:root {
  --ink: #07111f;
  --ink-soft: #10243a;
  --paper: #f4f6f0;
  --paper-deep: #e8ece4;
  --cyan: #62e7ff;
  --lime: #b9ff5f;
  --violet: #a78bfa;
  --coral: #ff8a68;
  --line: rgba(7, 17, 31, 0.14);
  --shell: min(1180px, calc(100vw - 64px));
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: "Noto Sans SC", "Microsoft YaHei", "PingFang SC", system-ui, sans-serif;
  line-height: 1.65;
  text-rendering: optimizeLegibility;
}
a { color: inherit; text-decoration: none; }

.skip-link {
  position: fixed;
  z-index: 100;
  top: 12px;
  left: 12px;
  padding: 10px 16px;
  background: white;
  transform: translateY(-150%);
}
.skip-link:focus { transform: translateY(0); }

.site-header {
  position: absolute;
  z-index: 10;
  inset: 0 0 auto;
  width: var(--shell);
  height: 92px;
  margin: auto;
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  color: white;
  border-bottom: 1px solid rgba(255, 255, 255, 0.2);
}
.brand { display: inline-flex; align-items: center; gap: 12px; width: fit-content; }
.brand-mark {
  display: grid;
  place-items: center;
  width: 42px;
  aspect-ratio: 1;
  color: var(--ink);
  background: var(--lime);
  border-radius: 50%;
  font-weight: 900;
}
.brand-text { display: flex; flex-direction: column; line-height: 1.2; }
.brand-text strong { font-size: 17px; letter-spacing: 0.14em; }
.brand-text small { margin-top: 3px; font-size: 8px; letter-spacing: 0.25em; opacity: 0.65; }
nav { display: flex; gap: 38px; font-size: 14px; }
nav a, .header-cta { transition: opacity 180ms ease; }
nav a:hover, .header-cta:hover { opacity: 0.65; }
.header-cta { justify-self: end; font-size: 14px; border-bottom: 1px solid currentColor; }

.hero {
  position: relative;
  min-height: 820px;
  overflow: hidden;
  color: white;
  background:
    radial-gradient(circle at 78% 42%, rgba(98, 231, 255, 0.14), transparent 29%),
    linear-gradient(115deg, #07111f 0%, #0b1b31 57%, #071522 100%);
}
.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  opacity: 0.2;
  background-image:
    linear-gradient(rgba(255,255,255,.08) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,.08) 1px, transparent 1px);
  background-size: 72px 72px;
  mask-image: linear-gradient(to right, black, transparent 72%);
}
.hero-copy {
  position: relative;
  z-index: 2;
  width: var(--shell);
  margin: auto;
  padding-top: 190px;
}
.eyebrow, .section-kicker {
  margin: 0 0 28px;
  font-size: 11px;
  font-weight: 800;
  letter-spacing: 0.24em;
  text-transform: uppercase;
}
.eyebrow { display: flex; align-items: center; gap: 10px; color: var(--cyan); }
.eyebrow span { width: 22px; height: 1px; background: currentColor; }
h1, h2, h3, p { margin-top: 0; }
h1 {
  max-width: 750px;
  margin-bottom: 30px;
  font-size: clamp(52px, 6.2vw, 90px);
  line-height: 1.08;
  letter-spacing: -0.055em;
}
h1 em { color: var(--lime); font-style: normal; }
.hero-lead { max-width: 630px; color: rgba(255,255,255,.68); font-size: 17px; }
.hero-actions { display: flex; gap: 14px; margin-top: 40px; }
.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 40px;
  min-height: 52px;
  padding: 0 24px;
  font-size: 14px;
  border: 1px solid rgba(255,255,255,.28);
  transition: transform 180ms ease, background 180ms ease;
}
.button:hover { transform: translateY(-2px); }
.button-primary { color: var(--ink); background: var(--lime); border-color: var(--lime); }
.button-quiet { color: white; }

.hero-visual {
  position: absolute;
  top: 170px;
  right: max(-100px, calc((100vw - 1420px) / 2));
  width: 570px;
  aspect-ratio: 1;
}
.orbit { position: absolute; inset: 50%; border: 1px solid rgba(255,255,255,.24); border-radius: 50%; transform: translate(-50%,-50%); }
.orbit-one { width: 33%; height: 33%; }
.orbit-two { width: 68%; height: 68%; border-style: dashed; animation: spin 28s linear infinite; }
.orbit-three { width: 100%; height: 100%; }
.core {
  position: absolute;
  z-index: 2;
  inset: 50% auto auto 50%;
  width: 128px;
  aspect-ratio: 1;
  display: grid;
  place-content: center;
  text-align: center;
  color: var(--ink);
  background: var(--cyan);
  border-radius: 50%;
  transform: translate(-50%,-50%);
  box-shadow: 0 0 70px rgba(98,231,255,.3);
}
.core span { font-family: Georgia, serif; font-size: 52px; line-height: 1; }
.core small { font-size: 10px; letter-spacing: .15em; }
.node {
  position: absolute;
  display: grid;
  place-items: center;
  min-width: 64px;
  height: 64px;
  padding: 0 10px;
  color: var(--ink);
  background: white;
  border-radius: 50%;
  font-family: Georgia, serif;
  font-weight: 700;
  box-shadow: 0 12px 30px rgba(0,0,0,.3);
}
.node-ai { top: 7%; left: 47%; background: var(--violet); }
.node-physics { right: 3%; top: 45%; background: var(--coral); }
.node-math { bottom: 3%; left: 38%; background: var(--lime); }
.node-chemistry { left: 3%; top: 40%; background: var(--cyan); }
.hero-footnote {
  position: absolute;
  z-index: 2;
  left: max(32px, calc((100vw - 1180px) / 2));
  bottom: 35px;
  display: flex;
  align-items: center;
  gap: 20px;
  font-size: 11px;
  color: rgba(255,255,255,.48);
}
.hero-footnote span { color: var(--lime); }
.hero-footnote p { margin: 0; line-height: 1.55; }

.section-shell { width: var(--shell); margin: auto; }
.intro {
  display: grid;
  grid-template-columns: 1fr 3fr;
  gap: 40px;
  padding: 128px 0;
  border-bottom: 1px solid var(--line);
}
.section-kicker { color: #587080; }
.intro h2, .section-heading h2, .method h2, .about h2, .closing h2 {
  margin-bottom: 26px;
  font-size: clamp(36px, 4.2vw, 62px);
  line-height: 1.15;
  letter-spacing: -0.045em;
}
.intro > div { display: grid; grid-template-columns: 2fr 1fr; gap: 60px; align-items: end; }
.intro p:last-child { color: #52606a; font-size: 16px; }

.fields { padding: 120px 0 140px; }
.section-heading { display: flex; justify-content: space-between; align-items: end; gap: 40px; margin-bottom: 60px; }
.section-heading h2 { margin: 0; }
.section-heading > p { max-width: 350px; color: #52606a; }
.field-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 16px; }
.field-card {
  min-height: 390px;
  padding: 34px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  overflow: hidden;
  position: relative;
  border: 1px solid var(--line);
  background: rgba(255,255,255,.38);
  transition: transform 200ms ease, box-shadow 200ms ease;
}
.field-card:hover { transform: translateY(-5px); box-shadow: 0 24px 60px rgba(7,17,31,.09); }
.field-card::after {
  content: "";
  position: absolute;
  right: -80px;
  bottom: -100px;
  width: 240px;
  height: 240px;
  border: 1px solid currentColor;
  border-radius: 50%;
  opacity: .18;
}
.card-top { display: flex; justify-content: space-between; align-items: start; font-size: 12px; }
.card-symbol { font-family: Georgia, serif; font-size: 54px; line-height: 1; }
.field-card h3 { margin-bottom: 10px; font-size: 30px; }
.field-card p { max-width: 450px; color: #3f515e; }
.card-tag { font-size: 11px; letter-spacing: .08em; color: #587080; }
.card-ai { border-top: 4px solid var(--violet); }
.card-physics { border-top: 4px solid var(--coral); }
.card-math { border-top: 4px solid #87bd31; }
.card-chemistry { border-top: 4px solid #24abc5; }

.method { padding: 130px 0; color: white; background: var(--ink); }
.method-inner { display: grid; grid-template-columns: 1fr 1.25fr; gap: 100px; }
.method-copy > p:last-child { max-width: 440px; color: rgba(255,255,255,.56); }
.method-list { margin: 0; padding: 0; list-style: none; }
.method-list li {
  display: grid;
  grid-template-columns: 62px 1fr;
  gap: 20px;
  padding: 30px 0;
  border-top: 1px solid rgba(255,255,255,.18);
}
.method-list li:last-child { border-bottom: 1px solid rgba(255,255,255,.18); }
.method-list li > span { color: var(--cyan); font-size: 12px; }
.method-list h3 { margin-bottom: 8px; font-size: 22px; }
.method-list p { margin: 0; color: rgba(255,255,255,.52); }

.about { display: grid; grid-template-columns: .9fr 1.1fr; gap: 110px; padding: 140px 0; align-items: center; }
.about-mark {
  position: relative;
  display: grid;
  place-items: center;
  aspect-ratio: 1;
  max-width: 440px;
  background: var(--paper-deep);
  border-radius: 50%;
}
.about-mark span { z-index: 2; font-family: Georgia, serif; font-size: 84px; letter-spacing: -.08em; }
.about-mark i { position: absolute; width: 72%; height: 72%; border: 1px solid rgba(7,17,31,.18); border-radius: 50%; }
.about-mark i:nth-of-type(2) { width: 96%; height: 38%; transform: rotate(45deg); border-color: rgba(36,171,197,.5); }
.about-mark i:nth-of-type(3) { width: 96%; height: 38%; transform: rotate(-45deg); border-color: rgba(135,189,49,.5); }
.about-lead { font-size: 20px; font-weight: 700; }
.about-copy > p:not(.section-kicker):not(.about-lead) { color: #52606a; }
.about-values { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 30px; }
.about-values span { padding: 7px 16px; border: 1px solid var(--line); border-radius: 99px; font-size: 13px; }

.closing { padding: 130px 32px; text-align: center; color: white; background: #10243a; }
.closing > p { color: var(--cyan); font-size: 11px; font-weight: 800; letter-spacing: .28em; }
.closing h2 { margin-left: auto; margin-right: auto; }

footer {
  padding: 45px max(32px, calc((100vw - 1180px) / 2));
  display: flex;
  justify-content: space-between;
  align-items: end;
  color: white;
  background: var(--ink);
}
.footer-brand { display: flex; align-items: center; gap: 14px; }
.footer-brand > div { display: flex; flex-direction: column; }
.footer-brand small { color: rgba(255,255,255,.45); font-size: 11px; }
.footer-meta { display: flex; flex-direction: column; align-items: end; gap: 5px; color: rgba(255,255,255,.45); font-size: 11px; }
.footer-meta a:hover { color: white; }

@keyframes spin { to { transform: translate(-50%,-50%) rotate(360deg); } }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .orbit-two { animation: none; }
  *, *::before, *::after { transition-duration: .01ms !important; }
}

@media (max-width: 980px) {
  :root { --shell: min(100% - 40px, 760px); }
  .site-header { grid-template-columns: 1fr auto; }
  nav { display: none; }
  .hero { min-height: 900px; }
  .hero-copy { padding-top: 160px; }
  .hero-visual { top: auto; bottom: -40px; right: -90px; width: 520px; opacity: .65; }
  .intro { grid-template-columns: 1fr; }
  .intro > div { grid-template-columns: 1fr; gap: 10px; }
  .method-inner, .about { grid-template-columns: 1fr; gap: 70px; }
  .about-mark { width: min(100%, 440px); margin: auto; }
}

@media (max-width: 680px) {
  :root { --shell: calc(100% - 32px); }
  .site-header { height: 76px; }
  .brand-text small, .header-cta { display: none; }
  .hero { min-height: 780px; }
  .hero-copy { padding-top: 130px; }
  h1 { font-size: clamp(46px, 14vw, 66px); }
  .hero-lead { font-size: 15px; }
  .hero-actions { align-items: stretch; flex-direction: column; width: min(100%, 320px); }
  .hero-visual { width: 360px; right: -140px; bottom: -10px; }
  .node { min-width: 48px; height: 48px; font-size: 12px; }
  .core { width: 94px; }
  .core span { font-size: 40px; }
  .hero-footnote { display: none; }
  .intro, .fields, .about { padding-top: 90px; padding-bottom: 90px; }
  .section-heading { align-items: start; flex-direction: column; }
  .field-grid { grid-template-columns: 1fr; }
  .field-card { min-height: 340px; padding: 26px; }
  .method { padding: 90px 0; }
  .method-inner { gap: 45px; }
  .about { gap: 50px; }
  .closing { padding: 90px 20px; }
  footer { align-items: start; flex-direction: column; gap: 30px; }
  .footer-meta { align-items: start; }
}