: grid; grid-template-columns: repeat(2, 1fr); gap: .6rem 2rem; }.footer-grid a { text-decoration: none; }.back-top { align-self: start; }.copyright { margin-top: 3rem; padding-top: 1rem; border-top: 1px solid #515759; color: #bec3c4; font-size: .75rem; }

/* 23. Reveal */
.js-enabled .reveal { opacity: 0; transform: translateY(22px); transition: opacity 600ms ease, transform 600ms ease; }.js-enabled .reveal.is-visible { opacity: 1; transform: none; }

/* 24. Responsive */
@media (max-width: 1080px) {
  .menu-toggle { display: block; }
  #primary-navigation { position: absolute; left: 0; right: 0; top: 100%; display: none; padding: 1rem max(1rem, calc((100% - var(--container))/2)); border-bottom: var(--border); background: var(--sand); box-shadow: var(--shadow); }
  #primary-navigation.is-open { display: grid; } #primary-navigation a { padding: .65rem 0; }
  .hero-grid { grid-template-columns: 1fr; }.pivot-board { width: min(100%, 680px); margin-inline: auto; }.scales { grid-template-columns: repeat(2, 1fr); }.profiles { grid-template-columns: repeat(2, 1fr); }.checklist ul { columns: 2; }
}
@media (max-width: 720px) {
  .section { padding-block: 4rem; }.brand, .brand img { width: 205px; }
  .pivot-board { min-height: auto; display: grid; gap: 1rem; }.pivot-board::before, .pivot-board::after { display: none; }.board-module { position: relative; inset: auto; width: 100%; }.hinge { position: relative; inset: auto; order: -1; margin: auto; }.board-note { position: static; }
  .statements, .scales, .profiles, .notes-grid, .about-grid, .final-grid, .footer-grid { grid-template-columns: 1fr; }.statements p { border-right: 0; }.scale { min-height: auto; }.transfer-panel, .method-step { width: 100%; }.profile.offset { transform: none; }.checklist ul { columns: 1; }.principles { grid-template-columns: 1fr; }.final-mechanism { min-height: 350px; gap: 2rem; }.footer-grid nav { grid-template-columns: 1fr; }.search-box { grid-template-columns: 1fr; }.search-box > p { grid-row: 2; }.search-box > div { grid-row: 3; }.search-box input { min-width: 0; }
}
@media (max-width: 380px) {
  .container { width: min(calc(100% - 1.2rem), var(--container)); }.brand, .brand img { width: 178px; }.method-step { grid-template-columns: 1fr; }.transfer-panel { padding-inline: 1rem; }.pivot-label { display: grid; gap: .4rem; }.principles { grid-template-columns: 1fr; }.final-mechanism { gap: 1rem; }.final-mechanism span { font-size: .58rem; }
}

/* 25. Reduced motion */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { scroll-behavior: auto !important; animation-duration: .01ms !important; animation-iteration-count: 1 !important; transition-duration: .01ms !important; }
  .js-enabled .reveal { opacity: 1; transform: none; }
}