/* ============================================================
   中欧中国官方主页 · Site Kit
   星际档案 · 技术蓝图 · 双层导航 · 控制台状态
   ============================================================ */

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

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

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

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

img, video, canvas { display: block; max-width: 100%; height: auto; }

button {
  font: inherit;
  background: none;
  border: none;
  color: inherit;
  cursor: pointer;
}

a { color: inherit; }

body {
  font-family: var(--font-body);
  font-weight: 400;
  line-height: 1.7;
  color: var(--color-cream);
  background-color: var(--color-space);
  background-image:
    linear-gradient(rgba(147, 165, 196, 0.045) 1px, transparent 1px),
    linear-gradient(90deg, rgba(147, 165, 196, 0.045) 1px, transparent 1px);
  background-size: 32px 32px;
  overflow-x: clip;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

::selection { background: var(--color-orange); color: var(--color-cream); }

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-head);
  font-weight: 900;
  letter-spacing: 0.05em;
  line-height: 1.3;
  color: inherit;
}

p { overflow-wrap: break-word; }

#main-content { scroll-margin-top: 24px; }

/* ---------- 2. Variables ---------- */
:root {
  --color-space: #0B1B3F;
  --color-ink: #2B241C;
  --color-cream: #F5EFE2;
  --color-orange: #FF4D2E;
  --color-lime: #00E68A;
  --color-bluegray: #93A5C4;
  --color-line: #FF6B35;
  --color-coal: #111827;

  --font-head: 'Noto Sans SC', 'Microsoft YaHei', sans-serif;
  --font-body: 'Source Han Sans', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  --font-mono: 'Roboto Mono', 'SFMono-Regular', Consolas, 'Liberation Mono', monospace;

  --container: 1240px;

  --header-z: 200;
  --float-z: 400;
  --progress-z: 500;
  --skip-z: 600;
}

/* ---------- 3. Layout Primitives ---------- */
.container { width: 100%; max-width: var(--container); margin-inline: auto; padding-inline: 28px; }
.container--narrow { max-width: 880px; }

.section { padding-block: 64px; }
.section--tight { padding-block: 40px; }
.section--cream {
  background-color: var(--color-cream);
  background-image: repeating-linear-gradient(45deg, rgba(43, 36, 28, 0.015) 0 1px, transparent 1px 7px);
  color: var(--color-ink);
  border-block: 1px solid var(--color-line);
}
.section--cream .section__desc { color: rgba(43, 36, 28, 0.72); }

.section__header { margin-bottom: 40px; }
.section__meta { font-family: var(--font-mono); font-size: 12px; letter-spacing: 0.24em; color: var(--color-lime); text-transform: uppercase; }
.section__title { font-size: clamp(26px, 3.6vw, 40px); margin-top: 8px; }
.section__desc { color: var(--color-bluegray); max-width: 680px; margin-top: 12px; font-size: 16px; line-height: 1.8; }

/* ---------- 4. Header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: var(--header-z);
  background-color: var(--color-space);
  background-image:
    linear-gradient(rgba(245, 239, 226, 0.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(245, 239, 226, 0.05) 1px, transparent 1px);
  background-size: 24px 24px;
  border-bottom: 1px solid var(--color-line);
}

.site-header::after {
  content: "";
  position: absolute;
  right: 0;
  bottom: -1px;
  width: 220px;
  height: 3px;
  background: linear-gradient(90deg, var(--color-lime), var(--color-orange));
  clip-path: polygon(16px 0, 100% 0, calc(100% - 10px) 100%, 0 100%);
  pointer-events: none;
}

.site-header__inner { max-width: var(--container); margin-inline: auto; padding-inline: 28px; }

.site-header__upper {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding-block: 10px;
}

.brand { display: inline-flex; align-items: center; gap: 12px; text-decoration: none; line-height: 1.2; }

.brand__mark {
  display: grid;
  place-items: center;
  width: 42px;
  height: 42px;
  flex: 0 0 auto;
  font-family: var(--font-head);
  font-weight: 900;
  font-size: 20px;
  color: var(--color-cream);
  background: var(--color-orange);
  clip-path: polygon(0 0, 100% 0, 100% 68%, 50% 100%, 0 68%);
}

.brand__text { display: flex; flex-direction: column; }
.brand__name { font-family: var(--font-head); font-weight: 900; font-size: 20px; letter-spacing: 0.1em; color: var(--color-cream); }
.brand__name em { font-style: normal; color: var(--color-orange); }
.brand__tagline { font-family: var(--font-mono); font-size: 11px; letter-spacing: 0.26em; color: var(--color-lime); }

.site-header__slogan {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--color-lime);
  border-left: 2px solid var(--color-line);
  padding-left: 14px;
  white-space: nowrap;
}

.site-header__status {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--color-bluegray);
  border: 1px solid rgba(147, 165, 196, 0.28);
  padding: 6px 12px;
  white-space: nowrap;
}

.status-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--color-lime);
  box-shadow: 0 0 8px rgba(0, 230, 138, 0.8);
  animation: status-blink 2s ease-in-out infinite;
}

@keyframes status-blink {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.35; }
}

.nav-toggle {
  display: none;
  align-items: center;
  gap: 10px;
  padding: 10px 14px;
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 14px;
  letter-spacing: 0.1em;
  color: var(--color-cream);
  border: 1px solid var(--color-line);
  transition: border-color 0.2s, color 0.2s;
}

.nav-toggle:hover { border-color: var(--color-lime); color: var(--color-lime); }
.nav-toggle__label { font-size: 13px; }
.nav-toggle__icon { position: relative; width: 18px; height: 14px; }
.nav-toggle__icon span {
  position: absolute;
  left: 0;
  width: 18px;
  height: 2px;
  background: currentColor;
  transition: transform 0.25s ease, opacity 0.2s ease, top 0.25s ease;
}
.nav-toggle__icon span:nth-child(1) { top: 0; }
.nav-toggle__icon span:nth-child(2) { top: 6px; }
.nav-toggle__icon span:nth-child(3) { top: 12px; }
.nav-toggle[aria-expanded="true"] .nav-toggle__icon span:nth-child(1) { top: 6px; transform: rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle__icon span:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] .nav-toggle__icon span:nth-child(3) { top: 6px; transform: rotate(-45deg); }

/* ---------- 5. Primary Nav ---------- */
.site-nav {
  border-top: 1px solid rgba(255, 107, 53, 0.35);
  border-bottom: 1px solid rgba(255, 107, 53, 0.35);
}

.site-nav__inner { max-width: var(--container); margin-inline: auto; padding-inline: 28px; }

.site-nav__list { display: flex; flex-wrap: wrap; list-style: none; margin: 0; padding: 0; }

.site-nav__link {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 12px 18px;
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 14px;
  letter-spacing: 0.08em;
  color: var(--color-cream);
  text-decoration: none;
  border-left: 1px solid rgba(255, 107, 53, 0.2);
  white-space: nowrap;
  transition: background 0.2s ease, color 0.2s ease;
}

.site-nav__item:last-child .site-nav__link { border-right: 1px solid rgba(255, 107, 53, 0.2); }
.site-nav__index { font-family: var(--font-mono); font-size: 11px; color: var(--color-orange); }
.site-nav__label { display: inline-block; }

.site-nav__link:hover { background: rgba(255, 107, 53, 0.12); color: var(--color-lime); }
.site-nav__link:hover .site-nav__index { color: var(--color-lime); }

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

/* ---------- 6. Footer ---------- */
.site-footer {
  position: relative;
  background-color: var(--color-coal);
  background-image:
    linear-gradient(rgba(147, 165, 196, 0.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(147, 165, 196, 0.05) 1px, transparent 1px);
  background-size: 28px 28px;
  border-top: 2px solid var(--color-line);
  color: var(--color-bluegray);
}

.site-footer::after {
  content: "";
  position: absolute;
  top: -2px;
  right: 0;
  width: 260px;
  height: 4px;
  background: linear-gradient(90deg, var(--color-orange), var(--color-lime));
  clip-path: polygon(20px 0, 100% 0, calc(100% - 20px) 100%, 0 100%);
  pointer-events: none;
}

.site-footer__inner { max-width: var(--container); margin-inline: auto; padding: 56px 28px 24px; }

.site-footer__grid { display: grid; grid-template-columns: 1.8fr 1fr 1fr 1.6fr; gap: 40px; }

.site-footer__brand { display: grid; gap: 12px; align-content: start; }
.site-footer__brandname { font-family: var(--font-head); font-weight: 900; font-size: 22px; letter-spacing: 0.08em; color: var(--color-cream); }
.site-footer__brandname em { font-style: normal; color: var(--color-orange); }
.site-footer__slogan { font-family: var(--font-mono); font-size: 12px; letter-spacing: 0.2em; color: var(--color-lime); }
.site-footer__note { font-size: 14px; line-height: 1.8; color: var(--color-bluegray); max-width: 360px; }

.site-footer__col { display: grid; gap: 12px; align-content: start; }

.site-footer__heading {
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--color-orange);
  border-left: 3px solid var(--color-orange);
  padding-left: 10px;
  margin-bottom: 8px;
}

.site-footer__list { list-style: none; margin: 0; padding: 0; display: grid; gap: 10px; }

.site-footer__link {
  color: var(--color-bluegray);
  font-size: 14px;
  text-decoration: none;
  transition: color 0.2s ease, padding-left 0.2s ease;
}

.site-footer__link:hover { color: var(--color-lime); padding-left: 4px; }
.site-footer__meta { font-size: 14px; line-height: 1.7; color: var(--color-bluegray); }

.site-footer__contact { display: grid; gap: 12px; align-content: start; }
.site-footer__contact .site-footer__list { gap: 12px; }

.site-footer__trust {
  font-size: 12px;
  line-height: 1.8;
  color: var(--color-bluegray);
  opacity: 0.75;
  border-top: 1px solid rgba(147, 165, 196, 0.2);
  margin-top: 20px;
  padding-top: 14px;
}

.site-footer__bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 8px 24px;
  margin-top: 44px;
  padding-top: 16px;
  border-top: 1px solid rgba(147, 165, 196, 0.2);
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--color-bluegray);
}

.site-footer__copyright,
.site-footer__icp { margin: 0; }

/* ---------- 7. Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 13px 28px;
  font-family: var(--font-head);
  font-weight: 900;
  font-size: 14px;
  letter-spacing: 0.08em;
  color: var(--color-cream);
  background: var(--color-orange);
  border: 1px solid var(--color-orange);
  text-decoration: none;
  cursor: pointer;
  clip-path: polygon(10px 0, 100% 0, calc(100% - 10px) 100%, 0 100%);
  transition: background 0.2s ease, color 0.2s ease, border-color 0.2s ease;
}

.btn:hover,
.btn:focus-visible {
  background: var(--color-lime);
  border-color: var(--color-lime);
  color: var(--color-coal);
}

.btn--ghost {
  background: transparent;
  border-color: var(--color-line);
  color: var(--color-cream);
  clip-path: none;
}

.btn--ghost:hover {
  background: var(--color-space);
  border-color: var(--color-lime);
  color: var(--color-lime);
}

/* ---------- 8. Breadcrumb ---------- */
.breadcrumb { padding: 20px 0 4px; font-family: var(--font-mono); font-size: 13px; }

.breadcrumb__list { display: flex; flex-wrap: wrap; gap: 6px; list-style: none; margin: 0; padding: 0; }

.breadcrumb__item { display: inline-flex; align-items: center; gap: 6px; color: var(--color-bluegray); }
.breadcrumb__item + .breadcrumb__item::before { content: "›"; color: var(--color-orange); }

.breadcrumb__link { color: var(--color-bluegray); text-decoration: none; transition: color 0.2s; }
.breadcrumb__link:hover { color: var(--color-lime); }
.breadcrumb__item[aria-current="page"] { color: var(--color-cream); }

/* ---------- 9. Grid ---------- */
.grid { display: grid; gap: 24px; }
.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)); }

/* ---------- 10. Card / Tag / Data ---------- */
.card {
  position: relative;
  background-color: var(--color-cream);
  background-image: repeating-linear-gradient(45deg, rgba(43, 36, 28, 0.02) 0 1px, transparent 1px 6px);
  color: var(--color-ink);
  border: 1px solid var(--color-line);
  padding: 24px 22px;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 5px;
  height: 100%;
  background: var(--color-orange);
}

.card:hover { transform: translateY(-4px); box-shadow: 10px 10px 0 rgba(255, 107, 53, 0.18); }

.card__meta { font-family: var(--font-mono); font-size: 12px; letter-spacing: 0.12em; color: var(--color-orange); text-transform: uppercase; }
.card__title { font-size: 19px; font-weight: 900; line-height: 1.4; margin: 10px 0; color: var(--color-ink); }
.card__body { font-size: 14px; line-height: 1.75; color: var(--color-ink); opacity: 0.85; }

.tag {
  display: inline-block;
  padding: 4px 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  border: 1px solid rgba(0, 230, 138, 0.55);
  background: rgba(0, 230, 138, 0.1);
  color: var(--color-lime);
}

.card .tag {
  border-color: rgba(255, 77, 46, 0.6);
  background: rgba(255, 77, 46, 0.08);
  color: var(--color-orange);
}

.panel {
  display: grid;
  gap: 8px;
  background: var(--color-coal);
  border: 1px solid var(--color-line);
  padding: 20px;
}

.panel__label { font-family: var(--font-mono); font-size: 11px; letter-spacing: 0.2em; color: var(--color-lime); text-transform: uppercase; }
.panel__value { font-family: var(--font-mono); font-size: 26px; font-weight: 700; line-height: 1.2; color: var(--color-cream); }

.data-row {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
  padding: 12px 0;
  border-bottom: 1px dashed rgba(255, 107, 53, 0.35);
  font-family: var(--font-mono);
  font-size: 13px;
}

.data-row:last-child { border-bottom: 0; }
.data-row__label { color: var(--color-bluegray); }
.data-row__value { color: var(--color-lime); font-weight: 700; letter-spacing: 0.04em; }

.coord {
  display: inline-block;
  padding: 3px 9px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--color-orange);
  border: 1px solid rgba(255, 107, 53, 0.45);
  background: rgba(255, 77, 46, 0.06);
}

/* ---------- 11. Prose ---------- */
.prose { max-width: 780px; font-size: 16px; line-height: 1.9; color: var(--color-bluegray); }
.prose p { margin-bottom: 1.4em; }
.prose h2 { font-size: 23px; color: var(--color-cream); margin: 2.2em 0 0.7em; padding-top: 1em; border-top: 1px solid rgba(255, 107, 53, 0.3); }
.prose h3 { font-size: 18px; color: var(--color-cream); margin: 1.6em 0 0.6em; }
.prose ul, .prose ol { padding-left: 1.5em; margin-bottom: 1.4em; }
.prose li { margin-bottom: 0.4em; }
.prose a { color: var(--color-lime); text-decoration: underline; text-underline-offset: 4px; }
.prose strong { color: var(--color-cream); font-weight: 700; }
.prose blockquote { margin: 1.6em 0; padding: 14px 18px; border-left: 4px solid var(--color-orange); background: rgba(255, 107, 53, 0.07); color: var(--color-bluegray); }

.prose--cream { color: var(--color-ink); }
.prose--cream h2,
.prose--cream h3,
.prose--cream strong { color: var(--color-ink); }
.prose--cream a { color: var(--color-orange); }
.prose--cream blockquote { background: rgba(255, 77, 46, 0.08); color: var(--color-ink); }

/* ---------- 12. Page Hero ---------- */
.page-hero {
  position: relative;
  padding: 56px 0 40px;
  overflow: hidden;
  border-bottom: 1px solid rgba(255, 107, 53, 0.4);
}

.page-hero::before {
  content: "";
  position: absolute;
  top: -30px;
  right: -40px;
  width: 220px;
  height: 220px;
  background: rgba(255, 77, 46, 0.07);
  clip-path: polygon(100% 0, 100% 62%, 38% 100%, 0 100%, 0 38%);
  pointer-events: none;
}

.page-hero__meta { font-family: var(--font-mono); font-size: 13px; letter-spacing: 0.22em; color: var(--color-lime); text-transform: uppercase; }
.page-hero__title { font-size: clamp(30px, 5vw, 50px); letter-spacing: 0.06em; line-height: 1.2; margin-top: 10px; }
.page-hero__lead { color: var(--color-bluegray); font-size: 17px; line-height: 1.8; max-width: 720px; margin-top: 14px; }
.page-hero__ref {
  position: absolute;
  right: 0;
  bottom: -10px;
  font-family: var(--font-mono);
  font-size: clamp(60px, 10vw, 120px);
  font-weight: 700;
  line-height: 1;
  color: rgba(147, 165, 196, 0.12);
  pointer-events: none;
  user-select: none;
}

/* ---------- 13. Image Frame ---------- */
.image-frame {
  position: relative;
  display: grid;
  place-items: center;
  aspect-ratio: 16 / 9;
  background: var(--color-coal);
  border: 1px solid var(--color-line);
  overflow: hidden;
}

.image-frame::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(147, 165, 196, 0.08) 1px, transparent 1px),
    linear-gradient(90deg, rgba(147, 165, 196, 0.08) 1px, transparent 1px);
  background-size: 20px 20px;
  pointer-events: none;
}

.image-frame__placeholder {
  position: relative;
  padding: 8px 14px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.24em;
  text-transform: uppercase;
  color: var(--color-bluegray);
  border: 1px dashed rgba(147, 165, 196, 0.55);
}

.image-frame__img { position: absolute; inset: 0; width: 100%; height: 100%; object-fit: cover; }

/* ---------- 14. Skip / Scroll / Back to Top / Utility ---------- */
.skip-link {
  position: fixed;
  top: 0;
  left: -9999px;
  z-index: var(--skip-z);
  display: inline-block;
  padding: 12px 20px;
  background: var(--color-orange);
  color: var(--color-cream);
  font-family: var(--font-head);
  font-weight: 900;
  font-size: 14px;
  letter-spacing: 0.06em;
  text-decoration: none;
}

.skip-link:focus { left: 0; }

.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  z-index: var(--progress-z);
  pointer-events: none;
}

.scroll-progress span {
  display: block;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, var(--color-orange), var(--color-lime));
  transform: scaleX(0);
  transform-origin: 0 50%;
}

.back-to-top {
  position: fixed;
  right: 24px;
  bottom: 24px;
  z-index: var(--float-z);
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 12px 16px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-lime);
  background: rgba(17, 24, 39, 0.92);
  border: 1px solid var(--color-lime);
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition: opacity 0.25s ease, transform 0.25s ease, visibility 0.25s ease, background 0.2s ease;
}

.back-to-top[data-show] { opacity: 1; visibility: visible; transform: translateY(0); }
.back-to-top:hover { background: var(--color-lime); color: var(--color-coal); }
.back-to-top__label { font-weight: 700; }
.back-to-top__icon { font-size: 16px; line-height: 1; }

.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;
}

/* ---------- 15. Focus ---------- */
:focus-visible {
  outline: 3px solid var(--color-lime);
  outline-offset: 2px;
}

/* ---------- 16. Responsive ---------- */
@media (max-width: 991px) {
  .site-header__slogan { display: none; }
  .site-nav__link { padding: 12px 14px; font-size: 13px; gap: 8px; }
  .site-footer__grid { grid-template-columns: 1fr 1fr; gap: 32px; }
  .section { padding-block: 48px; }
  .grid--4 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .grid--3 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 767px) {
  .container,
  .site-header__inner,
  .site-footer__inner { padding-inline: 18px; }

  .site-header__upper { padding-block: 8px; }
  .site-header__status { display: none; }

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

  .site-nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    max-height: 0;
    overflow: hidden;
    background: var(--color-space);
    border-top: 1px solid var(--color-line);
    border-bottom: 1px solid var(--color-line);
    box-shadow: 0 24px 32px rgba(0, 0, 0, 0.4);
    transition: max-height 0.35s ease;
  }

  .site-nav[data-open] { max-height: calc(100vh - 64px); overflow-y: auto; }

  .site-nav__inner { padding: 0; }
  .site-nav__list { flex-direction: column; }
  .site-nav__item { width: 100%; }
  .site-nav__item:last-child .site-nav__link { border-right: 0; }

  .site-nav__link {
    width: 100%;
    padding: 15px 18px;
    border-left: 0;
    border-bottom: 1px solid rgba(255, 107, 53, 0.16);
  }

  .site-nav__link[aria-current="page"] { background: var(--color-orange); color: var(--color-cream); }

  .site-footer__grid { grid-template-columns: 1fr; gap: 28px; }
  .site-footer__inner { padding-top: 40px; }
  .site-footer__bottom { margin-top: 32px; flex-direction: column; align-items: flex-start; }

  .grid--2,
  .grid--3,
  .grid--4 { grid-template-columns: 1fr; }

  .page-hero { padding: 40px 0 32px; }

  .back-to-top { right: 16px; bottom: 16px; }
}

/* ---------- 17. Reduced Motion ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }

  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }

  .status-dot { animation: none; }
  .site-nav { transition: none; }
  .back-to-top { transition: none; }
}