:root {
  --color-surface: #fbfbfb;
  --color-surface-alt: #f2f2f2;
  --color-surface-deep: #e5e6e6;
  --color-ink: #424a4d;
  --color-ink-soft: #667175;
  --color-ink-muted: #788387;
  --color-line: #dadbdc;
  --color-primary: #3f7e97;
  --color-primary-ink: #ffffff;
  --color-primary-soft: #e1eaed;
  --color-accent: #db1f81;
  --color-accent-ink: #ffffff;
  --color-highlight: #f5d3e5;
  --color-focus: #da1179;
  --color-contrast-surface: #13191b;
  --color-contrast-ink: #e4e6e7;
  --color-contrast-line: #414648;
  --color-contrast-accent: #e43f95;
  --overlay-scrim: linear-gradient(180deg, rgba(19, 25, 27, 0.35) 0%, rgba(19, 25, 27, 0.72) 55%, rgba(19, 25, 27, 0.92) 100%);
  --font-heading: "PingFang SC", "HarmonyOS Sans SC", "Microsoft YaHei", "Source Han Sans SC", sans-serif;
  --font-body: "PingFang SC", "HarmonyOS Sans SC", "Microsoft YaHei", "Source Han Sans SC", sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  --text-xs: 11.4px;
  --text-sm: 13.7px;
  --text-base: 15px;
  --text-lg: 18.0px;
  --text-xl: 21.6px;
  --text-2xl: 25.9px;
  --text-3xl: 31.1px;
  --text-4xl: 37.3px;
  --text-display: clamp(34px, 5.9vw, 76px);
  --text-figure: clamp(28px, 4.3vw, 55px);
  --weight-heading: 637;
  --weight-body: 400;
  --leading-body: 1.79;
  --leading-heading: 1.25;
  --tracking-heading: -0.003em;
  --radius-sm: 5px;
  --radius-md: 8px;
  --radius-lg: 10px;
  --radius-pill: 999px;
  --border-thin: 1px;
  --border-thick: 2px;
  --shadow-1: 0 1px 0 rgba(66, 74, 77, 0.12);
  --shadow-2: 0 2px 0 rgba(66, 74, 77, 0.18);
  --space-1: 8px;
  --space-2: 16px;
  --space-3: 24px;
  --space-4: 32px;
  --space-6: 48px;
  --space-8: 64px;
  --container: 1180px;
  --measure: 73ch;
  --gutter: 32px;
  --section-y: 85px;
  --section-y-lg: 119px;
}

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

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

body {
  margin: 0;
  background-color: 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);
  font-kerning: normal;
  overflow-wrap: break-word;
  word-break: break-word;
}

h1, h2, h3, h4, h5, h6 {
  margin: 0 0 var(--space-2);
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  color: var(--color-ink);
  word-break: keep-all;
}

h1 { font-size: var(--text-3xl); }
h2 { font-size: var(--text-2xl); }
h3 { font-size: var(--text-xl); }
h4 { font-size: var(--text-lg); }

p { margin: 0 0 var(--space-2); }
p:last-child { margin-bottom: 0; }

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

img { display: block; max-width: 100%; height: auto; }
button { font: inherit; color: inherit; }
table { border-collapse: collapse; width: 100%; }
[id] { scroll-margin-top: 132px; }

code, kbd, samp, .mono {
  font-family: var(--font-mono);
  font-feature-settings: "tnum" 1;
  font-size: var(--text-sm);
}

:focus-visible {
  outline: var(--border-thick) solid var(--color-focus);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}

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

/* ---------- layout ---------- */
.container {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: clamp(18px, 4vw, var(--gutter));
}

.section { padding-block: var(--section-y); }
.section--lg { padding-block: var(--section-y-lg); }
.section--tight { padding-block: var(--space-6); }
.section--alt { background-color: var(--color-surface-alt); }
.section--deep {
  background-color: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
}
.section--deep h1, .section--deep h2, .section--deep h3, .section--deep h4 { color: var(--color-contrast-ink); }
.section--deep .lede { color: color-mix(in srgb, var(--color-contrast-ink) 72%, transparent); }

.grid {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: var(--gutter);
}
.col-3 { grid-column: span 3; }
.col-4 { grid-column: span 4; }
.col-6 { grid-column: span 6; }
.col-8 { grid-column: span 8; }
.col-12 { grid-column: span 12; }

.section-head {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: var(--space-3);
  flex-wrap: wrap;
  padding-bottom: var(--space-2);
  margin-bottom: var(--space-4);
  border-bottom: var(--border-thin) solid var(--color-line);
}
.section-head > * { margin-bottom: 0; }

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  line-height: 1.1;
  letter-spacing: 0.18em;
  color: var(--color-primary);
  margin-bottom: var(--space-1);
}
.eyebrow::before {
  content: "";
  width: 24px;
  height: var(--border-thin);
  background-color: var(--color-primary);
  flex: none;
}
.section--deep .eyebrow { color: var(--color-contrast-accent); }
.section--deep .eyebrow::before { background-color: var(--color-contrast-accent); }

.section-title { font-size: var(--text-2xl); margin-bottom: 0; }

.lede {
  font-size: var(--text-lg);
  line-height: 1.6;
  color: var(--color-ink-soft);
  max-width: var(--measure);
}

.divider { height: var(--border-thin); border: 0; background-color: var(--color-line); margin: 0; }
.divider--dotted { height: 0; border-top: var(--border-thin) dotted var(--color-line); background: none; }

/* ---------- header ---------- */
.skip-link {
  position: absolute;
  left: var(--space-2);
  top: var(--space-1);
  z-index: 200;
  transform: translateY(-220%);
  padding: 10px 14px;
  background-color: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  border-radius: var(--radius-sm);
  transition: transform 0.18s ease-out;
}
.skip-link:focus { transform: translateY(0); color: var(--color-contrast-ink); }

.site-header {
  position: sticky;
  top: 0;
  z-index: 90;
  background-color: var(--color-surface);
  border-bottom: var(--border-thin) solid var(--color-line);
}
.site-header[data-stuck] { box-shadow: var(--shadow-1); }

.progress-rail { height: 2px; background-color: var(--color-line); }
.progress-fill {
  display: block;
  height: 100%;
  width: 0;
  background: linear-gradient(90deg, var(--color-primary) 0%, var(--color-primary) 62%, var(--color-accent) 100%);
  transition: width 0.12s linear;
}

.masthead { background-color: var(--color-surface); }

.masthead-inner {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto minmax(0, 1fr);
  align-items: center;
  gap: var(--space-2);
  padding-block: var(--space-4) var(--space-3);
  transition: padding-block 0.2s ease-out;
}
.site-header[data-stuck] .masthead-inner { padding-block: var(--space-2); }

.masthead-util { display: flex; align-items: center; gap: var(--space-2); min-width: 0; }
.masthead-util--start { justify-self: start; }
.masthead-util--end { justify-self: end; }
.masthead-brand { justify-self: center; text-align: center; }

.brand {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  color: var(--color-ink);
  text-decoration: none;
}
.brand-name {
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: var(--text-2xl);
  line-height: 1;
  letter-spacing: -0.01em;
  color: var(--color-ink);
  transition: font-size 0.2s ease-out, color 0.18s ease-out;
}
.brand-sep { color: var(--color-accent); font-weight: 700; line-height: 1; }
.brand-sub {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  line-height: 1.1;
  letter-spacing: 0.18em;
  color: var(--color-ink-muted);
}
.brand:hover .brand-name { color: var(--color-primary); }
.site-header[data-stuck] .brand-name { font-size: var(--text-lg); }

.version-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin: 0;
  padding: 6px 10px;
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-sm);
  background-color: var(--color-primary-soft);
  color: var(--color-primary);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  line-height: 1.1;
  letter-spacing: 0.06em;
  white-space: nowrap;
}
.version-dot { width: 8px; height: 8px; flex: none; background-color: var(--color-accent); border-radius: 50%; }
.version-note {
  color: var(--color-ink-muted);
  padding-left: 8px;
  border-left: var(--border-thin) dotted var(--color-line);
}
@media (max-width: 1120px) { .version-note { display: none; } }

.shortcut {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 14px;
  background-color: var(--color-accent);
  color: var(--color-accent-ink);
  border-radius: var(--radius-sm);
  font-family: var(--font-heading);
  font-weight: 600;
  font-size: var(--text-sm);
  line-height: 1;
  white-space: nowrap;
  transition: background-color 0.18s ease-out, color 0.18s ease-out;
}
.shortcut:hover { background-color: var(--color-contrast-surface); color: var(--color-contrast-ink); }
.shortcut-dot { width: 8px; height: 8px; flex: none; background-color: currentColor; border-radius: 1px; }

.nav-toggle {
  display: none;
  align-items: center;
  gap: 8px;
  padding: 9px 12px;
  background-color: transparent;
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-sm);
  color: var(--color-ink-soft);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.12em;
  line-height: 1;
  cursor: pointer;
  transition: color 0.18s ease-out, border-color 0.18s ease-out;
}
.nav-toggle:hover { color: var(--color-primary); border-color: var(--color-primary); }
.nav-toggle[aria-expanded="true"] { color: var(--color-primary); border-color: var(--color-primary); }
.nav-toggle-bars { display: inline-flex; flex-direction: column; justify-content: center; gap: 3px; width: 16px; }
.nav-toggle-bars span { display: block; height: var(--border-thin); background-color: currentColor; }

.site-nav {
  border-top: var(--border-thin) solid var(--color-line);
  border-bottom: var(--border-thin) solid var(--color-line);
}
.nav-list { display: flex; justify-content: center; align-items: stretch; gap: var(--space-6); }
.nav-item { display: flex; }

.nav-link {
  position: relative;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 2px;
  color: var(--color-ink-soft);
  font-family: var(--font-heading);
  font-weight: 500;
  font-size: var(--text-sm);
  line-height: 1;
  letter-spacing: 0.02em;
  text-decoration: none;
  transition: color 0.18s ease-out;
}
.nav-link::before {
  content: "";
  width: 6px;
  height: 6px;
  flex: none;
  border-radius: 50%;
  background-color: var(--color-line);
  transition: background-color 0.18s ease-out, border-radius 0.18s ease-out;
}
.nav-link::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: -1px;
  height: var(--border-thick);
  background-color: var(--color-accent);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform 0.2s ease-out;
}
.nav-link:hover { color: var(--color-ink); }
.nav-link:hover::before { background-color: var(--color-primary); }
.nav-link[aria-current="page"] { color: var(--color-primary); }
.nav-link[aria-current="page"]::before { background-color: var(--color-accent); border-radius: 1px; }
.nav-link[aria-current="page"]::after { transform: scaleX(1); }

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

.footer-top { padding-block: var(--section-y) var(--space-6); }

.footer-kicker {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin: 0 0 var(--space-4);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  line-height: 1.1;
  letter-spacing: 0.16em;
  color: color-mix(in srgb, var(--color-contrast-ink) 62%, transparent);
}
.footer-kicker-code { color: var(--color-contrast-accent); }
.footer-kicker::after {
  content: "";
  width: 60px;
  height: var(--border-thin);
  background-color: var(--color-contrast-line);
}

.footer-index {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: var(--gutter);
  align-items: start;
}
.footer-col {
  position: relative;
  padding-left: var(--space-3);
  border-left: var(--border-thin) solid var(--color-contrast-line);
}
.footer-col::before {
  content: "";
  position: absolute;
  left: 0;
  top: 4px;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background-color: var(--color-primary);
  transform: translateX(-50%);
}
.footer-col:nth-child(2) { margin-top: var(--space-4); }
.footer-col:nth-child(3) { margin-top: var(--space-6); }
.footer-col:nth-child(2)::before { background-color: var(--color-accent); }
.footer-col:nth-child(3)::before { background-color: var(--color-contrast-accent); border-radius: 1px; }

.footer-col-title {
  display: flex;
  align-items: baseline;
  gap: 10px;
  margin: 0 0 var(--space-2);
  font-family: var(--font-heading);
  font-size: var(--text-sm);
  font-weight: 600;
  letter-spacing: 0.04em;
  color: var(--color-contrast-ink);
}
.footer-col-code {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  color: var(--color-contrast-accent);
}

.footer-links { display: flex; flex-direction: column; }
.footer-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 7px 0;
  font-size: var(--text-sm);
  line-height: 1.35;
  color: color-mix(in srgb, var(--color-contrast-ink) 76%, transparent);
  text-decoration: none;
  transition: color 0.18s ease-out;
}
.footer-link::before {
  content: "";
  width: 5px;
  height: 5px;
  flex: none;
  background-color: var(--color-contrast-line);
  border-radius: 1px;
  transition: background-color 0.18s ease-out;
}
.footer-link:hover { color: var(--color-contrast-ink); }
.footer-link:hover::before { background-color: var(--color-contrast-accent); }

.footer-step {
  height: 12px;
  background: linear-gradient(90deg, var(--color-primary) 0 33%, var(--color-accent) 33% 66%, var(--color-contrast-accent) 66% 100%);
  clip-path: polygon(0 0, 100% 0, calc(100% - 180px) 100%, 0 100%);
}

.footer-bottom { background-color: var(--color-surface-alt); color: var(--color-ink); }
.footer-bottom-inner {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: center;
  gap: var(--space-3) var(--space-4);
  padding-block: var(--space-4) var(--space-3);
}
.footer-brand { display: flex; align-items: baseline; flex-wrap: wrap; gap: 10px; }
.brand-name--footer { font-size: var(--text-lg); color: var(--color-ink); }
.brand-sub--footer { color: var(--color-ink-muted); }

.footer-legal-links { display: flex; flex-wrap: wrap; gap: var(--space-3); }
.footer-legal-link {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  color: var(--color-ink-soft);
  padding-bottom: 2px;
  border-bottom: var(--border-thin) dotted var(--color-line);
  text-decoration: none;
  transition: color 0.18s ease-out, border-color 0.18s ease-out;
}
.footer-legal-link:hover { color: var(--color-accent); border-bottom-color: var(--color-accent); }

.footer-meta {
  grid-column: 1 / -1;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: var(--space-2) var(--space-4);
  margin: 0;
  padding-top: var(--space-2);
  border-top: var(--border-thin) dotted var(--color-line);
}
.footer-meta-item { min-width: 0; }
.footer-meta dt {
  margin-bottom: 4px;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.12em;
  color: var(--color-ink-muted);
}
.footer-meta dd { margin: 0; font-size: var(--text-sm); line-height: 1.5; color: var(--color-ink-soft); }

.footer-note {
  grid-column: 1 / -1;
  margin: 0;
  font-size: var(--text-xs);
  line-height: 1.6;
  color: var(--color-ink-muted);
}
.footer-copy {
  grid-column: 1 / -1;
  margin: 0;
  padding-top: var(--space-2);
  border-top: var(--border-thin) solid var(--color-line);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.06em;
  color: var(--color-ink-muted);
}

/* ---------- buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-1);
  padding: 12px 20px;
  border: var(--border-thin) solid transparent;
  border-radius: var(--radius-sm);
  font-family: var(--font-heading);
  font-weight: 600;
  font-size: var(--text-sm);
  line-height: 1;
  letter-spacing: 0.02em;
  text-decoration: none;
  cursor: pointer;
  transition: background-color 0.18s ease-out, color 0.18s ease-out, border-color 0.18s ease-out;
}
.btn::before {
  content: "";
  width: 7px;
  height: 7px;
  flex: none;
  background-color: currentColor;
  border-radius: 50%;
}
.btn--primary { background-color: var(--color-primary); color: var(--color-primary-ink); }
.btn--primary:hover { background-color: var(--color-contrast-surface); color: var(--color-contrast-ink); }
.btn--accent { background-color: var(--color-accent); color: var(--color-accent-ink); }
.btn--accent:hover { background-color: var(--color-contrast-surface); color: var(--color-contrast-ink); }
.btn--ghost { background-color: transparent; color: var(--color-primary); border-color: var(--color-line); }
.btn--ghost:hover { background-color: var(--color-primary-soft); border-color: var(--color-primary); color: var(--color-primary); }
.btn--on-dark { background-color: transparent; color: var(--color-contrast-ink); border-color: var(--color-contrast-line); }
.btn--on-dark:hover { background-color: var(--color-contrast-accent); color: var(--color-contrast-ink); border-color: var(--color-contrast-accent); }

/* ---------- tags ---------- */
.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 8px;
  border: var(--border-thin) solid transparent;
  border-radius: var(--radius-sm);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  line-height: 1.1;
  letter-spacing: 0.06em;
  background-color: var(--color-surface-deep);
  color: var(--color-ink-soft);
}
.tag::before {
  content: "";
  width: 6px;
  height: 6px;
  flex: none;
  border-radius: 50%;
  background-color: currentColor;
}
.tag--content { background-color: var(--color-primary-soft); color: var(--color-primary); }
.tag--data { background-color: var(--color-highlight); color: var(--color-accent); }
.tag--data::before { border-radius: 1px; }
.tag--live { background-color: var(--color-accent); color: var(--color-accent-ink); }
.tag--live::before { border-radius: 1px; }

/* ---------- breadcrumb ---------- */
.breadcrumb {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.06em;
  color: var(--color-ink-muted);
  margin-bottom: var(--space-2);
}
.breadcrumb-list { display: flex; flex-wrap: wrap; align-items: center; gap: 0; }
.breadcrumb-item { display: inline-flex; align-items: center; }
.breadcrumb-item + .breadcrumb-item::before {
  content: "/";
  margin: 0 0.6em;
  color: var(--color-line);
}
.breadcrumb-link { color: var(--color-ink-soft); text-decoration: none; }
.breadcrumb-link:hover { color: var(--color-accent); }
.breadcrumb-item[aria-current="page"] { color: var(--color-primary); }

/* ---------- panels ---------- */
.panel {
  padding: var(--space-3);
  background-color: var(--color-surface);
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-md);
}
.panel--alt { background-color: var(--color-surface-alt); }
.panel--deep {
  background-color: var(--color-contrast-surface);
  border-color: var(--color-contrast-line);
  color: var(--color-contrast-ink);
}
.panel--deep h2, .panel--deep h3, .panel--deep h4 { color: var(--color-contrast-ink); }
.panel--deep .timeline-meta, .panel--deep .stat-label { color: color-mix(in srgb, var(--color-contrast-ink) 62%, transparent); }

/* ---------- timeline ---------- */
.timeline {
  position: relative;
  padding-left: var(--space-4);
  margin: 0;
  list-style: none;
}
.timeline::before {
  content: "";
  position: absolute;
  left: 4px;
  top: 0;
  bottom: 0;
  width: var(--border-thin);
  background-color: var(--color-line);
}
.timeline-item { position: relative; }
.timeline-item + .timeline-item { margin-top: var(--space-4); }

.timeline-node {
  position: absolute;
  left: calc(-1 * var(--space-4));
  top: 6px;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background-color: var(--color-primary);
  box-shadow: 0 0 0 3px var(--color-surface);
}
.timeline-node--data { border-radius: 1px; background-color: var(--color-primary); }
.timeline-node--accent { border-radius: 1px; background-color: var(--color-accent); }
.timeline-item[data-active] .timeline-node { box-shadow: 0 0 0 3px var(--color-highlight); }

.timeline-meta {
  display: inline-block;
  margin-bottom: 6px;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  line-height: 1.1;
  letter-spacing: 0.12em;
  color: var(--color-ink-muted);
}
.timeline-title { font-size: var(--text-lg); margin-bottom: 6px; }
.timeline-text { color: var(--color-ink-soft); max-width: var(--measure); }

@media (min-width: 1024px) {
  .timeline--split { padding-left: 0; }
  .timeline--split::before { left: 50%; }
  .timeline--split .timeline-item {
    width: 50%;
    padding-left: 0;
    padding-right: var(--space-4);
  }
  .timeline--split .timeline-item:nth-child(even) {
    margin-left: 50%;
    padding-left: var(--space-4);
    padding-right: 0;
  }
  .timeline--split .timeline-node { left: calc(100% - 4px); }
  .timeline--split .timeline-item:nth-child(even) .timeline-node { left: -4px; }
}

/* ---------- media / figure ---------- */
.media {
  position: relative;
  display: block;
  overflow: hidden;
  aspect-ratio: 3 / 2;
  background-color: var(--color-surface-deep);
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-md);
}
.media--1x1 { aspect-ratio: 1 / 1; }
.media > img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center;
}
.media-scrim {
  position: absolute;
  inset: 0;
  background: var(--overlay-scrim);
  pointer-events: none;
}
.media-caption {
  position: absolute;
  left: var(--space-2);
  right: var(--space-2);
  bottom: var(--space-2);
  margin: 0;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  line-height: 1.4;
  letter-spacing: 0.06em;
  color: var(--color-contrast-ink);
}
.media-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: var(--space-2);
}

/* ---------- quote / note ---------- */
.quote-block {
  margin: 0;
  padding: var(--space-3) var(--space-3) var(--space-3) var(--space-4);
  border-left: var(--border-thick) solid var(--color-accent);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  background-color: var(--color-highlight);
  color: var(--color-ink);
  font-size: var(--text-lg);
  line-height: 1.6;
}
.quote-block::before {
  content: "\201C";
  display: block;
  font-family: var(--font-heading);
  font-size: var(--text-2xl);
  line-height: 1;
  color: var(--color-accent);
  margin-bottom: 4px;
}
.note {
  margin: 0;
  padding-left: var(--space-2);
  border-left: var(--border-thin) dotted var(--color-line);
  font-size: var(--text-sm);
  color: var(--color-ink-muted);
}

/* ---------- stats ---------- */
.stat-row {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-4);
  padding-block: var(--space-2);
  border-top: var(--border-thin) solid var(--color-line);
  border-bottom: var(--border-thin) solid var(--color-line);
}
.stat { min-width: 120px; }
.stat-value {
  display: block;
  font-family: var(--font-mono);
  font-size: var(--text-3xl);
  font-weight: 600;
  line-height: 1.05;
  letter-spacing: -0.01em;
  color: var(--color-primary);
}
.stat-value--display { font-size: var(--text-figure); }
.stat-label {
  display: block;
  margin-top: 4px;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.12em;
  color: var(--color-ink-muted);
}
.section--deep .stat-value, .panel--deep .stat-value { color: var(--color-contrast-accent); }

/* ---------- prose ---------- */
.prose { max-width: var(--measure); }
.prose h2 { font-size: var(--text-xl); margin: var(--space-4) 0 var(--space-1); }
.prose h3 { font-size: var(--text-lg); margin: var(--space-3) 0 var(--space-1); }
.prose p { margin-bottom: var(--space-2); line-height: 1.79; }
.prose ul, .prose ol { margin: 0 0 var(--space-2); padding-left: 1.4em; }
.prose li { line-height: 1.79; margin-bottom: 4px; }
.prose ul li { list-style: square; }
.prose ol li { list-style: decimal; }
.prose a { border-bottom: var(--border-thin) solid var(--color-primary); }
.prose--numbered ol { padding-left: 1.6em; }

/* ---------- motion ---------- */
.is-js [data-reveal] {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity 220ms ease-out, transform 220ms ease-out;
}
.is-js [data-reveal][data-visible] { opacity: 1; transform: none; }

@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;
  }
  .is-js [data-reveal] { opacity: 1; transform: none; transition: none; }
  .progress-fill { transition: none; }
}

/* ---------- responsive ---------- */
@media (max-width: 1023px) {
  .grid { grid-template-columns: repeat(6, minmax(0, 1fr)); }
  .col-3, .col-4 { grid-column: span 3; }
  .col-6, .col-8 { grid-column: span 6; }
  .section { padding-block: var(--space-6); }
  .section--lg { padding-block: var(--section-y); }
  .nav-list { gap: var(--space-4); }
}

@media (max-width: 900px) {
  .masthead-inner {
    grid-template-columns: minmax(0, 1fr) auto;
    grid-template-areas:
      "brand end"
      "version version";
    row-gap: var(--space-1);
    padding-block: var(--space-3) var(--space-2);
  }
  .masthead-brand { grid-area: brand; justify-self: start; text-align: left; }
  .masthead-util--end { grid-area: end; }
  .masthead-util--start { grid-area: version; justify-self: start; }

  .nav-toggle { display: inline-flex; }

  .site-nav { display: none; }
  .site-nav[data-open] { display: block; }
  .nav-list { flex-direction: column; gap: 0; padding-block: var(--space-1) var(--space-2); }
  .nav-item { border-bottom: var(--border-thin) dotted var(--color-line); }
  .nav-item:last-child { border-bottom: 0; }
  .nav-link { width: 100%; padding: 14px 4px; font-size: var(--text-lg); }
  .nav-link::after { display: none; }
  .nav-link[aria-current="page"] {
    background: linear-gradient(90deg, var(--color-highlight), transparent 72%);
  }

  .footer-top { padding-block: var(--space-6) var(--space-4); }
}

@media (max-width: 820px) {
  .footer-index { grid-template-columns: 1fr; gap: var(--space-3); }
  .footer-col:nth-child(2), .footer-col:nth-child(3) { margin-top: 0; }
  .footer-col { padding-left: var(--space-2); }
  .footer-col::before { display: none; }
  .footer-col { border-left-color: var(--color-contrast-line); }
}

@media (max-width: 640px) {
  .grid { grid-template-columns: 1fr; gap: var(--space-3); }
  .col-3, .col-4, .col-6, .col-8, .col-12 { grid-column: 1 / -1; }
  .brand-name { font-size: var(--text-xl); }
  .site-header[data-stuck] .brand-name { font-size: var(--text-lg); }
  .version-badge { padding: 5px 8px; letter-spacing: 0.02em; }
  .footer-bottom-inner { grid-template-columns: 1fr; align-items: start; }
  .footer-meta { grid-template-columns: 1fr; }
  .stat-row { gap: var(--space-3); }
  .stat { min-width: 96px; }
}