/* ============ 1. Reset ============ */
*,
*::before,
*::after {
  box-sizing: border-box;
}

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

body {
  margin: 0;
  min-height: 100vh;
}

h1, h2, h3, h4, h5, h6, p, figure, blockquote, dl, dd {
  margin: 0;
}

ul, ol {
  margin: 0;
  padding: 0;
  list-style: none;
}

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

a {
  color: inherit;
  text-decoration: none;
}

button, input, select, textarea {
  font: inherit;
  color: inherit;
}

button {
  background: none;
  border: 0;
  cursor: pointer;
}

/* ============ 2. Tokens ============ */
:root {
  --ink: #0B1B2B;
  --ink-deep: #06101A;
  --midnight: #102A43;
  --haze: #8FA6B8;
  --cyan: #22D3EE;
  --teal: #14B8A6;
  --mint: #67E8F9;
  --amber: #F5B84B;
  --amber-soft: #FFE1A3;
  --paper: #F4F7FA;

  --font-display: "Noto Sans SC", "Source Han Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, sans-serif;
  --font-body: "PingFang SC", "Hiragino Sans GB", "Noto Sans SC", "Microsoft YaHei", system-ui, sans-serif;
  --font-mono: ui-monospace, "SFMono-Regular", Menlo, Consolas, "Liberation Mono", monospace;

  --stroke: rgba(143, 166, 184, 0.28);
  --stroke-soft: rgba(143, 166, 184, 0.16);
  --stroke-cyan: rgba(34, 211, 238, 0.5);

  --container: 1240px;
  --gutter: clamp(18px, 4vw, 48px);
  --ease: cubic-bezier(0.2, 0.7, 0.3, 1);
  --shadow-lift: 0 18px 40px -24px rgba(6, 16, 26, 0.92);
  --shadow-panel: 0 34px 70px -40px #000;
}

/* ============ 3. Base typography ============ */
body {
  font-family: var(--font-body);
  font-size: clamp(15px, 1.05vw, 17px);
  font-weight: 400;
  line-height: 1.75;
  color: var(--paper);
  background-color: var(--ink);
  background-image:
    linear-gradient(rgba(143, 166, 184, 0.055) 1px, transparent 1px),
    linear-gradient(90deg, rgba(143, 166, 184, 0.055) 1px, transparent 1px);
  background-size: 64px 64px;
  background-attachment: fixed;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 900;
  letter-spacing: -0.02em;
  line-height: 1.12;
  color: var(--paper);
}

h1 { font-size: clamp(48px, 7vw, 104px); line-height: 1.02; letter-spacing: -0.045em; }
h2 { font-size: clamp(28px, 3.4vw, 48px); }
h3 { font-size: clamp(20px, 2vw, 28px); letter-spacing: -0.01em; }
h4 { font-size: clamp(17px, 1.3vw, 20px); letter-spacing: 0; line-height: 1.3; }

p { line-height: 1.75; }

strong { font-weight: 800; color: var(--paper); }

::selection {
  background: var(--cyan);
  color: #04212B;
}

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

main [id],
section[id] {
  scroll-margin-top: clamp(96px, 16vh, 160px);
}

/* ============ 4. Layout helpers ============ */
.container {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.container--wide {
  max-width: 1480px;
}

.section {
  position: relative;
  padding-block: clamp(44px, 6vw, 86px);
}

.section--mint {
  background: linear-gradient(158deg, rgba(20, 184, 166, 0.18), rgba(103, 232, 249, 0.06) 52%, rgba(11, 27, 43, 0) 82%);
}

.section--amber {
  background: linear-gradient(180deg, rgba(245, 184, 75, 0.14), rgba(11, 27, 43, 0) 72%);
}

.section--slate {
  background: linear-gradient(180deg, rgba(143, 166, 184, 0.16), rgba(16, 42, 67, 0.32));
}

.section__head {
  display: grid;
  gap: 10px;
  max-width: 68ch;
  margin-bottom: clamp(20px, 2.6vw, 34px);
}

.section__title {
  font-size: clamp(24px, 3vw, 40px);
}

.section__lead {
  font-size: clamp(15px, 1.2vw, 17px);
  color: var(--haze);
  line-height: 1.75;
}

.divider-band {
  background: var(--midnight);
  border-top: 1px solid var(--stroke-soft);
  border-bottom: 1px solid var(--stroke-soft);
  padding-block: 13px;
}

.divider-band__inner {
  display: flex;
  flex-wrap: wrap;
  gap: 8px var(--gutter);
  align-items: center;
  justify-content: space-between;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--haze);
}

.grid {
  display: grid;
  gap: clamp(16px, 2vw, 28px);
}

.grid--2 {
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
}

.grid--3 {
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
}

.grid--asym {
  grid-template-columns: repeat(12, minmax(0, 1fr));
}

.grid--asym > * {
  grid-column: span 12;
}

/* ============ 5. Micro components ============ */
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.24em;
  text-transform: uppercase;
  color: var(--cyan);
}

.eyebrow::before {
  content: "";
  width: 22px;
  height: 1px;
  background: currentColor;
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px;
  border: 1px solid var(--stroke);
  border-radius: 999px;
  background: rgba(16, 42, 67, 0.62);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--haze);
  white-space: nowrap;
}

.tag--mint {
  border-color: rgba(103, 232, 249, 0.45);
  color: var(--mint);
  background: rgba(20, 184, 166, 0.12);
}

.tag--amber {
  border-color: rgba(245, 184, 75, 0.5);
  color: var(--amber);
  background: rgba(245, 184, 75, 0.1);
}

.numeral {
  display: inline-block;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(26px, 3vw, 40px);
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--amber);
  font-variant-numeric: tabular-nums;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 22px;
  border: 1px solid transparent;
  border-radius: 2px;
  font-family: var(--font-display);
  font-size: 15px;
  font-weight: 700;
  letter-spacing: 0.06em;
  line-height: 1.2;
  transition: background-color 0.18s var(--ease), color 0.18s var(--ease), border-color 0.18s var(--ease), transform 0.18s var(--ease);
}

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

.btn--primary {
  background: var(--cyan);
  border-color: var(--cyan);
  color: #04212B;
}

.btn--primary:hover {
  background: var(--mint);
  border-color: var(--mint);
}

.btn--ghost {
  background: transparent;
  border-color: var(--stroke-cyan);
  color: var(--paper);
}

.btn--ghost:hover {
  background: rgba(34, 211, 238, 0.1);
  border-color: var(--cyan);
}

.btn--amber {
  background: var(--amber);
  border-color: var(--amber);
  color: #231605;
}

.btn--amber:hover {
  background: var(--amber-soft);
  border-color: var(--amber-soft);
}

.btn--block {
  width: 100%;
}

.card {
  position: relative;
  padding: clamp(18px, 2.2vw, 28px);
  background: rgba(16, 42, 67, 0.72);
  border: 1px solid var(--stroke);
  border-radius: 4px;
  transition: transform 0.18s var(--ease), border-color 0.18s var(--ease), box-shadow 0.18s var(--ease);
}

.card:hover {
  transform: translateY(-2px);
  border-color: var(--stroke-cyan);
  box-shadow: var(--shadow-lift);
}

.card--mint {
  border-color: rgba(20, 184, 166, 0.42);
  background: linear-gradient(155deg, rgba(20, 184, 166, 0.22), rgba(16, 42, 67, 0.78));
}

.card--amber {
  border-color: rgba(245, 184, 75, 0.38);
  background: linear-gradient(155deg, rgba(245, 184, 75, 0.16), rgba(16, 42, 67, 0.78));
}

.card--slate {
  background: linear-gradient(180deg, rgba(143, 166, 184, 0.18), rgba(16, 42, 67, 0.76));
}

.card__title {
  font-family: var(--font-display);
  font-size: clamp(19px, 1.6vw, 23px);
  font-weight: 800;
  letter-spacing: -0.01em;
  line-height: 1.3;
  color: var(--paper);
}

.card__text {
  margin-top: 10px;
  font-size: 15px;
  line-height: 1.7;
  color: var(--haze);
}

.prose {
  max-width: 68ch;
}

.prose > * + * {
  margin-top: 1.05em;
}

.prose p {
  color: var(--paper);
  line-height: 1.78;
}

.prose h2,
.prose h3 {
  margin-top: 1.6em;
}

.prose a {
  color: var(--cyan);
  border-bottom: 1px solid rgba(34, 211, 238, 0.4);
}

.prose a:hover {
  border-color: var(--cyan);
}

.prose ul,
.prose ol {
  display: grid;
  gap: 0.5em;
}

.prose li {
  position: relative;
  padding-left: 18px;
  line-height: 1.7;
}

.prose li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.78em;
  width: 8px;
  height: 1px;
  background: var(--cyan);
}

/* ============ 6. Media frame ============ */
.media-frame {
  position: relative;
  overflow: hidden;
  border: 1px solid var(--stroke);
  border-radius: 4px;
  background: linear-gradient(140deg, var(--midnight), var(--ink));
  aspect-ratio: 16 / 9;
}

.media-frame__inner {
  position: absolute;
  inset: 0;
}

.media-frame__img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: saturate(0.72) contrast(1.05);
}

.media-frame__caption {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  padding: 12px 14px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--haze);
  background: linear-gradient(0deg, rgba(6, 16, 26, 0.9), rgba(6, 16, 26, 0));
}

.media-frame--grid::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(rgba(34, 211, 238, 0.16) 1px, transparent 1px),
    linear-gradient(90deg, rgba(34, 211, 238, 0.16) 1px, transparent 1px);
  background-size: 48px 48px;
  mix-blend-mode: screen;
}

/* ============ 7. Breadcrumb ============ */
.breadcrumb {
  padding-block: 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--haze);
}

.breadcrumb ol {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
}

.breadcrumb li {
  display: inline-flex;
  align-items: center;
}

.breadcrumb li + li::before {
  content: "/";
  margin-right: 8px;
  color: rgba(143, 166, 184, 0.5);
}

.breadcrumb a:hover {
  color: var(--cyan);
}

.breadcrumb [aria-current="page"] {
  color: var(--paper);
}

/* ============ 8. Skip link & progress ============ */
.skip-link {
  position: fixed;
  left: 12px;
  top: -72px;
  z-index: 300;
  padding: 10px 18px;
  background: var(--cyan);
  color: #04212B;
  font-weight: 700;
  font-size: 14px;
  letter-spacing: 0.04em;
  border-radius: 2px;
  transition: top 0.2s var(--ease);
}

.skip-link:focus {
  top: 12px;
}

.progress-bar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  z-index: 120;
  background: rgba(143, 166, 184, 0.14);
  pointer-events: none;
}

.progress-bar__fill {
  display: block;
  width: 0;
  height: 100%;
  background: linear-gradient(90deg, var(--teal), var(--cyan) 58%, var(--amber));
}

/* ============ 9. Header ============ */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--ink);
  border-bottom: 1px solid var(--stroke);
  transition: box-shadow 0.24s var(--ease);
}

.site-header.is-compact {
  box-shadow: var(--shadow-panel);
}

.masthead-top {
  background: var(--ink-deep);
  border-bottom: 1px solid var(--stroke-soft);
  color: var(--haze);
}

.masthead-top__inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 6px 24px;
  max-width: var(--container);
  margin-inline: auto;
  padding: 7px var(--gutter);
}

.masthead-top__notice {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  line-height: 1.6;
}

.masthead-top__links {
  display: flex;
  gap: 18px;
  font-size: 12px;
  letter-spacing: 0.06em;
}

.masthead-top__links a {
  color: var(--haze);
  border-bottom: 1px solid transparent;
  padding-bottom: 1px;
  transition: color 0.18s var(--ease), border-color 0.18s var(--ease);
}

.masthead-top__links a:hover {
  color: var(--cyan);
  border-color: var(--cyan);
}

.masthead {
  position: relative;
  background: radial-gradient(120% 190% at 50% -50%, rgba(34, 211, 238, 0.18), rgba(34, 211, 238, 0) 62%);
}

.masthead::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(34, 211, 238, 0.45), transparent);
}

.masthead__inner {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: clamp(12px, 2vw, 28px);
  max-width: var(--container);
  margin-inline: auto;
  padding: clamp(14px, 2vw, 22px) var(--gutter);
}

.masthead__tagline {
  font-family: var(--font-mono);
  font-size: 11px;
  line-height: 1.8;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--haze);
}

.masthead__brand {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  padding-inline: clamp(8px, 2vw, 26px);
  text-align: center;
}

.masthead__brand-cn {
  font-family: var(--font-display);
  font-size: clamp(26px, 3.6vw, 40px);
  font-weight: 900;
  letter-spacing: -0.045em;
  line-height: 1;
  color: var(--paper);
  transition: color 0.18s var(--ease);
}

.masthead__brand-en {
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.34em;
  text-transform: uppercase;
  color: var(--cyan);
}

.masthead__brand:hover .masthead__brand-cn {
  color: var(--mint);
}

.masthead__actions {
  display: flex;
  align-items: center;
  gap: 10px;
  justify-self: end;
}

.masthead__cta {
  white-space: nowrap;
}

.nav-toggle {
  display: none;
  align-items: center;
  gap: 9px;
  padding: 9px 13px;
  border: 1px solid var(--stroke);
  border-radius: 2px;
  color: var(--paper);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  transition: border-color 0.18s var(--ease), color 0.18s var(--ease);
}

.nav-toggle:hover {
  border-color: var(--cyan);
  color: var(--cyan);
}

.nav-toggle__bars {
  display: inline-flex;
  flex-direction: column;
  gap: 3px;
  width: 16px;
}

.nav-toggle__bars span {
  display: block;
  height: 2px;
  width: 100%;
  background: currentColor;
  transition: transform 0.2s var(--ease), opacity 0.2s var(--ease);
}

.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:nth-child(1) {
  transform: translateY(5px) rotate(45deg);
}

.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:nth-child(2) {
  opacity: 0;
}

.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:nth-child(3) {
  transform: translateY(-5px) rotate(-45deg);
}

.nav-toggle__label {
  line-height: 1;
}

.primary-nav {
  position: relative;
  z-index: 6;
  background: rgba(6, 16, 26, 0.62);
  border-top: 1px solid var(--stroke);
}

.primary-nav__list {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: clamp(10px, 2vw, 34px);
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.primary-nav__list a {
  position: relative;
  display: inline-block;
  padding: 14px 2px;
  font-size: 15px;
  font-weight: 600;
  letter-spacing: 0.02em;
  color: var(--haze);
  transition: color 0.18s var(--ease);
}

.primary-nav__list a::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 8px;
  height: 2px;
  background: var(--cyan);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform 0.22s var(--ease);
}

.primary-nav__list a:hover {
  color: var(--paper);
}

.primary-nav__list a:hover::after {
  transform: scaleX(1);
}

.primary-nav__list a[aria-current="page"] {
  color: var(--paper);
}

.primary-nav__list a[aria-current="page"]::after {
  transform: scaleX(1);
  background: var(--amber);
}

/* 压缩态（桌面）：左品牌 + 右直达与栏目按钮 */
.site-header.is-compact .masthead-top {
  display: none;
}

.site-header.is-compact .masthead__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding-block: 9px;
}

.site-header.is-compact .masthead__tagline {
  display: none;
}

.site-header.is-compact .masthead__brand {
  flex-direction: row;
  align-items: baseline;
  gap: 10px;
  padding-inline: 0;
  text-align: left;
}

.site-header.is-compact .masthead__brand-cn {
  font-size: clamp(19px, 2vw, 24px);
  letter-spacing: -0.03em;
}

.site-header.is-compact .masthead__brand-en {
  font-size: 9px;
  letter-spacing: 0.22em;
}

.site-header.is-compact .masthead__cta {
  padding: 9px 16px;
  font-size: 13px;
}

.site-header.is-compact .nav-toggle {
  display: inline-flex;
}

/* ============ 10. Footer ============ */
.site-footer {
  position: relative;
  overflow: hidden;
  background: var(--ink-deep);
  border-top: 1px solid rgba(34, 211, 238, 0.42);
  color: var(--haze);
  padding: clamp(38px, 5vw, 68px) 0 clamp(56px, 7vw, 88px);
}

.site-footer::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(rgba(143, 166, 184, 0.07) 1px, transparent 1px),
    linear-gradient(90deg, rgba(143, 166, 184, 0.07) 1px, transparent 1px);
  background-size: 56px 56px;
}

.site-footer__inner {
  position: relative;
  z-index: 1;
}

.site-footer__top {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-end;
  justify-content: space-between;
  gap: 10px 24px;
  padding-bottom: clamp(18px, 2.6vw, 30px);
  border-bottom: 1px solid var(--stroke);
}

.site-footer__mark {
  font-family: var(--font-display);
  font-size: clamp(24px, 3vw, 34px);
  font-weight: 900;
  letter-spacing: -0.035em;
  line-height: 1;
  color: var(--paper);
}

.site-footer__mark-en {
  margin-left: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.3em;
  color: var(--cyan);
  vertical-align: middle;
}

.site-footer__note {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--haze);
}

.site-footer__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(22px, 3vw, 42px);
  padding-block: clamp(24px, 3.4vw, 44px);
}

.footer-col__heading {
  margin-bottom: 14px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--stroke);
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.24em;
  text-transform: uppercase;
  color: var(--cyan);
}

.footer-col__list {
  display: grid;
  gap: 9px;
  font-size: 14px;
  line-height: 1.65;
}

.footer-col__list--tight {
  gap: 7px;
  font-size: 13px;
  line-height: 1.7;
}

.footer-col__list--links a {
  display: inline-block;
  padding-bottom: 1px;
  font-weight: 600;
  color: var(--paper);
  border-bottom: 1px solid transparent;
  transition: color 0.18s var(--ease), border-color 0.18s var(--ease);
}

.footer-col__list--links a:hover {
  color: var(--cyan);
  border-color: var(--cyan);
}

.footer-col--manual {
  padding: clamp(14px, 1.8vw, 22px);
  background: rgba(16, 42, 67, 0.55);
  border: 1px solid rgba(34, 211, 238, 0.28);
  border-radius: 3px;
}

.site-footer__base {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 10px 24px;
  padding-top: clamp(16px, 2vw, 24px);
  border-top: 1px solid var(--stroke);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
}

.site-footer__copy {
  color: var(--haze);
}

.site-footer__legal {
  display: flex;
  flex-wrap: wrap;
  gap: 18px;
}

.site-footer__legal a {
  color: var(--haze);
  border-bottom: 1px solid transparent;
  transition: color 0.18s var(--ease), border-color 0.18s var(--ease);
}

.site-footer__legal a:hover {
  color: var(--amber);
  border-color: var(--amber);
}

/* ============ 11. Back to top ============ */
.to-top {
  position: fixed;
  right: clamp(14px, 2vw, 28px);
  bottom: clamp(14px, 2vw, 28px);
  z-index: 80;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 10px 14px;
  background: rgba(6, 16, 26, 0.92);
  border: 1px solid var(--stroke-cyan);
  border-radius: 2px;
  color: var(--paper);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  opacity: 0;
  visibility: hidden;
  transform: translateY(8px);
  transition: opacity 0.24s var(--ease), transform 0.24s var(--ease), visibility 0.24s var(--ease), border-color 0.18s var(--ease), color 0.18s var(--ease);
}

.to-top.is-visible {
  opacity: 1;
  visibility: visible;
  transform: none;
}

.to-top:hover {
  border-color: var(--cyan);
  color: var(--cyan);
}

/* ============ 12. Reveal ============ */
.js [data-reveal] {
  opacity: 0;
  transform: translateY(14px);
}

.js [data-reveal].is-revealed {
  opacity: 1;
  transform: none;
  transition: opacity 0.5s var(--ease), transform 0.5s var(--ease);
}

/* ============ 13. Tablet / desktop ============ */
@media (min-width: 820px) {
  .site-footer__grid {
    grid-template-columns: 1.35fr 1fr 0.85fr;
  }
}

@media (min-width: 900px) {
  .grid--asym > .span-4 { grid-column: span 4; }
  .grid--asym > .span-5 { grid-column: span 5; }
  .grid--asym > .span-6 { grid-column: span 6; }
  .grid--asym > .span-7 { grid-column: span 7; }
  .grid--asym > .span-8 { grid-column: span 8; }
}

@media (min-width: 901px) {
  .site-header.is-compact .primary-nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    max-height: 0;
    overflow: hidden;
    opacity: 0;
    visibility: hidden;
    background: rgba(6, 16, 26, 0.98);
    border-top: 1px solid var(--stroke);
    box-shadow: var(--shadow-panel);
    transition: max-height 0.32s var(--ease), opacity 0.2s var(--ease), visibility 0.32s var(--ease);
  }

  .site-header.is-compact .primary-nav[data-open="true"] {
    max-height: 320px;
    opacity: 1;
    visibility: visible;
  }
}

/* ============ 14. Mobile ============ */
@media (max-width: 900px) {
  .masthead-top__inner {
    justify-content: center;
    text-align: center;
    padding-block: 6px;
  }

  .masthead-top__notice {
    font-size: 10px;
    letter-spacing: 0.06em;
  }

  .masthead-top__links {
    display: none;
  }

  .masthead__inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    padding-block: 12px;
  }

  .masthead__tagline {
    display: none;
  }

  .masthead__brand {
    align-items: flex-start;
    padding-inline: 0;
    text-align: left;
  }

  .masthead__brand-cn {
    font-size: clamp(22px, 6vw, 28px);
  }

  .masthead__brand-en {
    font-size: 9px;
    letter-spacing: 0.24em;
  }

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

  .site-header.is-compact .masthead-top {
    display: block;
  }

  .site-header.is-compact .masthead__inner {
    padding-block: 10px;
  }

  .primary-nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    z-index: 20;
    max-height: 0;
    overflow: hidden;
    opacity: 0;
    visibility: hidden;
    background: rgba(6, 16, 26, 0.98);
    border-top: 1px solid var(--stroke);
    box-shadow: var(--shadow-panel);
    transition: max-height 0.34s var(--ease), opacity 0.24s var(--ease), visibility 0.34s var(--ease);
  }

  .primary-nav[data-open="true"] {
    max-height: min(76vh, 520px);
    overflow: auto;
    opacity: 1;
    visibility: visible;
  }

  .primary-nav__list {
    flex-direction: column;
    gap: 0;
    max-width: none;
    padding: 8px var(--gutter) 24px;
  }

  .primary-nav__list li {
    border-bottom: 1px solid var(--stroke-soft);
  }

  .primary-nav__list li:last-child {
    border-bottom: 0;
  }

  .primary-nav__list a {
    display: block;
    padding: 15px 0;
    font-size: 17px;
  }

  .primary-nav__list a::after {
    left: 0;
    right: auto;
    bottom: 10px;
    width: 26px;
  }

  .section__head {
    max-width: none;
  }
}

@media (max-width: 560px) {
  .masthead__cta {
    display: none;
  }

  .divider-band__inner {
    font-size: 11px;
    letter-spacing: 0.1em;
  }

  .to-top {
    padding: 9px 12px;
    font-size: 11px;
  }
}

/* ============ 15. Reduced motion ============ */
@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;
  }

  .js [data-reveal],
  .js [data-reveal].is-revealed {
    opacity: 1;
    transform: none;
  }

  .btn:hover,
  .card:hover {
    transform: none;
  }
}