:root {
  --color-surface: #eeeded;
  --color-surface-alt: #e6e4e4;
  --color-surface-deep: #dad8d8;
  --color-ink: #48403c;
  --color-ink-soft: #716560;
  --color-ink-muted: #897c76;
  --color-line: #d0cecd;
  --color-primary: #bd5828;
  --color-primary-ink: #ffffff;
  --color-primary-soft: #e7d8d1;
  --color-accent: #81771d;
  --color-accent-ink: #ffffff;
  --color-highlight: #dad8c8;
  --color-focus: #736a12;
  --color-contrast-surface: #251a14;
  --color-contrast-ink: #e7e5e4;
  --color-contrast-line: #504742;
  --color-contrast-accent: #d0c12f;
  --overlay-scrim: linear-gradient(180deg, rgba(37, 26, 20, 0.35) 0%, rgba(37, 26, 20, 0.72) 55%, rgba(37, 26, 20, 0.92) 100%);
  --font-heading: "Songti SC", "Source Han Serif SC", "Noto Serif SC", SimSun, serif;
  --font-body: "PingFang SC", "Microsoft YaHei", "Source Han Sans SC", sans-serif;
  --font-mono: ui-monospace, Menlo, Consolas, monospace;
  --text-xs: 13.7px;
  --text-sm: 16.4px;
  --text-base: 18px;
  --text-lg: 21.6px;
  --text-xl: 25.9px;
  --text-2xl: 31.1px;
  --text-3xl: 37.3px;
  --text-4xl: 44.8px;
  --text-display: clamp(34px, 7.0vw, 89px);
  --text-figure: clamp(28px, 5.0vw, 64px);
  --weight-heading: 693;
  --weight-body: 400;
  --leading-body: 1.77;
  --leading-heading: 1.22;
  --tracking-heading: -0.0em;
  --radius-sm: 10px;
  --radius-md: 11px;
  --radius-lg: 12px;
  --radius-pill: 999px;
  --border-thin: 1px;
  --border-thick: 1px;
  --shadow-1: 0 6px 18px rgba(72, 64, 60, 0.08);
  --shadow-2: 0 18px 44px rgba(72, 64, 60, 0.14);
  --space-1: 8px;
  --space-2: 16px;
  --space-3: 24px;
  --space-4: 32px;
  --space-6: 48px;
  --space-8: 64px;
  --container: 1100px;
  --measure: 74ch;
  --gutter: 32px;
  --section-y: 111px;
  --section-y-lg: 155px;
}

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

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
}

html[data-nav-open] { overflow: hidden; }

body {
  margin: 0;
  background: var(--color-surface);
  color: var(--color-ink);
  font-family: var(--font-body);
  font-size: var(--text-base);
  font-weight: var(--weight-body);
  line-height: var(--leading-body);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

h1, h2, h3, h4, h5 {
  margin: 0;
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  color: inherit;
  text-wrap: balance;
}

p { margin: 0; }
ul, ol { margin: 0; padding: 0; list-style: none; }
a { color: inherit; }
button { font: inherit; color: inherit; }
img, svg, video { display: block; max-width: 100%; height: auto; }

code, kbd, samp, .num { font-family: var(--font-mono); }

#main-content { scroll-margin-top: calc(var(--header-h, 76px) + var(--space-4)); }

:focus-visible {
  outline: 3px solid var(--color-focus);
  outline-offset: 3px;
  border-radius: var(--radius-sm);
}

.visually-hidden {
  position: absolute;
  width: 1px; height: 1px;
  margin: -1px; padding: 0;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}

.skip-link {
  position: fixed;
  top: var(--space-2);
  left: var(--space-2);
  z-index: 200;
  padding: 12px 18px;
  border-radius: var(--radius-md);
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  font-size: var(--text-sm);
  text-decoration: none;
  transform: translateY(-180%);
  transition: transform 180ms ease;
}

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

/* ================= layout ================= */
.shell {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: var(--space-4);
}

.section { padding-block: var(--section-y); }
.section--tight { padding-block: var(--space-8); }
.section--alt { background: var(--color-surface-alt); }

.section--deep {
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
}

.section--deep .section-head__note,
.section--deep .lead { color: color-mix(in srgb, var(--color-contrast-ink) 74%, transparent); }

.section--deep .section-head__kicker { color: var(--color-contrast-accent); }

.block {
  background: var(--color-surface-alt);
  border-radius: var(--radius-lg);
  padding: clamp(24px, 4vw, 48px);
}

.block--warm { background: var(--color-primary-soft); }
.block--deep {
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
}

.grid { display: grid; gap: var(--gutter); }
.grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid--split { grid-template-columns: minmax(0, 7fr) minmax(0, 5fr); }
.grid--split-rev { grid-template-columns: minmax(0, 5fr) minmax(0, 7fr); }

.rule {
  width: 56px;
  height: 8px;
  margin: var(--space-6) 0;
  border: 0;
  border-radius: var(--radius-pill);
  background: var(--color-surface-deep);
}

.section--deep .rule { background: var(--color-contrast-line); }

/* ================= header ================= */
.site-header {
  position: sticky;
  top: 0;
  z-index: 60;
  color: var(--color-ink);
  background: color-mix(in srgb, var(--color-surface) 94%, transparent);
  -webkit-backdrop-filter: blur(14px) saturate(1.1);
  backdrop-filter: blur(14px) saturate(1.1);
  border-bottom: var(--border-thin) solid transparent;
  transition: background 240ms ease, box-shadow 240ms ease, color 240ms ease, border-color 240ms ease;
}

.site-header[data-scrolled="true"] {
  background: var(--color-surface);
  border-bottom-color: var(--color-line);
  box-shadow: var(--shadow-1);
}

.site-header[data-variant="overlay"]:not([data-scrolled="true"]) {
  background: transparent;
  border-bottom-color: color-mix(in srgb, var(--color-contrast-ink) 22%, transparent);
  color: var(--color-contrast-ink);
  -webkit-backdrop-filter: none;
  backdrop-filter: none;
}

.site-header[data-variant="overlay"]:not([data-scrolled="true"]) .site-brand__line { color: color-mix(in srgb, var(--color-contrast-ink) 72%, transparent); }
.site-header[data-variant="overlay"]:not([data-scrolled="true"]) .site-brand__mark {
  background: color-mix(in srgb, var(--color-contrast-surface) 45%, transparent);
  border-color: var(--color-contrast-accent);
}
.site-header[data-variant="overlay"]:not([data-scrolled="true"]) .site-brand__mono { color: var(--color-contrast-accent); }
.site-header[data-variant="overlay"]:not([data-scrolled="true"]) .site-nav__link:hover {
  background: color-mix(in srgb, var(--color-contrast-ink) 16%, transparent);
  color: var(--color-contrast-accent);
}
.site-header[data-variant="overlay"]:not([data-scrolled="true"]) .site-nav__link[aria-current="page"] { color: var(--color-contrast-accent); }
.site-header[data-variant="overlay"]:not([data-scrolled="true"]) .site-nav__link[aria-current="page"]::after { background: var(--color-contrast-accent); }
.site-header[data-variant="overlay"]:not([data-scrolled="true"]) .nav-toggle { border-color: color-mix(in srgb, var(--color-contrast-ink) 34%, transparent); }
.site-header[data-scrolled="true"] .site-header__progress { background: var(--color-primary); }

.site-header__progress {
  position: absolute;
  left: 0;
  bottom: 0;
  display: block;
  width: 0;
  height: 2px;
  border-radius: var(--radius-pill);
  background: var(--color-contrast-accent);
  transition: width 90ms linear;
}

.site-header__inner {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  min-height: 76px;
}

.site-brand {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  flex: 0 0 auto;
  text-decoration: none;
  color: inherit;
}

.site-brand__mark {
  display: grid;
  place-items: center;
  width: 44px;
  height: 44px;
  border: var(--border-thick) solid var(--color-primary);
  border-radius: var(--radius-pill);
  background: var(--color-surface);
  box-shadow: var(--shadow-1);
  transition: transform 200ms ease, border-color 200ms ease;
}

.site-brand:hover .site-brand__mark {
  transform: translateY(-2px);
  border-color: var(--color-accent);
}

.site-brand__mono {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--color-primary);
}

.site-brand__text { display: flex; flex-direction: column; line-height: 1.16; }

.site-brand__name {
  font-family: var(--font-heading);
  font-size: var(--text-lg);
  font-weight: var(--weight-heading);
}

.site-brand__line {
  font-size: var(--text-xs);
  letter-spacing: 0.04em;
  color: var(--color-ink-muted);
}

.site-nav { margin-left: auto; }

.site-nav__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 2px;
}

.site-nav__link {
  position: relative;
  display: inline-block;
  padding: 10px 13px;
  border-radius: var(--radius-pill);
  font-size: var(--text-sm);
  text-decoration: none;
  color: inherit;
  transition: background 180ms ease, color 180ms ease;
}

.site-nav__link:hover {
  background: color-mix(in srgb, var(--color-primary) 12%, transparent);
  color: var(--color-primary);
}

.site-nav__link[aria-current="page"] {
  color: var(--color-primary);
  font-weight: 600;
}

.site-nav__link[aria-current="page"]::after {
  content: "";
  position: absolute;
  left: 13px;
  right: 13px;
  bottom: 5px;
  height: 2px;
  border-radius: var(--radius-pill);
  background: var(--color-primary);
}

.site-header__actions {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  margin-left: auto;
}

/* ================= buttons ================= */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-1);
  padding: 12px 21px;
  border: var(--border-thin) solid transparent;
  border-radius: var(--radius-pill);
  font-family: var(--font-body);
  font-size: var(--text-sm);
  font-weight: 500;
  line-height: 1.2;
  text-decoration: none;
  cursor: pointer;
  transition: transform 180ms ease, background 180ms ease, color 180ms ease, border-color 180ms ease, box-shadow 180ms ease;
}

.btn--primary {
  background: var(--color-primary);
  color: var(--color-primary-ink);
  box-shadow: var(--shadow-1);
}

.btn--primary:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-2);
}

.btn--ghost {
  background: transparent;
  color: inherit;
  border-color: color-mix(in srgb, var(--color-ink) 26%, transparent);
}

.btn--ghost:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
}

.btn--quiet {
  background: var(--color-surface-deep);
  color: var(--color-ink);
}

.btn--quiet:hover { background: var(--color-highlight); }

.btn--sm { padding: 9px 16px; font-size: var(--text-xs); }

/* ================= nav toggle ================= */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 8px;
  padding: 10px 14px;
  border: var(--border-thin) solid color-mix(in srgb, var(--color-ink) 22%, transparent);
  border-radius: var(--radius-pill);
  background: transparent;
  font-size: var(--text-xs);
  cursor: pointer;
  transition: border-color 180ms ease, color 180ms ease;
}

.nav-toggle:hover { border-color: var(--color-primary); color: var(--color-primary); }

.nav-toggle__bars {
  position: relative;
  display: block;
  width: 18px;
  height: 2px;
  border-radius: 2px;
  background: currentColor;
}

.nav-toggle__bars::before,
.nav-toggle__bars::after {
  content: "";
  position: absolute;
  left: 0;
  width: 18px;
  height: 2px;
  border-radius: 2px;
  background: currentColor;
  transition: transform 200ms ease, opacity 200ms ease;
}

.nav-toggle__bars::before { top: -6px; }
.nav-toggle__bars::after { top: 6px; }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars { background: transparent; }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars::before { transform: translateY(6px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars::after { transform: translateY(-6px) rotate(-45deg); }

/* ================= typography helpers ================= */
.section-head {
  max-width: 62ch;
  margin-bottom: var(--space-6);
}

.section-head__kicker {
  display: block;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.16em;
  color: var(--color-primary);
}

.section-head__title {
  margin-top: var(--space-2);
  font-size: var(--text-3xl);
}

.section-head__note {
  margin-top: var(--space-2);
  color: var(--color-ink-soft);
}

.lead {
  max-width: var(--measure);
  color: var(--color-ink-soft);
  font-size: var(--text-lg);
}

.prose {
  max-width: var(--measure);
  font-size: var(--text-base);
  line-height: var(--leading-body);
}

.prose > * + * { margin-top: var(--space-3); }
.prose h2 { font-size: var(--text-2xl); }
.prose h3 { font-size: var(--text-xl); }
.prose ul, .prose ol { padding-left: 1.2em; }
.prose ul { list-style: disc; }
.prose ol { list-style: decimal; }
.prose li + li { margin-top: var(--space-1); }

.hl {
  background-image: linear-gradient(var(--color-highlight), var(--color-highlight));
  background-repeat: no-repeat;
  background-size: 100% 0.62em;
  background-position: 0 0.72em;
  padding: 0 2px;
}

.section--deep .hl {
  background-image: linear-gradient(color-mix(in srgb, var(--color-contrast-accent) 40%, transparent), color-mix(in srgb, var(--color-contrast-accent) 40%, transparent));
}

.link-underline {
  text-decoration: none;
  padding-bottom: 3px;
  background-image: linear-gradient(var(--color-primary), var(--color-primary));
  background-repeat: no-repeat;
  background-position: 0 100%;
  background-size: 100% 2px;
  transition: color 180ms ease, background-size 180ms ease;
}

.link-underline:hover {
  color: var(--color-primary);
  background-size: 100% 100%;
  background-image: linear-gradient(color-mix(in srgb, var(--color-primary) 16%, transparent), color-mix(in srgb, var(--color-primary) 16%, transparent));
}

/* ================= cards / tags ================= */
.card {
  border-radius: var(--radius-lg);
  background: var(--color-surface);
  padding: var(--space-4);
}

.card--warm { background: var(--color-primary-soft); }
.card--quiet { background: var(--color-surface-deep); }
.card--float { box-shadow: var(--shadow-1); }

.card__title { font-size: var(--text-xl); }
.card__body { margin-top: var(--space-2); color: var(--color-ink-soft); font-size: var(--text-sm); }
.card__foot { margin-top: var(--space-3); }

.card--warm .card__body,
.block--warm .card__body { color: color-mix(in srgb, var(--color-ink) 78%, transparent); }

.section--deep .card {
  background: color-mix(in srgb, var(--color-contrast-ink) 8%, transparent);
  color: var(--color-contrast-ink);
}

.section--deep .card__body { color: color-mix(in srgb, var(--color-contrast-ink) 74%, transparent); }

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 5px 12px;
  border-radius: var(--radius-pill);
  background: var(--color-surface-deep);
  color: var(--color-ink-soft);
  font-size: var(--text-xs);
  letter-spacing: 0.04em;
  white-space: nowrap;
}

.tag--accent { background: var(--color-accent); color: var(--color-accent-ink); }

.tag--outline {
  background: transparent;
  border: var(--border-thin) solid var(--color-primary);
  color: var(--color-primary);
}

.section--deep .tag {
  background: color-mix(in srgb, var(--color-contrast-ink) 12%, transparent);
  color: var(--color-contrast-ink);
}

.section--deep .tag--outline { border-color: var(--color-contrast-accent); color: var(--color-contrast-accent); }

/* ================= figures ================= */
.figure { display: block; margin: 0; }

.figure__media {
  position: relative;
  display: block;
  background: var(--color-surface-deep);
}

.figure__img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 4 / 3;
  object-fit: cover;
  border-radius: 0;
}

.figure--wide .figure__img { aspect-ratio: 16 / 9; }
.figure--tall .figure__img { aspect-ratio: 3 / 4; }

.figure__caption {
  margin-top: 10px;
  max-width: 46ch;
  font-size: var(--text-xs);
  color: var(--color-ink-muted);
}

.section--deep .figure__caption { color: color-mix(in srgb, var(--color-contrast-ink) 66%, transparent); }

.figure__scrim {
  position: absolute;
  inset: 0;
  display: block;
  background: var(--overlay-scrim);
}

.figure__overlay {
  position: absolute;
  inset: auto 0 0 0;
  padding: var(--space-4);
  color: var(--color-contrast-ink);
  font-size: var(--text-sm);
}

/* ================= breadcrumbs ================= */
.breadcrumbs {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: var(--space-4);
  font-size: var(--text-xs);
  color: var(--color-ink-muted);
}

.breadcrumbs__item { display: inline-flex; align-items: center; gap: 8px; }
.breadcrumbs__item + .breadcrumbs__item::before { content: "/"; color: var(--color-line); }

.breadcrumbs__link {
  color: var(--color-ink-soft);
  text-decoration: none;
}

.breadcrumbs__link:hover { color: var(--color-primary); }

.breadcrumbs__current { color: var(--color-primary); }

/* ================= footer ================= */
.site-footer {
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  border-top: var(--border-thin) solid var(--color-contrast-line);
  padding-block: var(--space-8) var(--space-4);
}

.site-footer__grid {
  display: grid;
  grid-template-columns: minmax(0, 1.3fr) minmax(0, 1fr) minmax(0, 1.2fr);
  gap: var(--space-8) var(--space-6);
}

.site-footer__brand-name {
  font-family: var(--font-heading);
  font-size: var(--text-2xl);
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
}

.site-footer__brand-line {
  margin-top: 6px;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  color: color-mix(in srgb, var(--color-contrast-ink) 66%, transparent);
}

.site-footer__tagline {
  margin-top: var(--space-3);
  font-size: var(--text-sm);
  color: var(--color-contrast-accent);
}

.year-rail {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: var(--space-3);
}

.year-chip {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 64px;
  padding: 8px 12px;
  border: 1px solid var(--color-contrast-accent);
  border-radius: var(--radius-pill);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  color: var(--color-contrast-accent);
  transition: transform 200ms ease, border-color 200ms ease, background 200ms ease;
}

.year-chip--s1 { border-width: 1px; }
.year-chip--s2 { border-width: 2px; }
.year-chip--s3 { border-width: 3px; }
.year-chip--s4 {
  border-width: 4px;
  background: color-mix(in srgb, var(--color-contrast-accent) 16%, transparent);
}

.year-chip:hover {
  transform: translateY(-3px);
  background: color-mix(in srgb, var(--color-contrast-accent) 22%, transparent);
}

.site-footer__closing {
  margin-top: var(--space-4);
  max-width: 40ch;
  font-size: var(--text-sm);
  color: color-mix(in srgb, var(--color-contrast-ink) 78%, transparent);
}

.footer-label {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.16em;
  color: color-mix(in srgb, var(--color-contrast-ink) 60%, transparent);
}

.footer-links {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px var(--space-4);
  margin-top: var(--space-3);
}

.footer-links__link {
  position: relative;
  display: inline-block;
  font-size: var(--text-sm);
  color: color-mix(in srgb, var(--color-contrast-ink) 88%, transparent);
  text-decoration: none;
  transition: color 180ms ease;
}

.footer-links__link::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -3px;
  width: 0;
  height: 1px;
  background: var(--color-contrast-accent);
  transition: width 200ms ease;
}

.footer-links__link:hover { color: var(--color-contrast-accent); }
.footer-links__link:hover::after { width: 100%; }

.contact-list {
  display: grid;
  gap: var(--space-3);
  margin-top: var(--space-3);
}

.contact-list__item { display: grid; gap: 4px; justify-items: start; }

.contact-list__key {
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  color: color-mix(in srgb, var(--color-contrast-ink) 58%, transparent);
}

.contact-list__val {
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  letter-spacing: 0.02em;
  color: var(--color-contrast-ink);
  word-break: break-word;
}

.contact-list__val--text { font-family: var(--font-body); line-height: 1.6; }

.copy-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 12px;
  border: 1px solid var(--color-contrast-line);
  border-radius: var(--radius-pill);
  background: transparent;
  font-size: var(--text-xs);
  cursor: pointer;
  transition: border-color 180ms ease, color 180ms ease, background 180ms ease;
}

.copy-btn:hover {
  border-color: var(--color-contrast-accent);
  color: var(--color-contrast-accent);
}

.copy-btn[data-copied="true"] {
  border-color: var(--color-contrast-accent);
  background: color-mix(in srgb, var(--color-contrast-accent) 18%, transparent);
  color: var(--color-contrast-accent);
}

.footer-note {
  margin-top: var(--space-3);
  font-size: var(--text-xs);
  line-height: 1.7;
  color: color-mix(in srgb, var(--color-contrast-ink) 62%, transparent);
}

.site-footer__bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-3);
  margin-top: var(--space-8);
  padding-top: var(--space-4);
  border-top: 1px solid var(--color-contrast-line);
  font-size: var(--text-xs);
  color: color-mix(in srgb, var(--color-contrast-ink) 66%, transparent);
}

.footer-icp { font-family: var(--font-mono); letter-spacing: 0.04em; }

.legal-links { display: flex; flex-wrap: wrap; gap: var(--space-4); }

.legal-links__link {
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 180ms ease, border-color 180ms ease;
}

.legal-links__link:hover {
  color: var(--color-contrast-accent);
  border-bottom-color: currentColor;
}

/* ================= reveal ================= */
[data-reveal="wait"] {
  opacity: 0;
  transform: translateY(12px);
}

[data-reveal="in"] {
  opacity: 1;
  transform: translateY(0);
  transition: opacity 480ms ease, transform 480ms ease;
}

/* ================= responsive ================= */
@media (max-width: 1020px) {
  .site-nav__link { padding: 10px 9px; }
}

@media (max-width: 900px) {
  :root { --section-y: 80px; --section-y-lg: 104px; }

  .nav-toggle { display: inline-flex; }
  .site-header__cta { display: none; }

  .site-nav {
    position: fixed;
    inset: 0;
    z-index: 55;
    display: flex;
    flex-direction: column;
    gap: var(--space-2);
    margin-left: 0;
    padding: calc(var(--header-h, 76px) + var(--space-4)) var(--space-4) var(--space-8);
    background: var(--color-surface);
    overflow-y: auto;
    visibility: hidden;
    transform: translateX(100%);
    transition: transform 280ms ease, visibility 280ms ease;
  }

  .site-nav[data-open="true"] {
    visibility: visible;
    transform: translateX(0);
  }

  .site-nav__list {
    flex-direction: column;
    align-items: stretch;
    gap: 2px;
  }

  .site-nav__link {
    display: block;
    padding: var(--space-2);
    border-radius: var(--radius-md);
    font-family: var(--font-heading);
    font-size: var(--text-xl);
  }

  .site-nav__link[aria-current="page"]::after {
    left: var(--space-2);
    right: auto;
    bottom: 10px;
    width: 30px;
  }

  .site-footer__grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: var(--space-6) var(--space-4);
  }

  .site-footer__brand { grid-column: 1 / -1; }

  .grid--2,
  .grid--3,
  .grid--split,
  .grid--split-rev { grid-template-columns: minmax(0, 1fr); }

  .section { padding-block: var(--section-y); }
}

@media (max-width: 640px) {
  .shell { padding-inline: var(--space-3); }
  .site-header__inner { gap: var(--space-2); min-height: 68px; }
  .site-brand__line { display: none; }
  .site-footer__grid { grid-template-columns: minmax(0, 1fr); }
  .footer-links { grid-template-columns: minmax(0, 1fr); }
  .site-footer__bottom { flex-direction: column; align-items: flex-start; }
  .section-head__title { font-size: var(--text-2xl); }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }

  *,
  *::before,
  *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
  }

  [data-reveal="wait"] { opacity: 1; transform: none; }
  .site-header__progress { transition: none; }
}