:root {
  --ink: #181917;
  --paper: #f7f7f3;
  --white: #fff;
  --muted: #666b65;
  --teal: #1e7773;
  --moss: #465c4b;
  --line: rgba(24, 25, 23, .16);
  --header-h: 68px;
  --content: 1240px;
}

* { box-sizing: border-box; }
html { scroll-behavior: auto; }
body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  line-height: 1.75;
  text-rendering: optimizeLegibility;
}
body.menu-open { overflow: hidden; }
a { color: inherit; text-decoration: none; }
button { color: inherit; font: inherit; }
img { display: block; width: 100%; height: auto; }
.shell { width: min(calc(100% - 48px), var(--content)); margin: 0 auto; }

.site-header {
  position: sticky;
  top: 0;
  z-index: 40;
  height: var(--header-h);
  border-bottom: 1px solid var(--line);
  background: rgba(247, 247, 243, .95);
  backdrop-filter: blur(14px);
}
.nav {
  height: 100%;
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: 24px;
}
.brand { display: inline-flex; align-items: center; gap: 10px; width: fit-content; font-weight: 700; line-height: 1.15; }
.brand-logo { width: 30px; height: 48px; object-fit: contain; }
.brand small {
  display: block;
  margin-top: 2px;
  color: var(--muted);
  font-family: Georgia, serif;
  font-size: 9px;
  font-weight: 400;
  text-transform: uppercase;
}
.nav-links { display: flex; align-items: center; gap: 30px; font-size: 13px; }
.nav-links a { position: relative; }
.nav-links a::after {
  content: "";
  position: absolute;
  right: 0;
  bottom: -8px;
  left: 0;
  height: 1px;
  background: currentColor;
  transform: scaleX(0);
  transform-origin: right;
  transition: transform 180ms ease;
}
.nav-links a:hover::after, .nav-links a[aria-current="page"]::after { transform: scaleX(1); transform-origin: left; }
.nav-action { justify-self: end; }
.mobile-nav { display: none; }

.button {
  display: inline-flex;
  min-height: 42px;
  align-items: center;
  justify-content: center;
  padding: 10px 18px;
  border: 1px solid var(--ink);
  border-radius: 3px;
  background: transparent;
  cursor: pointer;
  font-size: 13px;
  font-weight: 700;
  transition: background-color 180ms ease, color 180ms ease, transform 180ms ease;
}
.button:hover { color: var(--white); background: var(--ink); transform: translateY(-2px); }
.button-dark { color: var(--white); background: var(--ink); }
.button-dark:hover { background: var(--moss); }
.button-light { color: var(--white); border-color: rgba(255,255,255,.8); }
.button-light:hover { color: var(--ink); background: var(--white); }

.service-hero {
  position: relative;
  min-height: min(720px, calc(100svh - var(--header-h)));
  display: flex;
  align-items: center;
  overflow: hidden;
  color: var(--white);
  background: #2d2924;
}
.service-hero::before { content: ""; position: absolute; inset: 0; background: var(--hero-image) center / cover no-repeat; transform: scale(1.015); }
.service-hero::after { content: ""; position: absolute; inset: 0; background: rgba(13,12,10,.46); }
.hero-craft { --hero-image: url("datai-assets/craft-material-hero-v2.png"); }
.hero-process { --hero-image: url("datai-assets/process-hero-v2.png"); }
.service-hero-inner { position: relative; z-index: 1; padding: 96px 0; }
.eyebrow { display: flex; align-items: center; gap: 12px; margin-bottom: 20px; font-size: 12px; font-weight: 700; letter-spacing: .05em; }
.eyebrow::before { content: ""; width: 30px; height: 1px; background: currentColor; }
.service-hero h1 {
  max-width: 760px;
  margin: 0;
  font-family: Georgia, "Songti SC", "STSong", serif;
  font-size: clamp(56px, 6vw, 88px);
  font-weight: 500;
  line-height: 1.08;
}
.service-hero h1 span { display: block; font-size: .52em; margin-bottom: 8px; }
.service-hero-copy { max-width: 590px; margin: 28px 0 0; color: rgba(255,255,255,.82); font-size: 16px; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 30px; }

.statement { padding: 120px 0 108px; }
.statement-grid { display: grid; grid-template-columns: minmax(0, 1.28fr) minmax(320px, .72fr); align-items: end; gap: 90px; }
.statement h2, .section-title {
  margin: 0;
  font-family: Georgia, "Songti SC", "STSong", serif;
  font-weight: 500;
  line-height: 1.18;
}
.statement h2 { max-width: 780px; font-size: clamp(42px, 4.7vw, 68px); }
.statement-copy { margin: 0; padding-left: 24px; border-left: 2px solid var(--teal); color: var(--muted); font-size: 15px; }
.section-kicker { margin-bottom: 14px; color: var(--teal); font-size: 12px; font-weight: 700; }
.section-title { font-size: clamp(38px, 4vw, 56px); }
.section-intro { max-width: 620px; margin: 20px 0 0; color: var(--muted); }

.materials { padding-bottom: 118px; }
.craft-materials { padding-top: 72px; }
.material-row {
  display: grid;
  grid-template-columns: minmax(0, 1.23fr) minmax(320px, .77fr);
  align-items: center;
  gap: 72px;
  padding: 80px 0;
  border-top: 1px solid var(--line);
}
.material-row:nth-child(even) { grid-template-columns: minmax(320px, .77fr) minmax(0, 1.23fr); }
.material-row:nth-child(even) .material-media { order: 2; }
.material-media { min-height: 440px; overflow: hidden; background: #e7e5df; }
.material-media img { width: 100%; height: 100%; min-height: 440px; object-fit: cover; transition: transform 600ms ease; }
.material-row:hover .material-media img { transform: scale(1.018); }
.material-index { color: var(--teal); font-family: Georgia, serif; font-size: 13px; }
.material-copy h2 { margin: 12px 0 18px; font-family: Georgia, "Songti SC", serif; font-size: 44px; font-weight: 500; line-height: 1.15; }
.material-copy > p { margin: 0; color: var(--muted); }
.spec-list { margin: 30px 0 0; border-top: 1px solid var(--line); }
.spec-row { display: grid; grid-template-columns: 84px 1fr; gap: 18px; padding: 13px 0; border-bottom: 1px solid var(--line); font-size: 12px; }
.spec-row span { color: var(--muted); }
.spec-row strong { font-weight: 650; }

.details-section { padding: 108px 0; background: var(--white); }
.details-head { display: grid; grid-template-columns: 1fr .75fr; align-items: end; gap: 64px; margin-bottom: 48px; }
.detail-grid { display: grid; grid-template-columns: repeat(4, 1fr); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.detail-card { min-width: 0; padding: 0 18px 24px; border-right: 1px solid var(--line); }
.detail-card:first-child { padding-left: 0; }
.detail-card:last-child { padding-right: 0; border-right: 0; }
.detail-card img { height: 220px; object-fit: cover; margin-bottom: 22px; }
.detail-card h3 { margin: 0; font-family: Georgia, "Songti SC", serif; font-size: 21px; font-weight: 500; }
.detail-card p { margin: 10px 0 0; color: var(--muted); font-size: 12px; }

.promise-strip { color: var(--white); background: var(--moss); }
.promise-grid { display: grid; grid-template-columns: repeat(3, 1fr); }
.promise-item { padding: 42px 36px; border-right: 1px solid rgba(255,255,255,.2); }
.promise-item:first-child { padding-left: 0; }
.promise-item:last-child { border-right: 0; }
.promise-item strong { display: block; font-family: Georgia, "Songti SC", serif; font-size: 23px; font-weight: 500; }
.promise-item p { margin: 8px 0 0; color: rgba(255,255,255,.72); font-size: 12px; }

.process-overview { padding: 114px 0 40px; }
.process-overview-grid { display: grid; grid-template-columns: minmax(0, .82fr) minmax(420px, 1.18fr); gap: 100px; align-items: start; }
.overview-aside { position: sticky; top: calc(var(--header-h) + 36px); }
.overview-aside p { max-width: 460px; margin: 22px 0 0; color: var(--muted); }
.process-list { border-top: 1px solid var(--line); }
.process-step { display: grid; grid-template-columns: 68px 1fr; gap: 24px; padding: 32px 0 34px; border-bottom: 1px solid var(--line); }
.process-no { color: var(--teal); font-family: Georgia, serif; font-size: 22px; }
.process-step h2 { margin: 0; font-family: Georgia, "Songti SC", serif; font-size: 30px; font-weight: 500; line-height: 1.25; }
.process-step > div > p { margin: 10px 0 0; color: var(--muted); font-size: 14px; }
.deliverables { display: grid; grid-template-columns: 1fr 1fr; gap: 12px 24px; margin-top: 20px; }
.deliverables div { padding-top: 12px; border-top: 1px solid var(--line); }
.deliverables span { display: block; color: var(--muted); font-size: 10px; }
.deliverables strong { display: block; margin-top: 3px; font-size: 12px; font-weight: 650; }

.routine-note { padding: 90px 0 110px; }
.routine-card { display: grid; grid-template-columns: minmax(0, 1fr) minmax(360px, .8fr); gap: 70px; padding: 54px 58px; color: var(--white); background: var(--ink); }
.routine-card h2 { margin: 0; font-family: Georgia, "Songti SC", serif; font-size: 38px; font-weight: 500; line-height: 1.3; }
.routine-card p { margin: 0; color: rgba(255,255,255,.72); }
.routine-points { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; margin-top: 34px; }
.routine-points div { padding-top: 14px; border-top: 1px solid rgba(255,255,255,.28); font-size: 12px; }

.page-cta {
  position: relative;
  min-height: 500px;
  display: grid;
  place-items: center;
  overflow: hidden;
  color: var(--white);
  text-align: center;
  background: #2a2d29 url("datai-assets/residential-03-hero.png") center / cover no-repeat;
}
.page-cta::before { content: ""; position: absolute; inset: 0; background: rgba(16,18,16,.68); }
.page-cta-inner { position: relative; z-index: 1; width: min(calc(100% - 40px), 780px); }
.page-cta h2 { margin: 0; font-family: Georgia, "Songti SC", serif; font-size: clamp(42px, 5vw, 62px); font-weight: 500; line-height: 1.18; }
.page-cta p { margin: 18px auto 28px; color: rgba(255,255,255,.76); }

footer { padding: 42px 0; color: var(--white); background: var(--ink); }
.footer-grid { display: flex; align-items: center; justify-content: space-between; gap: 30px; }
.footer-meta { color: rgba(255,255,255,.55); font-size: 11px; }
.footer-links { display: flex; flex-wrap: wrap; gap: 24px; font-size: 12px; }

.reveal { opacity: 1; transform: none; }
.js .reveal { opacity: 0; transform: translateY(24px); transition: opacity 680ms ease, transform 680ms ease; }
.js .reveal.is-visible { opacity: 1; transform: none; }

@media (max-width: 960px) {
  .nav { grid-template-columns: 1fr auto; }
  .nav-links { display: none; }
  .statement-grid, .details-head, .process-overview-grid, .routine-card { grid-template-columns: 1fr; gap: 32px; }
  .statement-copy { max-width: 620px; }
  .material-row, .material-row:nth-child(even) { grid-template-columns: 1fr; gap: 38px; }
  .material-row:nth-child(even) .material-media { order: 0; }
  .detail-grid { grid-template-columns: 1fr 1fr; }
  .detail-card { padding: 24px; border-bottom: 1px solid var(--line); }
  .detail-card:nth-child(2) { border-right: 0; }
  .detail-card:nth-child(3), .detail-card:nth-child(4) { border-bottom: 0; }
  .overview-aside { position: static; }
}

@media (max-width: 680px) {
  :root { --header-h: 62px; }
  .shell { width: min(calc(100% - 32px), var(--content)); }
  .brand { font-size: 13px; }
  .brand-logo { width: 27px; height: 44px; }
  .nav-action { display: none; }
  .mobile-nav { position: relative; display: block; justify-self: end; }
  .mobile-nav summary { padding: 7px 11px; border: 1px solid var(--ink); border-radius: 3px; cursor: pointer; font-size: 12px; font-weight: 700; list-style: none; }
  .mobile-nav summary::-webkit-details-marker { display: none; }
  .mobile-nav div { position: absolute; top: 44px; right: 0; width: 176px; display: grid; padding: 8px 14px; border: 1px solid var(--line); background: var(--paper); box-shadow: 0 14px 38px rgba(0,0,0,.12); }
  .mobile-nav a { padding: 10px 0; border-bottom: 1px solid var(--line); font-size: 12px; }
  .mobile-nav a:last-child { border-bottom: 0; }
  .mobile-nav a[aria-current="page"] { color: var(--teal); font-weight: 700; }
  .service-hero { min-height: 590px; }
  .service-hero::before { background-position: 60% center; }
  .service-hero::after { background: rgba(12,11,9,.54); }
  .hero-process::before { background-position: 78% center; }
  .hero-process::after { background: rgba(12,11,9,.42); }
  .service-hero-inner { padding: 72px 0; }
  .service-hero h1 { font-size: 52px; }
  .service-hero-copy { font-size: 14px; }
  .statement { padding: 78px 0 72px; }
  .statement-grid { gap: 28px; }
  .statement h2 { font-size: 39px; }
  .materials { padding-bottom: 72px; }
  .craft-materials { padding-top: 36px; }
  .material-row { padding: 56px 0; }
  .material-media, .material-media img { min-height: 300px; }
  .material-copy h2 { font-size: 36px; }
  .details-section { padding: 76px 0; }
  .detail-grid { grid-template-columns: 1fr; }
  .detail-card, .detail-card:first-child, .detail-card:last-child { padding: 26px 0; border-right: 0; border-bottom: 1px solid var(--line); }
  .detail-card:last-child { border-bottom: 0; }
  .detail-card img { height: 250px; }
  .promise-grid { grid-template-columns: 1fr; }
  .promise-item, .promise-item:first-child { padding: 30px 0; border-right: 0; border-bottom: 1px solid rgba(255,255,255,.2); }
  .promise-item:last-child { border-bottom: 0; }
  .process-overview { padding-top: 78px; }
  .process-step { grid-template-columns: 52px 1fr; gap: 12px; }
  .process-step h2 { font-size: 25px; }
  .deliverables { grid-template-columns: 1fr; }
  .routine-note { padding: 64px 0 76px; }
  .routine-card { padding: 34px 24px; }
  .routine-card h2 { font-size: 31px; }
  .routine-points { grid-template-columns: 1fr; }
  .page-cta { min-height: 460px; }
  .footer-grid { align-items: flex-start; flex-direction: column; }
}

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