:root {
  --paper: #f4f2ed;
  --paper-deep: #e8e5de;
  --ink: #141b1d;
  --muted: #667174;
  --line: rgba(20, 27, 29, 0.14);
  --cyan: #3ad4dc;
  --blue: #1d60ff;
  --card: rgba(255, 255, 255, 0.7);
  --radius: 24px;
  --shadow: 0 20px 70px rgba(25, 40, 42, 0.08);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--ink);
  background:
    radial-gradient(circle at 92% 4%, rgba(58, 212, 220, 0.12), transparent 30rem),
    var(--paper);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; text-decoration: none; }
img { display: block; width: 100%; }
button { font: inherit; }

.shell { width: min(1180px, calc(100% - 48px)); margin: 0 auto; }
.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  border-bottom: 1px solid transparent;
  backdrop-filter: blur(16px);
  transition: background .25s ease, border-color .25s ease;
}
.site-header.scrolled { background: rgba(244, 242, 237, .88); border-color: var(--line); }
.nav { min-height: 78px; display: flex; align-items: center; justify-content: space-between; gap: 24px; }
.brand { display: inline-flex; align-items: center; gap: 11px; font-weight: 760; letter-spacing: .08em; }
.brand-mark { width: 10px; height: 10px; border-radius: 50%; background: var(--cyan); box-shadow: 0 0 0 6px rgba(58,212,220,.14); }
.nav-links { display: flex; align-items: center; gap: 28px; color: #394346; font-size: 14px; }
.nav-links a:hover, .text-link:hover { color: var(--blue); }
.nav-toggle { display: none; border: 0; background: transparent; padding: 8px; }

.hero { min-height: 72vh; display: grid; grid-template-columns: 1.35fr .65fr; align-items: end; gap: 72px; padding: 10vh 0 11vh; border-bottom: 1px solid var(--line); }
.eyebrow { margin: 0 0 20px; color: var(--blue); font-size: 12px; font-weight: 750; letter-spacing: .18em; text-transform: uppercase; }
h1, h2, h3, p { margin-top: 0; }
.hero h1 { max-width: 850px; margin-bottom: 28px; font-size: clamp(48px, 8vw, 104px); line-height: .98; letter-spacing: -.06em; font-weight: 650; }
.hero h1 em { display: block; color: var(--muted); font-family: Georgia, "Songti SC", serif; font-weight: 400; }
.hero-note { max-width: 360px; margin: 0 0 4px; color: var(--muted); font-size: 17px; }
.hero-meta { align-self: end; border-top: 1px solid var(--line); padding-top: 22px; color: var(--muted); font-size: 13px; }
.hero-meta strong { display: block; color: var(--ink); margin-bottom: 8px; font-size: 15px; }

.section { padding: 120px 0; }
.section-head { display: flex; justify-content: space-between; align-items: end; gap: 28px; margin-bottom: 48px; }
.section-head h2 { margin: 0; font-size: clamp(34px, 5vw, 58px); letter-spacing: -.045em; line-height: 1.05; }
.section-head p { max-width: 420px; margin: 0; color: var(--muted); }
.project-list { display: grid; gap: 28px; }
.project-card {
  display: grid;
  grid-template-columns: minmax(0, 1.35fr) minmax(280px, .65fr);
  min-height: 470px;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--card);
  box-shadow: var(--shadow);
}
.project-cover { position: relative; min-height: 400px; overflow: hidden; background: #d9dfdf; }
.project-cover img { height: 100%; object-fit: cover; transition: transform .7s cubic-bezier(.2,.7,.2,1); }
.project-card:hover .project-cover img { transform: scale(1.025); }
.project-number { position: absolute; left: 22px; top: 20px; padding: 7px 11px; color: white; background: rgba(8,17,19,.64); border: 1px solid rgba(255,255,255,.25); border-radius: 99px; font-size: 12px; backdrop-filter: blur(8px); }
.project-copy { display: flex; flex-direction: column; justify-content: space-between; padding: 44px; }
.project-copy h3 { margin-bottom: 16px; font-size: clamp(28px, 3.2vw, 44px); letter-spacing: -.04em; line-height: 1.08; }
.project-copy p { color: var(--muted); }
.tags { display: flex; flex-wrap: wrap; gap: 8px; margin: 30px 0; }
.tag { padding: 6px 10px; border: 1px solid var(--line); border-radius: 99px; color: #445053; font-size: 12px; }
.arrow-link { display: inline-flex; align-items: center; gap: 10px; font-weight: 700; }
.arrow-link::after { content: "↗"; color: var(--blue); font-size: 20px; transition: transform .2s ease; }
.project-card:hover .arrow-link::after { transform: translate(3px, -3px); }

.about-grid { display: grid; grid-template-columns: .85fr 1.15fr; gap: 80px; padding-top: 48px; border-top: 1px solid var(--line); }
.about-grid h2 { font-size: clamp(34px, 5vw, 60px); letter-spacing: -.05em; }
.about-copy { max-width: 680px; font-size: clamp(20px, 2.3vw, 28px); line-height: 1.45; }
.about-copy .sub { color: var(--muted); font-size: 16px; }

.site-footer { border-top: 1px solid var(--line); padding: 32px 0 44px; color: var(--muted); font-size: 13px; }
.footer-row { display: flex; justify-content: space-between; align-items: center; gap: 20px; }
.footer-links { display: flex; gap: 18px; }

/* Case pages */
.case-hero { padding: 9vh 0 64px; }
.case-back { display: inline-flex; align-items: center; gap: 8px; margin-bottom: 54px; color: var(--muted); font-size: 14px; }
.case-back:hover { color: var(--blue); }
.case-title { display: grid; grid-template-columns: 1.25fr .75fr; gap: 60px; align-items: end; }
.case-title h1 { margin: 0; font-size: clamp(50px, 8vw, 102px); line-height: .98; letter-spacing: -.06em; }
.case-deck { margin: 0 0 8px; color: var(--muted); font-size: clamp(18px, 2vw, 23px); }
.case-cover { margin: 48px 0 0; aspect-ratio: 16 / 9; overflow: hidden; border-radius: var(--radius); background: var(--paper-deep); box-shadow: var(--shadow); }
.case-cover img { height: 100%; object-fit: cover; }
.case-caption { margin: 12px 0 0; color: var(--muted); font-size: 12px; }
.case-body { width: min(980px, calc(100% - 48px)); margin: 0 auto; padding: 40px 0 120px; }
.case-section { display: grid; grid-template-columns: 220px 1fr; gap: 56px; padding: 76px 0; border-bottom: 1px solid var(--line); }
.case-section h2 { font-size: 16px; letter-spacing: .03em; }
.case-section h3 { font-size: clamp(28px, 4vw, 44px); letter-spacing: -.04em; line-height: 1.15; }
.case-section p { color: #4f5b5e; }
.case-lead { color: var(--ink) !important; font-size: clamp(21px, 2.6vw, 30px); line-height: 1.5; }
.fact-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; margin-top: 34px; }
.fact { min-height: 150px; padding: 22px; border: 1px solid var(--line); border-radius: 18px; background: rgba(255,255,255,.45); }
.fact small { display: block; color: var(--muted); margin-bottom: 28px; }
.fact strong { font-size: 17px; }
.flow { display: grid; grid-template-columns: repeat(4, 1fr); gap: 10px; margin-top: 34px; }
.flow-step { position: relative; min-height: 142px; padding: 18px; border-radius: 16px; background: #172124; color: white; }
.flow-step:not(:last-child)::after { content: "→"; position: absolute; right: -17px; top: 48%; z-index: 2; width: 24px; height: 24px; display: grid; place-items: center; border-radius: 50%; background: var(--cyan); color: var(--ink); }
.flow-step span { color: var(--cyan); font-size: 12px; }
.flow-step strong { display: block; margin-top: 42px; line-height: 1.35; }
.principles { display: grid; grid-template-columns: repeat(2, 1fr); gap: 16px; margin-top: 28px; }
.principle { padding: 28px; border-left: 3px solid var(--cyan); background: rgba(255,255,255,.38); }
.principle strong { display: block; margin-bottom: 8px; }
.next-project { display: flex; justify-content: space-between; align-items: center; gap: 30px; padding: 52px; border-radius: var(--radius); color: white; background: #172124; }
.next-project small { color: #9db0b3; }
.next-project h2 { margin: 8px 0 0; font-size: clamp(30px, 4vw, 54px); letter-spacing: -.04em; }
.next-project .arrow-link::after { color: var(--cyan); }

.reveal { opacity: 0; transform: translateY(18px); transition: opacity .65s ease, transform .65s ease; }
.reveal.visible { opacity: 1; transform: none; }

@media (max-width: 860px) {
  .shell, .case-body { width: min(100% - 32px, 720px); }
  .hero { grid-template-columns: 1fr; gap: 48px; min-height: 66vh; }
  .project-card { grid-template-columns: 1fr; }
  .project-cover { min-height: 300px; aspect-ratio: 16/10; }
  .project-copy { padding: 30px; }
  .about-grid, .case-title, .case-section { grid-template-columns: 1fr; gap: 24px; }
  .fact-grid { grid-template-columns: 1fr; }
  .flow { grid-template-columns: repeat(2, 1fr); }
  .flow-step:nth-child(2)::after { display: none; }
}

@media (max-width: 560px) {
  .nav-toggle { display: block; }
  .nav-links { position: absolute; left: 16px; right: 16px; top: 68px; display: none; flex-direction: column; align-items: stretch; gap: 0; padding: 10px; border: 1px solid var(--line); border-radius: 14px; background: rgba(244,242,237,.98); }
  .nav-links.open { display: flex; }
  .nav-links a { padding: 12px; }
  .hero { padding-top: 7vh; }
  .section { padding: 84px 0; }
  .section-head, .footer-row, .next-project { align-items: flex-start; flex-direction: column; }
  .flow, .principles { grid-template-columns: 1fr; }
  .flow-step:not(:last-child)::after { display: none; }
  .case-cover { border-radius: 16px; }
  .case-section { padding: 54px 0; }
}

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