:root {
  --surface: #0d0c0b;
  --surface-2: #151311;
  --surface-3: #211f1e;
  --text: #fefcf9;
  --muted: #d7c2b7;
  --line: rgba(160, 141, 131, 0.32);
  --copper: #ac6c40;
  --peach: #ffb688;
  --sage: #bdcbad;
  --cyan: #85d3de;
  color-scheme: dark;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  min-width: 320px;
  margin: 0;
  background: var(--surface);
  color: var(--text);
  font-family: "Hanken Grotesk", "Helvetica Neue", Arial, sans-serif;
}

body::before {
  position: fixed;
  inset: 0;
  z-index: -2;
  background:
    radial-gradient(circle at 9% 18%, rgba(172, 108, 64, 0.12), transparent 28rem),
    radial-gradient(circle at 91% 52%, rgba(133, 211, 222, 0.07), transparent 32rem),
    var(--surface);
  content: "";
}

a { color: inherit; }

.project-grain {
  position: fixed;
  inset: 0;
  z-index: 100;
  background-image:
    linear-gradient(0deg, rgba(255, 255, 255, 0.06) 1px, transparent 1px),
    linear-gradient(90deg, rgba(0, 0, 0, 0.12) 1px, transparent 1px);
  background-size: 3px 3px, 5px 5px;
  mix-blend-mode: overlay;
  opacity: 0.07;
  pointer-events: none;
}

.project-nav {
  position: sticky;
  top: 0;
  z-index: 50;
  display: flex;
  min-height: 82px;
  align-items: center;
  justify-content: space-between;
  padding: 0 clamp(20px, 5vw, 72px);
  border-bottom: 1px solid var(--line);
  background: rgba(13, 12, 11, 0.84);
  backdrop-filter: blur(12px);
}

.project-brand,
.project-site-links a,
.project-language-toggle,
.section-label,
.project-hero-copy > p,
.project-hero-index,
.project-hero-foot a,
.metric span,
.story-number,
.flow-step > span,
.evidence-stamp,
.impact-model > span,
.application-band span,
.privacy-boundary strong,
.next-case > span,
.project-footer {
  font-family: "Geist", "Helvetica Neue", Arial, sans-serif;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.project-brand,
.project-site-links a,
.project-language-toggle {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-size: 12px;
  font-weight: 700;
  text-decoration: none;
}

.project-brand { font-size: 17px; letter-spacing: 0; }

.project-brand img {
  width: 30px;
  height: 30px;
  border-radius: 6px;
}

.project-site-links {
  display: flex;
  gap: clamp(18px, 2.4vw, 32px);
  align-items: center;
}

.project-site-links a {
  color: var(--muted);
}

.project-language-toggle {
  border: 0;
  border-left: 1px solid var(--line);
  background: transparent;
  color: var(--cyan);
  cursor: pointer;
  padding-left: 18px;
}

.project-site-links a:hover,
.project-site-links a:focus-visible,
.project-language-toggle:hover,
.project-language-toggle:focus-visible {
  color: var(--text);
  outline: none;
}

.project-site-links .project-login {
  border: 1px solid rgba(255, 182, 136, 0.4);
  border-radius: 20px;
  color: var(--peach);
  padding: 7px 14px;
}

html[lang="zh-CN"] body,
html[lang="zh-CN"] button {
  font-family: "PingFang SC", "Microsoft YaHei", "Noto Sans CJK SC", system-ui, sans-serif;
}

html[lang="zh-CN"] .project-hero h1,
html[lang="zh-CN"] .project-thesis blockquote,
html[lang="zh-CN"] .story-row h2,
html[lang="zh-CN"] .flow-heading h2,
html[lang="zh-CN"] .impact-heading h2,
html[lang="zh-CN"] .technical-copy h2,
html[lang="zh-CN"] .next-case strong {
  font-family: "PingFang SC", "Microsoft YaHei", "Noto Sans CJK SC", system-ui, sans-serif;
}

html[lang="zh-CN"] .project-site-links a,
html[lang="zh-CN"] .project-language-toggle,
html[lang="zh-CN"] .section-label,
html[lang="zh-CN"] .project-hero-copy > p,
html[lang="zh-CN"] .project-hero-index,
html[lang="zh-CN"] .project-hero-foot a,
html[lang="zh-CN"] .metric span,
html[lang="zh-CN"] .evidence-stamp,
html[lang="zh-CN"] .impact-model > span,
html[lang="zh-CN"] .application-band span,
html[lang="zh-CN"] .privacy-boundary strong,
html[lang="zh-CN"] .next-case > span {
  font-family: "PingFang SC", "Microsoft YaHei", "Noto Sans CJK SC", system-ui, sans-serif;
  letter-spacing: 0.04em;
}

.project-hero {
  position: relative;
  display: grid;
  min-height: min(820px, calc(100dvh - 110px));
  align-items: end;
  overflow: hidden;
  padding: clamp(84px, 12vh, 140px) clamp(20px, 6.5vw, 96px) clamp(42px, 7vh, 74px);
  isolation: isolate;
}

.project-hero-image,
.project-hero-overlay {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
}

.project-hero-image {
  z-index: -3;
  object-fit: cover;
  animation: hero-image-enter 1.8s cubic-bezier(0.16, 1, 0.3, 1) both;
}

.project-hero-overlay {
  z-index: -2;
  background:
    linear-gradient(90deg, rgba(6, 5, 4, 0.9) 0%, rgba(6, 5, 4, 0.58) 52%, rgba(6, 5, 4, 0.2)),
    linear-gradient(180deg, rgba(6, 5, 4, 0.08) 40%, rgba(6, 5, 4, 0.9) 100%);
}

.project-hero::after {
  position: absolute;
  inset: 0;
  z-index: -1;
  background: linear-gradient(rgba(133, 211, 222, 0.055) 1px, transparent 1px);
  background-size: 100% 5px;
  content: "";
  opacity: 0.24;
}

.project-hero-index {
  position: absolute;
  top: 32px;
  right: clamp(20px, 5vw, 72px);
  color: var(--cyan);
  font-size: 12px;
  font-weight: 700;
}

.project-hero-copy {
  width: min(1180px, 100%);
  animation: hero-copy-enter 1s cubic-bezier(0.16, 1, 0.3, 1) 180ms both;
}

.project-hero-copy > p {
  margin: 0 0 22px;
  color: var(--cyan);
  font-size: 13px;
  font-weight: 700;
}

.project-hero h1,
.project-thesis blockquote,
.story-row h2,
.flow-heading h2,
.impact-heading h2,
.technical-copy h2,
.next-case strong {
  margin: 0;
  font-family: "Source Serif 4", Georgia, serif;
  font-weight: 500;
  letter-spacing: 0;
}

.project-hero h1 {
  max-width: 980px;
  font-family: "Orbitron", "Geist", "Helvetica Neue", sans-serif;
  font-size: clamp(42px, 6.2vw, 84px);
  font-weight: 700;
  line-height: 0.91;
  text-wrap: balance;
}

.project-hero-foot {
  display: grid;
  grid-template-columns: minmax(0, 680px) auto;
  gap: 32px;
  align-items: end;
  margin-top: clamp(28px, 5vh, 58px);
  padding-top: 22px;
  border-top: 1px solid rgba(254, 252, 249, 0.28);
}

.project-hero-foot strong {
  max-width: 55ch;
  color: var(--muted);
  font-size: clamp(16px, 1.7vw, 22px);
  font-weight: 400;
  line-height: 1.5;
}

.project-hero-foot a {
  display: inline-flex;
  gap: 14px;
  align-items: center;
  justify-self: end;
  color: var(--peach);
  font-size: 12px;
  font-weight: 700;
  text-decoration: none;
}

.section-label {
  margin: 0 0 20px;
  color: var(--cyan);
  font-size: 12px;
  font-weight: 700;
}

.project-thesis {
  display: grid;
  grid-template-columns: minmax(140px, 0.28fr) minmax(0, 1fr);
  gap: clamp(30px, 8vw, 120px);
  max-width: 1440px;
  margin: 0 auto;
  padding: clamp(84px, 11vw, 170px) clamp(20px, 6.5vw, 96px);
}

.project-thesis blockquote {
  max-width: 980px;
  font-size: clamp(30px, 4.3vw, 56px);
  line-height: 1.08;
  text-wrap: balance;
}

.metric-strip {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  max-width: 1560px;
  margin: 0 auto;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.metric {
  display: grid;
  min-height: 180px;
  align-content: center;
  gap: 12px;
  padding: 30px clamp(20px, 3vw, 48px);
  border-right: 1px solid var(--line);
}

.metric:last-child { border-right: 0; }

.metric strong {
  color: var(--sage);
  font-size: clamp(30px, 3.5vw, 48px);
  font-weight: 600;
  letter-spacing: 0;
}

.metric span {
  color: var(--muted);
  font-size: 12px;
  font-weight: 700;
  line-height: 1.5;
}

.story-sections {
  max-width: 1440px;
  margin: 0 auto;
  padding: clamp(90px, 12vw, 180px) clamp(20px, 6.5vw, 96px);
}

.story-row {
  display: grid;
  grid-template-columns: 54px minmax(280px, 0.85fr) minmax(300px, 0.7fr);
  gap: clamp(24px, 5vw, 74px);
  align-items: start;
  padding: clamp(42px, 6vw, 78px) 0;
  border-top: 1px solid var(--line);
}

.story-row:last-child { border-bottom: 1px solid var(--line); }

.story-number {
  color: var(--peach);
  font-size: 12px;
  font-weight: 700;
}

.story-row h2 {
  max-width: 17ch;
  font-size: clamp(28px, 3.2vw, 44px);
  line-height: 1.06;
}

.story-row > p,
.impact-heading > p,
.technical-copy > p,
.privacy-boundary p {
  margin: 0;
  color: var(--muted);
  font-size: 17px;
  line-height: 1.75;
}

.project-flow {
  overflow: hidden;
  padding: clamp(90px, 12vw, 180px) clamp(20px, 6.5vw, 96px);
  background:
    linear-gradient(rgba(133, 211, 222, 0.045) 1px, transparent 1px),
    linear-gradient(90deg, rgba(133, 211, 222, 0.035) 1px, transparent 1px),
    #0a0908;
  background-size: 48px 48px;
}

.flow-heading,
.flow-track,
.impact-heading,
.impact-evidence,
.technical-section,
.application-band,
.privacy-boundary {
  max-width: 1240px;
  margin-inline: auto;
}

.flow-heading {
  display: grid;
  grid-template-columns: 0.38fr 1fr;
  gap: 40px;
  align-items: start;
  margin-bottom: clamp(70px, 9vw, 120px);
}

.flow-heading h2,
.impact-heading h2,
.technical-copy h2 {
  font-size: clamp(34px, 4.5vw, 58px);
  line-height: 1.02;
  text-wrap: balance;
}

.flow-track {
  --flow-progress: 0%;
  position: relative;
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 22px;
}

.flow-line {
  position: absolute;
  top: 25px;
  left: 5%;
  right: 5%;
  height: 1px;
  background: var(--line);
}

.flow-line span {
  display: block;
  width: var(--flow-progress);
  height: 100%;
  background: var(--cyan);
  box-shadow: 0 0 14px rgba(133, 211, 222, 0.6);
}

.flow-step {
  position: relative;
  z-index: 2;
  padding-right: 12px;
}

.flow-step > span {
  display: grid;
  width: 50px;
  height: 50px;
  place-items: center;
  border: 1px solid var(--cyan);
  border-radius: 50%;
  background: #0a0908;
  color: var(--cyan);
  font-size: 12px;
  font-weight: 700;
}

.flow-step h3 {
  margin: 28px 0 13px;
  font-size: 19px;
  letter-spacing: 0;
}

.flow-step p {
  margin: 0;
  color: var(--muted);
  font-size: 15px;
  line-height: 1.65;
}

.impact-band {
  padding: clamp(94px, 12vw, 180px) clamp(20px, 6.5vw, 96px);
  border-top: 1px solid rgba(255, 182, 136, 0.26);
  background: #1d1713;
}

.impact-heading {
  display: grid;
  grid-template-columns: 0.45fr 1fr;
  gap: 32px clamp(36px, 7vw, 100px);
}

.impact-heading .section-label { grid-column: 1; }
.impact-heading h2 { grid-column: 2; }

.impact-heading > p {
  grid-column: 2;
  max-width: 760px;
  margin-top: 12px;
}

.impact-evidence {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1px;
  margin-top: clamp(60px, 8vw, 110px);
  border: 1px solid rgba(255, 182, 136, 0.32);
  background: rgba(255, 182, 136, 0.28);
}

.evidence-list,
.impact-model {
  min-width: 0;
  background: #18120f;
  padding: clamp(28px, 4.5vw, 64px);
}

.evidence-stamp,
.impact-model > span {
  display: block;
  width: fit-content;
  margin-bottom: 36px;
  border: 1px solid currentColor;
  color: var(--sage);
  font-size: 12px;
  font-weight: 700;
  padding: 7px 10px;
}

.evidence-list p {
  margin: 0;
  border-top: 1px solid var(--line);
  color: var(--muted);
  line-height: 1.6;
  padding: 18px 0;
}

.impact-model > span { color: var(--peach); }

.impact-model p {
  margin: 0 0 34px;
  color: var(--text);
  font-family: "Source Serif 4", Georgia, serif;
  font-size: clamp(22px, 2.5vw, 32px);
  line-height: 1.28;
}

.impact-model strong {
  display: block;
  border-left: 2px solid var(--peach);
  color: var(--muted);
  font-size: 15px;
  font-weight: 400;
  line-height: 1.7;
  padding-left: 18px;
}

.technical-section {
  display: grid;
  grid-template-columns: minmax(0, 0.92fr) minmax(320px, 0.72fr);
  gap: clamp(54px, 9vw, 140px);
  padding: clamp(100px, 13vw, 200px) clamp(20px, 2vw, 30px);
}

.technical-copy > p { margin-top: 32px; }

.principle-list {
  margin: 0;
  padding: 0;
  list-style: none;
}

.principle-list li {
  display: grid;
  grid-template-columns: 42px 1fr;
  gap: 18px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  line-height: 1.5;
  padding: 22px 0;
}

.principle-list li:last-child { border-bottom: 1px solid var(--line); }
.principle-list span { color: var(--cyan); font-size: 12px; }

.application-band {
  display: grid;
  grid-template-columns: 0.36fr 1fr;
  gap: 42px;
  padding: 64px 30px;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.application-band > div {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.application-band span {
  border: 1px solid rgba(189, 203, 173, 0.38);
  color: var(--sage);
  font-size: 12px;
  font-weight: 700;
  padding: 11px 13px;
}

.privacy-boundary {
  display: grid;
  grid-template-columns: 0.36fr 1fr;
  gap: 42px;
  padding: 54px 30px clamp(100px, 12vw, 170px);
}

.privacy-boundary strong {
  color: var(--peach);
  font-size: 12px;
}

.privacy-boundary p { max-width: 820px; font-size: 16px; }

.next-case {
  position: relative;
  display: grid;
  grid-template-columns: 0.25fr 1fr auto;
  gap: 30px;
  align-items: center;
  min-height: 300px;
  padding: clamp(48px, 7vw, 90px) clamp(20px, 6.5vw, 96px);
  border-top: 1px solid var(--line);
  background: #131210;
  text-decoration: none;
  transition: background 250ms ease;
}

.next-case:hover,
.next-case:focus-visible { background: #211914; outline: none; }

.next-case > span {
  color: var(--cyan);
  font-size: 12px;
  font-weight: 700;
}

.next-case strong {
  font-size: clamp(32px, 4.4vw, 56px);
  line-height: 1;
}

.next-case b {
  color: var(--peach);
  font-size: clamp(36px, 5vw, 60px);
  font-weight: 300;
  transition: transform 250ms ease;
}

.next-case:hover b { transform: translateX(10px); }

.project-footer {
  display: flex;
  min-height: 110px;
  align-items: center;
  justify-content: space-between;
  padding: 30px clamp(20px, 6.5vw, 96px);
  color: var(--muted);
  font-size: 11px;
  font-weight: 700;
}

.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 720ms ease, transform 900ms cubic-bezier(0.16, 1, 0.3, 1);
}

.reveal.is-visible { opacity: 1; transform: translateY(0); }

@keyframes hero-image-enter {
  from { filter: blur(8px) saturate(0.5); transform: scale(1.08); }
  to { filter: blur(0) saturate(0.9); transform: scale(1); }
}

@keyframes hero-copy-enter {
  from { opacity: 0; transform: translateY(28px); }
  to { opacity: 1; transform: translateY(0); }
}

@media (max-width: 900px) {
  .project-hero-foot,
  .project-thesis,
  .flow-heading,
  .impact-heading,
  .technical-section,
  .application-band,
  .privacy-boundary {
    grid-template-columns: 1fr;
  }

  .project-hero-foot a { justify-self: start; }
  .project-thesis { gap: 18px; }
  .metric-strip { grid-template-columns: repeat(2, 1fr); }
  .metric:nth-child(2) { border-right: 0; }
  .metric:nth-child(-n + 2) { border-bottom: 1px solid var(--line); }

  .story-row {
    grid-template-columns: 42px 1fr;
  }

  .story-row > p { grid-column: 2; }

  .flow-track {
    grid-template-columns: 1fr;
    gap: 0;
  }

  .flow-line {
    top: 25px;
    bottom: 25px;
    left: 25px;
    right: auto;
    width: 1px;
    height: auto;
  }

  .flow-line span { width: 100%; height: var(--flow-progress); }

  .flow-step {
    display: grid;
    grid-template-columns: 50px 1fr;
    gap: 0 24px;
    min-height: 150px;
  }

  .flow-step h3 { margin: 7px 0 12px; }
  .flow-step p { grid-column: 2; }
  .impact-heading .section-label,
  .impact-heading h2,
  .impact-heading > p { grid-column: 1; }
  .impact-evidence { grid-template-columns: 1fr; }
  .technical-section { padding-inline: 20px; }
  .next-case { grid-template-columns: 1fr auto; }
  .next-case > span { grid-column: 1 / -1; }
}

@media (max-width: 560px) {
  .project-nav { min-height: 64px; padding-inline: 16px; }
  .project-brand { font-size: 14px; }
  .project-site-links {
    max-width: calc(100vw - 170px);
    gap: 18px;
    overflow-x: auto;
    scrollbar-width: none;
  }

  .project-site-links::-webkit-scrollbar { display: none; }

  .project-site-links a {
    flex: 0 0 auto;
    font-size: 11px;
  }

  .project-language-toggle {
    flex: 0 0 auto;
    font-size: 11px;
  }
  .project-hero { min-height: calc(100dvh - 102px); padding-inline: 16px; }
  .project-hero h1 { font-size: clamp(38px, 11.8vw, 56px); }
  .project-hero-foot { margin-top: 28px; }
  .project-thesis,
  .story-sections,
  .project-flow,
  .impact-band { padding-inline: 16px; }
  .project-thesis blockquote { font-size: clamp(30px, 10vw, 44px); }
  .metric { min-height: 150px; padding: 22px 16px; }
  .metric strong { font-size: 30px; }
  .story-row { grid-template-columns: 28px 1fr; gap: 18px; }
  .story-row h2 { font-size: 30px; }
  .story-row > p { font-size: 15px; }
  .impact-evidence { border-inline: 0; }
  .evidence-list,
  .impact-model { padding: 30px 20px; }
  .application-band,
  .privacy-boundary { padding-inline: 20px; }
  .next-case { min-height: 240px; padding-inline: 20px; }
  .project-footer { padding-inline: 20px; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .project-hero-image,
  .project-hero-copy { animation: none; }
  .reveal { opacity: 1; transform: none; transition: none; }
  .flow-line span { width: 100%; height: 100%; }
  .next-case,
  .next-case b { transition: none; }
}