:root {
  --ink: #071622;
  --ink-deep: #031019;
  --ink-soft: #0c2635;
  --cyan: #76d7dc;
  --cyan-bright: #b7f1ee;
  --copper: #c9834f;
  --copper-light: #e8b88d;
  --paper: #e8eff0;
  --muted: #9bb0b7;
  --line: rgba(183, 241, 238, 0.19);
  --display: "Songti SC", "STSong", "Noto Serif CJK SC", serif;
  --body: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --utility: "SFMono-Regular", Consolas, "Liberation Mono", monospace;
  color-scheme: dark;
}

*,
*::before,
*::after { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--ink);
  color: var(--paper);
  font-family: var(--body);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

body::before {
  position: fixed;
  inset: 0;
  z-index: -1;
  background-image:
    linear-gradient(rgba(118, 215, 220, 0.025) 1px, transparent 1px),
    linear-gradient(90deg, rgba(118, 215, 220, 0.025) 1px, transparent 1px);
  background-size: 48px 48px;
  content: "";
  pointer-events: none;
}

a { color: inherit; }

.skip-link {
  position: fixed;
  left: 1rem;
  top: 1rem;
  z-index: 100;
  padding: .65rem 1rem;
  background: var(--cyan-bright);
  color: var(--ink-deep);
  font-weight: 700;
  transform: translateY(-200%);
}

.skip-link:focus { transform: translateY(0); }

:focus-visible {
  outline: 3px solid var(--copper-light);
  outline-offset: 5px;
}

.site-header {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: min(100% - 3rem, 1320px);
  margin-inline: auto;
  padding-block: 1.3rem;
  border-bottom: 1px solid rgba(232, 239, 240, .2);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: .75rem;
  text-decoration: none;
}

.brand-mark {
  display: grid;
  width: 2.5rem;
  aspect-ratio: 1;
  place-items: center;
  border: 1px solid var(--copper-light);
  color: var(--copper-light);
  font-family: var(--utility);
  font-size: .75rem;
  letter-spacing: .08em;
}

.brand-copy { display: grid; line-height: 1.15; }
.brand-copy strong { font-size: .82rem; letter-spacing: .08em; }
.brand-copy small { margin-top: .25rem; color: var(--muted); font-size: .65rem; letter-spacing: .12em; }

.site-header nav { display: flex; align-items: center; gap: 1.6rem; }
.site-header nav a { color: #d7e5e7; font-size: .78rem; letter-spacing: .08em; text-decoration: none; }
.site-header nav a:hover { color: var(--cyan-bright); }
.site-header .back-home { padding: .55rem .85rem; border: 1px solid rgba(232, 239, 240, .3); }

.hero {
  position: relative;
  display: grid;
  min-height: 820px;
  height: 100svh;
  overflow: hidden;
  isolation: isolate;
}

.hero-image,
.hero-shade { position: absolute; inset: 0; }

.hero-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center 46%;
  filter: saturate(.78) contrast(1.08) brightness(.78);
  animation: settle 1.2s ease-out both;
}

.hero-shade {
  background:
    linear-gradient(90deg, rgba(3, 16, 25, .95) 0%, rgba(3, 16, 25, .8) 39%, rgba(3, 16, 25, .14) 72%),
    linear-gradient(0deg, var(--ink) 0%, transparent 24%),
    radial-gradient(circle at 72% 42%, transparent 5%, rgba(3, 16, 25, .35) 72%);
}

.hero-content {
  z-index: 1;
  display: grid;
  align-content: center;
  width: min(100% - 3rem, 1320px);
  margin: 4.6rem auto 5rem;
}

.overline {
  display: flex;
  justify-content: space-between;
  width: min(39rem, 100%);
  margin: 0 0 2rem;
  color: var(--cyan-bright);
  font-family: var(--utility);
  font-size: .69rem;
  letter-spacing: .14em;
  text-transform: uppercase;
}

.hero-title-wrap { position: relative; width: fit-content; }

.hero-code {
  position: absolute;
  top: 1rem;
  left: calc(100% + 2rem);
  width: max-content;
  margin: 0;
  color: var(--copper-light);
  font-family: var(--utility);
  font-size: .72rem;
  letter-spacing: .35em;
  writing-mode: vertical-rl;
}

.hero h1 {
  margin: 0;
  max-width: 8.5em;
  color: #f2f5f3;
  font-family: var(--display);
  font-size: clamp(3.5rem, 7.5vw, 7.4rem);
  font-weight: 600;
  line-height: .98;
  letter-spacing: -.065em;
  text-wrap: balance;
}

.hero h1 sup {
  position: relative;
  top: -.2em;
  margin-left: .15em;
  color: var(--copper-light);
  font-family: var(--utility);
  font-size: .15em;
  letter-spacing: 0;
}

.hero-thesis {
  display: grid;
  grid-template-columns: 15rem minmax(18rem, 27rem);
  gap: 3rem;
  align-items: start;
  width: fit-content;
  margin-top: 3.2rem;
  padding-top: 1.25rem;
  border-top: 1px solid rgba(232, 239, 240, .38);
}

.hero-thesis p { margin: 0; color: #c4d2d5; font-size: .88rem; }
.hero-thesis p:first-child { color: var(--paper); font-size: 1rem; }
.hero-thesis strong { color: var(--cyan-bright); font-weight: 550; }

.hero-ledger {
  position: absolute;
  right: max(1.5rem, calc((100% - 1320px) / 2));
  bottom: 4.2rem;
  z-index: 2;
  display: grid;
  gap: .8rem;
  color: var(--muted);
  font-family: var(--utility);
  font-size: .64rem;
  letter-spacing: .08em;
}

.hero-ledger span { display: flex; align-items: baseline; gap: .75rem; }
.hero-ledger b { min-width: 2.2rem; color: var(--copper-light); font-size: 1.25rem; font-weight: 400; }

.section-shell { width: min(100% - 3rem, 1180px); margin-inline: auto; }

.section-label {
  color: var(--muted);
  font-family: var(--utility);
  font-size: .66rem;
  letter-spacing: .14em;
  text-transform: uppercase;
}

.section-label span { margin-right: .75rem; color: var(--copper-light); }

.intro {
  display: grid;
  grid-template-columns: 9rem 1fr 20rem;
  gap: 3rem;
  padding-block: 10rem;
}

.intro h2,
.section-heading h2,
.boundary h2,
.copyright h2 {
  margin: 0;
  font-family: var(--display);
  font-size: clamp(2.2rem, 4vw, 4.3rem);
  font-weight: 500;
  line-height: 1.13;
  letter-spacing: -.045em;
}

.intro-copy .lead { margin: 2.2rem 0 1rem; color: #d8e2e3; font-size: 1.12rem; line-height: 1.85; }
.intro-copy > p:last-child { max-width: 42rem; margin-bottom: 0; color: var(--muted); }

.principles { margin: 0; padding: 1.3rem 0 0; border-top: 1px solid var(--cyan); }
.principles p { display: flex; justify-content: space-between; gap: 1rem; margin: 0; padding: .9rem 0; border-bottom: 1px solid var(--line); font-family: var(--display); }
.principles span { align-self: end; color: var(--muted); font-family: var(--utility); font-size: .56rem; letter-spacing: .04em; text-align: right; }

.process,
.architecture { padding-block: 8rem; border-top: 1px solid var(--line); }

.section-heading {
  display: grid;
  grid-template-columns: 9rem 1fr;
  gap: 3rem;
  margin-bottom: 5rem;
}

.section-heading > div:last-child { display: grid; grid-template-columns: 1fr 20rem; gap: 3rem; align-items: end; }
.section-heading p { margin: 0 0 .35rem; color: var(--muted); }

.process-track { margin: 0; padding: 0; list-style: none; counter-reset: steps; }
.process-track li {
  position: relative;
  display: grid;
  grid-template-columns: 1fr 4rem minmax(24rem, 1fr);
  gap: 2rem;
  min-height: 12rem;
  padding: 1.5rem 0;
  border-top: 1px solid var(--line);
  overflow: hidden;
}

.process-track li:last-child { border-bottom: 1px solid var(--line); }
.process-track li::after { position: absolute; left: calc(50% - 1px); top: 0; bottom: 0; width: 1px; background: linear-gradient(var(--cyan), transparent); content: ""; opacity: 0; transition: opacity .3s ease; }
.process-track li:hover::after { opacity: .65; }

.step-letter {
  align-self: center;
  color: rgba(183, 241, 238, .09);
  font-family: var(--utility);
  font-size: clamp(5rem, 10vw, 9rem);
  line-height: .8;
  transition: color .3s ease, transform .3s ease;
}

.process-track li:hover .step-letter { color: rgba(183, 241, 238, .2); transform: translateX(.2rem); }
.step-number { padding-top: .4rem; color: var(--copper-light); font-family: var(--utility); font-size: .65rem; }
.step-copy { display: grid; grid-template-columns: minmax(12rem, .75fr) 1fr; gap: 2rem; align-self: center; }
.step-copy h3 { margin: 0; color: var(--cyan-bright); font-family: var(--utility); font-size: 1.2rem; font-weight: 500; letter-spacing: .03em; }
.step-copy h3 span { display: block; margin-top: .6rem; color: var(--paper); font-family: var(--display); font-size: 2rem; }
.step-copy p { max-width: 30rem; margin: 0; color: var(--muted); }

.layer-map { display: grid; grid-template-columns: repeat(4, 1fr); border: 1px solid var(--line); }
.layer-map article { min-height: 19rem; padding: 1.5rem; border-right: 1px solid var(--line); background: rgba(12, 38, 53, .28); }
.layer-map article:last-child { border: 0; }
.layer-map span { color: var(--copper-light); font-family: var(--utility); font-size: .63rem; letter-spacing: .1em; text-transform: uppercase; }
.layer-map h3 { margin: 5rem 0 1rem; font-family: var(--display); font-size: 2.3rem; font-weight: 500; }
.layer-map p { margin: 0; color: var(--muted); font-size: .86rem; }

.axis {
  display: grid;
  grid-template-columns: 1.1fr 2fr;
  gap: 2rem;
  margin-top: 2rem;
  padding: 2.5rem;
  background: var(--cyan-bright);
  color: var(--ink-deep);
}

.axis-title { display: grid; align-content: start; }
.axis-title small { font-family: var(--utility); font-size: .62rem; letter-spacing: .15em; }
.axis-title strong { margin-top: .4rem; font-family: var(--display); font-size: 2.6rem; font-weight: 600; }
.axis-title p { max-width: 17rem; margin: .6rem 0 0; color: #28464d; font-size: .78rem; }
.axis ul { display: grid; grid-template-columns: 1fr 1fr; gap: 0; margin: 0; padding: 0; border-top: 1px solid rgba(3, 16, 25, .28); list-style: none; }
.axis li { padding: 1rem; border-right: 1px solid rgba(3, 16, 25, .28); border-bottom: 1px solid rgba(3, 16, 25, .28); }
.axis li:nth-child(2n) { border-right: 0; }
.axis li span { display: block; font-family: var(--display); font-size: 1.05rem; font-weight: 600; }
.axis li small { color: #466169; font-size: .67rem; }

.boundary {
  display: grid;
  grid-template-columns: 1.55fr 1fr;
  gap: 5rem;
  align-items: end;
  padding-block: 10rem;
  border-top: 1px solid var(--line);
}

.boundary-card h2 { margin: 2rem 0; }
.boundary-card > p { color: var(--muted); }
.boundary-card ul { display: grid; grid-template-columns: repeat(3, 1fr); gap: .5rem; margin: 2rem 0; padding: 0; list-style: none; }
.boundary-card li { min-height: 8rem; padding: 1rem; border-top: 2px solid var(--copper); background: rgba(201, 131, 79, .08); color: #e4d2c5; font-size: .83rem; }
.boundary-card .boundary-note { padding-left: 1.25rem; border-left: 1px solid var(--cyan); color: #c3d6d9; font-size: .83rem; }

.method-statement { margin: 0 0 .25rem; padding: 2rem 0 2rem 2rem; border-left: 1px solid var(--copper); }
.method-statement p { margin: 0; font-family: var(--display); font-size: 1.75rem; line-height: 1.55; }

.copyright {
  position: relative;
  display: grid;
  grid-template-columns: 1fr 2fr;
  gap: 4rem;
  padding-block: 8rem;
  border-top: 1px solid var(--line);
  overflow: hidden;
}

.copyright-mark { color: rgba(201, 131, 79, .16); font-family: var(--display); font-size: 19rem; line-height: .65; }
.copyright-content { max-width: 45rem; }
.copyright-content h2 { margin: 2rem 0; }
.copyright-content p { color: var(--muted); }
.copyright-content strong { color: var(--paper); }

.site-footer {
  display: grid;
  grid-template-columns: 1fr 1fr auto;
  gap: 2rem;
  align-items: end;
  width: min(100% - 3rem, 1320px);
  margin-inline: auto;
  padding-block: 3rem;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-family: var(--utility);
  font-size: .65rem;
}

.site-footer div { display: grid; }
.site-footer strong { color: var(--cyan-bright); font-size: 1rem; }
.site-footer p { margin: 0; }
.site-footer a { color: var(--copper-light); text-decoration: none; }

@keyframes settle {
  from { opacity: 0; transform: scale(1.035); }
  to { opacity: 1; transform: scale(1); }
}

@media (max-width: 960px) {
  .hero { min-height: 760px; }
  .hero-shade { background: linear-gradient(90deg, rgba(3, 16, 25, .93), rgba(3, 16, 25, .35)), linear-gradient(0deg, var(--ink), transparent 35%); }
  .hero-ledger { display: none; }
  .intro { grid-template-columns: 7rem 1fr; }
  .principles { grid-column: 2; }
  .section-heading { grid-template-columns: 7rem 1fr; }
  .section-heading > div:last-child { grid-template-columns: 1fr; }
  .process-track li { grid-template-columns: .7fr 3rem 1.3fr; }
  .step-copy { grid-template-columns: 1fr; gap: 1rem; }
  .layer-map { grid-template-columns: 1fr 1fr; }
  .layer-map article { border-bottom: 1px solid var(--line); }
  .layer-map article:nth-child(2n) { border-right: 0; }
  .boundary { grid-template-columns: 1fr; }
  .method-statement { max-width: 35rem; }
}

@media (max-width: 680px) {
  .site-header { width: min(100% - 2rem, 1320px); }
  .brand-copy small { display: none; }
  .site-header nav { gap: .25rem; }
  .site-header nav a { padding: .55rem .5rem; font-size: .64rem; }
  .hero { min-height: 720px; height: 100svh; }
  .hero-image img { object-position: 58% center; }
  .hero-shade { background: linear-gradient(90deg, rgba(3, 16, 25, .95) 0%, rgba(3, 16, 25, .62) 70%, rgba(3, 16, 25, .35)), linear-gradient(0deg, var(--ink), transparent 38%); }
  .hero-content { width: min(100% - 2rem, 1320px); margin-top: 6rem; }
  .overline { margin-bottom: 1.4rem; }
  .hero h1 { font-size: clamp(3.15rem, 16vw, 4.5rem); }
  .hero-code { display: none; }
  .hero-thesis { grid-template-columns: 1fr; gap: 1rem; margin-top: 2rem; }
  .hero-thesis p:last-child { max-width: 31rem; }
  .section-shell { width: min(100% - 2rem, 1180px); }
  .intro,
  .section-heading { grid-template-columns: 1fr; gap: 1.5rem; }
  .intro { padding-block: 6rem; }
  .principles { grid-column: 1; margin-top: 2rem; }
  .process,
  .architecture { padding-block: 6rem; }
  .section-heading { margin-bottom: 3rem; }
  .process-track li { grid-template-columns: 4rem 1fr; min-height: 0; padding: 2rem 0; }
  .step-letter { grid-row: 1 / 3; align-self: start; font-size: 4.5rem; }
  .step-number { display: none; }
  .step-copy { grid-column: 2; }
  .process-track li::after { display: none; }
  .layer-map { grid-template-columns: 1fr; }
  .layer-map article { min-height: 0; padding: 1.5rem; border-right: 0; }
  .layer-map h3 { margin-top: 2.5rem; }
  .axis { grid-template-columns: 1fr; padding: 1.5rem; }
  .axis ul { grid-template-columns: 1fr; }
  .axis li { border-right: 0; }
  .boundary { gap: 3rem; padding-block: 6rem; }
  .boundary-card ul { grid-template-columns: 1fr; }
  .boundary-card li { min-height: 0; }
  .copyright { grid-template-columns: 1fr; gap: 1rem; padding-block: 6rem; }
  .copyright-mark { position: absolute; right: 0; top: 6rem; font-size: 10rem; }
  .copyright-content { position: relative; }
  .site-footer { grid-template-columns: 1fr; width: min(100% - 2rem, 1320px); }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *,
  *::before,
  *::after { animation-duration: .01ms !important; animation-iteration-count: 1 !important; transition-duration: .01ms !important; }
}