:root {
  --ink: #1d1b19;
  --muted: #6b665e;
  --paper: #f7f4ed;
  --paper-deep: #ebe6dc;
  --white: #fffdf9;
  --line: #d9d1c5;
  --gold: #9b7c4a;
  --gold-soft: #d5c4a3;
  --night: #161512;
  --max: 1180px;
  --reading: 740px;
  --radius: 4px;
  --shadow: 0 22px 50px rgba(27, 24, 19, 0.09);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", Arial, sans-serif;
  font-size: 16px;
  line-height: 1.78;
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; }
img { display: block; max-width: 100%; }
h1, h2, h3, p { margin-top: 0; }
h1, h2, h3 { font-family: "Songti SC", "STSong", "Noto Serif SC", serif; font-weight: 500; }

.site-header {
  position: sticky;
  z-index: 20;
  top: 0;
  border-bottom: 1px solid rgba(217, 209, 197, 0.85);
  background: rgba(247, 244, 237, 0.94);
  backdrop-filter: blur(14px);
}
.nav-shell, .section-shell, .hero-shell, .footer-shell, .footer-bottom {
  width: min(calc(100% - 48px), var(--max));
  margin: 0 auto;
}
.nav-shell { display: flex; min-height: 82px; align-items: center; gap: 28px; justify-content: space-between; }
.brand { display: inline-flex; align-items: center; text-decoration: none; }
.brand-logo { width: 142px; height: auto; max-height: 51px; object-fit: contain; }
.nav-links { display: flex; align-items: center; gap: 2px; }
.nav-links a { padding: 9px 11px; color: #514c45; font-size: 14px; letter-spacing: 0.02em; text-decoration: none; }
.nav-links a:hover, .nav-links a[aria-current="page"] { color: var(--ink); }
.nav-links .nav-cta { margin-left: 10px; padding: 9px 15px; border: 1px solid var(--ink); color: var(--ink); }
.menu-button { display: none; width: 42px; height: 42px; border: 1px solid var(--line); color: var(--ink); background: transparent; font: inherit; white-space: nowrap; }

.hero { position: relative; overflow: hidden; padding: clamp(74px, 10vw, 140px) 0 86px; background: var(--paper); }
.hero-grid { display: grid; grid-template-columns: minmax(0, 0.93fr) minmax(360px, 0.72fr); align-items: center; gap: clamp(48px, 8vw, 116px); }
.page-hero { padding: clamp(72px, 10vw, 126px) 0 clamp(54px, 8vw, 92px); background: var(--paper); }
.page-hero .hero-shell { max-width: calc(var(--reading) + 48px); margin-left: max(24px, calc((100% - var(--max)) / 2)); }
.eyebrow { margin-bottom: 18px; color: var(--gold); font-size: 11px; font-weight: 700; letter-spacing: 0.18em; text-transform: uppercase; }
.hero h1, .page-hero h1 { max-width: 760px; margin-bottom: 24px; font-size: clamp(42px, 6vw, 78px); line-height: 1.14; letter-spacing: -0.045em; }
.page-hero h1 { font-size: clamp(38px, 5vw, 64px); }
.hero-lede { max-width: 660px; margin-bottom: 0; color: var(--muted); font-size: clamp(16px, 1.7vw, 18px); }
.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 32px; }
.button { display: inline-flex; min-height: 48px; align-items: center; justify-content: center; padding: 11px 22px; border: 1px solid var(--ink); color: var(--ink); font-size: 14px; font-weight: 650; text-decoration: none; transition: color .25s ease, background .25s ease, transform .25s ease; }
.button:hover { transform: translateY(-2px); }
.button-primary { color: var(--white); background: var(--ink); }
.button-primary:hover { background: #3a3732; }
.button-secondary { background: transparent; }

.hero-object { position: relative; min-height: 430px; overflow: hidden; border: 1px solid var(--line); background: #d8d0c1; box-shadow: var(--shadow); }
.hero-object::before, .hero-object::after { position: absolute; border-radius: 50%; content: ""; }
.hero-object::before { top: 15%; left: 18%; width: 58%; aspect-ratio: 1; border: 1px solid rgba(29, 27, 25, .56); box-shadow: 0 0 0 28px rgba(247,244,237,.24), 0 0 0 92px rgba(247,244,237,.14); }
.hero-object::after { right: -10%; bottom: -18%; width: 58%; aspect-ratio: 1; border: 1px solid rgba(29, 27, 25, .28); }
.hero-object .logo-study { position: absolute; z-index: 2; right: 10%; bottom: 12%; width: min(64%, 300px); padding: 24px; background: rgba(255, 253, 249, .92); }
.logo-study img { width: 100%; height: auto; }
.object-caption { position: absolute; z-index: 3; top: 25px; left: 25px; color: rgba(29,27,25,.76); font-size: 11px; letter-spacing: .15em; text-transform: uppercase; }
.hero-object--product { background: #ded8cc; }
.hero-object--product::before, .hero-object--product::after { display: none; }
.hero-product-image { position: absolute; inset: 0; width: 100%; height: 100%; object-fit: cover; }
.hero-product-note { position: absolute; z-index: 3; right: 24px; bottom: 22px; padding: 7px 10px; color: rgba(255,255,255,.92); background: rgba(29,27,25,.72); font-size: 10px; letter-spacing: .14em; }

/* Approved CHIHAO GEO Design System v1.0 homepage hero. */
.hero-v3 { padding: 38px 0; }
.hero-v3-grid {
  min-height: 544px;
  display: grid;
  grid-template-columns: minmax(0, .82fr) minmax(570px, 1.18fr);
  grid-template-rows: auto auto 1fr auto;
  grid-template-areas:
    "eyebrow media"
    "title media"
    "lede media"
    "meta media";
  column-gap: 62px;
  align-items: start;
}
.hero-v3-grid > * { min-width: 0; }
.hero-v3-eyebrow { grid-area: eyebrow; margin-bottom: 17px; color: #c97545; font-size: 13px; letter-spacing: .12em; text-transform: none; }
.hero-v3 .hero-v3-title { grid-area: title; max-width: 560px; margin: 0 0 24px; font-size: 51px; line-height: 1.19; letter-spacing: -.035em; font-weight: 600; overflow-wrap: anywhere; text-wrap: balance; }
.hero-v3-lede { grid-area: lede; max-width: 530px; font-size: 18px; line-height: 1.82; color: #55514d; }
.hero-v3-meta { grid-area: meta; align-self: end; margin-top: 38px; padding-top: 19px; border-top: 1px solid var(--line); color: #6b6b68; font-size: 14px; }
.hero-v3-media { grid-area: media; height: 544px; margin: 0; overflow: hidden; }
.hero-v3-media img { width: 100%; height: 100%; object-fit: cover; object-position: 50% 48%; }

.section { padding: clamp(68px, 9vw, 120px) 0; }
.section-dark { color: var(--white); background: var(--night); }
.section-soft { background: var(--paper-deep); }
.section-shell.narrow { max-width: var(--reading); }
.section-heading { display: grid; grid-template-columns: minmax(0, .78fr) minmax(220px, .32fr); gap: 42px; align-items: end; margin-bottom: 44px; }
.section-heading h2, .feature-copy h2 { margin-bottom: 0; font-size: clamp(32px, 4.2vw, 54px); line-height: 1.18; letter-spacing: -.04em; }
.section-note { margin: 0; color: var(--muted); font-size: 15px; }
.section-dark .section-note, .section-dark .card p { color: rgba(255,255,255,.68); }

.stat-line { display: grid; grid-template-columns: repeat(4, 1fr); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.stat-line div { min-height: 126px; padding: 22px 20px; border-left: 1px solid var(--line); }
.stat-line div:first-child { border-left: 0; }
.stat-line strong { display: block; margin-bottom: 8px; font-family: "Songti SC", "STSong", serif; font-size: 28px; font-weight: 500; }
.stat-line span { color: var(--muted); font-size: 13px; }

.card-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 24px; }
.card-grid.two { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.card { min-height: 100%; padding: 30px; border-top: 1px solid var(--ink); background: rgba(255,253,249,.7); }
.section-soft .card { background: rgba(255,253,249,.52); }
.card h3 { margin-bottom: 13px; font-size: 26px; line-height: 1.25; }
.card p, .card li { color: var(--muted); }
.card a:not(.button) { display: inline-block; margin-top: 12px; color: var(--ink); font-size: 14px; font-weight: 650; text-decoration: none; }
.card a:not(.button)::after, .text-link::after { margin-left: 8px; content: "→"; }
.card-index { display: block; margin-bottom: 46px; color: var(--gold); font-size: 11px; letter-spacing: .16em; }
.list-clean { margin: 10px 0 0; padding: 0; list-style: none; }
.list-clean li { padding: 11px 0; border-top: 1px solid var(--line); }
.list-clean li:first-child { border-top: 0; }

.product-gallery { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 16px; }
.product-gallery--rimless { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.product-figure { margin: 0; overflow: hidden; border: 1px solid var(--line); background: var(--white); }
.product-figure img { width: 100%; aspect-ratio: 1; object-fit: cover; background: #e7e1d6; transition: transform .35s ease; }
.product-figure:hover img { transform: scale(1.025); }
.product-figure figcaption, .feature-media figcaption { padding: 13px 15px 15px; color: var(--muted); font-size: 12px; line-height: 1.55; }

.feature-split { display: grid; grid-template-columns: minmax(0, .9fr) minmax(330px, .72fr); gap: clamp(44px, 8vw, 112px); align-items: center; }
.feature-copy p { max-width: 650px; margin-top: 22px; color: var(--muted); }
.material-panel { min-height: 410px; position: relative; overflow: hidden; background: #c6bdad; }
.material-panel::before { position: absolute; top: 12%; right: 12%; width: 58%; aspect-ratio: 1; border: 1px solid rgba(29,27,25,.46); border-radius: 50%; box-shadow: -80px 110px 0 -76px rgba(29,27,25,.75), -1px 1px 0 34px rgba(255,253,249,.17); content: ""; }
.material-panel::after { position: absolute; bottom: 24px; left: 24px; color: rgba(29,27,25,.72); font-size: 11px; letter-spacing: .15em; content: "MATERIAL · STRUCTURE · FIT"; }
.feature-media { margin: 0; overflow: hidden; background: var(--white); box-shadow: var(--shadow); }
.feature-media img { width: 100%; min-height: 410px; object-fit: cover; }

.process { display: grid; grid-template-columns: repeat(4, 1fr); border-top: 1px solid var(--line); }
.process-step { padding: 24px 24px 10px 0; border-right: 1px solid var(--line); }
.process-step + .process-step { padding-left: 24px; }
.process-step:last-child { border-right: 0; }
.process-step span { display: block; margin-bottom: 30px; color: var(--gold); font-size: 11px; letter-spacing: .15em; }
.process-step h3 { font-size: 23px; }
.process-step p { color: var(--muted); }

.quote-panel { max-width: 850px; padding: 54px; border-left: 2px solid var(--gold); background: var(--white); }
.quote-panel p { margin: 0; font-family: "Songti SC", "STSong", serif; font-size: clamp(24px, 3vw, 37px); line-height: 1.46; }
.quote-panel small { display: block; margin-top: 20px; color: var(--muted); font-size: 13px; }

.contact-panel { display: grid; grid-template-columns: repeat(2, 1fr); border-top: 1px solid var(--line); }
.contact-item { min-height: 142px; padding: 22px 28px 22px 0; border-bottom: 1px solid var(--line); }
.contact-item:nth-child(even) { padding-right: 0; padding-left: 28px; border-left: 1px solid var(--line); }
.contact-label { display: block; margin-bottom: 9px; color: var(--gold); font-size: 11px; letter-spacing: .14em; }
.contact-value { color: var(--ink); font-size: 20px; text-decoration: none; }

.accordion { display: grid; gap: 0; border-top: 1px solid var(--line); }
.accordion details { border-bottom: 1px solid var(--line); }
.accordion summary { display: flex; align-items: center; justify-content: space-between; padding: 20px 0; cursor: pointer; font-family: "Songti SC", "STSong", serif; font-size: 23px; list-style: none; }
.accordion summary::-webkit-details-marker { display: none; }
.accordion summary::after { color: var(--gold); font-family: Arial, sans-serif; font-size: 24px; content: "+"; }
.accordion details[open] summary::after { content: "−"; }
.accordion details p, .accordion details ul { max-width: var(--reading); margin: 0; padding: 0 0 22px; color: var(--muted); }

.evidence-table { width: 100%; border-collapse: collapse; background: var(--white); }
.evidence-table th, .evidence-table td { padding: 17px 15px; border-bottom: 1px solid var(--line); text-align: left; vertical-align: top; }
.evidence-table th { color: var(--gold); font-size: 11px; letter-spacing: .11em; text-transform: uppercase; }
.evidence-table td { color: var(--muted); }
.evidence-table td:first-child, .evidence-table td:nth-child(2) { color: var(--ink); }

.small-print { max-width: var(--reading); margin: 28px 0 0; color: var(--muted); font-size: 13px; }
.breadcrumb { margin-bottom: 26px; color: var(--muted); font-size: 13px; }
.breadcrumb a { text-decoration: none; }
.site-footer { padding: 64px 0 34px; color: rgba(255,255,255,.7); background: var(--night); }
.footer-shell { display: grid; grid-template-columns: 1.1fr 1fr; gap: 64px; }
.footer-title { color: var(--white); font-family: "Songti SC", "STSong", serif; font-size: 28px; }
.footer-columns { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; }
.footer-columns strong { display: block; margin-bottom: 12px; color: var(--gold-soft); font-size: 11px; letter-spacing: .14em; }
.footer-links { display: grid; gap: 7px; }
.footer-links a { color: rgba(255,255,255,.75); font-size: 14px; text-decoration: none; }
.footer-bottom { margin-top: 52px; padding-top: 18px; border-top: 1px solid rgba(255,255,255,.16); color: rgba(255,255,255,.45); font-size: 12px; }

@media (max-width: 1180px) {
  .hero-v3-grid { grid-template-columns: minmax(0, .88fr) minmax(460px, 1.12fr); column-gap: 38px; }
  .hero-v3 .hero-v3-title { font-size: clamp(38px, 4.2vw, 46px); }
}
@media (max-width: 960px) {
  .nav-shell { position: relative; min-height: 70px; }
  .menu-button { display: inline-grid; width: auto; min-width: 58px; padding: 0 14px; place-items: center; }
  .nav-links { position: absolute; top: calc(100% - 1px); right: 0; left: 0; display: none; padding: 16px 24px 22px; border-bottom: 1px solid var(--line); background: var(--paper); }
  .nav-links[data-open="true"] { display: grid; }
  .nav-links a { padding: 10px 0; }
  .nav-links .nav-cta { width: max-content; margin: 10px 0 0; padding: 9px 15px; }
  .hero-grid, .feature-split, .section-heading, .footer-shell { grid-template-columns: 1fr; }
  .hero-object { max-width: 620px; min-height: 380px; }
  .footer-columns { max-width: 680px; }
  .hero-v3 { padding: 34px 0 42px; }
  .hero-v3-grid {
    min-height: 0;
    grid-template-columns: 1fr;
    grid-template-rows: auto;
    grid-template-areas: "eyebrow" "title" "lede" "media" "meta";
    column-gap: 0;
  }
  .hero-v3-eyebrow { margin: 0 0 14px; }
  .hero-v3 .hero-v3-title { max-width: 760px; margin: 0 0 20px; font-size: clamp(40px, 5.8vw, 50px); line-height: 1.16; }
  .hero-v3-lede { max-width: 700px; margin: 0 0 28px; font-size: 18px; line-height: 1.72; }
  .hero-v3-media { width: 100%; height: auto; aspect-ratio: 16 / 9; }
  .hero-v3-meta { align-self: auto; margin: 20px 0 0; padding-top: 17px; }
}
@media (max-width: 700px) {
  .nav-shell, .section-shell, .hero-shell, .footer-shell, .footer-bottom { width: min(calc(100% - 32px), var(--max)); }
  .brand-logo { width: 130px; height: auto; max-height: 47px; }
  .hero { padding-top: 72px; }
  .hero h1, .page-hero h1 { font-size: clamp(38px, 11vw, 58px); line-height: 1.16; }
  .card-grid, .card-grid.two, .stat-line, .process, .contact-panel, .footer-columns { grid-template-columns: 1fr; }
  .stat-line div, .process-step, .process-step + .process-step, .contact-item, .contact-item:nth-child(even) { padding: 20px 0; border-right: 0; border-left: 0; }
  .stat-line div { min-height: auto; border-left: 0; border-top: 1px solid var(--line); }
  .stat-line div:first-child { border-top: 0; }
  .process-step { border-right: 0; border-top: 1px solid var(--line); }
  .process-step:first-child { border-top: 0; }
  .hero-object, .material-panel { min-height: 320px; }
  .product-gallery, .product-gallery--rimless { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .feature-media img { min-height: 320px; }
  .quote-panel { padding: 32px 24px; }
  .evidence-table { display: block; overflow-x: auto; }
  .evidence-table th, .evidence-table td { min-width: 150px; }
  .hero-v3 { padding: 28px 0 32px; }
  .hero-v3-grid {
    min-height: 0;
    grid-template-columns: 1fr;
    grid-template-rows: auto;
    grid-template-areas: "eyebrow" "title" "lede" "media" "meta";
    column-gap: 0;
  }
  .hero-v3-eyebrow { margin: 0 0 14px; }
  .hero-v3 .hero-v3-title { max-width: none; margin: 0 0 20px; font-size: clamp(34px, 9.5vw, 40px); line-height: 1.18; }
  .hero-v3-lede { max-width: none; margin: 0 0 25px; font-size: 17px; line-height: 1.75; }
  .hero-v3-media { height: auto; aspect-ratio: 4 / 3; }
  .hero-v3-meta { align-self: auto; margin: 19px 0 0; padding-top: 17px; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition-duration: .01ms !important; }
}