/* A small, shared design system. No framework, remote fonts, or runtime dependencies. */
:root {
  --paper: #f4f6f7;
  --ink: #11212e;
  --muted: #587080;
  --blue: #7895a7;
  --line: #bfc9ce;
  --night: #07131d;
  --lime: #dcfa88;
  --link: #155dde;
  --gutter: clamp(24px, 3.9vw, 76px);
  --ease: cubic-bezier(.22, 1, .36, 1);
  color-scheme: light;
  font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
  color: var(--ink);
  background: var(--paper);
  font-synthesis: none;
  -webkit-font-smoothing: antialiased;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 24px; }
body { margin: 0; }
/* Verified drug structures stay behind the page, giving normal scrolling depth.
   This layer has no animation loop, interaction targets, or layout footprint. */
.chemistry-background { position: fixed; inset: 0; z-index: 0; overflow: hidden; pointer-events: none; user-select: none; }
.drug-structure { position: absolute; display: block; height: auto; opacity: .2; }
.drug-structure-imatinib { width: clamp(440px, 43vw, 800px); top: -17%; left: -12%; transform: rotate(-22deg); }
.drug-structure-osimertinib { width: clamp(500px, 49vw, 900px); top: 15%; right: -19%; transform: rotate(18deg); opacity: .17; }
.drug-structure-olaparib { width: clamp(480px, 48vw, 860px); bottom: -24%; left: 19%; transform: rotate(-18deg); opacity: .16; }
body > main, body > .site-footer { position: relative; z-index: 1; }
button, a, summary { -webkit-tap-highlight-color: transparent; }
button { font: inherit; }
a { color: inherit; text-decoration: none; }
button, summary { cursor: pointer; }
button { color: inherit; }
button:disabled { cursor: default; }
button, h1, h2, h3, h4, p { margin: 0; }
[hidden] { display: none !important; }
::selection { color: var(--ink); background: var(--lime); }
:focus-visible { outline: 2px solid var(--link); outline-offset: 6px; border-radius: 2px; }
.wrap { width: calc(100% - var(--gutter) * 2); max-width: 1680px; margin-inline: auto; }
.svg-library { position: absolute; width: 0; height: 0; overflow: hidden; }
.icon { width: 24px; height: 24px; fill: none; stroke: currentColor; stroke-width: 1.4; stroke-linecap: round; stroke-linejoin: round; flex: 0 0 auto; }
.down { transform: rotate(90deg); }
.up { transform: rotate(-90deg); }
.mono, .section-label { font-family: "SFMono-Regular", Consolas, "Liberation Mono", monospace; font-size: 11px; letter-spacing: .15em; line-height: 1.5; text-transform: uppercase; font-weight: 400; }
.section-label { font-size: clamp(11px, .85vw, 14px); }
.skip-link { position: fixed; top: -100px; left: 20px; padding: 16px; background: var(--ink); color: white; z-index: 100; }
.skip-link:focus { top: 20px; }
.reading-progress { height: 2px; position: fixed; top: 0; left: 0; right: 0; background: var(--blue); z-index: 50; transform-origin: left; transform: scaleX(0); pointer-events: none; }
.site-header { height: 92px; display: flex; align-items: center; gap: 48px; border-bottom: 1px solid #8998a3; position: relative; z-index: 5; }
.wordmark { font-size: 42px; font-weight: 650; letter-spacing: -.065em; line-height: 1; white-space: nowrap; }
.site-header nav { display: flex; align-items: center; gap: clamp(24px, 3vw, 52px); margin-left: auto; font-size: 16px; }
.site-header nav a { position: relative; padding-block: 8px; }
.site-header nav a::after { content: ""; position: absolute; bottom: 1px; height: 1px; width: 100%; left: 0; background: currentColor; transform: scaleX(0); transform-origin: left; transition: transform .3s var(--ease); }
.site-header nav a:hover::after { transform: scaleX(1); }
.button { display: inline-flex; justify-content: center; align-items: center; gap: 26px; border: 1px solid transparent; border-radius: 99px; font-size: 16px; padding: 20px 27px; min-height: 58px; transition: background .25s, color .25s, transform .35s var(--ease); width: fit-content; }
.button:hover { transform: translateY(-3px); }
.button .icon { transition: transform .35s var(--ease); }
.button-outline { border-color: var(--ink); padding: 12px 22px; min-height: 46px; gap: 16px; }
.button-outline:hover { background: var(--ink); color: var(--paper); }
.button-dark { background: var(--ink); color: var(--paper); }
.button-dark:hover { background: #233e4d; }
.button-dark:hover .down { transform: translateY(3px) rotate(90deg); }

/* The opening composition: the image has its own layer; all copy is real text. */
.hero { min-height: 710px; height: calc(100svh - 92px); display: flex; flex-direction: column; overflow: clip; overflow-clip-margin: 12px; }
.hero-main { position: relative; flex: 1; display: flex; flex-direction: column; justify-content: space-between; padding: clamp(70px, 10svh, 130px) 0 75px; isolation: isolate; }
.hero h1 { position: relative; z-index: 2; font-size: clamp(62px, 6.85vw, 123px); font-weight: 400; letter-spacing: -.055em; line-height: 1.035; width: max-content; max-width: 100%; }
.hero h1 > span { display: block; }
.blue-text { color: var(--blue); }
.hero-art { position: absolute; inset: 0 -3.5% 0 auto; width: 73%; z-index: -1; pointer-events: none; transform-origin: 65% 50%; will-change: transform; }
.hero-art img { display: block; width: 100%; height: 100%; object-fit: contain; mix-blend-mode: multiply; mask-image: radial-gradient(ellipse 64% 68% at 50% 50%, #000 66%, transparent 100%); }
.hero-intro { position: relative; z-index: 2; max-width: 385px; padding-top: 50px; }
.hero-intro p { font-size: clamp(18px, 1.4vw, 23px); line-height: 1.45; letter-spacing: -.02em; margin-bottom: 34px; }
.molecule-caption { position: absolute; right: 0; bottom: 35%; display: flex; gap: 15px; align-items: flex-start; font-size: 12px; line-height: 1.5; }
.molecule-caption > span { width: 84px; height: 1px; background: var(--muted); margin-top: 9px; }
.hero-foot { display: flex; justify-content: space-between; align-items: center; min-height: 120px; border-top: 1px solid var(--line); gap: 20px; font-size: 12px; }
.hero-foot a { display: flex; align-items: center; gap: 20px; }

/* The scrolling chapter uses normal document scrolling and a native sticky scene. */
.approach { color: var(--paper); background: var(--night); position: relative; }
.motion-ready .approach { height: 300svh; }
.approach-sticky { padding-block: 42px 34px; min-height: 760px; }
.motion-ready .approach-sticky { position: sticky; top: 0; height: 100svh; }
.approach-inner { display: flex; flex-direction: column; height: 100%; }
.approach .section-label span { color: var(--lime); margin-right: 5px; }
.approach-scene { display: grid; grid-template-columns: 52% 48%; align-items: center; flex: 1; min-height: 460px; max-height: 68svh; }
.network { width: 100%; height: 100%; min-height: 430px; position: relative; }
.network canvas { display: block; position: absolute; inset: 0; width: 100%; height: 100%; }
.network-target { position: absolute; top: 50%; left: 50%; width: 112px; height: 112px; margin: -56px 0 0 -56px; display: grid; place-items: center; pointer-events: none; }
.network-target i { position: absolute; width: 112px; height: 112px; border: 1px solid #c2f27c55; border-radius: 50%; transition: transform .1s linear; }
.network-target i:nth-child(2) { width: 77px; height: 77px; border-color: #c2f27c77; }
.network-target i:nth-child(3) { width: 41px; height: 41px; border-color: #c2f27c99; }
.network-target span { width: 7px; height: 7px; border-radius: 50%; background: var(--lime); box-shadow: 0 0 24px 5px #b5f66a55; }
.approach-copy { padding-left: 20px; position: relative; }
.approach-copy h2 { font-size: clamp(44px, 5.35vw, 94px); letter-spacing: -.055em; line-height: 1.1; font-weight: 400; }
.approach-copy h2 span { color: var(--lime); }
.approach-copy > p { max-width: 570px; font-size: clamp(18px, 1.65vw, 27px); line-height: 1.65; letter-spacing: -.03em; margin-top: 42px; color: #d2dbe1; }
.process-steps { display: grid; grid-template-columns: repeat(3, 1fr); gap: 30px; margin: 0; padding: 0; list-style: none; }
.process-steps li { position: relative; padding-top: 24px; }
.step-track { position: absolute; top: 0; left: 0; right: 0; height: 1px; background: #7e8b9660; }
.step-track::after { content: ""; position: absolute; inset: 0; background: var(--lime); transform: scaleX(var(--step-progress, 0)); transform-origin: left; }
.process-steps h3 { font-family: "SFMono-Regular", Consolas, monospace; font-size: clamp(12px, 1.03vw, 17px); letter-spacing: .035em; font-weight: 400; transition: color .3s; }
.process-steps h3 span { margin-right: 6px; }
.process-steps p { line-height: 1.55; font-size: 14px; color: #a8bac6; max-width: 370px; margin-top: 18px; min-height: 44px; transition: opacity .4s, color .4s; }
.motion-ready .process-steps li:not(.is-active) p { opacity: .8; }
.process-steps .is-active h3, .process-steps .is-active p { color: var(--lime); }
.approach-foot { display: flex; align-items: center; justify-content: space-between; gap: 24px; margin-top: auto; padding-top: 44px; }
.approach-foot > a { display: flex; align-items: center; gap: 24px; font-size: 10px; }
.approach-foot .down { color: var(--lime); }
.motion-toggle { border: 0; background: transparent; display: inline-flex; align-items: center; gap: 6px; padding: 8px 0 8px 8px; color: #b7c7d3; font-size: 11px; white-space: nowrap; }
.motion-toggle .icon { width: 16px; height: 16px; }
.approach :focus-visible { outline-color: var(--lime); }

/* A small, fully local exploration. Native details elements work without JS. */
.explorations { padding-top: 90px; }
.section-rule { border-top: 1px solid #8998a3; margin-bottom: 42px; }
.explorations-heading { display: flex; justify-content: space-between; align-items: flex-start; gap: 36px; margin-top: 25px; margin-bottom: 42px; }
.explorations h2 { font-size: clamp(48px, 6.1vw, 108px); font-weight: 400; letter-spacing: -.055em; line-height: 1; }
.explorations-heading > p { font-size: clamp(18px, 1.5vw, 24px); line-height: 1.45; padding-top: 8px; }
.exploration-tabs { display: flex; gap: 24px; border-bottom: 1px solid var(--line); }
.exploration-tabs button { position: relative; padding: 0 28px 20px; border: 0; background: none; color: var(--muted); font-size: clamp(17px, 1.5vw, 23px); letter-spacing: -.02em; }
.exploration-tabs button::after { content: ""; height: 3px; background: var(--ink); position: absolute; inset: auto 0 -1px; transform: scaleX(0); transition: transform .3s var(--ease); }
.exploration-tabs button[aria-selected="true"] { color: var(--ink); }
.exploration-tabs button[aria-selected="true"]::after { transform: scaleX(1); }
.exploration-tabs button:hover { color: var(--ink); }
.exploration-panel { border-bottom: 1px solid #8998a3; }
.no-js-label { padding-block: 24px; }
.enhanced .no-js-label { display: none; }
.question-details summary { list-style: none; display: grid; grid-template-columns: 15% 1fr 25%; gap: 3.5%; padding: 42px 0; align-items: stretch; }
.question-details summary::-webkit-details-marker { display: none; }
.question-label { padding-top: 8px; }
.question-copy { display: block; padding-left: 30px; border-left: 1px solid var(--line); padding-block: 6px; }
.question-title { display: block; font-size: clamp(28px, 2.65vw, 46px); letter-spacing: -.045em; line-height: 1.12; }
.question-description { display: block; max-width: 610px; font-size: clamp(16px, 1.45vw, 23px); line-height: 1.45; letter-spacing: -.02em; margin-top: 20px; }
.question-action { border-left: 1px solid var(--line); padding-left: 32px; display: flex; align-items: center; gap: 16px; color: var(--link); font-size: 16px; letter-spacing: -.02em; }
.circle-arrow { border: 1px solid var(--link); border-radius: 50%; height: 58px; width: 58px; display: grid; place-items: center; flex: 0 0 auto; transition: background .3s, color .3s; }
.circle-arrow .icon { width: 30px; height: 30px; transition: transform .4s var(--ease); }
summary:hover .circle-arrow { color: var(--paper); background: var(--link); }
.when-open { display: none; }
details[open] .when-closed { display: none; }
details[open] .when-open { display: inline; }
details[open] .circle-arrow .icon { transform: rotate(-90deg); }
.question-expansion { padding: 0 0 40px; }
.expansion-intro { color: var(--muted); font-size: 16px; border-top: 1px solid var(--line); padding-top: 30px; }
.question-lenses { display: grid; grid-template-columns: repeat(3, 1fr); gap: 45px; padding: 32px 0; }
.question-lenses .mono { font-size: 10px; color: var(--muted); letter-spacing: .1em; }
.question-lenses h4 { font-size: 24px; font-weight: 400; letter-spacing: -.03em; margin-top: 18px; }
.question-lenses p { font-size: 16px; line-height: 1.6; color: var(--muted); margin-top: 14px; }
.exploration-note { color: var(--muted); font-size: 12px; line-height: 1.5; }
.about { padding-top: 48px; padding-bottom: 38px; }
.about-content { display: grid; grid-template-columns: 72% 1fr; gap: 3%; margin-top: 30px; }
.about h2 { font-size: clamp(40px, 4.35vw, 78px); font-weight: 400; letter-spacing: -.055em; line-height: 1.07; }
.about-content > p { font-size: clamp(17px, 1.45vw, 23px); line-height: 1.5; letter-spacing: -.02em; }
.back-top { display: inline-flex; align-items: center; gap: 16px; margin-top: 36px; color: var(--link); font-size: 18px; }
.back-top .icon { transition: transform .3s var(--ease); }
.back-top:hover .icon { transform: translateY(-4px) rotate(-90deg); }
.site-footer { border-top: 1px solid #8998a3; padding-block: 24px 30px; display: flex; justify-content: space-between; align-items: center; gap: 24px; }
.site-footer p { font-size: 17px; letter-spacing: .04em; }
.reveal-ready .reveal { opacity: 0; transform: translateY(35px); transition: opacity 1s var(--ease), transform 1s var(--ease); }
.reveal-ready .reveal.is-visible { opacity: 1; transform: none; }

@media (min-width: 1700px) { .hero-art { right: 0; width: 70%; } }
@media (max-width: 1100px) {
  .site-header { gap: 30px; height: 82px; }
  .wordmark { font-size: 28px; }
  .hero { height: calc(100svh - 82px); min-height: 690px; }
  .hero-main { padding-top: 80px; }
  .hero-intro { max-width: 325px; }
  .hero-art { width: 70%; right: -2%; top: -10%; bottom: 14%; }
  .hero h1 { font-size: 7vw; }
  .molecule-caption { display: none; }
  .approach-copy > p { margin-top: 26px; font-size: 19px; }
  .process-steps { gap: 22px; }
  .process-steps h3 { font-size: 12px; }
  .process-steps h3 span { display: block; margin-bottom: 8px; }
  .question-details summary { grid-template-columns: 13% 1fr 23%; gap: 3%; }
  .question-copy, .question-action { padding-left: 22px; }
  .question-action { font-size: 14px; flex-direction: column; justify-content: center; text-align: center; gap: 12px; }
  .about-content { grid-template-columns: 67% 1fr; gap: 4%; }
}
@media (max-width: 760px) {
  :root { --gutter: 24px; }
  .drug-structure { opacity: .13; }
  .drug-structure-imatinib { width: 390px; top: -8%; left: -230px; }
  .drug-structure-osimertinib { width: 430px; top: 27%; right: -285px; }
  .drug-structure-olaparib { width: 410px; bottom: -15%; left: 5%; }
  .site-header { height: 104px; gap: 14px; flex-direction: column; align-items: flex-start; justify-content: center; }
  .site-header nav { font-size: 13px; gap: 24px; width: 100%; margin-left: 0; justify-content: space-between; }
  .header-cta { display: none; }
  .wordmark { font-size: 28px; }
  .hero { min-height: 840px; height: calc(100svh - 104px); }
  .hero-main { padding: 50px 0 32px; justify-content: flex-start; }
  .hero h1 { font-size: clamp(38px, 11.8vw, 70px); letter-spacing: -.06em; line-height: 1.08; }
  .hero-art { inset: 135px -20px auto auto; width: calc(100% + 16px); height: 460px; }
  .hero-intro { margin-top: auto; padding-top: 320px; max-width: 320px; }
  .hero-intro p { font-size: 17px; line-height: 1.45; margin-bottom: 23px; }
  .button { font-size: 14px; min-height: 52px; padding: 15px 23px; gap: 24px; }
  .hero-foot { min-height: 70px; }
  .hero-foot > span { max-width: 210px; font-size: 9px; line-height: 1.7; }
  .hero-foot a { font-size: 0; gap: 0; }
  .hero-foot a .icon { width: 24px; height: 24px; }
  .approach-sticky { padding-block: 28px 22px; min-height: 730px; }
  .approach-scene { grid-template-columns: 1fr; grid-template-rows: 1fr auto; min-height: 0; max-height: none; padding-bottom: 26px; }
  .network { min-height: 240px; height: 100%; }
  .approach-copy { padding-left: 0; }
  .approach-copy h2 { font-size: clamp(37px, 7.3vw, 54px); line-height: 1.07; }
  .approach-copy > p { font-size: 15px; line-height: 1.6; margin-top: 20px; max-width: 480px; }
  .process-steps { gap: 16px; }
  .process-steps li { padding-top: 15px; }
  .process-steps h3 { font-size: 11px; line-height: 1.5; letter-spacing: 0; }
  .process-steps h3 span { display: block; margin-bottom: 6px; }
  .process-steps p { font-size: 11px; line-height: 1.5; margin-top: 12px; }
  .approach-foot { margin-top: 22px; padding-top: 0; gap: 20px; }
  .approach-foot > a { font-size: 8px; line-height: 1.7; gap: 10px; max-width: 230px; }
  .motion-toggle { font-size: 10px; }
  .explorations { padding-top: 58px; }
  .section-rule { margin-bottom: 30px; }
  .explorations-heading { display: block; margin-bottom: 34px; }
  .explorations h2 { font-size: clamp(44px, 8.8vw, 65px); }
  .explorations-heading > p { margin-top: 24px; font-size: 17px; padding-top: 0; }
  .explorations-heading > p br { display: none; }
  .exploration-tabs { gap: 20px; justify-content: space-between; }
  .exploration-tabs button { padding: 0 0 15px; font-size: 15px; }
  .question-details summary { grid-template-columns: 1fr; padding: 28px 0 32px; gap: 20px; }
  .question-label { padding-top: 0; font-size: 10px; }
  .question-copy { padding: 0; border: 0; }
  .question-title { font-size: 30px; max-width: 480px; }
  .question-description { font-size: 17px; margin-top: 17px; }
  .question-action { border: 0; padding-left: 0; flex-direction: row; justify-content: flex-start; gap: 14px; font-size: 15px; }
  .circle-arrow { width: 44px; height: 44px; }
  .circle-arrow .icon { width: 25px; height: 25px; }
  .question-lenses { grid-template-columns: 1fr; gap: 28px; }
  .question-lenses h4 { font-size: 23px; margin-top: 10px; }
  .question-lenses p { font-size: 16px; margin-top: 8px; }
  .expansion-intro { font-size: 15px; line-height: 1.5; }
  .about { padding-top: 34px; padding-bottom: 32px; }
  .about-content { grid-template-columns: 1fr; gap: 24px; margin-top: 28px; }
  .about h2 { font-size: clamp(35px, 7.3vw, 52px); line-height: 1.1; }
  .about-content > p { max-width: 400px; font-size: 17px; }
  .back-top { font-size: 16px; margin-top: 30px; }
  .site-footer { padding-block: 22px; flex-wrap: wrap; gap: 16px; }
  .site-footer p { max-width: 190px; text-align: right; font-size: 12px; line-height: 1.7; letter-spacing: .02em; }
}
@media (max-width: 370px) {
  :root { --gutter: 18px; }
  .site-header nav { gap: 15px; font-size: 12px; }
  .hero-art { height: 400px; right: -16px; }
  .hero-intro { padding-top: 265px; }
  .hero { min-height: 770px; }
  .exploration-tabs { gap: 12px; }
  .exploration-tabs button { font-size: 14px; }
}
/* Small landscape screens get the complete chapter without a pinned scroll trap. */
@media (max-height: 730px), (max-width: 760px) and (max-height: 800px) {
  .motion-ready .approach { height: auto; }
  .motion-ready .approach-sticky { position: relative; height: auto; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation-duration: .01ms !important; transition-duration: .01ms !important; }
  .motion-ready .approach { height: auto; }
  .motion-ready .approach-sticky { position: relative; height: auto; }
  .hero-art { transform: none !important; will-change: auto; }
  .reveal-ready .reveal { opacity: 1; transform: none; }
  .motion-ready .process-steps li:not(.is-active) p { opacity: 1; }
}