/* ============================================================
   Chiều Cao Trẻ Em — Hồ sơ bằng chứng
   Design: "thước đo" (stadiometer) — calibrated, clinical, warm
   ============================================================ */

/* ---------- Tokens: light (base) ---------- */
:root {
  --paper:        #F1F3F0;
  --paper-deep:   #E7EBE7;
  --card:         #FFFFFF;
  --card-sunk:    #F7F9F7;

  --ink:          #101714;
  --ink-soft:     #59655F;
  --ink-faint:    #8A968F;

  --pine:         #14574A;
  --pine-deep:    #0C3830;
  --pine-wash:    #E4EEEA;

  --rule:         #DCE2DE;
  --rule-strong:  #C2CCC6;

  --ev-strong:    #1B6E47;
  --ev-strong-bg: #E3F1E8;
  --ev-mod:       #8A6310;
  --ev-mod-bg:    #F6EEDC;
  --ev-weak:      #A53A30;
  --ev-weak-bg:   #F8E6E3;

  --shadow-sm: 0 1px 2px rgba(16, 23, 20, .05);
  --shadow-md: 0 2px 14px rgba(16, 23, 20, .07);

  --font-display: "Fraunces", "Iowan Old Style", Georgia, serif;
  --font-body: "Be Vietnam Pro", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-mono: "IBM Plex Mono", ui-monospace, SFMono-Regular, Menlo, monospace;

  --measure: 39rem;
  --wide: 62rem;
  --radius: 10px;

  color-scheme: light;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --paper:        #0D1310;
    --paper-deep:   #080C0A;
    --card:         #151D19;
    --card-sunk:    #111814;

    --ink:          #E7EDE9;
    --ink-soft:     #A0ADA6;
    --ink-faint:    #74827B;

    --pine:         #5EC0A5;
    --pine-deep:    #8FD8C3;
    --pine-wash:    #13332B;

    --rule:         #25302B;
    --rule-strong:  #35443D;

    --ev-strong:    #5FCC91;
    --ev-strong-bg: #113025;
    --ev-mod:       #E0B252;
    --ev-mod-bg:    #33290F;
    --ev-weak:      #F08A7E;
    --ev-weak-bg:   #3A1B18;

    --shadow-sm: 0 1px 2px rgba(0, 0, 0, .3);
    --shadow-md: 0 2px 14px rgba(0, 0, 0, .35);

    color-scheme: dark;
  }
}

:root[data-theme="dark"] {
  --paper:        #0D1310;
  --paper-deep:   #080C0A;
  --card:         #151D19;
  --card-sunk:    #111814;

  --ink:          #E7EDE9;
  --ink-soft:     #A0ADA6;
  --ink-faint:    #74827B;

  --pine:         #5EC0A5;
  --pine-deep:    #8FD8C3;
  --pine-wash:    #13332B;

  --rule:         #25302B;
  --rule-strong:  #35443D;

  --ev-strong:    #5FCC91;
  --ev-strong-bg: #113025;
  --ev-mod:       #E0B252;
  --ev-mod-bg:    #33290F;
  --ev-weak:      #F08A7E;
  --ev-weak-bg:   #3A1B18;

  --shadow-sm: 0 1px 2px rgba(0, 0, 0, .3);
  --shadow-md: 0 2px 14px rgba(0, 0, 0, .35);

  color-scheme: dark;
}

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

html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation-duration: .01ms !important; transition-duration: .01ms !important; }
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-body);
  font-size: 17px;
  line-height: 1.72;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

img, svg { max-width: 100%; }
img { height: auto; }

a { color: var(--pine); text-decoration-thickness: 1px; text-underline-offset: 3px; }
a:hover { color: var(--pine-deep); }

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

/* ---------- Ruler rail (stadiometer) ---------- */
.rail {
  position: fixed;
  left: 0; top: 0; bottom: 0;
  width: 58px;
  pointer-events: none;
  z-index: 5;
  display: none;
  border-right: 1px solid var(--rule);
  background: var(--paper);
}
.rail__ticks { position: absolute; inset: 0; }
.rail__tick {
  position: absolute;
  right: 0;
  height: 1px;
  background: var(--rule-strong);
  width: 7px;
}
.rail__tick--major { width: 16px; background: var(--ink-faint); }
.rail__label {
  position: absolute;
  right: 21px;
  transform: translateY(-50%);
  font-family: var(--font-mono);
  font-size: 9.5px;
  color: var(--ink-faint);
  letter-spacing: .04em;
}
.rail__marker {
  position: absolute;
  right: 0;
  width: 100%;
  height: 2px;
  background: var(--pine);
  transition: top .12s linear;
}
.rail__marker::after {
  content: attr(data-pct);
  position: absolute;
  right: 6px; top: 4px;
  font-family: var(--font-mono);
  font-size: 9.5px;
  font-weight: 500;
  color: var(--pine);
}
@media (min-width: 1180px) {
  .rail { display: block; }
}

/* ---------- Top nav ---------- */
.nav {
  position: sticky;
  top: 0;
  z-index: 20;
  background: color-mix(in srgb, var(--paper) 88%, transparent);
  backdrop-filter: saturate(180%) blur(12px);
  -webkit-backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid var(--rule);
}
.nav__in {
  max-width: var(--wide);
  margin: 0 auto;
  padding: 0 1.25rem;
  display: flex;
  align-items: center;
  gap: 1.25rem;
  min-height: 58px;
}
.nav__brand {
  font-family: var(--font-display);
  font-optical-sizing: auto;
  font-weight: 600;
  font-size: 1.02rem;
  color: var(--ink);
  text-decoration: none;
  letter-spacing: -.01em;
  white-space: nowrap;
  display: flex;
  align-items: center;
  gap: .5rem;
}
.nav__brand:hover { color: var(--ink); }
.nav__mark {
  width: 18px; height: 18px;
  flex: none;
  color: var(--pine);
}
.nav__links {
  display: flex;
  gap: .15rem;
  margin-left: auto;
  overflow-x: auto;
  scrollbar-width: none;
}
.nav__links::-webkit-scrollbar { display: none; }
.nav__links a {
  font-size: 14px;
  font-weight: 500;
  color: var(--ink-soft);
  text-decoration: none;
  padding: .4rem .62rem;
  border-radius: var(--radius);
  white-space: nowrap;
}
.nav__links a:hover { background: var(--paper-deep); color: var(--ink); }
.nav__links a[aria-current="page"] { color: var(--pine); background: var(--pine-wash); }

.theme-toggle {
  flex: none;
  width: 32px; height: 32px;
  display: grid; place-items: center;
  border: 1px solid var(--rule);
  background: var(--card);
  color: var(--ink-soft);
  border-radius: var(--radius);
  cursor: pointer;
  padding: 0;
}
.theme-toggle:hover { border-color: var(--rule-strong); color: var(--ink); }
.theme-toggle svg { width: 15px; height: 15px; }

/* ---------- Page shell ---------- */
.wrap {
  max-width: var(--measure);
  margin: 0 auto;
  padding: 0 1.25rem;
}
.wrap--wide { max-width: var(--wide); }

main { padding-bottom: 5rem; }

/* ---------- Typography ---------- */
h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-optical-sizing: auto;
  color: var(--ink);
  text-wrap: balance;
  letter-spacing: -.015em;
  line-height: 1.2;
  margin: 0;
}

h1 { font-weight: 600; font-size: clamp(2rem, 5.2vw, 3rem); }
h2 { font-weight: 600; font-size: clamp(1.45rem, 3.2vw, 1.95rem); margin-top: 3.25rem; margin-bottom: .85rem; }
h3 { font-weight: 600; font-size: 1.2rem; margin-top: 2.1rem; margin-bottom: .5rem; }
h4 { font-weight: 600; font-size: 1.02rem; margin-top: 1.5rem; margin-bottom: .35rem; font-family: var(--font-body); letter-spacing: 0; }

p { margin: 0 0 1.05rem; }

main ul, main ol { margin: 0 0 1.15rem; padding-left: 1.25rem; }
main li { margin-bottom: .42rem; }
main li::marker { color: var(--ink-faint); }

strong { font-weight: 600; color: var(--ink); }

hr {
  border: 0;
  border-top: 1px solid var(--rule);
  margin: 2.75rem 0;
}

code {
  font-family: var(--font-mono);
  font-size: .86em;
  background: var(--card-sunk);
  border: 1px solid var(--rule);
  border-radius: 4px;
  padding: .08em .34em;
}

/* Section eyebrow — numbers a real sequence only */
.eyebrow {
  font-family: var(--font-mono);
  font-size: 11.5px;
  font-weight: 500;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--pine);
  margin: 0 0 .6rem;
  display: block;
}

.lede {
  font-size: 1.16rem;
  line-height: 1.62;
  color: var(--ink-soft);
  margin-bottom: 1.6rem;
}

/* ---------- Hero ---------- */
.hero {
  padding: 3.75rem 0 2.25rem;
  border-bottom: 1px solid var(--rule);
  margin-bottom: 2.5rem;
}
.hero h1 { margin-bottom: .9rem; }
.hero__meta {
  display: flex;
  flex-wrap: wrap;
  gap: .5rem 1.15rem;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--ink-faint);
  margin-top: 1.4rem;
  padding-top: 1.1rem;
  border-top: 1px solid var(--rule);
}

/* ---------- Evidence tags ---------- */
.ev {
  display: inline-flex;
  align-items: center;
  gap: .34rem;
  font-family: var(--font-body);
  font-size: 11.5px;
  font-weight: 600;
  letter-spacing: .02em;
  padding: .16rem .52rem;
  border-radius: 100px;
  white-space: nowrap;
  vertical-align: middle;
}
.ev::before {
  content: "";
  width: 6px; height: 6px;
  border-radius: 50%;
  background: currentColor;
  flex: none;
}
.ev--strong { background: var(--ev-strong-bg); color: var(--ev-strong); }
.ev--mod    { background: var(--ev-mod-bg);    color: var(--ev-mod); }
.ev--weak   { background: var(--ev-weak-bg);   color: var(--ev-weak); }

/* ---------- Callouts ---------- */
.callout {
  border-left: 3px solid var(--pine);
  border-radius: 0;
  background: var(--card-sunk);
  padding: 1rem 1.15rem;
  margin: 1.6rem 0;
  font-size: .96rem;
}
.callout > :last-child { margin-bottom: 0; }
.callout__title {
  font-weight: 600;
  font-size: .93rem;
  margin-bottom: .3rem;
  display: flex;
  align-items: center;
  gap: .42rem;
  color: var(--ink);
}
.callout--warn  { border-left-color: var(--ev-mod);  background: var(--ev-mod-bg); }
.callout--warn .callout__title { color: var(--ev-mod); }
.callout--danger { border-left-color: var(--ev-weak); background: var(--ev-weak-bg); }
.callout--danger .callout__title { color: var(--ev-weak); }
.callout--good  { border-left-color: var(--ev-strong); background: var(--ev-strong-bg); }
.callout--good .callout__title { color: var(--ev-strong); }

/* ---------- Cards ---------- */
.card {
  background: var(--card);
  border: 1px solid var(--rule);
  border-radius: 12px;
  padding: 1.35rem;
}

.grid {
  display: grid;
  gap: .85rem;
  margin: 1.5rem 0;
}
.grid--2 { grid-template-columns: repeat(auto-fit, minmax(min(250px, 100%), 1fr)); }
.grid--3 { grid-template-columns: repeat(auto-fit, minmax(min(210px, 100%), 1fr)); }

/* Pillar cards — index */
.pillar {
  display: block;
  text-decoration: none;
  background: var(--card);
  border: 1px solid var(--rule);
  border-radius: 12px;
  padding: 1.4rem;
  transition: border-color .15s, transform .15s;
}
.pillar:hover { border-color: var(--pine); transform: translateY(-2px); color: inherit; }
.pillar__n {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .12em;
  color: var(--pine);
  display: block;
  margin-bottom: .55rem;
}
.pillar h3 { margin: 0 0 .4rem; font-size: 1.15rem; }
.pillar p { font-size: .92rem; color: var(--ink-soft); margin: 0; line-height: 1.6; }
.pillar__go {
  font-size: .86rem;
  font-weight: 600;
  color: var(--pine);
  margin-top: .8rem;
  display: inline-block;
}

/* Stat tiles */
.stat {
  background: var(--card-sunk);
  border-radius: var(--radius);
  padding: .95rem 1rem;
}
.stat__label {
  font-size: 11.5px;
  color: var(--ink-soft);
  text-transform: uppercase;
  letter-spacing: .07em;
  font-weight: 500;
  margin-bottom: .18rem;
}
.stat__value {
  font-family: var(--font-display);
  font-optical-sizing: auto;
  font-weight: 600;
  font-size: 1.65rem;
  line-height: 1.15;
  color: var(--ink);
  font-variant-numeric: tabular-nums;
}
.stat__unit { font-size: .9rem; font-weight: 500; color: var(--ink-soft); }
.stat__note { font-size: 12px; color: var(--ink-faint); margin-top: .18rem; line-height: 1.45; }

/* ---------- Tables ---------- */
.table-wrap {
  overflow-x: auto;
  border: 1px solid var(--rule);
  border-radius: 12px;
  margin: 1.6rem 0;
  background: var(--card);
}
table {
  width: 100%;
  border-collapse: collapse;
  font-size: .9rem;
  min-width: 480px;
}
caption {
  caption-side: bottom;
  text-align: left;
  font-size: 12.5px;
  color: var(--ink-faint);
  padding: .7rem 1rem 0;
  line-height: 1.5;
}
th, td {
  text-align: left;
  padding: .62rem .85rem;
  border-bottom: 1px solid var(--rule);
  vertical-align: top;
}
thead th {
  background: var(--card-sunk);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: .04em;
  text-transform: uppercase;
  color: var(--ink-soft);
  white-space: nowrap;
  position: sticky;
  top: 0;
}
tbody tr:last-child td { border-bottom: 0; }
tbody tr:hover { background: var(--card-sunk); }
td.num, th.num { text-align: right; font-family: var(--font-mono); font-variant-numeric: tabular-nums; white-space: nowrap; }

/* ---------- Myth check ---------- */
.myth {
  border: 1px solid var(--rule);
  border-radius: 12px;
  overflow: hidden;
  margin: 1.1rem 0;
  background: var(--card);
}
.myth__claim {
  padding: 1rem 1.2rem;
  background: var(--card-sunk);
  border-bottom: 1px solid var(--rule);
}
.myth__claim q {
  font-family: var(--font-display);
  font-optical-sizing: auto;
  font-size: 1.05rem;
  font-weight: 500;
  font-style: italic;
  color: var(--ink);
  quotes: "“" "”";
  line-height: 1.45;
  display: block;
}
.myth__src {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--ink-faint);
  margin-top: .5rem;
  display: block;
}
.myth__verdict { padding: 1.05rem 1.2rem; }
.myth__verdict > :last-child { margin-bottom: 0; }
.myth__verdict p { font-size: .95rem; }
.myth__tag { margin-bottom: .6rem; display: block; }

/* ---------- Calculator ---------- */
.calc {
  background: var(--card);
  border: 1px solid var(--rule);
  border-radius: 12px;
  padding: 1.5rem;
  margin: 1.75rem 0;
}
.calc__row {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(150px, 100%), 1fr));
  gap: .85rem;
  margin-bottom: 1.1rem;
}
.field label {
  display: block;
  font-size: 12.5px;
  font-weight: 600;
  color: var(--ink-soft);
  margin-bottom: .3rem;
  letter-spacing: .01em;
}
.field__in { position: relative; display: flex; align-items: center; }
.field input, .field select {
  width: 100%;
  font-family: var(--font-body);
  font-size: 1rem;
  padding: .58rem .7rem;
  border: 1px solid var(--rule-strong);
  border-radius: var(--radius);
  background: var(--card-sunk);
  color: var(--ink);
  appearance: none;
}
.field input { font-family: var(--font-mono); font-variant-numeric: tabular-nums; padding-right: 2.6rem; }
.field select {
  background-image: linear-gradient(45deg, transparent 50%, currentColor 50%), linear-gradient(135deg, currentColor 50%, transparent 50%);
  background-position: calc(100% - 17px) 55%, calc(100% - 12px) 55%;
  background-size: 5px 5px, 5px 5px;
  background-repeat: no-repeat;
  padding-right: 2rem;
}
.field input:focus, .field select:focus { border-color: var(--pine); background: var(--card); }
.field__unit {
  position: absolute;
  right: .7rem;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--ink-faint);
  pointer-events: none;
}
.field__err {
  display: block;
  font-size: 12.5px;
  color: var(--ev-weak);
  margin-top: .28rem;
  min-height: 0;
}

.btn {
  font-family: var(--font-body);
  font-size: .95rem;
  font-weight: 600;
  padding: .62rem 1.25rem;
  border-radius: var(--radius);
  border: 1px solid transparent;
  background: var(--pine);
  color: var(--paper);
  cursor: pointer;
}
:root[data-theme="dark"] .btn, :root:not([data-theme="light"]) .btn { color: #08130F; }
@media (prefers-color-scheme: light) {
  :root:not([data-theme="dark"]) .btn { color: #FFFFFF; }
}
.btn:hover { background: var(--pine-deep); }
.btn--ghost {
  background: transparent;
  color: var(--ink-soft);
  border-color: var(--rule-strong);
}
.btn--ghost:hover { background: var(--card-sunk); color: var(--ink); }

.calc__out {
  margin-top: 1.25rem;
  padding-top: 1.25rem;
  border-top: 1px solid var(--rule);
}
.calc__result {
  font-family: var(--font-display);
  font-optical-sizing: auto;
  font-weight: 600;
  font-size: 2.3rem;
  color: var(--pine);
  font-variant-numeric: tabular-nums;
  line-height: 1.1;
}
.calc__range {
  font-family: var(--font-mono);
  font-size: .9rem;
  color: var(--ink-soft);
  margin-top: .3rem;
}
.calc__bar {
  position: relative;
  height: 38px;
  margin: 1.1rem 0 .4rem;
}
.calc__bar-track {
  position: absolute;
  left: 0; right: 0; top: 16px;
  height: 6px;
  border-radius: 3px;
  background: var(--paper-deep);
}
.calc__bar-range {
  position: absolute;
  top: 16px; height: 6px;
  border-radius: 3px;
  background: var(--pine-wash);
  border: 1px solid var(--pine);
}
.calc__bar-mid {
  position: absolute;
  top: 8px;
  width: 2px; height: 22px;
  background: var(--pine);
  transform: translateX(-1px);
}
.calc__bar-scale {
  display: flex;
  justify-content: space-between;
  font-family: var(--font-mono);
  font-size: 10.5px;
  color: var(--ink-faint);
}

/* ---------- Chart ---------- */
.chart {
  background: var(--card);
  border: 1px solid var(--rule);
  border-radius: 12px;
  padding: 1.35rem 1.1rem 1rem;
  margin: 1.75rem 0;
}
.chart__head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: .6rem;
  margin-bottom: 1rem;
}
.chart__title { font-weight: 600; font-size: .98rem; }
.chart__legend { display: flex; gap: .95rem; font-size: 12.5px; color: var(--ink-soft); }
.chart__key { display: inline-flex; align-items: center; gap: .38rem; }
.chart__swatch { width: 14px; height: 3px; border-radius: 2px; flex: none; }
.chart__scroll { overflow-x: auto; }
.chart svg { display: block; min-width: 460px; }
.chart__foot { font-size: 12.5px; color: var(--ink-faint); margin-top: .7rem; line-height: 1.5; }

/* ---------- Table of contents ---------- */
.toc {
  background: var(--card-sunk);
  border: 1px solid var(--rule);
  border-radius: 12px;
  padding: 1.1rem 1.3rem;
  margin: 2rem 0;
}
.toc__title {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .13em;
  text-transform: uppercase;
  color: var(--ink-faint);
  margin-bottom: .6rem;
}
.toc ol { margin: 0; padding-left: 1.15rem; }
.toc li { margin-bottom: .28rem; font-size: .93rem; }
.toc a { text-decoration: none; color: var(--ink-soft); }
.toc a:hover { color: var(--pine); text-decoration: underline; }

/* ---------- Sources ---------- */
.sources {
  margin-top: 3rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--rule);
}
.sources h2 { font-size: 1.15rem; margin-top: 0; }
.sources ol { padding-left: 1.3rem; font-size: .875rem; color: var(--ink-soft); line-height: 1.6; }
.sources li { margin-bottom: .5rem; }
.sources a { word-break: break-word; }

sup.ref {
  font-family: var(--font-mono);
  font-size: 10.5px;
  font-weight: 500;
  color: var(--pine);
  vertical-align: super;
  line-height: 0;
  padding-left: 1px;
}
sup.ref a { text-decoration: none; }
sup.ref a:hover { text-decoration: underline; }

/* ---------- Next / prev ---------- */
.pager {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(220px, 100%), 1fr));
  gap: .85rem;
  margin-top: 3rem;
  padding-top: 1.75rem;
  border-top: 1px solid var(--rule);
}
.pager a {
  display: block;
  text-decoration: none;
  border: 1px solid var(--rule);
  border-radius: 12px;
  padding: .95rem 1.1rem;
  background: var(--card);
}
.pager a:hover { border-color: var(--pine); }
.pager__dir {
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: .12em;
  text-transform: uppercase;
  color: var(--ink-faint);
  display: block;
  margin-bottom: .2rem;
}
.pager__t { font-weight: 600; color: var(--ink); font-size: .96rem; }

/* ---------- Footer ---------- */
.foot {
  border-top: 1px solid var(--rule);
  background: var(--paper-deep);
  padding: 2.5rem 0 3rem;
  font-size: .86rem;
  color: var(--ink-soft);
}
.foot__in {
  max-width: var(--wide);
  margin: 0 auto;
  padding: 0 1.25rem;
  display: grid;
  gap: 1.5rem;
  grid-template-columns: repeat(auto-fit, minmax(min(230px, 100%), 1fr));
}
.foot h4 { font-family: var(--font-body); font-size: .86rem; margin: 0 0 .5rem; letter-spacing: .04em; text-transform: uppercase; color: var(--ink-faint); font-weight: 600; }
.foot ul { list-style: none; margin: 0; padding: 0; }
.foot li { margin-bottom: .3rem; }
.foot a { color: var(--ink-soft); text-decoration: none; }
.foot a:hover { color: var(--pine); text-decoration: underline; }
.foot__note { line-height: 1.6; }

/* ---------- Disclaimer banner ---------- */
.disclaimer {
  background: var(--ev-mod-bg);
  border: 1px solid color-mix(in srgb, var(--ev-mod) 35%, transparent);
  border-radius: 12px;
  padding: 1rem 1.2rem;
  font-size: .9rem;
  line-height: 1.6;
  color: var(--ink);
  margin: 2rem 0;
}
.disclaimer strong { color: var(--ev-mod); }

/* ---------- Breakout ----------
   Escapes the measure column for wide data panels. Declared last on purpose:
   .chart / .table-wrap set their own `margin` shorthand, which would otherwise
   reset margin-left at equal specificity and pull the panel off-centre. */
.breakout {
  width: min(var(--wide), calc(100vw - 2.5rem));
  margin-left: 50%;
  margin-right: 0;
  transform: translateX(-50%);
}

/* ---------- Utilities ---------- */
.mt0 { margin-top: 0; }
.center { text-align: center; }
.mono { font-family: var(--font-mono); font-variant-numeric: tabular-nums; }
.visually-hidden {
  position: absolute; width: 1px; height: 1px;
  padding: 0; margin: -1px; overflow: hidden;
  clip: rect(0,0,0,0); white-space: nowrap; border: 0;
}
.skip {
  position: absolute; left: -9999px; top: 0;
  background: var(--pine); color: var(--paper);
  padding: .6rem 1rem; z-index: 100; border-radius: 0 0 var(--radius) 0;
}
.skip:focus { left: 0; }