:root {
  --bg: #f7f3ea;
  --ink: #171714;
  --muted: #6b675e;
  --line: #d9d1c2;
  --accent: #1c5f86;
  --warm: #b5623d;
  --panel: #eee7db;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  letter-spacing: 0;
}
body.lang-en [data-lang="zh"], body.lang-zh [data-lang="en"] { display: none !important; }
a { color: inherit; text-decoration: none; }
img { display: block; width: 100%; height: 100%; object-fit: cover; }

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  padding: 13px clamp(16px, 3vw, 42px);
  border-bottom: 1px solid color-mix(in srgb, var(--line) 72%, transparent);
  background: color-mix(in srgb, var(--bg) 91%, transparent);
  backdrop-filter: blur(18px);
}
.brand { display: inline-flex; align-items: center; width: clamp(154px, 14vw, 220px); height: 42px; }
.brand img { object-fit: contain; object-position: left center; }
.nav { display: flex; align-items: center; gap: clamp(13px, 2vw, 28px); color: var(--muted); font-size: 13px; }
.nav a { transition: color 180ms ease; }
.nav a:hover { color: var(--accent); }
.language-toggle {
  border: 1px solid var(--line);
  background: transparent;
  color: var(--ink);
  min-width: 56px;
  height: 32px;
  padding: 0 11px;
  font: inherit;
  cursor: pointer;
}
.language-toggle:hover { border-color: var(--accent); color: var(--accent); }

h1, h2, h3, p { margin-top: 0; }
.project-index { padding: clamp(18px, 3vw, 42px); }
.project-tile { display: block; }
.project-frame {
  margin: 0;
  width: 100%;
  height: min(78vh, 860px);
  min-height: 480px;
  background: var(--panel);
  overflow: hidden;
}
.project-frame img { transform: scale(1.001); transition: transform 700ms ease, filter 700ms ease; }
.project-tile:hover .project-frame img { transform: scale(1.018); filter: saturate(0.96); }
.project-line {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(240px, 0.34fr);
  gap: clamp(18px, 4vw, 72px);
  padding: 17px 0 46px;
  border-bottom: 1px solid var(--line);
  align-items: start;
}
.project-number {
  margin-bottom: 6px;
  color: var(--warm);
  font-size: 12px;
  font-weight: 800;
  letter-spacing: 0.08em;
}
h1 {
  max-width: 940px;
  margin-bottom: 0;
  font-size: clamp(24px, 4.4vw, 66px);
  font-weight: 520;
  line-height: 1.02;
}
.project-summary { margin: 3px 0 0; color: var(--muted); font-size: 14px; line-height: 1.5; }

.intro {
  display: grid;
  grid-template-columns: minmax(180px, 0.35fr) minmax(0, 0.65fr);
  gap: clamp(22px, 7vw, 118px);
  padding: clamp(56px, 8vw, 108px) clamp(18px, 4vw, 54px);
  border-bottom: 1px solid var(--line);
}
.kicker {
  margin: 0;
  color: var(--warm);
  font-size: 12px;
  font-weight: 760;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}
.intro-note {
  max-width: 760px;
  margin-bottom: 0;
  color: var(--ink);
  font-family: Georgia, "Times New Roman", serif;
  font-size: clamp(28px, 4vw, 58px);
  line-height: 1.06;
}

.case-detail {
  display: grid;
  grid-template-columns: minmax(220px, 0.45fr) minmax(0, 0.55fr);
  gap: clamp(24px, 7vw, 112px);
  padding: clamp(64px, 10vw, 132px) clamp(18px, 4vw, 54px);
  border-bottom: 1px solid var(--line);
}
.case-heading { border-top: 1px solid var(--line); padding-top: 16px; }
.case-type { color: var(--warm); font-size: 12px; font-weight: 760; letter-spacing: 0.08em; text-transform: uppercase; }
.case-heading h2 {
  margin-bottom: 0;
  font-family: Georgia, "Times New Roman", serif;
  font-size: clamp(28px, 4.3vw, 64px);
  font-weight: 400;
  line-height: 1.05;
}
.case-copy > p { margin-bottom: 30px; color: var(--muted); font-size: 16px; line-height: 1.72; }
.case-facts { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 18px; margin: 0; }
.case-facts div { border-top: 1px solid var(--line); padding-top: 12px; }
.case-facts dt { color: var(--muted); font-size: 12px; margin-bottom: 8px; }
.case-facts dd { margin: 0; font-size: 14px; line-height: 1.45; }

.case-story {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: clamp(18px, 3vw, 34px);
  padding: clamp(56px, 8vw, 108px) clamp(18px, 4vw, 54px);
  border-bottom: 1px solid var(--line);
}
.story-block { border-top: 1px solid var(--line); padding-top: 14px; }
.story-block span { display: block; margin-bottom: 26px; color: var(--warm); font-size: 12px; font-weight: 800; }
.story-block h3 { margin-bottom: 14px; font-size: 20px; }
.story-block p { margin-bottom: 0; color: var(--muted); line-height: 1.62; }

.about {
  display: grid;
  grid-template-columns: minmax(220px, 0.34fr) minmax(0, 0.66fr);
  gap: clamp(28px, 8vw, 120px);
  padding: clamp(70px, 10vw, 132px) clamp(18px, 4vw, 54px);
  border-bottom: 1px solid var(--line);
}
.about-head { border-top: 1px solid var(--line); padding-top: 16px; }
.about h2 { margin-bottom: 0; font-size: clamp(28px, 4vw, 58px); font-weight: 520; line-height: 1.05; }
.about-body { max-width: 980px; }
.about-lead {
  max-width: 860px;
  color: var(--ink);
  font-family: Georgia, "Times New Roman", serif;
  font-size: clamp(28px, 4vw, 58px);
  line-height: 1.06;
}
.about-text {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px clamp(22px, 3vw, 42px);
  margin-top: clamp(34px, 5vw, 62px);
}
.about-text p { margin-bottom: 0; color: var(--muted); line-height: 1.68; }
.service-list {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 14px;
  margin-top: clamp(42px, 6vw, 72px);
}
.service-list div { border-top: 1px solid var(--line); padding-top: 14px; }
.service-list span { display: block; margin-bottom: 22px; color: var(--warm); font-size: 12px; font-weight: 800; }
.service-list p { margin-bottom: 0; color: var(--muted); font-size: 14px; line-height: 1.55; }
.method-note {
  margin: clamp(42px, 6vw, 72px) 0 0;
  padding-top: 14px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 13px;
  line-height: 1.62;
}

.footer {
  display: flex;
  justify-content: space-between;
  gap: 24px;
  padding: 30px clamp(18px, 4vw, 54px);
  color: var(--muted);
  font-size: 14px;
}
.footer p { margin-bottom: 4px; }
.footer-title { color: var(--ink); font-weight: 750; letter-spacing: 0.08em; }
.footer-contact { display: grid; gap: 6px; text-align: right; }
.footer a { color: var(--ink); text-decoration: underline; text-decoration-thickness: 1px; text-underline-offset: 4px; }

.will-reveal { opacity: 0; transform: translateY(18px); transition: opacity 700ms ease, transform 700ms ease; }
.will-reveal.is-visible { opacity: 1; transform: translateY(0); }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .project-frame img, .will-reveal { opacity: 1; transform: none; transition: none; }
}
@media (max-width: 980px) {
  .project-line, .intro, .case-detail, .about { grid-template-columns: 1fr; }
  .case-story, .service-list, .about-text { grid-template-columns: 1fr; }
  .project-frame { height: min(70vh, 720px); }
}
@media (max-width: 640px) {
  .site-header { align-items: center; gap: 14px; }
  .brand { width: 142px; height: 36px; }
  .nav { gap: 12px; font-size: 12px; }
  .nav a:nth-child(2) { display: none; }
  .language-toggle { min-width: 52px; height: 32px; padding: 0 9px; }
  .project-index { padding: 14px; }
  .project-frame { min-height: 330px; height: 58vh; }
  .project-line { padding-bottom: 32px; }
  h1 { font-size: clamp(28px, 9vw, 44px); }
  .case-facts { grid-template-columns: 1fr; }
  .footer { display: block; }
  .footer-contact { margin-top: 12px; text-align: left; }
  .footer a { display: inline-block; }
}