:root {
  --ink: #11171d;
  --ink-soft: #25303a;
  --paper: #f4f1ea;
  --paper-deep: #e8e4dc;
  --silver: #a7b0ba;
  --line: #c9c6bf;
  --red: #e43d3d;
  --white: #fff;
  --sans: "PingFang SC", "Microsoft YaHei", "Noto Sans CJK SC", sans-serif;
  --mono: "Cascadia Mono", "SFMono-Regular", Consolas, monospace;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; color: var(--ink); background: var(--paper); font-family: var(--sans); line-height: 1.65; -webkit-font-smoothing: antialiased; }
a { color: inherit; }
img { max-width: 100%; }
button, input { font: inherit; }
.skip-link { position: fixed; top: -100px; left: 1rem; z-index: 99; padding: .7rem 1rem; background: var(--red); color: white; }
.skip-link:focus { top: 1rem; }
.section-shell { width: min(1180px, calc(100% - 48px)); margin-inline: auto; position: relative; }
.site-header { position: sticky; top: 0; z-index: 50; background: rgba(244,241,234,.91); backdrop-filter: blur(18px); border-bottom: 1px solid rgba(17,23,29,.13); }
.nav-wrap { width: min(1320px, calc(100% - 48px)); min-height: 84px; margin: auto; display: flex; align-items: center; justify-content: space-between; }
.brand { display: flex; width: 248px; }
.brand img { display: block; width: 100%; height: auto; }
nav { display: flex; align-items: center; gap: 34px; font-size: 14px; font-weight: 600; }
nav a { text-decoration: none; transition: opacity .2s; }
nav a:hover { opacity: .55; }
.nav-cta { padding: 12px 20px; color: white; background: var(--ink); }
.menu-button { display: none; border: 0; background: none; font-weight: 700; }
.hero { min-height: calc(100vh - 84px); display: grid; grid-template-columns: 1.12fr .88fr; align-items: center; gap: 70px; padding-block: 90px 76px; overflow: hidden; }
.hero::before { content: ""; position: absolute; left: 48%; top: 0; bottom: 0; border-left: 1px solid var(--line); }
.eyebrow, .kicker { margin: 0 0 24px; font: 600 12px/1.3 var(--mono); letter-spacing: .16em; }
.eyebrow { display: flex; align-items: center; gap: 10px; }
.eyebrow span { width: 7px; height: 7px; background: var(--red); }
h1, h2, h3, p { margin-top: 0; }
h1 { margin-bottom: 30px; font-size: clamp(58px, 7.4vw, 108px); line-height: .98; letter-spacing: -.065em; font-weight: 900; }
h1 em { color: var(--red); font-style: normal; }
.hero-lead { max-width: 650px; font-size: 19px; line-height: 1.85; color: #3e4850; }
.hero-actions { display: flex; gap: 28px; align-items: center; margin-top: 44px; }
.button { display: inline-flex; align-items: center; justify-content: space-between; gap: 44px; min-width: 210px; padding: 15px 18px; border: 1px solid var(--ink); text-decoration: none; font-weight: 700; font-size: 14px; transition: transform .2s, background .2s, color .2s; }
.button:hover { transform: translateY(-3px); }
.button.primary, .button.dark { background: var(--ink); color: white; }
.button.text { min-width: auto; border: 0; padding-inline: 0; }
.hero-system { position: relative; aspect-ratio: 1; display: grid; place-items: center; }
.radar-ring { position: absolute; border: 1px solid #8d9296; border-radius: 50%; }
.ring-one { inset: 14%; animation: spin 22s linear infinite; border-right-color: var(--red); }
.ring-two { inset: 27%; border-style: dashed; animation: spin 16s linear infinite reverse; }
.system-core { position: relative; z-index: 2; width: 155px; height: 155px; display: grid; place-content: center; text-align: center; background: var(--ink); color: white; transform: rotate(45deg); }
.system-core span, .system-core small { transform: rotate(-45deg); }
.system-core span { font: 800 32px/1 var(--mono); letter-spacing: .08em; }
.system-core small { margin-top: 10px; color: var(--silver); font-size: 11px; letter-spacing: .15em; }
.orbit-node { position: absolute; display: flex; gap: 8px; align-items: center; font-size: 12px; font-weight: 700; background: var(--paper); padding: 5px 8px; }
.orbit-node b { color: var(--red); font: 600 10px var(--mono); }
.node-a { top: 10%; left: 42%; }.node-b { top: 45%; right: 0; }.node-c { bottom: 8%; left: 42%; }.node-d { top: 45%; left: 0; }
.system-status { position: absolute; bottom: 0; right: 0; font: 500 11px var(--mono); letter-spacing: .08em; }
.system-status i { display: inline-block; width: 6px; height: 6px; background: var(--red); margin-right: 8px; animation: pulse 1.4s infinite; }
.hero-index, .section-number { position: absolute; font: 500 11px var(--mono); letter-spacing: .14em; }
.hero-index { right: 0; bottom: 18px; }.section-number { top: 8px; right: 0; }
.definition, .method, .research, .about { padding-block: 130px; border-top: 1px solid var(--line); }
.definition-grid, .about-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 10%; }
.kicker { color: var(--red); }
.kicker.light { color: #ef7777; }
h2 { font-size: clamp(40px, 5vw, 72px); line-height: 1.08; letter-spacing: -.055em; font-weight: 800; }
.definition-copy { padding-top: 48px; font-size: 22px; line-height: 1.9; }
.source-note { margin-top: 28px; font: 500 11px/1.6 var(--mono); color: #687078; }
.responsibility-chain { display: grid; grid-template-columns: repeat(4, 1fr); margin-top: 92px; border-top: 1px solid var(--ink); border-bottom: 1px solid var(--ink); }
.responsibility-chain article { padding: 28px 24px 36px; border-right: 1px solid var(--line); }
.responsibility-chain article:last-child { border: 0; }
.responsibility-chain b { font: 600 11px var(--mono); color: var(--red); }
.responsibility-chain h3 { margin: 62px 0 15px; font-size: 22px; }
.responsibility-chain p { margin: 0; color: #566068; font-size: 14px; }
.services, .fit, .contact { background: var(--ink); color: white; }
.services { padding-block: 130px; }
.section-heading { display: grid; grid-template-columns: 1.45fr .55fr; align-items: end; gap: 80px; }
.section-heading h2 { margin-bottom: 0; }.section-heading > p { color: var(--silver); font-size: 16px; }
.service-grid { display: grid; grid-template-columns: 1fr 1fr; margin-top: 70px; border: 1px solid #42484e; }
.service-card { min-height: 590px; padding: 38px 44px 42px; position: relative; overflow: hidden; }
.service-card + .service-card { border-left: 1px solid #42484e; }
.service-card::after { content: ""; position: absolute; width: 280px; height: 280px; right: -130px; bottom: -130px; border: 1px solid #4b5157; transform: rotate(45deg); }
.card-top { display: flex; align-items: center; justify-content: space-between; color: var(--silver); font: 500 11px var(--mono); letter-spacing: .12em; }
.card-top i { width: 8px; height: 8px; background: var(--red); }
.service-card h3 { margin: 85px 0 10px; font-size: 42px; letter-spacing: -.04em; }
.service-subtitle { min-height: 62px; max-width: 480px; color: #c6cbd0; font-size: 17px; }
.service-card ul { list-style: none; padding: 0; margin: 44px 0 50px; border-top: 1px solid #42484e; }
.service-card li { padding: 13px 0; border-bottom: 1px solid #32383e; color: #d8dbde; font-size: 14px; }
.service-card li::before { content: "—"; color: var(--red); margin-right: 12px; }
.service-card a { position: absolute; left: 44px; bottom: 38px; display: flex; gap: 50px; text-decoration: none; font-weight: 700; }
.service-card a span { color: var(--red); }
.method-layout { display: grid; grid-template-columns: .78fr 1.22fr; gap: 11%; }
.method-intro { position: sticky; top: 130px; align-self: start; }.method-intro > p:last-child { max-width: 400px; color: #59636b; }
.timeline { list-style: none; margin: 0; padding: 0; border-top: 1px solid var(--ink); }
.timeline li { display: grid; grid-template-columns: 80px 1fr; gap: 20px; padding: 34px 0; border-bottom: 1px solid var(--line); }
.timeline li > span { font: 600 12px var(--mono); color: var(--red); }
.timeline h3 { margin-bottom: 8px; font-size: 25px; }.timeline p { margin: 0; color: #566068; }
.fit { padding-block: 120px; }
.fit-grid { display: grid; grid-template-columns: .75fr 1.25fr; gap: 12%; }
.fit-list { border-top: 1px solid #555c62; }
.fit-list p { display: grid; grid-template-columns: 60px 1fr; gap: 10px; margin: 0; padding: 23px 0; border-bottom: 1px solid #41484e; font-size: 18px; }
.fit-list span { color: #ef7777; font: 500 11px var(--mono); }
.research-grid { display: grid; grid-template-columns: .9fr 1.1fr; gap: 10%; align-items: end; }
.research-copy > p:not(.kicker) { max-width: 550px; color: #566068; font-size: 17px; }
.research-actions { margin-top: 25px; }
.research-data { display: grid; grid-template-columns: repeat(3, 1fr); border-top: 1px solid var(--ink); border-bottom: 1px solid var(--ink); }
.research-data div { padding: 28px 20px 26px; border-right: 1px solid var(--line); }
.research-data div:last-child { border: 0; }
.research-data strong { display: block; font: 600 clamp(34px, 4vw, 54px)/1 var(--mono); letter-spacing: -.06em; }
.research-data span { display: block; min-height: 58px; margin-top: 18px; font-weight: 700; font-size: 14px; }
.research-data small { color: #6b747c; font-size: 10px; line-height: 1.5; }
.about-grid > div:last-child { padding-top: 42px; font-size: 18px; color: #49535b; }
.about-grid dl { margin-top: 50px; border-top: 1px solid var(--ink); }
.about-grid dl div { display: grid; grid-template-columns: 110px 1fr; padding: 18px 0; border-bottom: 1px solid var(--line); }
.about-grid dt { font: 500 11px var(--mono); color: #737b82; }.about-grid dd { margin: 0; color: var(--ink); font-size: 14px; font-weight: 600; }
.contact { padding-block: 110px; }
.contact-grid { display: grid; grid-template-columns: 1fr .72fr; gap: 12%; align-items: center; }
.contact h2 { margin-bottom: 24px; }.contact-grid > div:first-child > p:last-child { max-width: 620px; color: #b9c0c5; }
.contact-panel { padding: 36px; border: 1px solid #535a60; background: #181f25; }
.contact-label { font: 500 11px var(--mono); color: var(--silver); letter-spacing: .12em; }
.contact-panel h3 { font-size: 34px; margin-bottom: 28px; }
.contact-panel a, .copy-wechat { width: 100%; display: flex; justify-content: space-between; padding: 15px 0; color: white; background: none; border: 0; border-top: 1px solid #40474d; text-decoration: none; text-align: left; cursor: pointer; }
.copy-wechat { border-bottom: 1px solid #40474d; }.contact-panel a span, .copy-wechat span { color: #ef7777; }
.contact-note { margin: 18px 0 0; color: #8f989f; font-size: 12px; }
footer { padding-block: 54px; background: #090d10; color: #acb3b8; }
.footer-grid { display: grid; grid-template-columns: 1fr auto 1fr; align-items: end; gap: 60px; }
footer img { display: block; width: 205px; height: auto; filter: brightness(0) invert(1); opacity: .88; }
footer p { margin: 12px 0 0; font-size: 12px; }.footer-links { display: flex; gap: 26px; }.footer-links a, .legal a { color: inherit; font-size: 12px; text-decoration: none; }
.legal { text-align: right; }.legal p { margin: 0 0 8px; }
.reveal { opacity: 0; transform: translateY(18px); transition: opacity .8s ease, transform .8s ease; }.reveal.visible { opacity: 1; transform: none; }
@keyframes spin { to { transform: rotate(360deg); } } @keyframes pulse { 50% { opacity: .25; } }

@media (max-width: 900px) {
  .section-shell { width: min(100% - 32px, 720px); }
  .nav-wrap { width: calc(100% - 32px); min-height: 70px; }.brand { width: 205px; }.menu-button { display: block; }
  nav { display: none; position: absolute; top: 70px; left: 0; right: 0; padding: 22px 16px; flex-direction: column; align-items: stretch; gap: 0; background: var(--paper); border-bottom: 1px solid var(--line); }
  nav.open { display: flex; } nav a { padding: 12px 0; }.nav-cta { margin-top: 8px; padding-inline: 14px; }
  .hero { grid-template-columns: 1fr; gap: 30px; padding-block: 72px 45px; }.hero::before { display: none; }.hero-system { width: min(100%, 520px); margin: auto; }.hero-index { display: none; }
  h1 { font-size: clamp(52px, 15vw, 82px); }.definition, .method, .research, .about { padding-block: 90px; }
  .definition-grid, .about-grid, .section-heading, .method-layout, .fit-grid, .research-grid, .contact-grid { grid-template-columns: 1fr; gap: 40px; }
  .definition-copy, .about-grid > div:last-child { padding-top: 0; }.responsibility-chain { grid-template-columns: 1fr 1fr; }.responsibility-chain article:nth-child(2) { border-right: 0; }.responsibility-chain article:nth-child(-n+2) { border-bottom: 1px solid var(--line); }
  .section-heading > p { max-width: 500px; }.service-grid { grid-template-columns: 1fr; }.service-card + .service-card { border-left: 0; border-top: 1px solid #42484e; }
  .method-intro { position: static; }.research-data { margin-top: 20px; }.footer-grid { grid-template-columns: 1fr; align-items: start; gap: 30px; }.legal { text-align: left; }
}

@media (max-width: 560px) {
  .hero { min-height: auto; }.hero-actions { align-items: stretch; flex-direction: column; gap: 10px; }.button { width: 100%; }.button.text { padding: 14px 0; }
  .hero-system { margin-top: 10px; }.orbit-node { font-size: 10px; }.system-core { width: 112px; height: 112px; }.system-core span { font-size: 24px; }
  h2 { font-size: 42px; }.definition-copy { font-size: 18px; }.responsibility-chain { grid-template-columns: 1fr; }.responsibility-chain article { border-right: 0; border-bottom: 1px solid var(--line); }.responsibility-chain article:nth-child(3) { border-bottom: 1px solid var(--line); }.responsibility-chain h3 { margin-top: 30px; }
  .service-card { padding: 30px 24px 90px; min-height: auto; }.service-card h3 { margin-top: 55px; font-size: 34px; }.service-card a { left: 24px; bottom: 28px; }
  .research-data { grid-template-columns: 1fr; }.research-data div { border-right: 0; border-bottom: 1px solid var(--line); }.research-data div:last-child { border-bottom: 0; }.research-data span { min-height: auto; }
  .fit-list p { grid-template-columns: 42px 1fr; font-size: 16px; }.contact-panel { padding: 28px 22px; }.footer-links { flex-wrap: wrap; }
}

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

/* Shared cross-domain navigation overrides. Content sections keep the original brand system. */
.cross-site-header { min-height: 0; }
.cross-site-nav-wrap { width: min(1320px, calc(100% - 48px)); min-height: 78px; }
.cross-site-brand { width: 206px; min-height: 52px; }
.cross-site-nav { gap: clamp(18px, 2.2vw, 34px); font-size: 12px; }
.cross-site-nav a { min-height: 44px; padding: 0; }
.cross-site-nav .cross-site-cta { min-height: 44px; padding: 0 16px; }
.cross-site-menu-button { min-width: 44px; min-height: 44px; }
.footer-brand-link { display: inline-flex; text-decoration: none; }
.footer-brand-link:focus-visible { outline: 3px solid var(--red); outline-offset: 5px; }

@media (max-width: 1080px) {
  .cross-site-nav-wrap { min-height: 70px; width: calc(100% - 32px); }
  .cross-site-brand { width: 184px; }
  .cross-site-nav { top: 70px; left: 16px; right: 16px; display: none; gap: 0; }
  .cross-site-nav.is-open { display: flex; }
  .cross-site-nav a { min-height: 48px; padding: 4px 0; }
  .cross-site-nav .cross-site-cta { margin-top: 8px; padding-inline: 14px; }
}

@media (max-width: 560px) {
  .cross-site-nav-wrap { width: calc(100% - 32px); }
  .cross-site-nav { left: 8px; right: 8px; }
}