/* =========================================================================
   Payout Hub — editorial fintech system (variant A)
   Tokens live here and nowhere else. Nothing below :root hardcodes a color.
   ========================================================================= */
:root {
  /* surfaces */
  --canvas: #ffffff;
  --surface: #ffffff;
  --surface-alt: #fafcfe;
  --surface-sunken: #f4f7fb;
  --border: #e5edf5;
  --border-strong: #d3dfeb;
  /* ink */
  --ink: #061b31;
  --ink-soft: #273951;
  --ink-muted: #64748d;
  --ink-faint: #64748d;
  /* accent */
  --accent: #533afd;
  --accent-deep: #3a22e0;
  --accent-ink: #ffffff;
  --accent-soft: #efeaff;
  --accent-tint: #f6f3ff;
  --accent-line: #d9d1ff;
  --success: #15be53;
  --success-soft: #e6f9ee;
  /* dark band */
  --dark: #1c1e54;
  --dark-2: #14163d;
  --dark-ink: #ffffff;
  --dark-muted: #b9bde0;
  --dark-border: #33356e;
  /* elevation — three steps, blue-tinted */
  --shadow-1: 0 1px 2px rgba(6, 27, 49, .06), 0 1px 1px rgba(6, 27, 49, .04);
  --shadow-2: 0 12px 24px -14px rgba(50, 50, 93, .18), 0 4px 10px -6px rgba(6, 27, 49, .08);
  --shadow-3: rgba(50, 50, 93, .25) 0 30px 45px -30px, rgba(0, 0, 0, .1) 0 18px 36px -18px;
  /* gradients / washes */
  --grad-hero: radial-gradient(120% 90% at 88% 6%, #efeaff 0%, #f7f4ff 34%, #ffffff 68%);
  --grad-cta: linear-gradient(122deg, #3a22e0 0%, #533afd 46%, #6b4bff 100%);
  --grad-line: linear-gradient(90deg, #533afd 0%, #8f7dff 42%, #e5edf5 100%);
  --glow: radial-gradient(closest-side, rgba(83, 58, 253, .28), rgba(83, 58, 253, 0));
  --focus: #533afd;
  /* geometry */
  --radius-xs: 4px;
  --radius-sm: 6px;
  --radius-md: 8px;
  --radius-lg: 8px;
  --hairline: 1px;
  /* type */
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "Helvetica Neue", Arial, "Noto Sans", sans-serif;
  --mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, "Liberation Mono", monospace;
  --fs-mono: clamp(.6875rem, .66rem + .14vw, .75rem);
  --fs-xs: clamp(.8125rem, .79rem + .12vw, .875rem);
  --fs-sm: clamp(.875rem, .85rem + .18vw, .9375rem);
  --fs-base: clamp(.9375rem, .92rem + .18vw, 1.0625rem);
  --fs-lead: clamp(1.0625rem, 1rem + .5vw, 1.375rem);
  --fs-h3: clamp(1.125rem, 1.04rem + .45vw, 1.375rem);
  --fs-h2: clamp(1.75rem, 1.34rem + 1.5vw, 2.75rem);
  --fs-h1: clamp(2rem, 1.15rem + 3.1vw, 3.5rem);
  --lh-tight: 1.08;
  --lh-snug: 1.35;
  --lh-body: 1.62;
  --track-h1: -0.02em;
  --track-h2: -0.022em;
  --space-1: .25rem;
  --space-2: .5rem;
  --space-3: .75rem;
  --space-4: 1rem;
  --space-5: 1.5rem;
  --space-6: 2rem;
  --space-7: 3rem;
  --space-8: 4rem;
  --space-9: 6rem;
  --wrap: 1200px;
  --pad: clamp(1.15rem, .6rem + 3vw, 2.5rem);
  --dur: .18s;
  --ease: cubic-bezier(.32, .72, .28, 1);
  /* dark palette carriers (mapped below, never used directly) */
  --d-canvas: #0b1020;
  --d-surface: #101731;
  --d-alt: #0d1428;
  --d-sunken: #121a35;
  --d-border: #1f2a44;
  --d-border-strong: #2b3856;
  --d-ink: #f2f6fc;
  --d-ink-soft: #d3ddec;
  --d-ink-muted: #a7b6cc;
  --d-ink-faint: #8d9db5;
  --d-accent: #8f7dff;
  --d-accent-deep: #a698ff;
  --d-soft: #1b1f4a;
  --d-tint: #131735;
  --d-line: #332c72;
  --d-grad-hero: radial-gradient(120% 90% at 88% 6%, #1a1740 0%, #12142e 38%, #0b1020 70%);
  --d-gradient-cta: linear-gradient(122deg, #2a1c8f 0%, #4a34d6 50%, #6b4bff 100%);
  --d-glow: radial-gradient(closest-side, rgba(143, 125, 255, .22), rgba(143, 125, 255, 0));
}

/* Dark palette. Two carriers of the same map: system preference (unless the
   user forced light) and the explicit toggle value. */
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --canvas: var(--d-canvas);
    --surface: var(--d-surface);
    --surface-alt: var(--d-alt);
    --surface-sunken: var(--d-sunken);
    --border: var(--d-border);
    --border-strong: var(--d-border-strong);
    --ink: var(--d-ink);
    --ink-soft: var(--d-ink-soft);
    --ink-muted: var(--d-ink-muted);
    --ink-faint: var(--d-ink-faint);
    --accent: var(--d-accent);
    --accent-deep: var(--d-accent-deep);
    --accent-soft: var(--d-soft);
    --accent-tint: var(--d-tint);
    --accent-line: var(--d-line);
    --grad-hero: var(--d-grad-hero);
    --grad-cta: var(--d-gradient-cta);
    --glow: var(--d-glow);
    --focus: var(--d-accent);
  }
}
:root[data-theme="dark"] {
  --canvas: var(--d-canvas);
  --surface: var(--d-surface);
  --surface-alt: var(--d-alt);
  --surface-sunken: var(--d-sunken);
  --border: var(--d-border);
  --border-strong: var(--d-border-strong);
  --ink: var(--d-ink);
  --ink-soft: var(--d-ink-soft);
  --ink-muted: var(--d-ink-muted);
  --ink-faint: var(--d-ink-faint);
  --accent: var(--d-accent);
  --accent-deep: var(--d-accent-deep);
  --accent-soft: var(--d-soft);
  --accent-tint: var(--d-tint);
  --accent-line: var(--d-line);
  --grad-hero: var(--d-grad-hero);
  --grad-cta: var(--d-gradient-cta);
  --glow: var(--d-glow);
  --focus: var(--d-accent);
}

/* ---------------------------------------------------------------- reset */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--canvas);
  color: var(--ink-muted);
  font-family: var(--sans);
  font-size: var(--fs-base);
  line-height: var(--lh-body);
  font-weight: 400;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}
img, svg { max-width: 100%; }
a { color: var(--accent); text-decoration: none; }
p { margin: 0 0 1.05em; overflow-wrap: break-word; }
p:last-child { margin-bottom: 0; }
ul { margin: 0; padding: 0; list-style: none; }
h1, h2, h3, h4 {
  margin: 0;
  color: var(--ink);
  font-weight: 300;
  letter-spacing: var(--track-h2);
  line-height: 1.14;
  text-wrap: balance;
}
h1 { font-size: var(--fs-h1); line-height: var(--lh-tight); letter-spacing: var(--track-h1); }
h2 { font-size: var(--fs-h2); }
h3 { font-size: var(--fs-h3); font-weight: 400; letter-spacing: -0.01em; line-height: var(--lh-snug); }
button { font: inherit; color: inherit; }
:focus-visible {
  outline: 2px solid var(--focus);
  outline-offset: 3px;
  border-radius: var(--radius-xs);
}
.svg-sprite { position: absolute; width: 0; height: 0; overflow: hidden; }
.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: absolute; left: var(--space-4); top: -100px; z-index: 60;
  display: inline-flex; align-items: center; min-height: 44px;
  padding: 0 var(--space-5);
  background: var(--accent); color: var(--accent-ink);
  border-radius: var(--radius-sm); font-weight: 500;
}
.skip-link:focus-visible { top: var(--space-4); }

/* ------------------------------------------------------------- helpers */
.wrap {
  width: 100%; max-width: var(--wrap);
  margin-inline: auto;
  padding-inline: var(--pad);
}
.section { padding-block: clamp(3.25rem, 1.4rem + 6vw, 6.5rem); }
.section-alt {
  background: var(--surface-alt);
  border-block: var(--hairline) solid var(--border);
}
.mono {
  font-family: var(--mono);
  font-size: var(--fs-mono);
  letter-spacing: .1em;
  text-transform: uppercase;
  font-weight: 500;
  color: var(--ink-faint);
}
.num { font-variant-numeric: tabular-nums; font-feature-settings: "tnum" 1; }
.eyebrow {
  display: inline-flex; align-items: center; gap: .55em;
  margin: 0 0 var(--space-4);
  font-family: var(--mono); font-size: var(--fs-mono); font-weight: 500;
  letter-spacing: .14em; text-transform: uppercase; color: var(--accent);
}
.eyebrow::before {
  content: ""; width: 18px; height: 1px; background: var(--accent); display: block;
}
.section-head { max-width: 46rem; margin-bottom: clamp(2rem, 1rem + 2.4vw, 3.25rem); }
.section-head h2 { margin-bottom: var(--space-4); }
.section-head p { font-size: var(--fs-lead); line-height: 1.5; color: var(--ink-muted); max-width: 40rem; }

/* -------------------------------------------------------------- header */
.site-header {
  position: sticky; top: 0; z-index: 40;
  background: var(--canvas);
  border-bottom: var(--hairline) solid var(--border);
  backdrop-filter: saturate(140%) blur(8px);
}
.header-inner {
  display: flex; align-items: center; gap: var(--space-5);
  min-height: 68px;
}
.brand {
  display: inline-flex; align-items: center; gap: .6rem;
  color: var(--ink); font-weight: 500; letter-spacing: -.01em;
  min-height: 44px; flex: 0 0 auto;
}
.brand-mark {
  width: 20px; height: 20px; border-radius: var(--radius-xs);
  background: var(--grad-cta);
  box-shadow: inset 0 0 0 1px var(--accent-line);
  position: relative;
}
.brand-mark::after {
  content: ""; position: absolute; inset: 6px 6px auto auto;
  width: 5px; height: 5px; border-radius: 1px; background: var(--accent-ink);
}
/* ------------------------------------------------- motion (single rule set) */
/* One shared transition declaration drives every interactive surface.
   Per-element rules below only change values (transform/shadow), never timing. */
a, button, summary, .card, .lang-card, .faq-icon, .metric {
  transition-property: color, background-color, border-color, box-shadow, transform, opacity;
  transition-duration: var(--dur);
  transition-timing-function: var(--ease);
}
.site-nav { display: none; }
.site-nav ul { display: flex; gap: var(--space-1); }
.site-nav a {
  display: inline-flex; align-items: center; min-height: 44px;
  padding: 0 .7rem; color: var(--ink-soft); font-size: var(--fs-sm);
  border-radius: var(--radius-xs);
}
.site-nav a:hover { color: var(--ink); }
.header-tools { margin-left: auto; display: flex; align-items: center; gap: var(--space-2); }
.lang-switch { display: inline-flex; align-items: center; gap: 2px; }
.lang-switch a {
  display: inline-flex; align-items: center; justify-content: center;
  min-width: 44px; min-height: 44px; padding: 0 .35rem;
  font-family: var(--mono); font-size: var(--fs-mono); letter-spacing: .06em;
  text-transform: uppercase; color: var(--ink-faint);
  border-radius: var(--radius-xs);
}
.lang-switch a:hover { color: var(--ink); }
.lang-switch a[aria-current="true"] { color: var(--ink); box-shadow: inset 0 -2px 0 0 var(--accent); }
.theme-toggle {
  display: inline-flex; align-items: center; justify-content: center;
  width: 44px; height: 44px; padding: 0;
  background: var(--surface); color: var(--ink-soft);
  border: var(--hairline) solid var(--border); border-radius: var(--radius-sm);
  cursor: pointer;
}
.theme-toggle:hover { border-color: var(--border-strong); color: var(--ink); }
.theme-icon { width: 18px; height: 18px; fill: none; }
.theme-icon-moon { display: none; }
:root[data-theme="dark"] .theme-icon-moon { display: block; }
:root[data-theme="dark"] .theme-icon-sun { display: none; }
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .theme-icon-moon { display: block; }
  :root:not([data-theme="light"]) .theme-icon-sun { display: none; }
}

/* ---------------------------------------------------------------- hero */
.hero {
  position: relative;
  background: var(--grad-hero);
  border-bottom: var(--hairline) solid var(--border);
  padding-block: clamp(2rem, .8rem + 3.6vw, 3.75rem) clamp(2.25rem, 1rem + 4vw, 4.5rem);
  overflow: hidden;
}
.hero::before {
  content: ""; position: absolute; width: 720px; height: 720px; right: -180px; top: -320px;
  background: var(--glow); pointer-events: none;
}
.hero-grid {
  position: relative;
  display: grid; gap: clamp(2rem, 1rem + 4vw, 4rem);
  align-items: center;
}
.hero-copy { max-width: 34rem; }
.hero h1 { margin-bottom: var(--space-5); }
.hero-lede {
  font-size: var(--fs-lead); line-height: 1.5; color: var(--ink-soft);
  max-width: 30rem; margin-bottom: var(--space-6);
}
.hero-actions { display: flex; flex-wrap: wrap; gap: var(--space-3); margin-bottom: var(--space-5); }
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: .6em;
  min-height: 48px; padding: 0 1.35rem;
  border-radius: var(--radius-sm); border: var(--hairline) solid transparent;
  font-size: var(--fs-sm); font-weight: 500; letter-spacing: -.005em;
  cursor: pointer;
}
.btn svg { width: 16px; height: 16px; flex: 0 0 auto; }
.btn-primary { background: var(--accent); color: var(--accent-ink); box-shadow: var(--shadow-2); }
.btn-primary:hover { background: var(--accent-deep); transform: translateY(-1px); box-shadow: var(--shadow-3); }
.btn-ghost { background: var(--surface); color: var(--ink); border-color: var(--border-strong); }
.btn-ghost:hover { border-color: var(--ink-faint); transform: translateY(-1px); }
.btn-light { background: var(--canvas); color: var(--accent-deep); box-shadow: var(--shadow-3); }
.btn-light:hover { transform: translateY(-1px); }
.hero-note {
  display: flex; align-items: center; gap: .6rem;
  font-family: var(--mono); font-size: var(--fs-mono); letter-spacing: .08em;
  text-transform: uppercase; color: var(--ink-faint); margin: 0;
}
.dot { width: 7px; height: 7px; border-radius: 50%; background: var(--success); flex: 0 0 auto; }

/* hero visual: a settlement ledger, not a stock illustration */
.hero-visual { position: relative; min-height: clamp(400px, 36vw, 560px); display: flex; align-items: center; }
.ledger {
  position: relative; width: 100%;
  background: var(--surface);
  border: var(--hairline) solid var(--border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-3);
  padding: clamp(1rem, .7rem + 1vw, 1.5rem);
}
.ledger::after {
  content: ""; position: absolute; inset: 0; border-radius: inherit; pointer-events: none;
  background: linear-gradient(160deg, var(--accent-tint), transparent 42%);
  opacity: .8;
}
.ledger-top { display: flex; align-items: center; justify-content: space-between; gap: var(--space-3); margin-bottom: var(--space-5); }
.ledger-badge {
  display: inline-flex; align-items: center; gap: .4rem;
  font-family: var(--mono); font-size: var(--fs-mono); letter-spacing: .06em;
  color: var(--success); background: var(--success-soft);
  padding: .25rem .5rem; border-radius: var(--radius-xs);
}
.ledger-rows { display: grid; gap: var(--space-3); position: relative; z-index: 1; }
.ledger-row { display: grid; grid-template-columns: 4.2rem 1fr 2rem; align-items: center; gap: var(--space-3); }
.ledger-lvl, .ledger-val {
  font-family: var(--mono); font-size: var(--fs-mono); letter-spacing: .08em;
  color: var(--ink-faint); font-variant-numeric: tabular-nums;
}
.ledger-val { text-align: right; color: var(--ink-soft); font-size: var(--fs-xs); }
.ledger-bar { height: 8px; background: var(--surface-sunken); border-radius: var(--radius-xs); overflow: hidden; }
.ledger-bar span { display: block; height: 100%; background: var(--grad-line); border-radius: var(--radius-xs); }
.w-100 { width: 100%; }
.w-62 { width: 62%; }
.w-38 { width: 38%; }
.ledger-graph { display: block; width: 100%; height: 74px; margin: var(--space-5) 0 var(--space-4); position: relative; z-index: 1; }
.ledger-graph .edge { fill: none; stroke: var(--accent-line); stroke-width: 1.2; }
.ledger-graph .node { fill: var(--accent); }
.ledger-graph .node-root { fill: var(--accent-deep); }
.ledger-foot {
  display: flex; justify-content: space-between; gap: var(--space-3);
  border-top: var(--hairline) solid var(--border); padding-top: var(--space-3);
  position: relative; z-index: 1;
}

/* ------------------------------------------------------------- metrics */
.metrics { background: var(--canvas); border-bottom: var(--hairline) solid var(--border); }
.metrics-grid {
  display: grid; grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: var(--hairline); background: var(--border);
  border-inline: var(--hairline) solid var(--border);
}
.metric {
  background: var(--canvas); padding: clamp(1.15rem, .8rem + 1.4vw, 2rem) clamp(.9rem, .5rem + 1.4vw, 1.75rem);
}
.metric-label {
  display: block; margin-bottom: .55rem;
  font-family: var(--mono); font-size: var(--fs-mono); letter-spacing: .12em;
  text-transform: uppercase; color: var(--ink-faint);
}
.metric-value {
  display: flex; align-items: baseline; gap: .2em;
  font-size: clamp(1.75rem, 1.3rem + 1.9vw, 2.85rem);
  font-weight: 300; line-height: 1; letter-spacing: -.03em;
  color: var(--ink);
  font-variant-numeric: tabular-nums; font-feature-settings: "tnum" 1;
}
.metric-value .unit { font-size: .42em; font-weight: 400; letter-spacing: 0; color: var(--ink-soft); }
.metric-note { display: block; margin-top: .6rem; font-size: var(--fs-xs); line-height: 1.45; color: var(--ink-muted); }

/* --------------------------------------------------------------- cards */
.cards {
  display: grid; gap: var(--space-4);
  grid-template-columns: repeat(auto-fit, minmax(min(100%, 250px), 1fr));
}
.card {
  position: relative;
  display: flex; flex-direction: column;
  background: var(--surface);
  border: var(--hairline) solid var(--border);
  border-radius: var(--radius-md);
  padding: clamp(1.1rem, .8rem + 1vw, 1.75rem);
  box-shadow: var(--shadow-1);
}
.card:hover { transform: translateY(-3px); box-shadow: var(--shadow-3); border-color: var(--border-strong); }
.card-icon {
  width: 40px; height: 40px; margin-bottom: var(--space-5);
  display: inline-flex; align-items: center; justify-content: center;
  color: var(--accent); background: var(--accent-tint);
  border: var(--hairline) solid var(--accent-line);
  border-radius: var(--radius-sm);
}
.card-icon svg { width: 21px; height: 21px; fill: none; }
.card-kicker {
  display: block; margin-bottom: .7rem;
  font-family: var(--mono); font-size: var(--fs-mono); letter-spacing: .12em;
  text-transform: uppercase; color: var(--ink-faint);
  font-variant-numeric: tabular-nums;
}
.card h3 { margin-bottom: .6rem; }
.card p { font-size: var(--fs-sm); line-height: 1.6; }

/* --------------------------------------------------------------- steps */
.steps {
  display: grid; gap: var(--space-6);
  grid-template-columns: repeat(auto-fit, minmax(min(100%, 220px), 1fr));
}
.step { position: relative; padding-top: var(--space-5); border-top: 2px solid var(--border-strong); }
.step::before {
  content: ""; position: absolute; top: -2px; left: 0; width: 34px; height: 2px; background: var(--accent);
}
.step-num {
  display: block; margin-bottom: var(--space-4);
  font-family: var(--mono); font-size: var(--fs-xs); letter-spacing: .1em;
  color: var(--accent); font-variant-numeric: tabular-nums;
}
.step h3 { margin-bottom: .55rem; font-size: var(--fs-h3); }
.step p { font-size: var(--fs-sm); line-height: 1.6; }

/* ---------------------------------------------------------- tree (dark) */
.tree {
  position: relative;
  background: var(--dark);
  color: var(--dark-muted);
  padding-block: clamp(3.25rem, 1.4rem + 6vw, 6rem);
  overflow: hidden;
}
.tree::before {
  content: ""; position: absolute; inset: 0; pointer-events: none;
  background: radial-gradient(90% 70% at 82% 0%, var(--dark-border), transparent 62%);
  opacity: .55;
}
.tree .wrap { position: relative; }
.tree-grid { display: grid; gap: clamp(2rem, 1rem + 4vw, 4rem); align-items: center; }
.tree h2 { color: var(--dark-ink); margin-bottom: var(--space-5); max-width: 22ch; }
.tree .eyebrow { color: var(--dark-muted); }
.tree .eyebrow::before { background: var(--dark-muted); }
.tree-body { color: var(--dark-muted); font-size: var(--fs-sm); line-height: 1.7; max-width: 34rem; }
.tree-body p { margin-bottom: 1em; }
.tree-legend {
  display: flex; flex-wrap: wrap; gap: var(--space-4);
  margin-top: var(--space-6); padding-top: var(--space-4);
  border-top: var(--hairline) solid var(--dark-border);
  font-family: var(--mono); font-size: var(--fs-mono); letter-spacing: .08em;
  text-transform: uppercase; color: var(--dark-muted);
}
.tree-legend span { display: inline-flex; align-items: center; gap: .5rem; }
.tree-legend i { width: 10px; height: 10px; border-radius: 2px; display: block; }
.tree-legend .l1 { background: var(--dark-ink); }
.tree-legend .l2 { background: var(--accent); }
.tree-legend .l3 { background: var(--dark-border); }
.tree-figure {
  margin: 0; padding: clamp(.75rem, .5rem + 1vw, 1.25rem);
  background: var(--dark-2);
  border: var(--hairline) solid var(--dark-border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-3);
}
.tree-svg { display: block; width: 100%; height: auto; }
.tree-svg .link { fill: none; stroke: var(--dark-border); stroke-width: 1.4; }
.tree-svg .link-accent { fill: none; stroke: var(--accent); stroke-width: 1.8; }
.tree-svg .box { fill: var(--dark); stroke: var(--dark-border); stroke-width: 1; }
.tree-svg .box-root { fill: var(--accent); stroke: var(--accent); }
.tree-svg .box-l2 { fill: var(--dark); stroke: var(--accent-line); }
.tree-svg .t-lvl {
  font-family: var(--mono); font-size: 9px; letter-spacing: 1.4px; fill: var(--dark-muted);
  text-transform: uppercase;
}
.tree-svg .t-label {
  font-family: var(--mono); font-size: 9.5px; letter-spacing: 1px; fill: var(--dark-muted);
  text-transform: uppercase;
}
.tree-svg .t-root { fill: var(--accent-ink); }
.tree-figure figcaption {
  display: flex; flex-wrap: wrap; justify-content: space-between; gap: var(--space-2);
  margin-top: var(--space-4); padding-top: var(--space-3);
  border-top: var(--hairline) solid var(--dark-border);
  font-family: var(--mono); font-size: var(--fs-mono); letter-spacing: .08em;
  text-transform: uppercase; color: var(--dark-muted);
}

/* --------------------------------------------------------------- about */
.about-grid { display: grid; gap: clamp(1.5rem, .8rem + 3vw, 3.5rem); }
.about-grid h2 { max-width: 20ch; }
.about-grid p { font-size: var(--fs-base); line-height: 1.7; }
.about-grid > div:last-child p:first-child { color: var(--ink-soft); }
.about-rule {
  display: flex; flex-wrap: wrap; gap: var(--space-4);
  margin-top: var(--space-5); padding-top: var(--space-4);
  border-top: var(--hairline) solid var(--border);
}

/* ----------------------------------------------------------------- faq */
.faq-list { border-top: var(--hairline) solid var(--border-strong); max-width: 60rem; }
.faq-item { border-bottom: var(--hairline) solid var(--border); }
.faq-item summary {
  display: flex; align-items: flex-start; justify-content: space-between; gap: var(--space-4);
  min-height: 56px; padding: 1.05rem 0;
  color: var(--ink); font-size: var(--fs-lead); font-weight: 400; letter-spacing: -.01em;
  line-height: 1.4; cursor: pointer; list-style: none;
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary:hover { color: var(--accent); }
.faq-icon {
  flex: 0 0 auto; width: 20px; height: 20px; margin-top: .2rem;
  color: var(--accent); fill: none;
}
.faq-item[open] .faq-icon { transform: rotate(45deg); }
.faq-body { padding: 0 2.5rem 1.4rem 0; font-size: var(--fs-sm); line-height: 1.65; color: var(--ink-muted); }
.faq-body p { margin: 0; }

/* ----------------------------------------------------------------- cta */
.cta { background: var(--grad-cta); color: var(--accent-ink); position: relative; overflow: hidden; }
.cta::before {
  content: ""; position: absolute; width: 560px; height: 560px; right: -140px; bottom: -300px;
  border-radius: 50%; border: 1px solid var(--accent-line); opacity: .4; pointer-events: none;
}
.cta-inner {
  position: relative;
  display: grid; gap: var(--space-6); align-items: center;
  padding-block: clamp(2.5rem, 1.2rem + 4vw, 4rem);
}
.cta h2 { color: var(--accent-ink); margin-bottom: .5rem; }
.cta p { color: var(--accent-ink); opacity: .82; font-size: var(--fs-lead); margin: 0; max-width: 32rem; }
.cta-actions { display: flex; }

/* -------------------------------------------------------------- footer */
.site-footer { background: var(--canvas); border-top: var(--hairline) solid var(--border); padding-block: clamp(2.5rem, 1.5rem + 3vw, 3.5rem) var(--space-6); }
.footer-grid { display: grid; gap: var(--space-6); }
.footer-brand p { margin-top: var(--space-4); font-size: var(--fs-xs); line-height: 1.65; max-width: 32rem; color: var(--ink-muted); }
.footer-col h3 {
  margin-bottom: var(--space-3);
  font-family: var(--mono); font-size: var(--fs-mono); font-weight: 500;
  letter-spacing: .12em; text-transform: uppercase; color: var(--ink-faint);
}
.footer-col a {
  display: inline-flex; align-items: center; min-height: 44px;
  font-size: var(--fs-sm); color: var(--ink-soft);
}
.footer-col a:hover { color: var(--accent); }
.footer-bottom {
  margin-top: var(--space-6); padding-top: var(--space-5);
  border-top: var(--hairline) solid var(--border);
  display: flex; flex-wrap: wrap; gap: var(--space-3); justify-content: space-between;
  align-items: baseline;
}
.disclaimer { margin: 0; font-size: var(--fs-mono); line-height: 1.6; color: var(--ink-faint); max-width: 54rem; }
.footer-meta { margin: 0; }

/* ------------------------------------------------------- hub (/, 404) */
.hub-main, .error-main {
  padding-block: clamp(2.5rem, 1rem + 6vw, 5.5rem) clamp(3rem, 1.5rem + 5vw, 5rem);
  background: var(--grad-hero);
  min-height: 62vh;
}
.hub-head { max-width: 42rem; margin-bottom: clamp(2rem, 1rem + 2.5vw, 3rem); }
.hub-head h1 { margin-bottom: var(--space-4); }
.hub-head p { font-size: var(--fs-lead); line-height: 1.5; color: var(--ink-soft); }
.lang-cards { display: grid; gap: var(--space-4); grid-template-columns: repeat(auto-fit, minmax(min(100%, 240px), 1fr)); }
.lang-card {
  display: flex; flex-direction: column; gap: var(--space-2);
  min-height: 170px; padding: clamp(1.25rem, .9rem + 1vw, 1.85rem);
  background: var(--surface); border: var(--hairline) solid var(--border);
  border-radius: var(--radius-md); box-shadow: var(--shadow-1);
}
.lang-card:hover { transform: translateY(-3px); box-shadow: var(--shadow-3); border-color: var(--accent-line); }
.lang-code {
  font-family: var(--mono); font-size: var(--fs-mono); letter-spacing: .12em;
  text-transform: uppercase; color: var(--accent);
}
.lang-name { font-size: var(--fs-h3); color: var(--ink); font-weight: 400; letter-spacing: -.01em; }
.lang-meta { margin-top: auto; font-size: var(--fs-xs); color: var(--ink-muted); display: flex; align-items: center; gap: .5rem; }
.lang-meta svg { width: 15px; height: 15px; fill: none; color: var(--accent); }
.hub-foot { margin-top: var(--space-7); padding-top: var(--space-4); border-top: var(--hairline) solid var(--border); }

.error-grid { display: grid; gap: clamp(1.5rem, .8rem + 3vw, 3rem); align-items: end; }
.error-code {
  margin: 0 0 var(--space-4);
  font-size: clamp(3.25rem, 2rem + 6vw, 6rem); font-weight: 300;
  line-height: .9; letter-spacing: -.05em; color: var(--ink);
}
.error-code span { color: var(--accent); }
.error-main h1 { margin-bottom: var(--space-4); }
.error-main p { font-size: var(--fs-lead); color: var(--ink-soft); max-width: 28rem; }
.error-langs { display: flex; flex-wrap: wrap; gap: var(--space-3); margin-top: var(--space-4); }
.error-langs a {
  display: inline-flex; align-items: center; gap: .5rem;
  min-height: 44px; padding: 0 1rem;
  background: var(--surface); color: var(--ink);
  border: var(--hairline) solid var(--border-strong); border-radius: var(--radius-sm);
  font-size: var(--fs-sm);
}
.error-langs a:hover { border-color: var(--accent); transform: translateY(-1px); }

/* ----------------------------------------------------------- responsive */
@media (min-width: 640px) {
  .metrics-grid { grid-template-columns: repeat(4, minmax(0, 1fr)); }
  .cta-inner { grid-template-columns: 1fr auto; }
  .footer-grid { grid-template-columns: 1.6fr 1fr 1fr; }
  .error-grid { grid-template-columns: 1.2fr 1fr; }
}
@media (min-width: 900px) {
  .site-nav { display: block; }
  .hero-grid { grid-template-columns: minmax(0, .86fr) minmax(0, 1.14fr); }
  .tree-grid { grid-template-columns: .92fr 1.08fr; }
  .about-grid { grid-template-columns: .85fr 1.15fr; }
  .hero h1 { letter-spacing: -0.025em; }
}
@media (min-width: 1200px) {
  .header-inner { min-height: 76px; }
}

/* --------------------------------------------------------------- motion */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    transition-duration: .001ms !important;
    transition-delay: 0ms !important;
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
  }
  .card:hover, .lang-card:hover, .btn:hover { transform: none; }
}