/* ============================================================
   开元品牌 / 共享站点样式  /assets/site.css
   ============================================================ */

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

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: 8rem;
}

body,
h1, h2, h3, h4,
p, figure, blockquote, dl, dd,
ul, ol { margin: 0; }

ul[class],
ol[class] { list-style: none; padding: 0; }

img,
svg { display: block; max-width: 100%; }

button { font: inherit; color: inherit; }

a { color: inherit; }

/* ---------- tokens ---------- */
:root {
  --ink: #0B1F33;
  --ink-2: #12324D;
  --ink-3: #1B4768;
  --gold: #E0A526;
  --gold-soft: #F3CB75;
  --red: #C24A3A;
  --sand: #F7F2E8;
  --sand-card: #EFE7D8;
  --slate: #8FA3B5;
  --text: #1A1A1A;

  --line: rgba(11, 31, 51, .12);
  --line-light: rgba(247, 242, 232, .14);
  --muted-ink: #3C5063;

  --shell: 1240px;
  --gutter: clamp(1.1rem, 3vw, 2.5rem);

  --r-lg: 28px;
  --r-md: 20px;
  --r-sm: 12px;

  --sans: "Noto Sans SC", "Source Han Sans SC", "PingFang SC", "Microsoft YaHei", system-ui, -apple-system, "Segoe UI", sans-serif;
  --mono: "IBM Plex Mono", "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;

  --ease: cubic-bezier(.2, .7, .2, 1);
}

/* ---------- typography ---------- */
body {
  font-family: var(--sans);
  font-size: 17px;
  line-height: 1.7;
  color: var(--text);
  background: var(--sand);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

h1, h2, h3, h4 {
  font-weight: 900;
  line-height: 1.12;
  letter-spacing: -.012em;
  color: var(--ink);
  text-wrap: balance;
}

h1 { font-size: clamp(2.25rem, 5.2vw, 4.5rem); }
h2 { font-size: clamp(1.75rem, 3.4vw, 2.65rem); }
h3 { font-size: clamp(1.15rem, 1.9vw, 1.6rem); font-weight: 800; }
h4 { font-size: 1.05rem; font-weight: 800; }

p { text-wrap: pretty; }

.mono {
  font-family: var(--mono);
  font-weight: 600;
  letter-spacing: .03em;
  font-variant-numeric: tabular-nums;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: .55rem;
  font-family: var(--mono);
  font-size: .72rem;
  font-weight: 600;
  letter-spacing: .2em;
  text-transform: uppercase;
  color: var(--ink-3);
}

.eyebrow::before {
  content: "";
  width: 20px;
  height: 2px;
  border-radius: 2px;
  background: var(--gold);
}

.lede {
  font-size: clamp(1rem, 1.4vw, 1.15rem);
  color: var(--muted-ink);
  max-width: 38em;
}

.prose {
  max-width: 40em;
  color: #26313B;
}

.prose p + p { margin-top: 1em; }
.prose h3 { margin: 1.9em 0 .55em; }
.prose ul, .prose ol { margin: 1em 0; padding-left: 1.15em; }
.prose li + li { margin-top: .4em; }
.prose a { color: var(--ink-3); text-decoration: underline; text-underline-offset: 3px; }
.prose strong { color: var(--ink); }

.hairline {
  border: 0;
  height: 1px;
  background: var(--line);
  margin-block: 2rem;
}

/* ---------- shell / utilities ---------- */
.shell {
  width: 100%;
  max-width: var(--shell);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.section { padding-block: clamp(2.6rem, 6vw, 5rem); }

.section--ink {
  background: radial-gradient(120% 100% at 88% 0%, rgba(27, 71, 104, .9), transparent 62%), var(--ink);
  color: #DCE6EF;
}

.section--ink :is(h1, h2, h3, h4) { color: var(--sand); }

.stack { display: grid; gap: 1rem; }
.stack--tight { display: grid; gap: .5rem; }
.pill-row { display: flex; flex-wrap: wrap; gap: .5rem; }

/* ---------- skip link ---------- */
.skip-link {
  position: fixed;
  top: .6rem;
  left: .6rem;
  z-index: 200;
  padding: .62rem 1.05rem;
  border-radius: 999px;
  background: var(--gold);
  color: #20180A;
  font-size: .85rem;
  font-weight: 800;
  text-decoration: none;
  transform: translateY(-180%);
  transition: transform .2s var(--ease);
}

.skip-link:focus,
.skip-link:focus-visible {
  transform: translateY(0);
  outline: 3px solid var(--sand);
  outline-offset: 2px;
}

#main-content { display: block; }

/* ---------- focus ---------- */
:where(a, button, summary, input, select, textarea):focus-visible {
  outline: 3px solid var(--gold);
  outline-offset: 3px;
  border-radius: 8px;
}

/* ============================================================
   HEADER
   ============================================================ */
.ky-head {
  position: sticky;
  top: 0;
  z-index: 80;
  background: var(--ink);
  border-bottom: 1px solid var(--line-light);
  box-shadow: 0 22px 46px -36px rgba(11, 31, 51, .95);
}

/* version bar */
.ky-versionbar {
  background: linear-gradient(100deg, #0B1F33 0%, #12324D 52%, #1B4768 100%);
  border-bottom: 1px solid rgba(247, 242, 232, .1);
  color: #E7EEF5;
}

.ky-versionbar__inner {
  display: flex;
  align-items: center;
  gap: .8rem;
  flex-wrap: wrap;
  min-height: 38px;
  padding-block: .3rem;
}

.ky-vb__tag {
  display: inline-flex;
  align-items: center;
  gap: .5rem;
  font-size: .7rem;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--slate);
}

.ky-vb__tag::before {
  content: "";
  width: 16px;
  height: 2px;
  border-radius: 2px;
  background: linear-gradient(90deg, var(--gold), var(--red));
}

.ky-vb__ver {
  padding: .12rem .55rem;
  border-radius: 999px;
  border: 1px solid rgba(224, 165, 38, .48);
  background: rgba(224, 165, 38, .15);
  color: var(--gold-soft);
  font-size: .74rem;
}

.ky-vb__note {
  margin-left: auto;
  font-size: .76rem;
  color: #B9C9D8;
  letter-spacing: .02em;
}

/* command bar */
.ky-commandbar {
  display: flex;
  align-items: center;
  gap: 1.25rem;
  min-height: 74px;
  padding-block: .5rem;
  flex-wrap: wrap;
}

.ky-brand {
  display: inline-flex;
  align-items: center;
  gap: .7rem;
  flex: 0 0 auto;
  color: var(--sand);
  text-decoration: none;
}

.ky-brand__sigil {
  width: 34px;
  height: 34px;
  flex: 0 0 auto;
  display: grid;
  place-items: center;
  border-radius: 11px;
  background: linear-gradient(135deg, var(--gold-soft), var(--gold) 46%, var(--red));
  box-shadow: 0 8px 18px -10px rgba(224, 165, 38, .95);
}

.ky-brand__sigil > span {
  width: 12px;
  height: 12px;
  border: 2px solid #0B1F33;
  border-radius: 3px;
  transform: rotate(45deg);
}

.ky-brand__text {
  display: grid;
  gap: .1rem;
  line-height: 1.1;
}

.ky-brand__name {
  font-size: 1.05rem;
  font-weight: 900;
  letter-spacing: .06em;
}

.ky-brand__sub {
  font-size: .62rem;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--slate);
}

/* nav */
.ky-nav { margin-left: auto; }

.ky-nav__list {
  display: flex;
  align-items: center;
  gap: .12rem;
}

.ky-nav__link {
  position: relative;
  display: inline-flex;
  align-items: baseline;
  gap: .42rem;
  padding: .52rem .7rem;
  border-radius: 999px;
  font-size: .9rem;
  font-weight: 700;
  color: #D7E2EC;
  text-decoration: none;
  transition: background .2s var(--ease), color .2s var(--ease);
}

.ky-nav__index {
  font-size: .64rem;
  letter-spacing: .06em;
  color: var(--slate);
  transition: color .2s var(--ease);
}

.ky-nav__link:hover {
  background: rgba(243, 203, 117, .14);
  color: #FFFFFF;
}

.ky-nav__link:hover .ky-nav__index { color: var(--gold-soft); }

.ky-nav__link[aria-current="page"] {
  background: rgba(224, 165, 38, .16);
  color: var(--gold-soft);
  box-shadow: inset 0 0 0 1px rgba(224, 165, 38, .4);
}

.ky-nav__link[aria-current="page"] .ky-nav__index { color: var(--gold); }

.ky-nav__link[aria-current="page"]::after {
  content: "";
  position: absolute;
  left: 50%;
  bottom: .12rem;
  width: 16px;
  height: 2px;
  transform: translateX(-50%);
  border-radius: 2px;
  background: var(--gold);
}

/* cta */
.ky-cta {
  display: inline-flex;
  align-items: center;
  gap: .4rem;
  padding: .56rem 1.05rem;
  border-radius: 999px;
  background: linear-gradient(135deg, var(--gold-soft), var(--gold));
  color: #20180A;
  font-size: .84rem;
  font-weight: 900;
  letter-spacing: .02em;
  text-decoration: none;
  white-space: nowrap;
  box-shadow: 0 14px 28px -18px rgba(224, 165, 38, .95);
  transition: transform .2s var(--ease), box-shadow .2s var(--ease);
}

.ky-cta:hover {
  transform: translateY(-2px);
  box-shadow: 0 18px 32px -18px rgba(224, 165, 38, 1);
}

/* mobile toggle */
.ky-navtoggle {
  display: none;
  align-items: center;
  gap: .5rem;
  padding: .48rem .8rem;
  border-radius: 999px;
  border: 1px solid rgba(247, 242, 232, .3);
  background: rgba(247, 242, 232, .08);
  color: var(--sand);
  font-size: .8rem;
  font-weight: 800;
  cursor: pointer;
}

.ky-navtoggle__bars {
  display: grid;
  gap: 4px;
  width: 16px;
}

.ky-navtoggle__bars span {
  display: block;
  height: 2px;
  border-radius: 2px;
  background: currentColor;
  transition: transform .22s var(--ease), opacity .22s var(--ease);
}

.ky-head[data-open] .ky-navtoggle {
  background: rgba(224, 165, 38, .18);
  border-color: rgba(224, 165, 38, .55);
  color: var(--gold-soft);
}

.ky-head[data-open] .ky-navtoggle__bars span:first-child {
  transform: translateY(6px) rotate(45deg);
}

.ky-head[data-open] .ky-navtoggle__bars span:last-child {
  transform: translateY(-6px) rotate(-45deg);
}

/* ============================================================
   FOOTER
   ============================================================ */
.ky-foot {
  position: relative;
  overflow: hidden;
  padding-block: clamp(2.6rem, 5vw, 4rem) 1.6rem;
  background:
    radial-gradient(120% 90% at 6% 0%, rgba(224, 165, 38, .16), transparent 56%),
    radial-gradient(90% 80% at 100% 10%, rgba(27, 71, 104, .8), transparent 60%),
    linear-gradient(180deg, #0B1F33 0%, #081727 100%);
  color: #D9E3EC;
  border-top: 1px solid rgba(247, 242, 232, .1);
}

.ky-foot::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: min(48%, 540px);
  height: 3px;
  background: linear-gradient(90deg, var(--gold), var(--red));
}

.ky-foot__grid {
  display: grid;
  grid-template-columns: 1.35fr .85fr 1.15fr;
  gap: clamp(1.6rem, 3.2vw, 3.2rem);
  align-items: start;
}

.ky-foot__brand { display: grid; gap: 1rem; justify-items: start; }

.ky-brand--foot .ky-brand__name { font-size: 1.18rem; }

.ky-foot__tagline {
  max-width: 30em;
  font-size: .92rem;
  line-height: 1.75;
  color: #B7C7D6;
}

.ky-foot__cta { margin-top: .15rem; }

.ky-foot__colhead {
  display: flex;
  align-items: center;
  gap: .55rem;
  margin-bottom: .95rem;
  font-family: var(--mono);
  font-size: .68rem;
  font-weight: 600;
  letter-spacing: .2em;
  text-transform: uppercase;
  color: var(--slate);
}

.ky-foot__colhead .mono { color: var(--gold); letter-spacing: .1em; }

.ky-foot__colhead::after {
  content: "";
  flex: 1;
  height: 1px;
  background: var(--line-light);
}

.ky-foot__list {
  display: grid;
  gap: .3rem;
}

.ky-foot__link {
  display: inline-block;
  padding-block: .18rem;
  font-size: .92rem;
  color: #C9D7E3;
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color .2s var(--ease), border-color .2s var(--ease);
}

.ky-foot__link:hover {
  color: var(--gold-soft);
  border-bottom-color: rgba(243, 203, 117, .6);
}

.ky-foot__list--contact { gap: .7rem; }

.ky-contactline {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: .5rem;
}

.ky-contactline__k {
  min-width: 2.6rem;
  font-size: .68rem;
  letter-spacing: .12em;
  text-transform: uppercase;
  color: var(--slate);
}

.ky-contactline__v {
  font-size: .84rem;
  color: var(--sand);
  word-break: break-all;
}

.ky-contactline__v--text {
  font-family: var(--sans);
  font-size: .86rem;
  line-height: 1.6;
  color: #C9D7E3;
  word-break: normal;
}

.ky-copy {
  padding: .16rem .5rem;
  border-radius: 999px;
  border: 1px solid rgba(243, 203, 117, .45);
  background: transparent;
  color: var(--gold-soft);
  font-family: var(--mono);
  font-size: .66rem;
  letter-spacing: .08em;
  cursor: pointer;
  transition: background .2s var(--ease), color .2s var(--ease), border-color .2s var(--ease);
}

.ky-copy:hover { background: rgba(243, 203, 117, .16); }

.ky-copy.is-copied {
  background: var(--gold);
  border-color: transparent;
  color: #20180A;
}

.ky-foot__note {
  margin-top: .9rem;
  font-size: .78rem;
  line-height: 1.7;
  color: #93A8BA;
}

.ky-foot__rule {
  border: 0;
  height: 1px;
  background: var(--line-light);
  margin-block: clamp(1.8rem, 4vw, 2.6rem) 1.1rem;
}

.ky-foot__legal {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: .5rem 1.4rem;
  font-size: .78rem;
  color: #9FB2C3;
}

.ky-foot__meta--code { margin-left: auto; letter-spacing: .14em; color: var(--slate); }

.ky-foot__legal-links {
  display: flex;
  flex-wrap: wrap;
  gap: .4rem 1rem;
}

.ky-foot__legal-links a {
  color: #C9D7E3;
  text-decoration: none;
  border-bottom: 1px solid rgba(201, 215, 227, .3);
  padding-bottom: 1px;
}

.ky-foot__legal-links a:hover {
  color: var(--gold-soft);
  border-bottom-color: var(--gold-soft);
}

/* ============================================================
   BUTTONS / TAGS / BREADCRUMBS
   ============================================================ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: .5rem;
  padding: .78rem 1.35rem;
  border: 1px solid transparent;
  border-radius: 999px;
  font-size: .95rem;
  font-weight: 800;
  text-decoration: none;
  cursor: pointer;
  transition: transform .2s var(--ease), background .2s var(--ease), color .2s var(--ease), box-shadow .2s var(--ease);
}

.btn:hover { transform: translateY(-2px); }

.btn--gold {
  background: linear-gradient(135deg, var(--gold-soft), var(--gold));
  color: #20180A;
  box-shadow: 0 14px 30px -18px rgba(224, 165, 38, .95);
}

.btn--red {
  background: var(--red);
  color: #FFFFFF;
  box-shadow: 0 14px 30px -20px rgba(194, 74, 58, .95);
}

.btn--ink { background: var(--ink); color: var(--sand); }

.btn--ghost {
  background: transparent;
  border-color: rgba(11, 31, 51, .28);
  color: var(--ink);
}

.btn--ghost-light {
  background: transparent;
  border-color: rgba(247, 242, 232, .38);
  color: var(--sand);
}

.btn--sm { padding: .5rem .95rem; font-size: .82rem; }

.tag {
  display: inline-flex;
  align-items: center;
  gap: .4rem;
  padding: .28rem .7rem;
  border-radius: 999px;
  border: 1px solid rgba(11, 31, 51, .16);
  background: #FFFFFF;
  color: var(--ink-2);
  font-family: var(--mono);
  font-size: .72rem;
  font-weight: 600;
  letter-spacing: .06em;
  text-decoration: none;
}

.tag--gold {
  background: rgba(243, 203, 117, .35);
  border-color: rgba(224, 165, 38, .5);
  color: #6B4A05;
}

.tag--red {
  background: rgba(194, 74, 58, .12);
  border-color: rgba(194, 74, 58, .45);
  color: var(--red);
}

.tag--ghost {
  background: rgba(247, 242, 232, .06);
  border-color: var(--line-light);
  color: #C9D7E3;
}

.crumbs {
  font-size: .8rem;
  color: #5A6E80;
  margin-bottom: clamp(1rem, 2vw, 1.6rem);
}

.crumbs__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: .4rem;
}

.crumbs a {
  text-decoration: none;
  border-bottom: 1px solid rgba(11, 31, 51, .22);
  padding-bottom: 1px;
}

.crumbs a:hover { color: var(--ink); border-bottom-color: var(--gold); }

.crumbs__sep { color: var(--slate); }

.crumbs [aria-current="page"] { color: var(--ink); font-weight: 700; }

/* ============================================================
   GRID / RAIL / TOC
   ============================================================ */
.grid { display: grid; gap: clamp(1.1rem, 2vw, 1.75rem); }

.grid--split {
  grid-template-columns: minmax(0, 2fr) minmax(0, 7fr) minmax(0, 3fr);
}

.grid--halves { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid--thirds { grid-template-columns: repeat(3, minmax(0, 1fr)); }

.rail { display: grid; gap: .8rem; align-content: start; }

.rail__label {
  writing-mode: vertical-rl;
  font-family: var(--mono);
  font-size: .7rem;
  letter-spacing: .34em;
  text-transform: uppercase;
  color: var(--slate);
}

.toc {
  display: grid;
  gap: .55rem;
  align-content: start;
}

.toc__list { display: grid; gap: 2px; }

.toc__link {
  display: flex;
  align-items: baseline;
  gap: .55rem;
  padding: .5rem .7rem;
  border-left: 2px solid transparent;
  border-radius: var(--r-sm);
  font-size: .88rem;
  color: #41586C;
  text-decoration: none;
  transition: background .2s var(--ease), color .2s var(--ease), border-color .2s var(--ease);
}

.toc__index {
  font-family: var(--mono);
  font-size: .7rem;
  font-weight: 600;
  color: var(--slate);
}

.toc__link:hover { background: rgba(11, 31, 51, .06); color: var(--ink); }

.toc__link.is-current {
  background: #FFFFFF;
  border-left-color: var(--gold);
  color: var(--ink);
  font-weight: 700;
  box-shadow: 0 12px 26px -22px rgba(11, 31, 51, .8);
}

.toc__link.is-current .toc__index { color: var(--gold); }

/* ============================================================
   CARDS / FIGURES
   ============================================================ */
.card {
  position: relative;
  display: grid;
  gap: .6rem;
  align-content: start;
  padding: clamp(1.1rem, 2vw, 1.6rem);
  border: 1px solid rgba(11, 31, 51, .1);
  border-radius: var(--r-md);
  background: var(--sand-card);
}

.card__head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: .75rem;
}

.card__title { font-size: 1.05rem; font-weight: 800; color: var(--ink); }

.card__meta {
  font-family: var(--mono);
  font-size: .72rem;
  letter-spacing: .06em;
  color: #5A6E80;
}

.card__body { font-size: .94rem; line-height: 1.7; color: #33475A; }

.card--ink {
  background: radial-gradient(120% 120% at 100% 0%, rgba(27, 71, 104, .95), transparent 62%), var(--ink-2);
  border-color: rgba(247, 242, 232, .16);
}

.card--ink .card__title { color: var(--sand); }
.card--ink .card__body { color: #C3D2DF; }
.card--ink .card__meta { color: var(--slate); }

.card--gold {
  background: linear-gradient(150deg, #FBEBC6, var(--gold-soft));
  border-color: rgba(224, 165, 38, .5);
}

.card--line { background: transparent; }

.figure { display: grid; gap: .55rem; margin: 0; }

.figure__media {
  position: relative;
  overflow: hidden;
  aspect-ratio: 16 / 10;
  border-radius: var(--r-lg);
  background:
    radial-gradient(120% 120% at 16% 8%, rgba(243, 203, 117, .55), transparent 56%),
    radial-gradient(95% 95% at 88% 94%, rgba(27, 71, 104, .7), transparent 60%),
    var(--ink-2);
}

.figure__media > img,
.figure__media > picture > img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.figure__cap {
  font-family: var(--mono);
  font-size: .76rem;
  letter-spacing: .04em;
  color: #5A6E80;
}

.figure--wide .figure__media { aspect-ratio: 21 / 9; }
.figure--tall .figure__media { aspect-ratio: 4 / 5; }
.figure--square .figure__media { aspect-ratio: 1 / 1; }

/* ============================================================
   FIXED UI
   ============================================================ */
.progress {
  position: fixed;
  inset: 0 0 auto 0;
  height: 3px;
  z-index: 90;
  pointer-events: none;
}

.progress__bar {
  display: block;
  height: 100%;
  width: 0;
  background: linear-gradient(90deg, var(--gold), var(--red));
}

.to-top {
  position: fixed;
  right: clamp(1rem, 3vw, 2.2rem);
  bottom: clamp(1rem, 3vw, 2.2rem);
  z-index: 70;
  display: grid;
  place-items: center;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  border: 1px solid rgba(247, 242, 232, .32);
  background: var(--ink);
  color: var(--sand);
  cursor: pointer;
  opacity: 0;
  transform: translateY(12px);
  pointer-events: none;
  box-shadow: 0 18px 34px -22px rgba(11, 31, 51, .9);
  transition: opacity .25s var(--ease), transform .25s var(--ease), background .2s var(--ease), color .2s var(--ease);
}

.to-top.is-visible {
  opacity: 1;
  transform: none;
  pointer-events: auto;
}

.to-top:hover {
  background: var(--gold);
  border-color: transparent;
  color: #20180A;
}

/* ============================================================
   REVEAL
   ============================================================ */
.reveal--armed {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity .5s var(--ease), transform .5s var(--ease);
}

.reveal--armed.is-in {
  opacity: 1;
  transform: none;
}

/* ============================================================
   RESPONSIVE
   ============================================================ */
@media (max-width: 1080px) {
  .grid--split { grid-template-columns: minmax(0, 1fr); }
  .rail__label { writing-mode: horizontal-tb; letter-spacing: .22em; }
  .ky-nav__link { padding: .5rem .55rem; font-size: .86rem; }
  .ky-nav__index { display: none; }
  .ky-foot__grid { grid-template-columns: 1.2fr 1fr; }
  .ky-foot__col:last-child { grid-column: 1 / -1; }
}

@media (min-width: 1081px) {
  .rail,
  .toc { position: sticky; top: 9.5rem; }
}

@media (max-width: 960px) {
  html { scroll-padding-top: 7rem; }

  .ky-commandbar {
    gap: .6rem;
    min-height: 64px;
    padding-block: .6rem;
  }

  .ky-cta { order: 2; margin-left: auto; }
  .ky-navtoggle { display: inline-flex; order: 3; }

  .ky-nav {
    display: none;
    order: 4;
    flex: 1 0 100%;
    margin-left: 0;
  }

  .ky-head[data-open] .ky-nav { display: block; }

  .ky-nav__list {
    flex-direction: column;
    align-items: stretch;
    gap: 2px;
    padding-block: .7rem .3rem;
    border-top: 1px solid var(--line-light);
  }

  .ky-nav__link {
    width: 100%;
    justify-content: flex-start;
    padding: .72rem .85rem;
    border-radius: 14px;
    font-size: .95rem;
  }

  .ky-nav__index { display: inline; }

  .ky-nav__link[aria-current="page"]::after { display: none; }

  .grid--thirds { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 760px) {
  body { font-size: 16px; }

  .ky-vb__note { display: none; }
  .ky-foot__grid { grid-template-columns: minmax(0, 1fr); }
  .ky-foot__legal { align-items: flex-start; }
  .ky-foot__meta--code { margin-left: 0; }
  .grid--halves,
  .grid--thirds { grid-template-columns: minmax(0, 1fr); }
  .figure--wide .figure__media { aspect-ratio: 16 / 10; }
}

@media (max-width: 520px) {
  .ky-brand__sub { display: none; }
  .ky-brand__name { font-size: .98rem; }
  .ky-cta { padding: .48rem .8rem; font-size: .78rem; }
  .ky-vb__tag { font-size: .64rem; letter-spacing: .1em; }
  .ky-navtoggle { padding: .44rem .66rem; }
  .to-top { width: 44px; height: 44px; }
}

/* ============================================================
   MOTION PREFERENCES
   ============================================================ */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }

  *,
  *::before,
  *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
  }

  .btn:hover,
  .ky-cta:hover { transform: none; }

  .reveal--armed {
    opacity: 1;
    transform: none;
  }

  .progress__bar { transition: none; }
}