:root {
  --color-surface: #fefefe;
  --color-surface-alt: #f4f4f4;
  --color-surface-deep: #e5e6e6;
  --color-ink: #2f3537;
  --color-ink-soft: #5b6367;
  --color-ink-muted: #768084;
  --color-line: #d9dada;
  --color-primary: #0a7cad;
  --color-primary-ink: #ffffff;
  --color-primary-soft: #dcecf3;
  --color-accent: #d93808;
  --color-accent-ink: #ffffff;
  --color-highlight: #f7dad2;
  --color-focus: #db3200;
  --color-contrast-surface: #0c181d;
  --color-contrast-ink: #e4e6e7;
  --color-contrast-line: #3c4549;
  --color-contrast-accent: #f63f09;
  --overlay-scrim: linear-gradient(180deg, rgba(12, 24, 29, 0.35) 0%, rgba(12, 24, 29, 0.72) 55%, rgba(12, 24, 29, 0.92) 100%);
  --font-heading: "Source Han Sans SC", "Noto Sans SC", SimHei, "Microsoft YaHei", sans-serif;
  --font-body: "PingFang SC", "Microsoft YaHei", "Source Han Sans SC", sans-serif;
  --font-mono: ui-monospace, Menlo, Consolas, monospace;
  --text-xs: 8.7px;
  --text-sm: 14.2px;
  --text-base: 18px;
  --text-lg: 29.1px;
  --text-xl: 47.1px;
  --text-2xl: 76.2px;
  --text-3xl: 123.4px;
  --text-4xl: 199.6px;
  --text-display: clamp(49px, 10.2vw, 130px);
  --text-figure: clamp(41px, 7.3vw, 94px);
  --weight-heading: 840;
  --weight-body: 400;
  --leading-body: 1.67;
  --leading-heading: 1.26;
  --tracking-heading: -0.034em;
  --radius-sm: 0px;
  --radius-md: 2px;
  --radius-lg: 4px;
  --radius-pill: 4px;
  --border-thin: 1px;
  --border-thick: 2px;
  --shadow-1: none;
  --shadow-2: none;
  --space-1: 8px;
  --space-2: 16px;
  --space-3: 24px;
  --space-4: 32px;
  --space-6: 48px;
  --space-8: 64px;
  --container: 1260px;
  --measure: 66ch;
  --gutter: 24px;
  --section-y: 108px;
  --section-y-lg: 151px;
}

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

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

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, h6 {
  margin: 0;
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  color: var(--color-ink);
}

p { margin: 0; }
ul, ol { margin: 0; padding: 0; }
img, svg, video { max-width: 100%; }
figure { margin: 0; }
address { font-style: normal; }
button { font: inherit; color: inherit; }
table { border-collapse: collapse; }

a { color: var(--color-primary); text-decoration: none; }
a:hover, a:focus-visible { text-decoration: underline; }

:focus-visible {
  outline: 3px solid var(--color-focus);
  outline-offset: 2px;
}

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

.mono { font-family: var(--font-mono); }

.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 ============ */
.skip-link {
  position: absolute;
  left: var(--space-2);
  top: -120px;
  z-index: 200;
  padding: var(--space-2) var(--space-3);
  background: var(--color-accent);
  color: var(--color-accent-ink);
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-sm);
  letter-spacing: .08em;
  border-radius: var(--radius-md);
  transition: top 180ms ease;
}
.skip-link:focus {
  top: var(--space-2);
  color: var(--color-accent-ink);
  text-decoration: none;
}

/* ============ header ============ */
.site-header {
  position: sticky;
  top: 0;
  z-index: 80;
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  border-bottom: var(--border-thick) solid var(--color-contrast-line);
}

.site-header__inner {
  display: flex;
  align-items: stretch;
  justify-content: space-between;
  gap: var(--space-4);
  width: min(100% - (var(--gutter) * 2), var(--container));
  margin-inline: auto;
  min-height: 78px;
}

.scroll-progress {
  position: absolute;
  left: 0;
  bottom: 0;
  height: 3px;
  width: 0;
  background: var(--color-accent);
  transition: width 120ms linear;
}
.site-header[data-scrolled="true"] {
  border-bottom-color: var(--color-primary);
}

/* brand */
.brand {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2) 0;
  color: var(--color-contrast-ink);
  text-decoration: none;
}
.brand:hover, .brand:focus-visible { text-decoration: none; }

.brand__mark {
  display: grid;
  place-items: center;
  flex: 0 0 auto;
  width: 46px;
  height: 46px;
  background: var(--color-accent);
  color: var(--color-accent-ink);
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: var(--text-sm);
  letter-spacing: 0;
  border-radius: var(--radius-sm);
  clip-path: polygon(0 0, 100% 0, 100% 68%, 68% 100%, 0 100%);
}

.brand__text {
  display: flex;
  flex-direction: column;
  gap: 2px;
  min-width: 0;
}

.brand__name {
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-lg);
  line-height: 1;
  letter-spacing: .01em;
  color: var(--color-contrast-ink);
}

.brand__meta {
  font-size: var(--text-sm);
  letter-spacing: .08em;
  color: color-mix(in srgb, var(--color-contrast-ink) 64%, var(--color-contrast-surface));
}

/* nav */
.site-nav {
  display: flex;
  align-items: stretch;
}

.nav-groups { display: none; }

.site-nav__list {
  display: flex;
  align-items: stretch;
  list-style: none;
}

.site-nav__item { display: flex; }

.site-nav__link {
  position: relative;
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 3px;
  padding: 0 var(--space-3);
  border-left: var(--border-thin) solid var(--color-contrast-line);
  color: var(--color-contrast-ink);
  font-size: var(--text-sm);
  letter-spacing: .04em;
  text-decoration: none;
  transition: background-color 180ms ease, color 180ms ease;
}
.site-nav__list .site-nav__item:last-child .site-nav__link {
  border-right: var(--border-thin) solid var(--color-contrast-line);
}

.site-nav__num {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: .16em;
  color: color-mix(in srgb, var(--color-contrast-ink) 58%, var(--color-contrast-surface));
}

.site-nav__label {
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
}

.site-nav__link:hover,
.site-nav__link:focus-visible {
  background: var(--color-primary);
  color: var(--color-primary-ink);
  text-decoration: none;
}
.site-nav__link:hover .site-nav__num,
.site-nav__link:focus-visible .site-nav__num {
  color: var(--color-primary-ink);
}

.site-nav__link[aria-current="page"] {
  background: color-mix(in srgb, var(--color-primary) 26%, var(--color-contrast-surface));
  color: var(--color-primary-ink);
}
.site-nav__link[aria-current="page"]::after {
  content: "";
  position: absolute;
  left: var(--space-3);
  right: var(--space-3);
  bottom: 0;
  height: 4px;
  background: var(--color-primary);
}
.site-nav__link[aria-current="page"] .site-nav__num {
  color: var(--color-primary-soft);
}

/* toggle */
.nav-toggle {
  display: none;
  align-items: center;
  gap: var(--space-1);
  align-self: center;
  padding: var(--space-1) var(--space-2);
  background: transparent;
  border: var(--border-thin) solid var(--color-contrast-line);
  border-radius: var(--radius-md);
  color: var(--color-contrast-ink);
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-sm);
  letter-spacing: .06em;
  cursor: pointer;
}
.nav-toggle:hover { border-color: var(--color-primary); }

.nav-toggle__bars {
  display: grid;
  gap: 4px;
  width: 18px;
}
.nav-toggle__bar {
  display: block;
  height: 2px;
  background: currentColor;
  transition: transform 180ms ease, opacity 180ms ease;
}
.nav-toggle[aria-expanded="true"] .nav-toggle__bar:first-child {
  transform: translateY(3px) rotate(45deg);
}
.nav-toggle[aria-expanded="true"] .nav-toggle__bar:last-child {
  transform: translateY(-3px) rotate(-45deg);
}

/* ============ footer ============ */
.site-footer {
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
}

.footer-tier { width: 100%; }

.footer-tier__inner {
  width: min(100% - (var(--gutter) * 2), var(--container));
  margin-inline: auto;
}

.footer-tier--index {
  border-top: 4px solid var(--color-primary);
}
.footer-tier--index .footer-tier__inner {
  display: grid;
  grid-template-columns: minmax(0, 2fr) minmax(0, 5fr);
  gap: var(--space-6);
  padding: var(--space-8) 0 var(--space-6);
}

.footer-brand {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
  align-items: flex-start;
}
.footer-brand__mark {
  display: grid;
  place-items: center;
  width: 56px;
  height: 56px;
  background: var(--color-primary);
  color: var(--color-primary-ink);
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: var(--text-base);
  clip-path: polygon(0 0, 100% 0, 100% 70%, 70% 100%, 0 100%);
}
.footer-brand__name {
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-lg);
  line-height: 1.1;
  letter-spacing: var(--tracking-heading);
  color: var(--color-contrast-ink);
}
.footer-brand__line {
  max-width: 22ch;
  font-size: var(--text-sm);
  color: color-mix(in srgb, var(--color-contrast-ink) 66%, var(--color-contrast-surface));
}

.footer-index {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: var(--space-4);
}
.footer-index__col {
  padding-left: var(--space-3);
  border-left: var(--border-thin) solid var(--color-contrast-line);
}
.footer-index__title {
  margin-bottom: var(--space-2);
  font-family: var(--font-mono);
  font-weight: var(--weight-body);
  font-size: var(--text-xs);
  letter-spacing: .2em;
  color: var(--color-primary-soft);
}
.footer-index__list {
  display: grid;
  gap: 6px;
  list-style: none;
}
.footer-index__list a {
  display: inline-block;
  font-size: var(--text-sm);
  color: var(--color-contrast-ink);
  border-bottom: var(--border-thin) solid transparent;
  text-decoration: none;
}
.footer-index__list a:hover,
.footer-index__list a:focus-visible {
  color: var(--color-primary-soft);
  border-bottom-color: var(--color-primary);
  text-decoration: none;
}

.footer-tier--legal {
  background: color-mix(in srgb, var(--color-contrast-surface) 90%, var(--color-contrast-ink));
  border-top: var(--border-thin) solid var(--color-contrast-line);
}
.footer-tier--legal .footer-tier__inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-3);
  padding: var(--space-3) 0;
}
.footer-legal {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-4);
  list-style: none;
}
.footer-legal a {
  font-size: var(--text-sm);
  color: var(--color-contrast-ink);
  text-decoration: none;
}
.footer-legal a:hover,
.footer-legal a:focus-visible {
  color: var(--color-primary-soft);
  text-decoration: underline;
}
.footer-legal__icp {
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  color: color-mix(in srgb, var(--color-contrast-ink) 72%, var(--color-contrast-surface));
}

.footer-tier--contact {
  background: var(--color-primary);
  color: var(--color-primary-ink);
}
.footer-tier--contact .footer-tier__inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-3);
  padding: var(--space-3) 0;
}
.footer-contact {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-4);
  font-size: var(--text-sm);
  color: var(--color-primary-ink);
}
.footer-contact__item { white-space: nowrap; }
.footer-contact__key {
  margin-right: 6px;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: .16em;
  opacity: .76;
}
.footer-note {
  font-size: var(--text-sm);
  color: var(--color-primary-ink);
}

.to-top {
  padding: 6px var(--space-2);
  background: transparent;
  border: var(--border-thin) solid currentColor;
  border-radius: var(--radius-md);
  color: var(--color-primary-ink);
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-sm);
  letter-spacing: .08em;
  cursor: pointer;
  transition: background-color 180ms ease, color 180ms ease;
}
.to-top:hover {
  background: var(--color-primary-ink);
  color: var(--color-primary);
}

/* ============ layout primitives ============ */
.container {
  width: min(100% - (var(--gutter) * 2), var(--container));
  margin-inline: auto;
}

.section { padding-block: var(--section-y); }
.section--lg { padding-block: var(--section-y-lg); }
.section--tight { padding-block: var(--space-8); }

.bg-alt { background: var(--color-surface-alt); }
.bg-deep { background: var(--color-surface-deep); }
.bg-primary {
  background: var(--color-primary);
  color: var(--color-primary-ink);
}
.bg-primary h1,
.bg-primary h2,
.bg-primary h3 { color: var(--color-primary-ink); }

.bg-dark {
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
}
.bg-dark h1,
.bg-dark h2,
.bg-dark h3,
.bg-dark h4 { color: var(--color-contrast-ink); }
.bg-dark a { color: var(--color-primary-soft); }

.edge-slant-top { clip-path: polygon(0 2.4vw, 100% 0, 100% 100%, 0 100%); }
.edge-slant-bottom { clip-path: polygon(0 0, 100% 0, 100% calc(100% - 2.4vw), 0 100%); }

.grid-7 {
  display: grid;
  grid-template-columns: repeat(7, minmax(0, 1fr));
  gap: var(--gutter);
}
.col-2 { grid-column: span 2; }
.col-3 { grid-column: span 3; }
.col-4 { grid-column: span 4; }
.col-5 { grid-column: span 5; }
.col-6 { grid-column: span 6; }
.col-7 { grid-column: span 7; }

/* ============ breadcrumbs ============ */
.breadcrumbs { margin-bottom: var(--space-4); }
.breadcrumbs__list {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  list-style: none;
  font-size: var(--text-sm);
  color: var(--color-ink-muted);
}
.breadcrumbs__list li + li::before {
  content: "/";
  margin-right: var(--space-2);
  color: var(--color-line);
}
.breadcrumbs a { color: var(--color-ink-soft); text-decoration: none; }
.breadcrumbs a:hover { color: var(--color-primary); text-decoration: underline; }
.breadcrumbs [aria-current="page"] { color: var(--color-ink); font-weight: 600; }

/* ============ typography helpers ============ */
.display-title {
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-display);
  line-height: .92;
  letter-spacing: var(--tracking-heading);
  text-transform: uppercase;
}
.figure-value {
  font-family: var(--font-mono);
  font-size: var(--text-figure);
  font-weight: 700;
  line-height: .9;
  letter-spacing: -.02em;
}
.eyebrow {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: .2em;
  text-transform: uppercase;
  color: var(--color-accent);
}

.section-head {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  margin-bottom: var(--space-6);
}
.section-head__num {
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  letter-spacing: .2em;
  color: var(--color-accent);
}
.section-head__title { font-size: var(--text-xl); }
.section-head__note {
  max-width: var(--measure);
  font-size: var(--text-sm);
  color: var(--color-ink-soft);
}

/* ============ prose ============ */
.prose {
  max-width: var(--measure);
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: var(--color-ink);
}
.prose > * + * { margin-top: var(--space-3); }
.prose > * + h2 { margin-top: var(--space-8); }
.prose > * + h3 { margin-top: var(--space-6); }
.prose h2 { font-size: var(--text-xl); }
.prose h3 { font-size: var(--text-lg); }
.prose ul, .prose ol { padding-left: 1.5em; }
.prose li + li { margin-top: var(--space-1); }
.prose strong, .prose b { font-weight: var(--weight-heading); }
.prose a { border-bottom: var(--border-thin) solid var(--color-primary); }
.prose blockquote {
  margin-inline: 0;
  padding: var(--space-3) var(--space-4);
  border-left: 4px solid var(--color-accent);
  background: var(--color-surface-alt);
  color: var(--color-ink-soft);
}
.bg-dark .prose,
.bg-dark .prose p,
.bg-dark .prose li { color: var(--color-contrast-ink); }

/* ============ buttons ============ */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  padding: var(--space-2) var(--space-4);
  border: var(--border-thick) solid transparent;
  border-radius: var(--radius-md);
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-sm);
  letter-spacing: .1em;
  text-decoration: none;
  cursor: pointer;
  transition: background-color 180ms ease, color 180ms ease, border-color 180ms ease;
}
.btn:hover, .btn:focus-visible { text-decoration: none; }

.btn--primary {
  background: var(--color-primary);
  color: var(--color-primary-ink);
}
.btn--primary:hover, .btn--primary:focus-visible {
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
}

.btn--accent {
  background: var(--color-accent);
  color: var(--color-accent-ink);
}
.btn--accent:hover, .btn--accent:focus-visible {
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
}

.btn--ghost {
  background: transparent;
  border-color: var(--color-line);
  color: var(--color-ink);
}
.btn--ghost:hover, .btn--ghost:focus-visible {
  border-color: var(--color-primary);
  color: var(--color-primary);
}

.btn--on-dark {
  background: transparent;
  border-color: var(--color-contrast-line);
  color: var(--color-contrast-ink);
}
.btn--on-dark:hover, .btn--on-dark:focus-visible {
  background: var(--color-primary);
  border-color: var(--color-primary);
  color: var(--color-primary-ink);
}

/* ============ panels ============ */
.panel {
  padding: var(--space-4);
  background: var(--color-surface);
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-lg);
}
.panel--dark {
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  border-color: var(--color-contrast-line);
}
.panel--dark h2,
.panel--dark h3,
.panel--dark h4 { color: var(--color-contrast-ink); }
.panel--accent { border-left: 4px solid var(--color-accent); }

/* ============ data table ============ */
.data-table-wrap {
  overflow-x: auto;
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-lg);
  background: var(--color-surface);
}
.data-table {
  width: 100%;
  font-size: var(--text-sm);
  font-variant-numeric: tabular-nums;
}
.data-table caption {
  padding: var(--space-2) var(--space-2) 0;
  text-align: left;
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-base);
  color: var(--color-ink);
}
.data-table th,
.data-table td {
  padding: var(--space-2);
  text-align: left;
  border-bottom: var(--border-thin) solid var(--color-line);
}
.data-table thead th {
  background: var(--color-primary);
  color: var(--color-primary-ink);
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-sm);
  letter-spacing: .08em;
  border-bottom-color: var(--color-primary);
  white-space: nowrap;
}
.data-table td.num,
.data-table th.num {
  font-family: var(--font-mono);
  text-align: right;
  white-space: nowrap;
}
.data-table tbody tr:nth-child(even) { background: var(--color-surface-alt); }
.data-table tbody tr[data-hit="true"],
.data-table tbody tr.is-highlight { background: var(--color-highlight); }
.panel--dark .data-table,
.bg-dark .data-table { color: var(--color-contrast-ink); }
.panel--dark .data-table th,
.panel--dark .data-table td,
.bg-dark .data-table th,
.bg-dark .data-table td { border-bottom-color: var(--color-contrast-line); }
.panel--dark .data-table thead th,
.bg-dark .data-table thead th {
  background: transparent;
  color: var(--color-primary-soft);
}
.panel--dark .data-table tbody tr:nth-child(even),
.bg-dark .data-table tbody tr:nth-child(even) {
  background: color-mix(in srgb, var(--color-contrast-ink) 6%, var(--color-contrast-surface));
}

/* ============ meter ============ */
.meter { display: grid; gap: var(--space-2); }
.meter__row {
  display: grid;
  grid-template-columns: 7ch minmax(0, 1fr) 6ch;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-sm);
}
.meter__label { color: var(--color-ink-soft); }
.meter__track {
  position: relative;
  height: 8px;
  background: var(--color-primary-soft);
  border-radius: var(--radius-sm);
  overflow: hidden;
}
.meter__fill {
  position: absolute;
  inset: 0 auto 0 0;
  width: 0;
  background: var(--color-primary);
}
.meter__row[data-state="key"] .meter__fill { background: var(--color-accent); }
.meter__value {
  font-family: var(--font-mono);
  text-align: right;
  color: var(--color-ink);
}
.bg-dark .meter__label { color: color-mix(in srgb, var(--color-contrast-ink) 72%, var(--color-contrast-surface)); }
.bg-dark .meter__track { background: color-mix(in srgb, var(--color-contrast-ink) 14%, var(--color-contrast-surface)); }
.bg-dark .meter__value { color: var(--color-contrast-ink); }

/* ============ figure block ============ */
.figure-block {
  position: relative;
  display: block;
  overflow: hidden;
  background: var(--color-surface-deep);
  border-radius: var(--radius-lg);
}
.figure-block img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.figure-block::after {
  content: "";
  position: absolute;
  inset: 0;
  background: var(--overlay-scrim);
  pointer-events: none;
}
.figure-block__body {
  position: absolute;
  inset: auto 0 0 0;
  z-index: 1;
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
  padding: var(--space-3) var(--space-4);
  color: var(--color-contrast-ink);
}
.figure-block__kicker {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: .2em;
  text-transform: uppercase;
  color: var(--color-contrast-accent);
}
.figure-block__title {
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-lg);
  line-height: var(--leading-heading);
  color: var(--color-contrast-ink);
}
.figure-block--wide { aspect-ratio: 16 / 9; }
.figure-block--square { aspect-ratio: 1 / 1; }
.figure-block--tall { aspect-ratio: 3 / 4; }
.figure-block--band { aspect-ratio: 21 / 8; }

/* ============ in-page helpers ============ */
.toc { list-style: none; display: grid; gap: var(--space-1); }
.toc a {
  display: block;
  padding: var(--space-1) var(--space-2);
  border-left: var(--border-thin) solid var(--color-line);
  font-size: var(--text-sm);
  color: var(--color-ink-soft);
  text-decoration: none;
  transition: color 180ms ease, border-color 180ms ease, background-color 180ms ease;
}
.toc a:hover { color: var(--color-ink); }
.toc a[aria-current="true"] {
  border-left: 4px solid var(--color-primary);
  background: var(--color-primary-soft);
  color: var(--color-ink);
  font-weight: var(--weight-heading);
}
.bg-dark .toc a { border-left-color: var(--color-contrast-line); color: var(--color-contrast-ink); }
.bg-dark .toc a[aria-current="true"] {
  background: color-mix(in srgb, var(--color-primary) 30%, var(--color-contrast-surface));
  border-left-color: var(--color-primary);
  color: var(--color-contrast-ink);
}

[data-reveal] {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 220ms ease, transform 220ms ease;
}
[data-reveal].is-in {
  opacity: 1;
  transform: none;
}

/* ============ tablet ============ */
@media (max-width: 1080px) {
  .site-header__inner {
    flex-wrap: wrap;
    align-items: center;
    min-height: 0;
  }
  .brand { padding: var(--space-2) 0; }
  .nav-toggle { display: inline-flex; }

  .site-nav {
    display: none;
    order: 3;
    flex-basis: 100%;
    align-items: stretch;
    border-top: var(--border-thin) solid var(--color-contrast-line);
  }
  .site-nav[data-open="true"] { display: block; }

  .nav-groups {
    display: flex;
    flex-wrap: wrap;
    border-bottom: var(--border-thin) solid var(--color-contrast-line);
  }
  .nav-group {
    flex: 1 1 auto;
    padding: var(--space-2);
    background: transparent;
    border: 0;
    border-right: var(--border-thin) solid var(--color-contrast-line);
    color: var(--color-contrast-ink);
    font-family: var(--font-mono);
    font-size: var(--text-xs);
    letter-spacing: .2em;
    cursor: pointer;
  }
  .nav-group[aria-pressed="true"] {
    background: var(--color-primary);
    color: var(--color-primary-ink);
  }

  .site-nav__list { flex-direction: column; }
  .site-nav__item { display: none; }
  .site-nav__item[data-nav-visible="true"] { display: flex; }

  .site-nav__link {
    flex: 1 1 auto;
    flex-direction: row;
    align-items: baseline;
    gap: var(--space-2);
    padding: var(--space-3);
    border-left: 0;
    border-bottom: var(--border-thin) solid var(--color-contrast-line);
  }
  .site-nav__list .site-nav__item:last-child .site-nav__link {
    border-right: 0;
    border-bottom: 0;
  }
  .site-nav__link[aria-current="page"]::after {
    left: 0;
    right: auto;
    top: 0;
    bottom: 0;
    width: 4px;
    height: auto;
  }

  .grid-7 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .col-3, .col-4, .col-5, .col-6, .col-7 { grid-column: span 2; }

  .footer-tier--index .footer-tier__inner {
    grid-template-columns: minmax(0, 1fr);
    gap: var(--space-4);
    padding: var(--space-6) 0 var(--space-4);
  }
  .footer-index { grid-template-columns: minmax(0, 1fr); gap: var(--space-3); }
  .footer-index__col {
    padding-left: 0;
    padding-top: var(--space-2);
    border-left: 0;
    border-top: var(--border-thin) solid var(--color-contrast-line);
  }
}

/* ============ mobile ============ */
@media (max-width: 640px) {
  :root { --section-y: 64px; --section-y-lg: 88px; }

  .brand__name { font-size: var(--text-base); }
  .brand__meta { font-size: var(--text-xs); letter-spacing: .06em; }
  .brand__mark { width: 38px; height: 38px; }

  .grid-7 { grid-template-columns: minmax(0, 1fr); }
  .col-2, .col-3, .col-4, .col-5, .col-6, .col-7 { grid-column: span 1; }

  .section-head__title { font-size: var(--text-lg); }
  .prose h2 { font-size: var(--text-lg); }

  .footer-tier--legal .footer-tier__inner,
  .footer-tier--contact .footer-tier__inner {
    flex-direction: column;
    align-items: flex-start;
    gap: var(--space-2);
  }
  .footer-contact { flex-direction: column; gap: var(--space-1); }
  .footer-contact__item { white-space: normal; }
  .to-top { align-self: flex-start; }

  .meter__row { grid-template-columns: 6ch minmax(0, 1fr) 5ch; }
}

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