:root {
  --black: #090909;
  --ink: #111111;
  --muted: #656565;
  --line: #d7d7d7;
  --soft: #f5f5f5;
  --white: #ffffff;
  --gutter: clamp(22px, 5vw, 76px);
  --max: 1536px;
  --ease: cubic-bezier(.2,.75,.25,1);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--ink);
  background: var(--white);
  font-family: "PingFang SC", "Microsoft YaHei", "Noto Sans CJK SC", Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; text-decoration: none; }
button { font: inherit; }
.skip-link { position: fixed; z-index: 999; left: 16px; top: -80px; padding: 12px 18px; background: #000; color: #fff; }
.skip-link:focus { top: 16px; }

.site-header {
  position: sticky;
  z-index: 100;
  top: 0;
  height: 88px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: var(--max);
  margin: 0 auto;
  padding: 0 var(--gutter);
  background: rgba(255,255,255,.94);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(12px);
}
.brand { display: flex; align-items: baseline; gap: 12px; letter-spacing: -.04em; }
.brand-cn { font-size: 22px; font-weight: 750; }
.brand-en { font-size: 14px; font-weight: 700; letter-spacing: .11em; }
.site-nav { display: flex; align-items: center; gap: clamp(26px, 3vw, 52px); font-size: 15px; }
.site-nav > a { position: relative; }
.site-nav > a:not(.nav-cta)::after { content: ""; position: absolute; left: 0; right: 100%; bottom: -8px; height: 1px; background: #000; transition: right .25s var(--ease); }
.site-nav > a:hover::after, .site-nav > a:focus-visible::after { right: 0; }
.nav-cta { padding: 14px 24px; border: 1px solid var(--ink); transition: background .25s, color .25s; }
.nav-cta:hover { color: #fff; background: #000; }
.menu-toggle { display: none; border: 0; background: none; padding: 8px 0 8px 12px; }

main, .site-footer { max-width: var(--max); margin: 0 auto; }
.hero {
  min-height: calc(100svh - 88px);
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(440px, 1fr);
  border-bottom: 1px solid var(--ink);
  overflow: hidden;
}
.hero-copy { position: relative; z-index: 2; display: flex; flex-direction: column; justify-content: center; padding: 80px var(--gutter) 90px; }
.hero h1 { margin: 0; max-width: 720px; font-size: clamp(54px, 4.8vw, 76px); font-weight: 760; line-height: 1.08; letter-spacing: -.065em; }
.hero-copy > p { max-width: 540px; margin: 38px 0 0; color: #333; font-size: clamp(17px, 1.35vw, 21px); line-height: 1.85; }
.hero-actions { display: flex; gap: 16px; margin-top: 48px; }
.button { width: 172px; min-height: 58px; display: flex; align-items: center; justify-content: space-between; padding: 0 22px; border: 1px solid var(--ink); font-size: 15px; transition: transform .25s var(--ease), background .25s, color .25s; }
.button:hover { transform: translateY(-3px); }
.button-dark { color: #fff; background: #000; }
.button-dark:hover { background: #242424; }
.button-light:hover { color: #fff; background: #000; }

.hero-visual { position: relative; min-height: 680px; background: linear-gradient(90deg, transparent 0 19%, rgba(0,0,0,.05) 19% 19.12%, transparent 19.12%); overflow: hidden; }
.visual-grid { position: absolute; inset: 16% -15% -15% 4%; transform: perspective(700px) rotateX(58deg) rotateZ(-7deg); transform-origin: bottom; background-image: linear-gradient(rgba(0,0,0,.12) 1px, transparent 1px), linear-gradient(90deg, rgba(0,0,0,.12) 1px, transparent 1px); background-size: 42px 42px; mask-image: linear-gradient(to bottom, transparent, #000 30%); }
.plane { position: absolute; border: 1px solid #aaa; background: rgba(255,255,255,.62); }
.plane::before, .plane::after { content: ""; position: absolute; background: #aaa; }
.plane::before { left: 33%; top: 0; bottom: 0; width: 1px; box-shadow: 75px 0 #aaa; }
.plane::after { left: 0; right: 0; top: 45%; height: 1px; box-shadow: 0 62px #aaa; }
.plane-a { width: 330px; height: 300px; left: 19%; top: 29%; transform: skewY(-22deg); }
.plane-b { width: 270px; height: 390px; right: 7%; top: 16%; transform: skewY(-22deg); }
.plane-c { width: 245px; height: 230px; left: 42%; bottom: 9%; transform: skewY(-22deg); }
.visual-core { position: absolute; z-index: 2; width: 86px; height: 112px; left: 45%; top: 43%; background: #050505; transform: skewY(-22deg); box-shadow: -52px 72px 0 rgba(0,0,0,.08), 65px -52px 0 rgba(0,0,0,.05); }
.code-block { position: absolute; z-index: 3; right: 5%; bottom: 14%; display: flex; flex-direction: column; gap: 8px; width: 230px; padding: 22px; background: rgba(255,255,255,.9); border: 1px solid #bdbdbd; color: #555; font: 11px/1.4 ui-monospace, SFMono-Regular, Consolas, monospace; }
.cross { position: absolute; width: 28px; height: 28px; }
.cross::before, .cross::after { content: ""; position: absolute; background: #777; }
.cross::before { left: 13px; width: 1px; height: 28px; }
.cross::after { top: 13px; width: 28px; height: 1px; }
.cross-a { top: 10%; right: 13%; }
.cross-b { bottom: 18%; left: 11%; transform: scale(.65); }

.intro { display: grid; grid-template-columns: .65fr 1.35fr 1fr; gap: 7%; align-items: end; padding: 80px var(--gutter); border-bottom: 1px solid var(--line); }
.section-label { color: var(--muted); font-size: 12px; font-weight: 650; letter-spacing: .12em; text-transform: uppercase; }
.intro h2, .section-heading h2, .process h2, .about h2, .contact h2 { margin: 0; letter-spacing: -.045em; }
.intro h2 { font-size: clamp(30px, 2.7vw, 44px); line-height: 1.32; }
.intro p { margin: 0; color: var(--muted); font-size: 15px; line-height: 1.8; }

.services { padding: 130px var(--gutter) 120px; }
.section-heading { display: grid; grid-template-columns: .65fr 2.35fr; gap: 7%; margin-bottom: 75px; }
.section-heading h2 { font-size: clamp(42px, 5vw, 76px); line-height: 1.15; }
.service-list { border-top: 1px solid var(--ink); }
.service-item { min-height: 164px; display: grid; grid-template-columns: 160px 1fr 80px; gap: 28px; align-items: center; border-bottom: 1px solid var(--line); transition: padding .32s var(--ease), background .32s; }
.service-item:hover { padding: 0 20px; background: var(--soft); }
.service-number { font-size: clamp(52px, 5vw, 76px); font-weight: 300; letter-spacing: -.07em; }
.service-item h3 { margin: 0 0 10px; font-size: clamp(24px, 2.4vw, 36px); letter-spacing: -.035em; }
.service-item p { margin: 0; color: var(--muted); font-size: 15px; }
.service-item svg { width: 64px; height: 64px; fill: none; stroke: currentColor; stroke-width: 1.5; stroke-linecap: round; stroke-linejoin: round; }

.process { color: #fff; background: #080808; padding: 110px var(--gutter) 0; }
.process-head { display: grid; grid-template-columns: .65fr 1.35fr 1fr; gap: 7%; align-items: end; padding-bottom: 66px; }
.process .section-label { color: #999; }
.process h2 { font-size: clamp(38px, 4.2vw, 64px); line-height: 1.15; }
.process-head p { margin: 0; color: #aaa; line-height: 1.8; }
.process-list { display: grid; grid-template-columns: repeat(4, 1fr); margin: 0; padding: 0; list-style: none; border-top: 1px solid #6a6a6a; }
.process-list li { min-height: 310px; padding: 38px 30px 50px 0; border-right: 1px solid #555; }
.process-list li + li { padding-left: 30px; }
.process-list li:last-child { border-right: 0; }
.step-number { font-size: 52px; font-weight: 300; letter-spacing: -.06em; }
.process-list h3 { margin: 52px 0 13px; font-size: 23px; }
.process-list p { max-width: 210px; margin: 0; color: #aaa; line-height: 1.75; font-size: 14px; }

.about { padding: 130px var(--gutter); }
.about-copy { display: grid; grid-template-columns: .65fr 1.35fr 1fr; gap: 7%; align-items: end; margin-bottom: 90px; }
.about h2 { font-family: "Songti SC", SimSun, serif; font-size: clamp(54px, 6vw, 92px); font-weight: 700; line-height: 1.12; }
.about-copy > p { margin: 0; color: #444; font-size: 16px; line-height: 1.95; }
.principles { display: grid; grid-template-columns: repeat(3, 1fr); border-top: 1px solid var(--line); }
.principles article { padding: 38px 54px 0 0; }
.principles article + article { padding-left: 54px; border-left: 1px solid var(--line); }
.principles span { font-size: 40px; font-weight: 300; }
.principles h3 { margin: 42px 0 14px; font-size: 24px; }
.principles p { max-width: 330px; margin: 0; color: var(--muted); font-size: 14px; line-height: 1.8; }

.contact { color: #fff; background: #050505; padding: 110px var(--gutter) 120px; border-bottom: 1px solid #444; }
.contact .section-label { color: #8d8d8d; }
.contact h2 { max-width: 1050px; margin-top: 32px; font-family: "Songti SC", SimSun, serif; font-size: clamp(54px, 7vw, 108px); font-weight: 700; line-height: 1.1; }
.contact-link { width: min(390px, 100%); min-height: 82px; display: flex; align-items: center; justify-content: space-between; margin-top: 64px; padding: 0 30px; border: 1px solid #fff; font-size: 19px; transition: color .25s, background .25s; }
.contact-link:hover { color: #000; background: #fff; }
.contact-link span:last-child { font-size: 28px; }

.site-footer { min-height: 185px; display: grid; grid-template-columns: 1.15fr 1.8fr 1fr 1fr; gap: 50px; align-items: center; padding: 44px var(--gutter); color: #ddd; background: #050505; font-size: 13px; }
.footer-brand { display: flex; flex-direction: column; padding-right: 42px; border-right: 1px solid #555; }
.footer-brand strong { color: #fff; font-size: 24px; }
.footer-brand span { margin-top: 5px; font-weight: 700; letter-spacing: .17em; }
.site-footer p { margin: 0; }
.site-footer a:hover { color: #fff; text-decoration: underline; }

@media (max-width: 980px) {
  .site-header { height: 74px; }
  .hero { min-height: auto; grid-template-columns: 1fr; }
  .hero-copy { min-height: 650px; padding-top: 90px; padding-bottom: 80px; }
  .hero-visual { min-height: 430px; border-top: 1px solid var(--line); }
  .intro, .process-head, .about-copy { grid-template-columns: 1fr 2fr; }
  .intro p, .process-head p, .about-copy > p { grid-column: 2; }
  .section-heading { grid-template-columns: 1fr 2fr; }
  .process-list { grid-template-columns: repeat(2, 1fr); }
  .process-list li:nth-child(2) { border-right: 0; }
  .process-list li:nth-child(n+3) { border-top: 1px solid #555; }
  .site-footer { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 720px) {
  :root { --gutter: 22px; }
  .site-header { padding-left: var(--gutter); padding-right: var(--gutter); }
  .brand-cn { font-size: 19px; }
  .brand-en { font-size: 11px; }
  .menu-toggle { display: flex; align-items: center; gap: 12px; }
  .menu-label { font-size: 13px; }
  .menu-icon { width: 25px; display: grid; gap: 6px; }
  .menu-icon i { display: block; height: 1px; background: #000; transition: transform .25s; }
  .menu-toggle[aria-expanded="true"] .menu-icon i:first-child { transform: translateY(3.5px) rotate(45deg); }
  .menu-toggle[aria-expanded="true"] .menu-icon i:last-child { transform: translateY(-3.5px) rotate(-45deg); }
  .site-nav { position: fixed; inset: 74px 0 auto 0; display: none; flex-direction: column; align-items: stretch; gap: 0; padding: 10px 22px 24px; background: #fff; border-bottom: 1px solid #000; }
  .site-nav.is-open { display: flex; }
  .site-nav > a { padding: 18px 0; border-bottom: 1px solid var(--line); font-size: 18px; }
  .site-nav .nav-cta { margin-top: 10px; padding: 16px; text-align: center; border: 1px solid #000; }
  .hero-copy { min-height: calc(100svh - 74px); justify-content: center; }
  .hero h1 { font-size: clamp(42px, 11.7vw, 54px); line-height: 1.12; }
  .hero-copy > p { margin-top: 30px; font-size: 16px; line-height: 1.75; }
  .hero-actions { margin-top: 38px; }
  .button { width: calc(50% - 7px); min-height: 54px; padding: 0 16px; }
  .hero-visual { min-height: 320px; }
  .plane-a { left: 7%; top: 25%; }
  .plane-b { right: -28%; }
  .code-block { display: none; }
  .visual-core { left: 43%; top: 39%; width: 63px; height: 86px; }
  .intro, .section-heading, .process-head, .about-copy { grid-template-columns: 1fr; gap: 24px; }
  .intro { align-items: start; padding-top: 64px; padding-bottom: 64px; }
  .intro p, .process-head p, .about-copy > p { grid-column: auto; }
  .services { padding-top: 84px; padding-bottom: 84px; }
  .section-heading { margin-bottom: 48px; }
  .section-heading h2 { font-size: 43px; }
  .service-item { min-height: 140px; grid-template-columns: 64px 1fr 44px; gap: 16px; }
  .service-number { font-size: 39px; }
  .service-item h3 { font-size: 21px; }
  .service-item p { font-size: 13px; line-height: 1.55; }
  .service-item svg { width: 42px; height: 42px; }
  .service-item:hover { padding: 0; }
  .process { padding-top: 78px; }
  .process-head { padding-bottom: 48px; }
  .process h2 { font-size: 42px; }
  .process-list { grid-template-columns: 1fr; }
  .process-list li, .process-list li + li { min-height: auto; padding: 34px 0 38px; border-right: 0; border-top: 1px solid #555; }
  .process-list li:first-child { border-top: 0; }
  .process-list h3 { margin: 20px 0 10px; }
  .step-number { font-size: 42px; }
  .about { padding-top: 86px; padding-bottom: 86px; }
  .about-copy { margin-bottom: 58px; }
  .about h2 { font-size: 54px; }
  .principles { grid-template-columns: 1fr; }
  .principles article, .principles article + article { padding: 28px 0 34px; border-left: 0; border-bottom: 1px solid var(--line); }
  .principles article:last-child { border-bottom: 0; }
  .principles span { font-size: 34px; }
  .principles h3 { margin: 18px 0 10px; }
  .contact { padding-top: 82px; padding-bottom: 88px; }
  .contact h2 { font-size: clamp(47px, 12vw, 68px); }
  .contact-link { margin-top: 46px; min-height: 70px; }
  .site-footer { grid-template-columns: 1fr; gap: 22px; padding-top: 48px; padding-bottom: 48px; }
  .footer-brand { border-right: 0; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition-duration: .01ms !important; }
}