:root {
  --paper: #f3f0e8;
  --paper-deep: #e8e3d8;
  --ink: #161716;
  --graphite: #252523;
  --muted: #65645f;
  --antimony: #8d918e;
  --copper: #a9522e;
  --copper-dark: #7b351f;
  --line: rgba(22, 23, 22, .18);
  --header-h: 94px;
  --gutter: clamp(22px, 4vw, 72px);
}

*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: calc(var(--header-h) + 14px); }
body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: "Noto Sans SC", "Microsoft YaHei", "PingFang SC", Arial, sans-serif;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}
body.menu-open { overflow: hidden; }
img { display: block; width: 100%; height: auto; }
a { color: inherit; }
button, input, textarea { font: inherit; }
button { color: inherit; }
.sr-only {
  position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0, 0, 0, 0); white-space: nowrap; border: 0;
}
.skip-link {
  position: fixed; left: 16px; top: 12px; z-index: 1000; padding: 10px 16px;
  background: var(--ink); color: #fff; transform: translateY(-150%); transition: transform .2s;
}
.skip-link:focus { transform: translateY(0); }
:focus-visible { outline: 3px solid var(--copper); outline-offset: 4px; }

.site-header {
  position: fixed; inset: 0 0 auto; z-index: 100;
  min-height: var(--header-h); padding: 16px var(--gutter);
  display: flex; align-items: center; justify-content: space-between; gap: 30px;
  background: color-mix(in srgb, var(--paper) 92%, transparent);
  border-bottom: 1px solid transparent;
  backdrop-filter: blur(16px);
  transition: border-color .25s, box-shadow .25s;
}
.site-header.is-scrolled { border-color: var(--line); box-shadow: 0 10px 30px rgba(22,23,22,.04); }
.brand { display: inline-flex; align-items: center; gap: 14px; text-decoration: none; min-width: 0; }
.brand-mark { width: 44px; height: 50px; flex: 0 0 auto; color: var(--copper); }
.brand-mark svg { width: 100%; height: 100%; fill: none; stroke: currentColor; stroke-width: 1.2; }
.brand-mark text { fill: currentColor; stroke: none; text-anchor: middle; font-family: Georgia, serif; }
.brand-mark text:first-of-type { font-size: 8px; }
.brand-mark text:last-of-type { font-size: 16px; }
.brand-type { display: grid; line-height: 1.2; }
.brand-type strong { font-family: Georgia, "Noto Serif SC", "Songti SC", serif; font-size: 17px; font-weight: 500; letter-spacing: .02em; }
.brand-type small { margin-top: 5px; font-size: 8px; letter-spacing: .12em; color: var(--muted); }
.site-nav { display: flex; align-items: center; gap: clamp(18px, 2vw, 34px); }
.site-nav a { position: relative; font-size: 13px; text-decoration: none; white-space: nowrap; }
.site-nav a:not(.nav-contact)::after {
  content: ""; position: absolute; left: 0; right: 100%; bottom: -6px; height: 1px; background: var(--copper); transition: right .2s;
}
.site-nav a:hover::after, .site-nav a[aria-current="true"]::after { right: 0; }
.nav-contact { padding: 9px 14px; border: 1px solid var(--ink); }
.menu-toggle { display: none; border: 0; background: transparent; width: 46px; height: 46px; padding: 12px; }
.menu-toggle span:not(.sr-only) { display: block; height: 1px; background: var(--ink); margin: 7px 0; transition: transform .2s; }

main { overflow: clip; }
.hero {
  position: relative; min-height: 100svh; padding: calc(var(--header-h) + 56px) var(--gutter) 80px;
  display: grid; grid-template-columns: minmax(310px, .82fr) minmax(480px, 1.55fr); align-items: center; gap: clamp(40px, 6vw, 110px);
  border-bottom: 1px solid var(--line);
}
.hero-copy { position: relative; z-index: 2; }
.eyebrow { margin: 0 0 24px; font-size: 11px; letter-spacing: .18em; font-weight: 700; color: var(--copper-dark); }
h1, h2, h3 { margin: 0; font-family: Georgia, "Noto Serif SC", "Songti SC", serif; font-weight: 500; }
h1 { font-size: clamp(58px, 6vw, 106px); line-height: .98; letter-spacing: -.055em; }
.hero-lead { max-width: 560px; margin: 34px 0 0; font-size: clamp(16px, 1.25vw, 20px); color: var(--muted); }
.hero-actions { margin-top: 34px; display: flex; align-items: center; gap: 28px; }
.button { display: inline-flex; min-height: 48px; align-items: center; justify-content: center; padding: 10px 20px; border: 1px solid var(--ink); text-decoration: none; cursor: pointer; }
.button-solid { background: var(--ink); color: #fff; transition: background .2s, border-color .2s; }
.button-solid:hover { background: var(--copper-dark); border-color: var(--copper-dark); }
.text-link { font-size: 14px; text-underline-offset: 5px; }
.hero-meta { margin: 54px 0 0; padding-top: 18px; border-top: 1px solid var(--line); display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
.hero-meta div { min-width: 0; }
.hero-meta dt { font-size: 10px; letter-spacing: .1em; color: var(--muted); }
.hero-meta dd { margin: 5px 0 0; font-family: Georgia, serif; font-size: 16px; }
.hero-visual { margin: 0; align-self: stretch; position: relative; min-height: 620px; }
.hero-visual img { width: 100%; height: 100%; object-fit: cover; object-position: center; filter: saturate(.8); }
.hero-visual figcaption { position: absolute; inset: auto 0 0; padding: 16px 18px; display: flex; justify-content: space-between; background: var(--graphite); color: #fff; font-size: 10px; letter-spacing: .08em; }
.path-line { position: absolute; pointer-events: none; }
.path-line-hero { left: calc(var(--gutter) + 24%); bottom: -65px; width: 34%; height: 130px; border-left: 2px solid var(--copper); border-bottom: 2px solid var(--copper); border-radius: 0 0 0 64px; }
.path-line-hero i { position: absolute; left: -5px; top: -4px; width: 8px; height: 8px; border: 2px solid var(--copper); border-radius: 50%; background: var(--paper); }

.materials, .technology, .applications, .about { position: relative; padding: clamp(110px, 12vw, 190px) var(--gutter); }
.materials { padding-top: clamp(140px, 15vw, 220px); }
.section-index { position: absolute; left: var(--gutter); top: clamp(78px, 8vw, 120px); width: 130px; }
.section-index span { display: block; font-family: Georgia, serif; font-size: 56px; line-height: 1; color: var(--copper); }
.section-index p { margin: 12px 0 0; padding-top: 10px; border-top: 1px solid var(--copper); font-family: Georgia, "Songti SC", serif; font-size: 20px; }
.section-intro { margin-left: min(24vw, 330px); display: grid; grid-template-columns: minmax(340px, 1.2fr) minmax(280px, .8fr); align-items: end; gap: 60px; }
.section-intro .eyebrow { grid-column: 1 / -1; margin-bottom: -10px; }
h2 { font-size: clamp(43px, 5.2vw, 78px); line-height: 1.08; letter-spacing: -.045em; }
.section-intro > p:last-child, .applications-head > p { margin: 0; color: var(--muted); font-size: 16px; }
.product-ledger { margin-top: clamp(80px, 9vw, 140px); border-top: 1px solid var(--ink); }
.product-entry { min-height: 470px; display: grid; grid-template-columns: 100px minmax(250px, .72fr) minmax(420px, 1.28fr); gap: clamp(24px, 4vw, 70px); align-items: center; padding: 42px 0; border-bottom: 1px solid var(--line); }
.product-entry-reverse { grid-template-columns: 100px minmax(420px, 1.28fr) minmax(250px, .72fr); }
.product-entry-reverse .product-copy { grid-column: 3; }
.product-entry-reverse figure { grid-column: 2; grid-row: 1; }
.product-number { align-self: start; padding-top: 10px; color: var(--copper-dark); font-size: 11px; letter-spacing: .16em; }
.product-copy h3 { font-size: clamp(34px, 3vw, 50px); }
.product-copy p { max-width: 410px; margin: 20px 0; color: var(--muted); }
.product-copy a { font-size: 13px; text-underline-offset: 6px; }
.product-entry figure { margin: 0; height: 390px; overflow: hidden; }
.product-entry img { height: 100%; object-fit: cover; transition: transform .6s cubic-bezier(.2,.7,.2,1); }
.product-entry:hover img { transform: scale(1.025); }

.technology { background: var(--graphite); color: #f5f2e9; }
.technology .eyebrow, .technology .section-index span { color: #d78b63; }
.technology .section-index p { color: #f5f2e9; }
.technology-stage { margin-left: min(24vw, 330px); display: grid; grid-template-columns: minmax(320px, .8fr) minmax(440px, 1.2fr); gap: 58px; }
.technology-copy p:last-child { max-width: 540px; color: #c9c7c0; }
.technology-visual { grid-column: 2; grid-row: 1 / span 2; margin: 0; min-height: 570px; }
.technology-visual img { height: 100%; object-fit: cover; }
.technology-steps { grid-column: 1; margin: 44px 0 0; padding: 0; list-style: none; border-top: 1px solid rgba(255,255,255,.22); }
.technology-steps li { display: grid; grid-template-columns: 54px 1fr; gap: 20px; padding: 22px 0; border-bottom: 1px solid rgba(255,255,255,.15); }
.technology-steps li > span { color: #d78b63; font-family: Georgia, serif; }
.technology-steps h3 { font-size: 21px; }
.technology-steps p { margin: 5px 0 0; color: #aba9a3; font-size: 13px; }
.technology-note { grid-column: 1 / -1; display: flex; align-items: baseline; gap: 30px; padding-top: 34px; border-top: 1px solid rgba(255,255,255,.22); }
.technology-note strong { font-size: 12px; letter-spacing: .12em; color: #d78b63; }
.technology-note p { margin: 0; color: #c9c7c0; }
.technology-note p span { color: #fff; font-family: Georgia, serif; font-size: 36px; margin-right: 5px; }
.technology-note small { margin-left: auto; color: #b8b6b0; }

.applications { background: #eae6dc; }
.applications-head { margin-left: min(24vw, 330px); display: grid; grid-template-columns: 1.3fr .7fr; gap: 60px; align-items: end; }
.application-panorama { margin: clamp(70px, 8vw, 120px) 0 0 min(12vw, 170px); height: min(54vw, 690px); min-height: 440px; }
.application-panorama img { height: 100%; object-fit: cover; }
.application-list { margin-left: min(12vw, 170px); display: grid; grid-template-columns: repeat(4, 1fr); border-bottom: 1px solid var(--ink); }
.application-list > div { padding: 26px 24px 34px 0; border-top: 1px solid var(--ink); }
.application-list > div + div { padding-left: 24px; border-left: 1px solid var(--line); }
.application-list span { font-size: 10px; letter-spacing: .12em; color: var(--copper-dark); }
.application-list h3 { margin-top: 16px; font-size: 25px; }
.application-list p { margin: 6px 0 0; color: var(--muted); font-size: 13px; }

.about { display: grid; grid-template-columns: minmax(190px, .42fr) minmax(360px, .9fr) minmax(360px, 1fr); gap: 60px; }
.about .section-index { position: static; width: 130px; }
.about-statement { grid-column: 2; }
.about-copy { grid-column: 3; padding-top: 48px; color: var(--muted); font-size: 17px; }
.about-copy p { margin: 0 0 24px; }
.about-facts { grid-column: 2 / 4; margin: 70px 0 0; display: grid; grid-template-columns: repeat(4, 1fr); border-top: 1px solid var(--ink); border-bottom: 1px solid var(--ink); }
.about-facts div { padding: 28px 20px 28px 0; }
.about-facts div + div { padding-left: 20px; border-left: 1px solid var(--line); }
.about-facts dt { font-family: Georgia, serif; font-size: clamp(30px, 3vw, 46px); }
.about-facts dd { margin: 6px 0 0; color: var(--muted); font-size: 12px; }

.contact { position: relative; min-height: 760px; padding: 110px var(--gutter); display: grid; grid-template-columns: 1fr 1fr; gap: clamp(50px, 8vw, 130px); align-items: center; overflow: hidden; }
.contact::after { content: ""; position: absolute; inset: 0; background: linear-gradient(90deg, rgba(243,240,232,.96) 0 51%, rgba(243,240,232,.72) 100%); }
.contact-background { position: absolute; inset: 0; margin: 0; }
.contact-background img { height: 100%; object-fit: cover; }
.contact-heading, .contact-form { position: relative; z-index: 2; }
.contact-heading h2 { max-width: 650px; }
.contact-heading > p:last-of-type { max-width: 520px; color: var(--muted); }
address { margin-top: 40px; display: grid; gap: 9px; font-style: normal; }
address a { width: fit-content; font-size: 17px; text-underline-offset: 5px; }
address span { margin-top: 10px; color: var(--muted); }
.contact-form { padding: clamp(26px, 4vw, 52px); background: rgba(243,240,232,.9); border: 1px solid rgba(22,23,22,.35); backdrop-filter: blur(10px); }
.contact-form label { display: grid; gap: 7px; margin-bottom: 20px; font-size: 12px; letter-spacing: .08em; }
.field-row { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
.contact-form input, .contact-form textarea { width: 100%; padding: 10px 0; border: 0; border-bottom: 1px solid var(--ink); border-radius: 0; background: transparent; resize: vertical; }
.contact-form input:focus, .contact-form textarea:focus { outline: 0; border-bottom-color: var(--copper); box-shadow: 0 1px 0 var(--copper); }
.contact-form .button { margin-top: 8px; width: 100%; }
.form-status { min-height: 28px; margin: 14px 0 0; color: var(--copper-dark); font-size: 13px; }

.site-footer { min-height: 170px; padding: 46px var(--gutter); display: grid; grid-template-columns: 1fr auto; align-items: start; gap: 30px; background: var(--ink); color: #fff; }
.footer-brand { display: grid; gap: 7px; }
.footer-brand strong { font-family: Georgia, serif; font-size: 28px; font-weight: 500; letter-spacing: .08em; }
.footer-brand span { color: #aaa9a4; font-size: 12px; }
.footer-meta { display: flex; gap: 24px; }
.footer-meta a { color: #d2d0c9; font-size: 12px; text-underline-offset: 5px; }
.site-footer > p { grid-column: 1 / -1; margin: 14px 0 0; padding-top: 18px; border-top: 1px solid rgba(255,255,255,.15); color: #8d8b86; font-size: 11px; }

.reveal { opacity: 0; transform: translateY(24px); transition: opacity .7s ease, transform .7s cubic-bezier(.2,.7,.2,1); }
.reveal-delay { transition-delay: .12s; }
.reveal.is-visible { opacity: 1; transform: none; }

@media (max-width: 1080px) {
  :root { --header-h: 82px; }
  .brand-type strong { font-size: 15px; }
  .brand-type small { display: none; }
  .site-nav { gap: 16px; }
  .hero { grid-template-columns: .82fr 1.18fr; gap: 38px; }
  .hero-visual { min-height: 520px; }
  .section-intro, .technology-stage, .applications-head { margin-left: 190px; }
  .product-entry, .product-entry-reverse { grid-template-columns: 70px minmax(230px,.7fr) minmax(350px,1.3fr); gap: 28px; }
  .technology-stage { grid-template-columns: 1fr; }
  .technology-visual { grid-column: 1; grid-row: auto; min-height: 460px; }
  .technology-steps { grid-column: 1; }
  .about { grid-template-columns: 140px 1fr 1fr; gap: 36px; }
}

@media (max-width: 820px) {
  :root { --header-h: 76px; --gutter: 22px; }
  .site-header { min-height: var(--header-h); padding-top: 11px; padding-bottom: 11px; }
  .brand-mark { width: 37px; height: 42px; }
  .site-header.menu-active { height: 100svh; align-items: flex-start; }
  .site-header.menu-active .brand { position: relative; z-index: 2; }
  .brand-type strong { font-size: 14px; max-width: 230px; }
  .menu-toggle { display: block; position: relative; z-index: 2; }
  .menu-toggle[aria-expanded="true"] span:nth-child(2) { transform: translateY(4px) rotate(45deg); }
  .menu-toggle[aria-expanded="true"] span:nth-child(3) { transform: translateY(-4px) rotate(-45deg); }
  .site-nav { position: absolute; inset: 0; z-index: 1; display: none; align-content: center; justify-content: center; flex-direction: column; gap: 28px; padding: 92px 22px 42px; background: var(--paper); }
  .site-nav.is-open { display: flex; }
  .site-nav a { font-family: Georgia, "Songti SC", serif; font-size: 27px; }
  .nav-contact { padding: 10px 22px; }

  .hero { min-height: auto; padding-top: calc(var(--header-h) + 42px); grid-template-columns: 1fr; gap: 44px; }
  h1 { font-size: clamp(54px, 16vw, 78px); }
  .hero-lead { margin-top: 24px; }
  .hero-actions { align-items: flex-start; flex-direction: column; gap: 20px; }
  .hero-meta { margin-top: 42px; }
  .hero-visual { min-height: 440px; }
  .path-line-hero { display: none; }

  .materials, .technology, .applications, .about { padding: 100px var(--gutter); }
  .section-index { position: static; width: 94px; margin-bottom: 48px; }
  .section-index span { font-size: 44px; }
  .section-index p { font-size: 17px; }
  .section-intro, .technology-stage, .applications-head { margin-left: 0; grid-template-columns: 1fr; gap: 24px; }
  .section-intro .eyebrow { grid-column: 1; margin-bottom: 0; }
  h2 { font-size: clamp(40px, 12vw, 62px); }
  .product-ledger { margin-top: 70px; }
  .product-entry, .product-entry-reverse { grid-template-columns: 42px 1fr; min-height: 0; padding: 36px 0 48px; }
  .product-entry .product-copy, .product-entry-reverse .product-copy { grid-column: 2; grid-row: 1; }
  .product-entry figure, .product-entry-reverse figure { grid-column: 1 / -1; grid-row: 2; height: min(78vw, 470px); }
  .product-number { grid-column: 1; grid-row: 1; }
  .technology-visual { min-height: 390px; }
  .technology-note { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
  .technology-note strong, .technology-note small { grid-column: 1 / -1; }
  .technology-note small { margin-left: 0; }
  .application-panorama { margin: 60px 0 0; min-height: 390px; }
  .application-list { margin-left: 0; grid-template-columns: 1fr 1fr; }
  .application-list > div + div { padding-left: 0; border-left: 0; }
  .application-list > div:nth-child(even) { padding-left: 18px; border-left: 1px solid var(--line); }
  .about { grid-template-columns: 1fr; }
  .about .section-index, .about-statement, .about-copy, .about-facts { grid-column: 1; }
  .about-copy { padding-top: 0; }
  .about-facts { grid-template-columns: 1fr 1fr; margin-top: 34px; }
  .about-facts div:nth-child(3) { border-left: 0; border-top: 1px solid var(--line); padding-left: 0; }
  .about-facts div:nth-child(4) { border-top: 1px solid var(--line); }
  .contact { min-height: auto; padding-top: 100px; padding-bottom: 100px; grid-template-columns: 1fr; }
  .contact::after { background: rgba(243,240,232,.9); }
  .contact-form { padding: 24px; }
  .field-row { grid-template-columns: 1fr; gap: 0; }
  .site-footer { grid-template-columns: 1fr; }
  .footer-meta { flex-wrap: wrap; }
}

@media (max-width: 420px) {
  .brand-type strong { max-width: 190px; font-size: 12px; }
  .hero-meta { grid-template-columns: 1fr 1fr; }
  .hero-meta div:last-child { grid-column: 1 / -1; }
  .hero-visual { min-height: 360px; }
  .technology-note { grid-template-columns: 1fr; }
  .technology-note strong, .technology-note small { grid-column: 1; }
  .application-list { grid-template-columns: 1fr; }
  .application-list > div:nth-child(even) { padding-left: 0; border-left: 0; }
  .about-facts { grid-template-columns: 1fr; }
  .about-facts div + div { padding-left: 0; border-left: 0; border-top: 1px solid var(--line); }
}

@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; }
}