/* =========================================================
   BG电子官网 — 共享外壳 / /assets/site.css
   深空蓝底 + 精密网格 + 电弧青信号 + 信号橙状态
   ========================================================= */

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

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

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

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

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

button { font: inherit; color: inherit; background: none; border: 0; }

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

table { border-collapse: collapse; }

/* ---------- 2. Tokens ---------- */
:root {
  --c-deep: #0A1633;
  --c-deep-2: #050B18;
  --c-cyan: #00E5FF;
  --c-orange: #FF6B1A;
  --c-white: #F5F9FF;
  --c-pure: #FFFFFF;
  --c-ice: #7DD3E8;
  --c-titan: #8A9BB8;
  --c-grid: #1E3A5F;
  --c-alert: #FF3D2E;

  --font-sans: 'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', 'Source Han Sans SC', sans-serif;
  --font-mono: 'JetBrains Mono', 'IBM Plex Mono', 'SFMono-Regular', Consolas, monospace;

  --shell: 1280px;
  --gutter: clamp(16px, 4vw, 44px);
  --bar-h: 34px;
  --ease: cubic-bezier(.22, .61, .36, 1);
  --line: 1px solid var(--c-grid);
}

/* ---------- 3. Base ---------- */
body {
  min-height: 100vh;
  background-color: var(--c-deep);
  background-image:
    linear-gradient(90deg, rgba(30, 58, 95, .55) 1px, transparent 1px),
    linear-gradient(180deg, rgba(30, 58, 95, .32) 1px, transparent 1px);
  background-size: 96px 96px, 96px 96px;
  background-position: center top;
  color: var(--c-white);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.75;
  font-weight: 400;
  letter-spacing: .01em;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4 {
  font-weight: 800;
  line-height: 1.15;
  letter-spacing: -.01em;
  color: var(--c-white);
}

h1 { font-size: clamp(2.2rem, 5.6vw, 4.4rem); line-height: 1.05; }
h2 { font-size: clamp(1.5rem, 3vw, 2.15rem); }
h3 { font-size: clamp(1.15rem, 2vw, 1.4rem); font-weight: 700; }
h4 { font-size: 1.02rem; font-weight: 700; }

p { color: var(--c-white); }

::selection { background: var(--c-cyan); color: #04121f; }

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

#main-content { scroll-margin-top: 150px; display: block; }

/* ---------- 4. Utilities ---------- */
.shell {
  width: 100%;
  max-width: var(--shell);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.mono {
  font-family: var(--font-mono);
  font-size: .92em;
  letter-spacing: .06em;
  font-feature-settings: "tnum" 1;
}

.text-cyan { color: var(--c-cyan); }
.text-orange { color: var(--c-orange); }
.text-mute { color: var(--c-titan); }

.sr-only {
  position: absolute;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}

.divider { height: 1px; background: var(--c-grid); border: 0; }

.hairline {
  height: 1px;
  border: 0;
  background: linear-gradient(90deg, var(--c-cyan), rgba(30, 58, 95, 0) 70%);
}

.stack > * + * { margin-top: 16px; }
.stack--lg > * + * { margin-top: 28px; }

/* ---------- 5. Skip link ---------- */
.skip-link {
  position: absolute;
  left: 12px;
  top: -80px;
  z-index: 300;
  background: var(--c-cyan);
  color: #04121f;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: .04em;
  padding: 10px 18px;
  transition: top .2s var(--ease);
}

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

/* ---------- 6. Header : 双层信息导航 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 90;
  background: var(--c-deep-2);
  border-bottom: 1px solid var(--c-grid);
}

.scroll-progress {
  position: absolute;
  left: 0; right: 0; bottom: -1px;
  height: 2px;
  background: rgba(30, 58, 95, .55);
  overflow: hidden;
  z-index: 4;
}

.scroll-progress__bar {
  display: block;
  width: 0%;
  height: 100%;
  background: linear-gradient(90deg, var(--c-cyan), var(--c-orange));
  transition: width .12s linear;
}

/* 上层：品牌说明条 */
.header-bar {
  background:
    linear-gradient(90deg, rgba(0, 229, 255, .10), rgba(5, 11, 24, 0) 62%),
    var(--c-deep-2);
  border-bottom: 1px solid var(--c-grid);
}

.header-bar__inner {
  display: flex;
  align-items: center;
  gap: clamp(12px, 2vw, 28px);
  height: var(--bar-h);
}

.brand-mini {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  flex: none;
}

.brand-mini__mark {
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: .12em;
  color: var(--c-cyan);
  border: 1px solid rgba(0, 229, 255, .5);
  padding: 1px 5px;
  line-height: 1.5;
}

.brand-mini__text {
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .16em;
  color: var(--c-white);
}

.header-bar__descriptor {
  font-size: 11px;
  letter-spacing: .1em;
  color: var(--c-ice);
  white-space: nowrap;
}

.header-bar__utility {
  font-size: 11px;
  color: var(--c-titan);
  margin-left: auto;
  white-space: nowrap;
}

.version-tag {
  flex: none;
  font-size: 11px;
  color: var(--c-orange);
  border: 1px solid rgba(255, 107, 26, .45);
  padding: 2px 8px;
  line-height: 1.6;
  white-space: nowrap;
}

.version-tag--footer {
  display: inline-block;
  margin-top: 16px;
  color: var(--c-ice);
  border-color: rgba(125, 211, 232, .4);
}

/* 下层：栏目索引条 */
.header-main { background: var(--c-deep); }

.header-main__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: clamp(16px, 3vw, 40px);
  min-height: 72px;
  padding-block: 10px;
}

.primary-nav__list {
  display: flex;
  align-items: center;
  gap: clamp(10px, 1.7vw, 26px);
}

.primary-nav__item { display: block; }

.primary-nav__link {
  position: relative;
  display: inline-flex;
  align-items: baseline;
  gap: 6px;
  padding: 8px 2px;
  color: var(--c-white);
  font-size: 15px;
  font-weight: 600;
  letter-spacing: .02em;
  transition: color .2s var(--ease);
}

.primary-nav__index {
  font-size: 10px;
  color: var(--c-titan);
  transition: color .2s var(--ease);
}

.primary-nav__label { position: relative; }

.primary-nav__link::after {
  content: "";
  position: absolute;
  left: 0; right: 0; bottom: 0;
  height: 1px;
  background: var(--c-cyan);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform .25s var(--ease);
}

.primary-nav__link:hover,
.primary-nav__link:focus-visible { color: var(--c-cyan); }

.primary-nav__link:hover .primary-nav__index,
.primary-nav__link:focus-visible .primary-nav__index { color: var(--c-orange); }

.primary-nav__link:hover::after,
.primary-nav__link:focus-visible::after { transform: scaleX(1); }

.primary-nav__link[aria-current="page"] { color: var(--c-cyan); }

.primary-nav__link[aria-current="page"] .primary-nav__index { color: var(--c-orange); }

.primary-nav__link[aria-current="page"]::after { transform: scaleX(1); }

/* 按钮 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 11px 18px;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: .05em;
  line-height: 1;
  white-space: nowrap;
  border: 1px solid transparent;
  border-radius: 0;
  cursor: pointer;
  transition: background-color .2s var(--ease), color .2s var(--ease), border-color .2s var(--ease), transform .2s var(--ease);
}

.btn--primary {
  background: var(--c-cyan);
  border-color: var(--c-cyan);
  color: #04121f;
}

.btn--primary:hover,
.btn--primary:focus-visible {
  background: var(--c-pure);
  border-color: var(--c-pure);
}

.btn--orange {
  background: var(--c-orange);
  border-color: var(--c-orange);
  color: #120500;
}

.btn--orange:hover,
.btn--orange:focus-visible {
  background: var(--c-pure);
  border-color: var(--c-pure);
  color: #120500;
}

.btn--ghost {
  background: transparent;
  border-color: var(--c-grid);
  color: var(--c-ice);
}

.btn--ghost:hover,
.btn--ghost:focus-visible {
  border-color: var(--c-orange);
  color: var(--c-orange);
}

.btn--line {
  background: transparent;
  border-color: var(--c-cyan);
  color: var(--c-cyan);
}

.btn--line:hover,
.btn--line:focus-visible {
  background: rgba(0, 229, 255, .12);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 10px;
  flex: none;
}

/* 移动菜单按钮 */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 10px;
  padding: 9px 12px;
  border: 1px solid var(--c-grid);
  color: var(--c-white);
  cursor: pointer;
  transition: border-color .2s var(--ease);
}

.nav-toggle:hover,
.nav-toggle:focus-visible { border-color: var(--c-cyan); }

.nav-toggle__label {
  font-size: 11px;
  letter-spacing: .16em;
  color: var(--c-ice);
}

.nav-toggle__bars {
  display: inline-flex;
  flex-direction: column;
  justify-content: space-between;
  width: 16px;
  height: 12px;
}

.nav-toggle__bars i {
  display: block;
  height: 1px;
  background: var(--c-cyan);
  transition: transform .25s var(--ease), opacity .2s var(--ease);
}

.nav-toggle[aria-expanded="true"] .nav-toggle__bars i:nth-child(1) { transform: translateY(5.5px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars i:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars i:nth-child(3) { transform: translateY(-5.5px) rotate(-45deg); }

/* 移动遮罩 */
.nav-scrim { display: none; }

/* ---------- 7. Footer ---------- */
.site-footer {
  margin-top: clamp(56px, 8vw, 110px);
  background: var(--c-deep-2);
  border-top: 1px solid var(--c-grid);
  color: var(--c-titan);
  font-size: 14px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.5fr 1fr 1fr 1.7fr;
  gap: clamp(24px, 4vw, 56px);
  padding-top: clamp(40px, 6vw, 72px);
}

.footer-brand__name {
  font-size: 22px;
  font-weight: 800;
  letter-spacing: .02em;
  color: var(--c-white);
}

.footer-brand__summary {
  margin-top: 14px;
  max-width: 34ch;
  color: var(--c-titan);
  font-size: 14px;
  line-height: 1.8;
}

.footer-heading {
  font-size: 11px;
  font-weight: 600;
  letter-spacing: .2em;
  color: var(--c-ice);
  margin-bottom: 16px;
}

.footer-nav__list li + li { margin-top: 10px; }

.footer-nav__link {
  position: relative;
  display: inline-block;
  color: var(--c-titan);
  font-size: 14px;
  padding-left: 0;
  transition: color .2s var(--ease), padding-left .2s var(--ease);
}

.footer-nav__link::before {
  content: "";
  position: absolute;
  left: 0; top: 50%;
  width: 0;
  height: 1px;
  background: var(--c-cyan);
  transition: width .2s var(--ease);
}

.footer-nav__link:hover,
.footer-nav__link:focus-visible {
  color: var(--c-cyan);
  padding-left: 14px;
}

.footer-nav__link:hover::before,
.footer-nav__link:focus-visible::before { width: 10px; }

.footer-contact__list { display: grid; gap: 12px; }

.footer-contact__row { display: grid; gap: 2px; }

.footer-contact__row dt {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .12em;
  color: var(--c-titan);
}

.footer-contact__row dd {
  color: var(--c-white);
  font-size: 14px;
  line-height: 1.7;
}

.footer-contact__note {
  margin-top: 16px;
  font-size: 12px;
  line-height: 1.7;
  color: var(--c-titan);
  border-left: 1px solid var(--c-grid);
  padding-left: 12px;
}

.footer-rule {
  height: 1px;
  margin-top: clamp(28px, 4vw, 48px);
  background: linear-gradient(90deg, var(--c-cyan), var(--c-orange) 38%, rgba(30, 58, 95, 0) 92%);
}

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  padding: 20px 0 28px;
  font-size: 12px;
}

.footer-bottom__legal { color: var(--c-titan); }

.footer-bottom__links {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: var(--c-titan);
}

.footer-bottom__links a {
  color: var(--c-ice);
  transition: color .2s var(--ease);
}

.footer-bottom__links a:hover,
.footer-bottom__links a:focus-visible { color: var(--c-cyan); }

.footer-bottom__copy { color: var(--c-titan); }

/* ---------- 8. 通用版面组件 ---------- */
.section { padding-block: clamp(44px, 6vw, 88px); }

.section--tight { padding-block: clamp(28px, 4vw, 48px); }

.section-head {
  display: grid;
  gap: 12px;
  margin-bottom: clamp(24px, 3vw, 44px);
  border-top: var(--line);
  padding-top: 18px;
}

.section-head__index {
  font-size: 11px;
  letter-spacing: .2em;
  color: var(--c-cyan);
}

.section-head__title { font-size: clamp(1.5rem, 3vw, 2.2rem); }

.section-head__note {
  color: var(--c-titan);
  font-size: 14px;
  max-width: 62ch;
}

.section.is-active .section-head__index { color: var(--c-orange); }

.section.is-active .section-head { border-top-color: var(--c-cyan); }

.eyebrow {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .2em;
  color: var(--c-cyan);
  border-left: 2px solid var(--c-orange);
  padding-left: 10px;
}

.lead {
  font-size: clamp(1.02rem, 1.6vw, 1.22rem);
  line-height: 1.8;
  color: var(--c-ice);
  max-width: 60ch;
}

.prose {
  max-width: 68ch;
  font-size: 17px;
  line-height: 1.85;
  color: var(--c-white);
}

.prose > * + * { margin-top: 18px; }

.prose h2 { margin-top: 40px; }
.prose h3 { margin-top: 30px; }
.prose ul { list-style: none; }
.prose li { position: relative; padding-left: 20px; }
.prose li + li { margin-top: 8px; }
.prose li::before {
  content: "";
  position: absolute;
  left: 0; top: .78em;
  width: 10px; height: 1px;
  background: var(--c-cyan);
}

.note {
  border-left: 1px solid var(--c-cyan);
  padding: 4px 0 4px 16px;
  color: var(--c-titan);
  font-size: 14px;
  line-height: 1.8;
  max-width: 52ch;
}

/* 网格 */
.grid { display: grid; gap: clamp(18px, 2.4vw, 32px); }
.grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid--4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }
.grid--split { grid-template-columns: minmax(0, 1.6fr) minmax(0, 1fr); }

/* 面板 */
.panel {
  position: relative;
  border: var(--line);
  background: linear-gradient(160deg, rgba(0, 229, 255, .07), rgba(5, 11, 24, .5) 60%);
  padding: clamp(18px, 2.4vw, 28px);
}

.panel > * + * { margin-top: 12px; }

/* 索引目录 */
.index-list { border-top: var(--line); }

.index-list__item {
  border-bottom: var(--line);
  display: grid;
  grid-template-columns: 64px minmax(0, 1fr) auto;
  gap: 16px;
  align-items: baseline;
  padding: 16px 2px;
  transition: background-color .2s var(--ease);
}

.index-list__num {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--c-orange);
  letter-spacing: .1em;
}

.index-link {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 6px 0;
  color: var(--c-titan);
  font-size: 14px;
  text-align: left;
  cursor: pointer;
  transition: color .2s var(--ease);
}

.index-link:hover,
.index-link:focus-visible { color: var(--c-cyan); }

.index-link.is-current { color: var(--c-cyan); }

.index-link.is-current::before {
  content: "";
  width: 14px;
  height: 1px;
  background: var(--c-orange);
}

/* 标签与数字 */
.tag {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .1em;
  padding: 2px 8px;
  border: 1px solid var(--c-grid);
  color: var(--c-titan);
  line-height: 1.7;
}

.tag--cyan { color: var(--c-cyan); border-color: rgba(0, 229, 255, .5); }
.tag--orange { color: var(--c-orange); border-color: rgba(255, 107, 26, .5); }

.stat { display: grid; gap: 6px; }

.stat__value {
  font-family: var(--font-mono);
  font-size: clamp(1.5rem, 3vw, 2.1rem);
  font-weight: 600;
  color: var(--c-pure);
  letter-spacing: -.01em;
  line-height: 1.1;
}

.stat__label {
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--c-titan);
}

.callout {
  border: 1px solid rgba(255, 107, 26, .5);
  background: rgba(255, 107, 26, .07);
  padding: 16px 18px;
  color: var(--c-white);
  font-size: 14px;
}

.callout--alert {
  border-color: rgba(255, 61, 46, .55);
  background: rgba(255, 61, 46, .08);
}

/* 面包屑 */
.breadcrumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--c-titan);
}

.breadcrumbs a { color: var(--c-ice); transition: color .2s var(--ease); }
.breadcrumbs a:hover,
.breadcrumbs a:focus-visible { color: var(--c-cyan); }

.breadcrumbs__sep { color: var(--c-grid); }

/* 图片容器 */
.media-frame {
  position: relative;
  overflow: hidden;
  border: var(--line);
  aspect-ratio: 16 / 9;
  background:
    linear-gradient(135deg, rgba(0, 229, 255, .18), rgba(10, 22, 51, .9) 55%, rgba(255, 107, 26, .16));
}

.media-frame img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.media-frame::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(90deg, rgba(30, 58, 95, .7) 1px, transparent 1px),
    linear-gradient(180deg, rgba(30, 58, 95, .7) 1px, transparent 1px);
  background-size: 40px 40px;
  mix-blend-mode: screen;
  opacity: .45;
}

.media-frame--wide { aspect-ratio: 21 / 9; }
.media-frame--tall { aspect-ratio: 3 / 4; }
.media-frame--square { aspect-ratio: 1 / 1; }

.media-frame--skew {
  clip-path: polygon(0 0, 100% 0, 100% 86%, 0 100%);
}

/* 手风琴 */
.accordion { border-top: var(--line); }

.accordion__item { border-bottom: var(--line); }

.accordion__trigger {
  width: 100%;
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 20px;
  padding: 18px 0;
  color: var(--c-white);
  font-size: 17px;
  font-weight: 600;
  text-align: left;
  cursor: pointer;
  transition: color .2s var(--ease);
}

.accordion__trigger:hover,
.accordion__trigger:focus-visible { color: var(--c-cyan); }

.accordion__mark {
  flex: none;
  font-family: var(--font-mono);
  font-size: 16px;
  color: var(--c-orange);
  line-height: 1.4;
  transition: transform .25s var(--ease);
}

.accordion__item[data-open] .accordion__mark { transform: rotate(45deg); }

.accordion__panel {
  max-height: 0;
  overflow: hidden;
  transition: max-height .3s var(--ease);
}

.accordion__item[data-open] .accordion__panel { max-height: 48rem; }

.accordion__body {
  padding: 0 0 20px;
  color: var(--c-titan);
  font-size: 15px;
  line-height: 1.85;
  max-width: 66ch;
}

/* 显现 */
.js [data-reveal] {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity .5s var(--ease), transform .5s var(--ease);
}

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

/* ---------- 9. 响应式 ---------- */
@media (max-width: 1080px) {
  .header-bar__utility { display: none; }
  .footer-grid { grid-template-columns: 1.4fr 1fr 1.4fr; }
  .footer-contact { grid-column: 1 / -1; }
  .grid--4 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 900px) {
  .site-header { position: sticky; }

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

  .header-main__inner { min-height: 62px; }

  .primary-nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    max-height: calc(100vh - 96px);
    overflow-y: auto;
    background: var(--c-deep-2);
    border-bottom: 1px solid var(--c-grid);
    border-top: 1px solid var(--c-grid);
    padding: 16px var(--gutter) 28px;
    transform: translateY(-8px);
    opacity: 0;
    visibility: hidden;
    transition: opacity .25s var(--ease), transform .25s var(--ease), visibility .25s var(--ease);
  }

  .primary-nav[data-open] {
    transform: none;
    opacity: 1;
    visibility: visible;
  }

  .primary-nav__list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
  }

  .primary-nav__item { border-bottom: var(--line); }

  .primary-nav__link {
    width: 100%;
    justify-content: flex-start;
    gap: 14px;
    padding: 16px 0;
    font-size: 18px;
  }

  .primary-nav__index { font-size: 12px; }

  .primary-nav__link::after { display: none; }

  .nav-scrim {
    display: block;
    position: fixed;
    inset: 0;
    background: rgba(5, 11, 24, .74);
    opacity: 0;
    pointer-events: none;
    transition: opacity .25s var(--ease);
  }

  .nav-scrim[data-visible] {
    opacity: 1;
    pointer-events: auto;
  }

  body[data-nav-open="true"] { overflow: hidden; }

  .grid--split,
  .grid--3 { grid-template-columns: minmax(0, 1fr); }

  .footer-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .footer-contact { grid-column: auto; }
}

@media (max-width: 720px) {
  .header-bar__descriptor { display: none; }
  .grid--2,
  .grid--4 { grid-template-columns: minmax(0, 1fr); }
}

@media (max-width: 560px) {
  .btn--ghost { display: none; }
  .btn { padding: 10px 14px; font-size: 12px; }
  .header-actions { gap: 8px; }
  .footer-grid { grid-template-columns: minmax(0, 1fr); }
  .footer-bottom { flex-direction: column; align-items: flex-start; }
  .index-list__item { grid-template-columns: 52px minmax(0, 1fr); }
  .prose { font-size: 16px; }
}

/* ---------- 10. 降低动效 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }

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

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

  .primary-nav { transform: none !important; }

  .accordion__panel { transition: none; }
}