:root {
  --ink: #161b22;
  --muted: #5d6672;
  --line: #dfe3e8;
  --soft: #f4f6f7;
  --paper: #ffffff;
  --accent: #276b45;
  --accent-dark: #1f5738;
  --max-width: 1120px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: Arial, Helvetica, sans-serif;
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

img, video { display: block; width: 100%; }
a { color: inherit; text-decoration: none; }

.container {
  width: min(calc(100% - 40px), var(--max-width));
  margin-inline: auto;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  background: rgba(255, 255, 255, .96);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(10px);
}

.header-inner {
  width: min(calc(100% - 40px), var(--max-width));
  min-height: 66px;
  margin-inline: auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 28px;
}

.brand {
  font-size: 20px;
  font-weight: 750;
  letter-spacing: -.02em;
}

nav {
  display: flex;
  align-items: center;
  gap: 24px;
  color: var(--muted);
  font-size: 14px;
  font-weight: 650;
}

nav a:hover { color: var(--ink); }

.nav-code {
  padding: 8px 13px;
  color: var(--accent);
  border: 1px solid #b9d0c2;
  border-radius: 7px;
}

.hero {
  padding-top: 112px;
  padding-bottom: 96px;
  text-align: center;
}

.kicker, .section-label, .method-copy > span, .video-copy > span {
  margin: 0 0 12px;
  color: var(--accent);
  font-size: 12px;
  font-weight: 750;
  letter-spacing: .1em;
  text-transform: uppercase;
}

.hero h1 {
  margin: 0;
  font-size: clamp(58px, 10vw, 100px);
  line-height: .98;
  letter-spacing: -.065em;
}

.subtitle {
  max-width: 900px;
  margin: 26px auto 0;
  font-family: Georgia, "Times New Roman", serif;
  font-size: clamp(22px, 3vw, 34px);
  line-height: 1.25;
  letter-spacing: -.02em;
}

.lead {
  max-width: 760px;
  margin: 26px auto 0;
  color: var(--muted);
  font-size: 18px;
}

.actions {
  margin-top: 34px;
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 10px;
}

.button {
  min-height: 46px;
  padding: 0 18px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--paper);
  font-weight: 700;
  transition: border-color .15s ease, background .15s ease;
}

.button:hover { border-color: #aab1ba; background: var(--soft); }
.button.primary { color: #fff; background: var(--accent); border-color: var(--accent); }
.button.primary:hover { background: var(--accent-dark); border-color: var(--accent-dark); }

.principle {
  max-width: 760px;
  margin: 54px auto 0;
  padding-top: 22px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
  color: var(--muted);
  border-top: 1px solid var(--line);
  font-size: 14px;
}

.principle span:first-child { text-align: right; }
.principle span:last-child { text-align: left; }
.principle strong { color: var(--ink); }

.section { padding-block: 92px; }
.section-tinted { padding-block: 92px; background: var(--soft); border-block: 1px solid var(--line); }
.section-heading { max-width: none; margin-bottom: 48px; }
.section-heading.compact { margin-bottom: 38px; }

.section-heading h2, .code-inner h2 {
  margin: 0;
  font-size: clamp(34px, 5vw, 54px);
  line-height: 1.08;
  letter-spacing: -.045em;
}

.section-heading > p:last-child, .code-inner p:last-child {
  margin: 20px 0 0;
  color: var(--muted);
  font-size: 18px;
}

.overview-contrast {
  margin-top: 24px;
  display: grid;
  gap: 10px;
}

.overview-contrast p {
  margin: 0;
  padding: 14px 16px;
  display: grid;
  grid-template-columns: 138px 1fr;
  gap: 14px;
  border-left: 3px solid #b8bec6;
  background: var(--soft);
}

.overview-contrast p:last-child {
  border-left-color: var(--accent);
  background: #f1f7f3;
}

.overview-contrast strong { color: var(--ink); }
.overview-contrast span { color: var(--muted); }

.method-purpose {
  margin-top: 24px;
  display: grid;
  gap: 10px;
}

.method-purpose p {
  margin: 0;
  padding: 14px 16px;
  display: grid;
  grid-template-columns: 250px 1fr;
  gap: 16px;
  background: #fff;
  border-left: 3px solid #b75d48;
}

.method-purpose p:last-child { border-left-color: #4777a8; }
.method-purpose strong { color: var(--ink); }
.method-purpose span { color: var(--muted); }

.paper-figure {
  margin: 0;
  padding: 20px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 10px;
}

.paper-figure img { height: auto; object-fit: contain; }
.paper-figure figcaption { margin-top: 14px; color: var(--muted); font-size: 13px; }
.paper-figure figcaption strong { display: block; margin-bottom: 4px; color: var(--ink); }
.paper-figure.wide { margin-top: 24px; }
.paper-figure.architecture { margin-top: 30px; }
.paper-figure.architecture img { max-height: 500px; }

.figure-intro {
  max-width: none;
  margin-bottom: 30px;
  padding: 10px 4px 24px;
  border-bottom: 1px solid var(--line);
}

.figure-intro h3 {
  margin: 0;
  font-size: clamp(26px, 3vw, 36px);
  line-height: 1.15;
  letter-spacing: -.035em;
}

.figure-intro p {
  margin: 14px 0 0;
  color: var(--muted);
  font-size: 18px;
  line-height: 1.55;
}

.figure-intro-lines span { display: block; }
.figure-intro-lines span + span { margin-top: 4px; }

.method-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
}

.method-card {
  padding: 28px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 12px;
}

.method-copy { min-height: 190px; }

.method-copy h3, .video-copy h3 {
  margin: 0;
  font-size: 24px;
  line-height: 1.2;
  letter-spacing: -.025em;
}

.method-copy p, .video-copy p { margin: 14px 0 0; color: var(--muted); }
.method-card .paper-figure { margin-top: 24px; padding: 14px; }
.method-card .paper-figure img { aspect-ratio: 16 / 9; }

.video-card {
  overflow: hidden;
  display: flex;
  flex-direction: column;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 12px;
}

.video-copy { padding: 24px; }
.video-card video { margin-top: auto; aspect-ratio: 16 / 9; background: #0c0f12; }

.video-card.featured {
  margin-bottom: 24px;
  display: grid;
  grid-template-columns: .34fr .66fr;
  align-items: center;
}

.video-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; }
.video-grid .video-copy { min-height: 178px; }
.video-grid .video-copy p { white-space: nowrap; }

.results-stack {
  display: grid;
  gap: 28px;
}

.result-figure {
  padding: 24px;
}

.result-figure img {
  width: 100%;
  max-height: none;
}

.result-figure figcaption {
  max-width: 900px;
  margin-top: 18px;
  font-size: 14px;
  line-height: 1.5;
}

.result-narrow {
  width: min(100%, 780px);
  margin-inline: auto;
}

.code-section { color: #fff; background: var(--ink); }

.code-inner {
  display: grid;
  grid-template-columns: 1fr auto;
  align-items: center;
  gap: 48px;
}

.code-inner > div { max-width: 720px; }
.code-inner .section-label { color: #7fc59a; }
.code-inner p:last-child { color: #b9c0c8; }
.code-inner .button { white-space: nowrap; }

footer { border-top: 1px solid var(--line); }

footer .container {
  min-height: 82px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  color: var(--muted);
  font-size: 13px;
}

footer .container span:first-child { color: var(--ink); font-weight: 750; }

@media (max-width: 820px) {
  nav a:not(.nav-code) { display: none; }
  .hero { padding-top: 86px; padding-bottom: 72px; }
  .section, .section-tinted { padding-block: 68px; }
  .method-grid, .video-grid, .video-card.featured, .code-inner { grid-template-columns: 1fr; }
  .method-copy { min-height: 0; }
  .video-grid .video-copy { min-height: 0; }
  .video-grid .video-copy p { white-space: normal; }
  .code-inner { gap: 28px; }
  .code-inner .button { justify-self: start; }
}

@media (max-width: 560px) {
  .container, .header-inner { width: min(calc(100% - 28px), var(--max-width)); }
  .hero { text-align: left; }
  .actions { justify-content: flex-start; }
  .principle { grid-template-columns: 1fr; gap: 8px; }
  .principle span:first-child, .principle span:last-child { text-align: left; }
  .overview-contrast p { grid-template-columns: 1fr; gap: 2px; }
  .method-purpose p { grid-template-columns: 1fr; gap: 3px; }
  .paper-figure, .method-card { padding: 14px; }
  .method-copy, .video-copy { padding: 18px; }
  footer .container { align-items: flex-start; flex-direction: column; justify-content: center; gap: 4px; }
}