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:root{--ink:#15333a;--muted:#71878c;--teal:#25828b;--blue:#537fba;--gold:#bfa16a;--paper:#fff;--chapter-height:145vh;--scene-x:22vw;--scene-y:0vh;--scene-scale:.83;--scene-opacity:1;--shade-x:0%;--shade-opacity:1;--progress:0;--hud-opacity:1;color-scheme:light;font-family:"Helvetica Neue",Arial,"PingFang SC","Hiragino Sans GB","Microsoft YaHei",sans-serif;color:var(--ink);background:var(--paper);font-synthesis:none}
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main{position:relative;z-index:2;pointer-events:none}.chapter{height:var(--chapter-height);position:relative;pointer-events:none}.chapter-copy{position:fixed;top:26vh;left:7vw;width:min(640px,47vw);visibility:hidden;opacity:var(--copy-opacity,0);transform:translate3d(0,var(--copy-offset,24px),0);will-change:transform,opacity;pointer-events:none}.chapter.is-active .chapter-copy{visibility:visible}.chapter.is-current .chapter-copy a{pointer-events:auto}.intro-copy{top:25vh}.copy-right{left:55%;width:40vw}.finale-copy{top:auto;bottom:16vh;width:680px}.eyebrow{display:flex;align-items:center;gap:13px;font-size:10px;font-weight:500;letter-spacing:2.5px;line-height:1.7;color:#6b8d94;white-space:nowrap}.signal{width:5px;height:5px;border-radius:50%;background:var(--teal);box-shadow:0 0 0 5px #1e8b9210}.chapter-index{color:var(--teal);margin-right:8px;font-family:monospace;font-size:12px;letter-spacing:1px}h1,h2,p{margin:0}h1,h2{font-weight:560;letter-spacing:-.065em;line-height:1.19}h1{font-size:clamp(58px,6.35vw,105px);margin-top:33px}h1>span,h2>span{display:block}h2{font-size:clamp(48px,5.35vw,88px);margin-top:30px}.accent{color:var(--teal);background:linear-gradient(105deg,#177f86 15%,#517eb5 96%);-webkit-background-clip:text;background-clip:text;-webkit-text-fill-color:transparent}.chapter-description{font-size:15px;line-height:2.15;letter-spacing:.04em;color:#526e76;margin-top:32px;font-weight:400}.input-equation{display:flex;gap:16px;align-items:center;font-size:11px;letter-spacing:1px;margin-top:30px;color:#5a7d84}.input-equation b{font-weight:400;color:#9db5bb}.explore-link{display:inline-flex;gap:16px;align-items:center;margin-top:44px;font-size:13px;letter-spacing:1px}.circle-arrow{display:grid;place-items:center;border:1px solid #b9d0d4;width:45px;height:45px;border-radius:50%;font-size:19px;transition:background .25s,color .25s,transform .25s}.explore-link:hover .circle-arrow{background:var(--teal);color:#fff;transform:translateY(3px)}.explore-link small{display:block;font-size:8px;letter-spacing:2.4px;margin-top:7px;color:#95a9ad}.context-route{display:flex;align-items:center;gap:25px;margin-top:38px;font-size:12px;letter-spacing:.025em}.context-route small{display:block;margin-top:10px;font-size:10px;letter-spacing:1px;color:#91a5aa}.context-route b{font-size:23px;font-weight:300;color:#b5a075}.target-context{color:var(--teal);font-size:17px}.chapter-footnote{display:block;color:#a0afb3;font-size:10px;letter-spacing:.06em;margin-top:24px}.knowledge-strip{display:flex;align-items:center;gap:14px;margin-top:38px;color:#6d8b93;font-size:12px;letter-spacing:2px}.knowledge-strip svg{width:31px;height:35px;fill:none;stroke:#4e99a0;stroke-width:1.05;stroke-linecap:round;stroke-linejoin:round}.knowledge-strip i{display:block;width:26px;height:1px;background:#b9c9b9;margin:0 4px}.response-note{display:flex;gap:24px;align-items:center;margin-top:40px;font-size:12px;letter-spacing:1px;color:#67868e}.response-note small{display:block;font-size:8px;letter-spacing:1.5px;color:#a0b1b5;margin-top:10px}.mini-wave{display:flex;align-items:center;gap:4px;height:32px}.mini-wave i{width:2px;height:12px;background:var(--teal);opacity:.5}.mini-wave i:nth-child(3n){height:27px;background:var(--blue)}.mini-wave i:nth-child(4n){height:20px;background:var(--gold)}.mini-wave i:nth-child(5n){height:35px}.text-link{display:inline-flex;gap:32px;margin-top:34px;padding-bottom:9px;border-bottom:1px solid #b5cbcf;font-size:13px;color:#547b85}.text-link span{transition:transform .2s}.text-link:hover span{transform:translate(3px,-3px)}.finale-copy h2{font-size:clamp(42px,4.25vw,72px)}.finale-copy .chapter-description{font-size:14px;margin-top:25px}
.research{position:relative;pointer-events:auto;padding:150px 7vw 30px;min-height:100vh;background:linear-gradient(180deg,rgba(255,255,255,0),rgba(255,255,255,.91) 20%,#fff 70%);z-index:4}.research-inner{max-width:1500px;margin:0 auto}.research-heading{display:flex;align-items:flex-end;justify-content:space-between;gap:50px;margin-top:30px}.research-heading h2{font-size:clamp(54px,5.4vw,90px);margin-top:0}.research-heading p{color:#738c93;font-size:14px;line-height:2.2;padding-bottom:10px}.research-stats{margin-top:67px;border-top:1px solid #ccdbde;border-bottom:1px solid #ccdbde;display:grid;grid-template-columns:repeat(2,minmax(0,1fr));padding:40px 0;gap:32px}.research-stats strong{font-family:"Helvetica Neue",Arial,sans-serif;font-weight:300;font-size:65px;letter-spacing:-3px;line-height:1}.research-stats strong span{font-size:14px;letter-spacing:0;margin-left:12px;color:#718c94}.research-stats p{font-size:13px;margin-top:17px}.research-stats small{font-size:9px;letter-spacing:1.7px;color:#8ca3aa;display:block;margin-top:10px}.paper-title{display:flex;align-items:flex-start;gap:24px;margin-top:30px;color:#81979f;font-size:11px;line-height:1.8;max-width:780px}.paper-title>span{font-family:monospace;color:#a8bac0}.concept-note{margin-top:25px;font-size:10px;line-height:1.8;color:#9aaeb3;letter-spacing:.03em}footer{display:flex;align-items:center;gap:30px;margin-top:70px;padding:24px 0;border-top:1px solid #e7edef;font-size:11px;color:#8b9ea4}.footer-brand{font-size:23px;font-weight:650;letter-spacing:-1px;color:#31565e}footer>span{flex:1;font-family:Georgia,serif;font-style:italic;font-size:14px}.back-top{display:grid;place-items:center;border:1px solid #c9dadd;border-radius:50%;height:38px;width:38px;color:#58808b;font-size:19px}
.journey-hud{position:fixed;inset:auto 5vw 32px;display:flex;align-items:center;justify-content:space-between;z-index:12;color:#75949c;font-size:10px;letter-spacing:1.5px;pointer-events:none;opacity:var(--hud-opacity)}.hud-chapter{display:flex;align-items:center;gap:13px}.hud-chapter b{font-size:21px;font-weight:300;font-family:"Helvetica Neue",Arial,sans-serif;letter-spacing:-.5px;color:#254a56}.hud-chapter>span:first-of-type{color:#a9bcc2;font-size:9px}.hud-chapter i{display:block;width:28px;height:1px;background:#bfd1d6;margin:0 4px}.hud-hint{position:absolute;left:50%;transform:translateX(-50%);font-size:8px;letter-spacing:2.5px;color:#9db1b6}.hud-hint>span{display:inline-block;margin-left:14px;font-size:16px;animation:scroll-hint 2s ease-in-out infinite}.hud-percent{font-family:monospace;font-size:10px;letter-spacing:1px}.reading-progress{position:fixed;bottom:0;left:0;right:0;height:2px;background:#f2f6f6;z-index:25}.reading-progress span{display:block;height:100%;width:100%;transform:scaleX(var(--progress));transform-origin:left;background:linear-gradient(90deg,#3a9a9f,#6b8fbd,#ceb780)}.no-js{position:fixed;inset:auto 0 0;background:#fff;padding:25px;z-index:100;border-top:1px solid #b6ced2}.no-js a{margin-left:20px;text-decoration:underline}
@keyframes scroll-hint{0%,100%{transform:translateY(-2px);opacity:.5}50%{transform:translateY(3px);opacity:1}}
@media(min-width:1800px){.chapter-copy{left:8vw;width:720px}.copy-right{left:57%;width:680px}h1{font-size:114px}h2{font-size:96px}.chapter-description{font-size:17px}.finale-copy{width:760px}}
@media(max-height:760px) and (min-width:901px){.chapter-copy{top:22vh}.finale-copy{top:auto;bottom:13vh}h1{font-size:clamp(53px,5.2vw,80px);margin-top:23px}h2{font-size:clamp(44px,4.5vw,68px);margin-top:20px}.chapter-description{margin-top:22px;font-size:15px;line-height:1.95}.explore-link{margin-top:25px}.input-equation{margin-top:21px}.context-route,.knowledge-strip,.response-note{margin-top:25px}}
@media(max-width:900px){.header-caption{display:none}.site-header{height:85px;padding:0 6vw}.wordmark{font-size:23px;gap:8px}.wordmark svg{width:24px}.site-header nav{gap:18px;font-size:11px}.chapter-nav{right:13px}.nav-caption{display:none}.chapter-copy,.copy-right{left:7vw;width:78vw;top:20vh}.chapter-copy h1{font-size:clamp(48px,8.4vw,72px)}.chapter-copy h2{font-size:clamp(43px,7.6vw,64px)}.chapter-description{font-size:13px}.eyebrow{font-size:9px;letter-spacing:1.6px}.finale-copy{top:auto;bottom:16vh}.finale-copy h2{font-size:clamp(37px,6.4vw,58px)}.research{padding:120px 7vw 25px}.research-heading{display:block}.research-heading p{margin-top:30px}.research-stats{grid-template-columns:1fr 1fr}.research-stats strong{font-size:54px}.journey-hud{inset:auto 7vw 25px}.hud-hint{display:none}footer{flex-wrap:wrap;gap:20px}footer>span{font-size:12px}.concept-note{max-width:500px}}
@media(max-width:500px){:root{--chapter-height:140vh}.site-header nav>a:first-child{display:none}.chapter-copy,.copy-right{top:17vh;left:7vw;width:81vw}h1,h2{letter-spacing:-.055em}.chapter-copy h1{font-size:45px;line-height:1.26;margin-top:24px}.chapter-copy h2{font-size:40px;line-height:1.28;margin-top:23px}.chapter-description{font-size:12px;line-height:2.1;margin-top:25px}.desktop-break{display:none}.input-equation{font-size:10px;gap:12px;margin-top:23px}.explore-link{margin-top:28px;font-size:11px}.circle-arrow{width:38px;height:38px}.eyebrow{font-size:8px;letter-spacing:1.3px}.chapter-index{margin-right:0}.context-route{gap:15px;font-size:10px;margin-top:29px}.context-route small{font-size:9px}.target-context{font-size:15px}.chapter-footnote{font-size:9px}.knowledge-strip{gap:10px;font-size:11px}.knowledge-strip i{width:15px}.response-note{gap:18px;font-size:10px}.response-note small{font-size:7px;letter-spacing:1px}.finale-copy{top:auto;bottom:13vh}.finale-copy h2{font-size:34px}.finale-copy .chapter-description{font-size:12px}.research-heading h2{font-size:46px}.research-heading p{font-size:12px}.research-stats strong{font-size:46px}.research-stats small{font-size:7px;letter-spacing:1px}.research-stats{gap:24px;margin-top:40px}.research{padding-top:105px}.paper-title{font-size:10px}.hud-chapter{gap:8px}.hud-chapter i{width:14px}.hud-chapter>span:last-child{font-size:9px}footer{margin-top:48px}footer>span{flex-basis:65%}.reading-progress{height:2px}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}.hud-hint>span{animation:none}*{transition:none!important}}
html.is-reduced{scroll-behavior:auto}html.is-reduced .hud-hint>span{animation:none}html.is-reduced *{transition:none!important}
.scene-shade{transform:none;opacity:var(--shade-left-opacity,1)}.scene-shade-right{background:linear-gradient(270deg,#fff 0%,rgba(255,255,255,.97) 15%,rgba(255,255,255,.7) 32%,rgba(255,255,255,0) 57%);opacity:var(--shade-right-opacity,0)}
@media(max-width:900px){.scene-shade{background:linear-gradient(180deg,#fff 2%,rgba(255,255,255,.94) 17%,rgba(255,255,255,.55) 39%,rgba(255,255,255,0) 64%)}}
.research-heading h2>.accent{display:inline}
.knowledge-caption{display:flex;align-items:center;gap:16px;margin-top:36px;color:#68888c;font-size:12px;letter-spacing:.1em}.knowledge-caption>span{width:37px;height:1px;background:linear-gradient(90deg,#288b92,#c7a669)}
@media(min-width:901px){.intro-copy h1{font-size:clamp(52px,5.6vw,100px)}}
@media(max-height:760px) and (min-width:901px){.intro-copy h1{font-size:clamp(50px,5.2vw,80px)}}

/* English narrative copy retains the original scene composition. */
html[lang="en"] .chapter-description { letter-spacing: .005em; line-height: 1.95; }
html[lang="en"] .input-equation { letter-spacing: .02em; gap: 12px; }
html[lang="en"] .chapter-footnote { line-height: 1.8; }
html[lang="en"] .knowledge-caption { letter-spacing: .025em; line-height: 1.8; }
html[lang="en"] .context-route small { letter-spacing: .03em; }
@media (min-width:901px) {
  html[lang="en"] .chapter-copy h2 { font-size: clamp(46px,4.8vw,82px); }
  html[lang="en"] .finale-copy h2 { font-size: clamp(42px,4.25vw,72px); }
}

/* Lift the opening copy clear of the fixed chapter indicator. */
.intro-copy { top: clamp(104px, 16vh, 180px); }
@media (min-width: 901px) {
  .intro-copy { top: clamp(112px, 18vh, 180px); }
}
@media (max-height: 760px) and (min-width: 901px) {
  .intro-copy { top: max(112px, 16vh); }
}

/* Keep the home navigation in step with its larger supporting text. */
body.journey-page .integration-header nav { font-size: 17px; }
body.journey-page .integration-header .header-caption { font-size: 11px; }
@media (max-width: 900px) {
  body.journey-page .integration-header nav { font-size: 15px; }
}