/* ============================================================
   星空赛场 /assets/site.css
   共享外壳 · 变量 · 排版 · 通用组件
   ============================================================ */

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

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

body {
  margin: 0;
  min-height: 100vh;
  font-family: var(--f-body);
  font-size: 16px;
  line-height: 1.75;
  font-weight: 400;
  letter-spacing: 0.01em;
  color: var(--c-silver);
  background-color: var(--c-space);
  background-image:
    repeating-linear-gradient(180deg, rgba(220, 229, 236, 0.028) 0 1px, transparent 1px 5px),
    radial-gradient(circle at 10% -12%, rgba(59, 242, 228, 0.11), transparent 44%),
    radial-gradient(circle at 90% -6%, rgba(255, 122, 51, 0.09), transparent 40%),
    linear-gradient(180deg, #06111F 0%, #050F1B 55%, #06111F 100%);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

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

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

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

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

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

#main-content {
  display: block;
  scroll-margin-top: 140px;
}

/* ---------- 2. Tokens ---------- */
:root {
  --c-void: #020914;
  --c-space: #06111F;
  --c-orbit: #0C2238;
  --c-stand: #173D5C;
  --c-silver: #DCE5EC;
  --c-paper: #F1E9D8;
  --c-cyan: #3BF2E4;
  --c-orange: #FF7A33;
  --c-mist: #8FA3B5;

  --f-display: 'Noto Sans SC', 'Source Han Sans SC', 'PingFang SC', 'Microsoft YaHei', system-ui, sans-serif;
  --f-body: 'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', system-ui, sans-serif;
  --f-mono: 'IBM Plex Mono', 'JetBrains Mono', 'SFMono-Regular', ui-monospace, 'Courier New', monospace;

  --gap: 24px;
  --pad-x: clamp(16px, 4vw, 40px);
  --shell: 1400px;
  --r: 3px;

  --shadow-hard: 6px 6px 0 var(--c-void);
  --shadow-soft: 3px 3px 0 var(--c-void);

  --dur: 200ms;
  --ease: cubic-bezier(0.2, 0.7, 0.25, 1);
}

/* ---------- 3. 焦点与可访问 ---------- */
:focus-visible {
  outline: 3px solid var(--c-cyan);
  outline-offset: 3px;
  border-radius: 2px;
}

.site-nav__link:focus-visible,
.footer-link:focus-visible,
.header__cta:focus-visible { outline-offset: 2px; }

/* ---------- 4. 头部：框架式轨道导航 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 90;
  background-color: var(--c-orbit);
  border-bottom: 3px solid var(--c-stand);
  box-shadow: 0 12px 0 -8px var(--c-void);
}

.site-header__edge {
  height: 10px;
  background-color: var(--c-void);
  background-image: repeating-linear-gradient(90deg, var(--c-stand) 0 1px, transparent 1px 36px);
  background-repeat: no-repeat;
  background-size: 100% 6px;
  background-position: 0 100%;
  border-bottom: 1px solid var(--c-stand);
}

.site-header__inner {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  align-items: center;
  gap: clamp(16px, 2.4vw, 40px);
  width: 100%;
  max-width: var(--shell);
  margin-inline: auto;
  padding: 12px var(--pad-x);
}

.skip-link {
  position: absolute;
  left: 12px;
  top: -72px;
  z-index: 120;
  padding: 10px 18px;
  background: var(--c-cyan);
  color: var(--c-void);
  font-family: var(--f-display);
  font-weight: 800;
  font-size: 14px;
  letter-spacing: 0.03em;
  border: 2px solid var(--c-void);
  border-radius: 2px;
  box-shadow: var(--shadow-soft);
  transition: top 160ms var(--ease);
}

.skip-link:focus { top: 8px; }

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  min-width: 0;
}

.brand__mark {
  display: grid;
  place-items: center;
  flex: 0 0 auto;
  width: 40px;
  height: 40px;
  background: var(--c-cyan);
  color: var(--c-void);
  font-family: var(--f-display);
  font-weight: 900;
  font-size: 20px;
  line-height: 1;
  border: 2px solid var(--c-void);
  border-radius: 2px;
  box-shadow: 3px 3px 0 var(--c-void);
  transition: background-color var(--dur) var(--ease), transform var(--dur) var(--ease);
}

.brand:hover .brand__mark {
  background: var(--c-orange);
  transform: translate(-1px, -1px);
}

.brand__text {
  display: flex;
  flex-direction: column;
  min-width: 0;
}

.brand__name {
  display: block;
  font-family: var(--f-display);
  font-weight: 900;
  font-size: clamp(17px, 1.6vw, 20px);
  line-height: 1.2;
  letter-spacing: 0.02em;
  color: var(--c-silver);
}

.brand__note {
  display: block;
  font-family: var(--f-mono);
  font-size: 10.5px;
  line-height: 1.5;
  letter-spacing: 0.14em;
  color: var(--c-mist);
  white-space: nowrap;
}

.brand--footer .brand__name { font-size: 18px; }

.site-nav {
  justify-self: end;
  min-width: 0;
}

.site-nav__list {
  display: flex;
  align-items: center;
  gap: clamp(2px, 0.8vw, 14px);
}

.site-nav__item { min-width: 0; }

.site-nav__link {
  position: relative;
  display: inline-flex;
  align-items: center;
  height: 38px;
  padding: 0 clamp(6px, 0.7vw, 11px);
  font-family: var(--f-body);
  font-size: clamp(13px, 1.05vw, 14.5px);
  font-weight: 500;
  line-height: 1;
  letter-spacing: 0.01em;
  color: var(--c-silver);
  border-radius: 2px;
  white-space: nowrap;
  transition: color var(--dur) var(--ease), background-color var(--dur) var(--ease);
}

.site-nav__link::after {
  content: "";
  position: absolute;
  left: clamp(6px, 0.7vw, 11px);
  right: clamp(6px, 0.7vw, 11px);
  bottom: 3px;
  height: 2px;
  background: var(--c-cyan);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform var(--dur) var(--ease), background-color var(--dur) var(--ease);
}

.site-nav__link:hover {
  color: var(--c-cyan);
  background: rgba(59, 242, 228, 0.07);
}

.site-nav__link:hover::after { transform: scaleX(1); }

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

.site-nav__link[aria-current="page"]::after {
  transform: scaleX(1);
  background: var(--c-orange);
}

.header__actions {
  display: flex;
  align-items: center;
  gap: 10px;
}

.header__cta {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  height: 42px;
  padding: 0 clamp(14px, 1.4vw, 20px);
  background: var(--c-cyan);
  color: var(--c-void);
  font-family: var(--f-display);
  font-weight: 800;
  font-size: 14px;
  line-height: 1;
  letter-spacing: 0.04em;
  white-space: nowrap;
  border: 2px solid var(--c-void);
  border-radius: 2px;
  box-shadow: var(--shadow-soft);
  transition: transform var(--dur) var(--ease), box-shadow var(--dur) var(--ease), background-color var(--dur) var(--ease);
}

.header__cta:hover {
  background: var(--c-orange);
  transform: translate(-2px, -2px);
  box-shadow: 5px 5px 0 var(--c-void);
}

.header__cta:active {
  transform: translate(2px, 2px);
  box-shadow: 1px 1px 0 var(--c-void);
}

.nav-toggle {
  display: none;
  align-items: center;
  gap: 9px;
  height: 42px;
  padding: 0 13px;
  color: var(--c-silver);
  font-family: var(--f-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  background: rgba(23, 61, 92, 0.35);
  border: 2px solid var(--c-stand);
  border-radius: 2px;
  transition: border-color var(--dur) var(--ease), color var(--dur) var(--ease);
}

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

.nav-toggle__bar {
  position: relative;
  display: block;
  width: 18px;
  height: 2px;
  background: currentColor;
  transition: background-color var(--dur) var(--ease);
}

.nav-toggle__bar::before,
.nav-toggle__bar::after {
  content: "";
  position: absolute;
  left: 0;
  width: 18px;
  height: 2px;
  background: currentColor;
  transition: transform var(--dur) var(--ease);
}

.nav-toggle__bar::before { top: -6px; }
.nav-toggle__bar::after { top: 6px; }

.nav-toggle[aria-expanded="true"] .nav-toggle__bar { background: transparent; }
.nav-toggle[aria-expanded="true"] .nav-toggle__bar::before { transform: translateY(6px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle__bar::after { transform: translateY(-6px) rotate(-45deg); }

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

.site-header__meta {
  display: flex;
  align-items: center;
  gap: 14px;
  width: 100%;
  max-width: var(--shell);
  margin-inline: auto;
  padding: 0 var(--pad-x) 10px;
  font-family: var(--f-mono);
  font-size: 11px;
  line-height: 1.4;
  letter-spacing: 0.16em;
  color: var(--c-mist);
}

.header__meta-item { white-space: nowrap; }

.header__meta-item--lead {
  color: var(--c-cyan);
  letter-spacing: 0.24em;
}

.header__meta-rule {
  flex: 1 1 auto;
  min-width: 24px;
  height: 1px;
  background-image: repeating-linear-gradient(90deg, var(--c-stand) 0 5px, transparent 5px 11px);
}

.site-progress {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 3px;
  pointer-events: none;
  overflow: hidden;
}

.site-progress__bar {
  display: block;
  width: 0;
  height: 100%;
  background: linear-gradient(90deg, var(--c-cyan) 0%, var(--c-orange) 100%);
  box-shadow: 0 0 12px rgba(59, 242, 228, 0.65);
  transition: width 120ms linear;
}

/* ---------- 5. 页脚：轨道收束 ---------- */
.site-footer {
  position: relative;
  margin-top: clamp(56px, 8vw, 110px);
  color: var(--c-silver);
  background-color: var(--c-orbit);
  border-top: 3px solid var(--c-stand);
  background-image:
    radial-gradient(circle at 100% 0%, rgba(59, 242, 228, 0.08), transparent 46%),
    radial-gradient(circle at 0% 100%, rgba(255, 122, 51, 0.07), transparent 44%);
}

.site-footer__edge {
  height: 10px;
  background-color: var(--c-void);
  background-image: repeating-linear-gradient(90deg, var(--c-stand) 0 1px, transparent 1px 36px);
  background-repeat: no-repeat;
  background-size: 100% 6px;
  background-position: 0 0;
  border-bottom: 1px solid var(--c-stand);
}

.site-footer__inner {
  display: grid;
  grid-template-columns: minmax(230px, 1.15fr) minmax(0, 1.7fr) minmax(210px, 0.95fr);
  gap: clamp(24px, 3.4vw, 56px);
  max-width: var(--shell);
  margin-inline: auto;
  padding: clamp(34px, 4.6vw, 60px) var(--pad-x) clamp(26px, 3.4vw, 44px);
}

.footer-brand {
  display: flex;
  flex-direction: column;
  gap: 14px;
  min-width: 0;
}

.footer-brand__line {
  padding-top: 12px;
  font-family: var(--f-display);
  font-weight: 800;
  font-size: 15px;
  line-height: 1.5;
  letter-spacing: 0.02em;
  color: var(--c-silver);
  border-top: 1px solid var(--c-stand);
}

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

.footer-nav {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: clamp(18px, 2.6vw, 36px);
}

.footer-col { min-width: 0; }

.footer-col__title {
  padding-bottom: 10px;
  margin-bottom: 14px;
  font-family: var(--f-mono);
  font-size: 11.5px;
  font-weight: 600;
  line-height: 1.4;
  letter-spacing: 0.2em;
  color: var(--c-orange);
  border-bottom: 1px solid var(--c-stand);
}

.footer-col__list {
  display: flex;
  flex-direction: column;
  gap: 9px;
}

.footer-col__item { min-width: 0; }

.footer-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 14px;
  line-height: 1.6;
  color: var(--c-silver);
  transition: color var(--dur) var(--ease), transform var(--dur) var(--ease);
}

.footer-link::before {
  content: "";
  flex: 0 0 auto;
  width: 5px;
  height: 5px;
  background: var(--c-stand);
  transition: background-color var(--dur) var(--ease);
}

.footer-link:hover {
  color: var(--c-cyan);
  transform: translateX(3px);
}

.footer-link:hover::before { background: var(--c-cyan); }

.footer-contact { min-width: 0; }

.footer-contact__list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.footer-contact__row {
  display: grid;
  grid-template-columns: 44px minmax(0, 1fr);
  gap: 10px;
  align-items: baseline;
}

.footer-contact__term {
  font-family: var(--f-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--c-mist);
}

.footer-contact__value {
  font-size: 13.5px;
  line-height: 1.65;
  color: var(--c-silver);
  overflow-wrap: anywhere;
}

.site-footer__base {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px 22px;
  max-width: var(--shell);
  margin-inline: auto;
  padding: 14px var(--pad-x) 26px;
  font-family: var(--f-mono);
  font-size: 11.5px;
  line-height: 1.6;
  letter-spacing: 0.1em;
  color: var(--c-mist);
  border-top: 1px solid var(--c-stand);
}

.footer-base__copy { color: var(--c-silver); }

.footer-base__icp { color: var(--c-mist); }

.footer-base__note {
  margin-inline-start: auto;
  color: var(--c-mist);
  opacity: 0.6;
}

/* ---------- 6. 容器与网格 ---------- */
.shell {
  width: 100%;
  max-width: var(--shell);
  margin-inline: auto;
  padding-inline: var(--pad-x);
}

.grid {
  display: grid;
  gap: var(--gap);
}

.grid--split { grid-template-columns: minmax(0, 7fr) minmax(0, 5fr); }
.grid--split-reverse { grid-template-columns: minmax(0, 5fr) minmax(0, 7fr); }
.grid--index { grid-template-columns: minmax(0, 3fr) minmax(0, 9fr); }
.grid--halves { grid-template-columns: repeat(2, minmax(0, 1fr)); }

@media (max-width: 980px) {
  .grid--split,
  .grid--split-reverse,
  .grid--index,
  .grid--halves { grid-template-columns: minmax(0, 1fr); }
}

/* ---------- 7. 面包屑 ---------- */
.breadcrumb { padding-block: clamp(18px, 2.6vw, 32px) 0; }

.breadcrumb__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-family: var(--f-mono);
  font-size: 11.5px;
  line-height: 1.6;
  letter-spacing: 0.1em;
  color: var(--c-mist);
}

.breadcrumb__item {
  display: inline-flex;
  align-items: center;
  gap: 8px;
}

.breadcrumb__item::after {
  content: "/";
  color: var(--c-stand);
}

.breadcrumb__item:last-child::after { content: none; }

.breadcrumb__link {
  color: var(--c-mist);
  transition: color var(--dur) var(--ease);
}

.breadcrumb__link:hover { color: var(--c-cyan); }

.breadcrumb__current { color: var(--c-silver); }

/* ---------- 8. 按钮 / 标签 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 9px;
  min-height: 46px;
  padding: 11px 22px;
  font-family: var(--f-display);
  font-weight: 800;
  font-size: 15px;
  line-height: 1.2;
  letter-spacing: 0.03em;
  text-align: center;
  color: var(--c-void);
  background: var(--c-cyan);
  border: 2px solid var(--c-void);
  border-radius: var(--r);
  box-shadow: var(--shadow-soft);
  transition:
    transform var(--dur) var(--ease),
    box-shadow var(--dur) var(--ease),
    background-color var(--dur) var(--ease),
    color var(--dur) var(--ease),
    border-color var(--dur) var(--ease);
}

.btn:hover {
  transform: translate(-2px, -2px);
  box-shadow: 5px 5px 0 var(--c-void);
}

.btn:active {
  transform: translate(2px, 2px);
  box-shadow: 1px 1px 0 var(--c-void);
}

.btn--primary { background: var(--c-cyan); color: var(--c-void); }
.btn--primary:hover { background: #5ff8ec; }

.btn--accent { background: var(--c-orange); color: var(--c-void); }
.btn--accent:hover { background: #ff9257; }

.btn--paper { background: var(--c-paper); color: var(--c-void); }
.btn--paper:hover { background: #fff8ea; }

.btn--ghost {
  background: transparent;
  color: var(--c-silver);
  border-color: var(--c-stand);
  box-shadow: none;
}

.btn--ghost:hover {
  color: var(--c-cyan);
  border-color: var(--c-cyan);
  transform: none;
  box-shadow: none;
}

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

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 3px 9px;
  font-family: var(--f-mono);
  font-size: 11px;
  line-height: 1.6;
  letter-spacing: 0.12em;
  color: var(--c-cyan);
  background: rgba(59, 242, 228, 0.1);
  border: 1px solid rgba(59, 242, 228, 0.45);
  border-radius: 2px;
}

.tag--accent {
  color: var(--c-orange);
  background: rgba(255, 122, 51, 0.12);
  border-color: rgba(255, 122, 51, 0.5);
}

.tag--paper {
  color: var(--c-void);
  background: var(--c-paper);
  border-color: var(--c-void);
}

/* ---------- 9. 章节头 / 面板 ---------- */
.section-head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 10px 18px;
  padding-bottom: 12px;
  margin-bottom: clamp(18px, 2.4vw, 28px);
  border-bottom: 2px solid var(--c-stand);
}

.section-head__index {
  font-family: var(--f-mono);
  font-size: 12px;
  line-height: 1.4;
  letter-spacing: 0.2em;
  color: var(--c-orange);
}

.section-head__title {
  font-family: var(--f-display);
  font-weight: 900;
  font-size: clamp(24px, 3.2vw, 36px);
  line-height: 1.1;
  letter-spacing: -0.01em;
  color: var(--c-silver);
}

.section-head__note {
  margin-inline-start: auto;
  font-size: 13px;
  line-height: 1.6;
  color: var(--c-mist);
}

.panel {
  padding: clamp(18px, 2.4vw, 28px);
  background: var(--c-orbit);
  border: 1px solid var(--c-stand);
  border-radius: var(--r);
}

.panel--paper {
  color: var(--c-void);
  background: var(--c-paper);
  border: 2px solid var(--c-void);
  box-shadow: var(--shadow-hard);
}

.panel--paper .section-head { border-bottom-color: rgba(2, 9, 20, 0.28); }

.panel--paper .section-head__title { color: var(--c-void); }

.panel--paper .section-head__index { color: #c2410c; }

.panel--paper .section-head__note { color: #4b5563; }

.panel--paper a {
  color: var(--c-void);
  text-decoration: underline;
  text-decoration-color: var(--c-orange);
  text-underline-offset: 3px;
}

/* ---------- 10. 正文排版 ---------- */
.prose {
  max-width: 70ch;
  font-size: 16.5px;
  line-height: 1.8;
  color: var(--c-silver);
}

.prose > * + * { margin-top: 1.1em; }

.prose h2 {
  margin-top: 1.7em;
  font-family: var(--f-display);
  font-weight: 900;
  font-size: clamp(22px, 2.4vw, 30px);
  line-height: 1.25;
  letter-spacing: -0.01em;
}

.prose h3 {
  margin-top: 1.5em;
  font-family: var(--f-display);
  font-weight: 800;
  font-size: clamp(18px, 2vw, 22px);
  line-height: 1.3;
}

.prose a {
  color: var(--c-cyan);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.prose strong { color: var(--c-paper); font-weight: 700; }

.prose ul > li {
  position: relative;
  padding-left: 20px;
}

.prose ul > li + li { margin-top: 0.5em; }

.prose ul > li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.72em;
  width: 8px;
  height: 2px;
  background: var(--c-orange);
}

.mono {
  font-family: var(--f-mono);
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.05em;
}

/* ---------- 11. 响应式图片容器 ---------- */
.media {
  position: relative;
  display: block;
  overflow: hidden;
  aspect-ratio: 16 / 9;
  background: var(--c-void);
  border: 2px solid var(--c-stand);
  border-radius: var(--r);
}

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

.media > img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.media__veil {
  position: absolute;
  inset: 0;
  pointer-events: none;
  background:
    linear-gradient(180deg, rgba(6, 17, 31, 0) 42%, rgba(2, 9, 20, 0.86) 100%),
    repeating-linear-gradient(180deg, rgba(220, 229, 236, 0.055) 0 1px, transparent 1px 4px);
}

.media__caption {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  padding: 14px 16px;
  font-family: var(--f-mono);
  font-size: 11.5px;
  line-height: 1.6;
  letter-spacing: 0.12em;
  color: var(--c-silver);
}

.media__placeholder {
  display: grid;
  place-items: center;
  width: 100%;
  height: 100%;
  padding: 16px;
  text-align: center;
  font-family: var(--f-mono);
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--c-mist);
  background-image:
    radial-gradient(circle at 30% 20%, rgba(59, 242, 228, 0.16), transparent 55%),
    radial-gradient(circle at 78% 75%, rgba(255, 122, 51, 0.14), transparent 55%),
    linear-gradient(160deg, #071528 0%, #0C2238 60%, #06111F 100%);
}

/* ---------- 12. 返回顶部 & 渐显 ---------- */
.to-top {
  position: fixed;
  right: clamp(14px, 2.4vw, 32px);
  bottom: clamp(14px, 2.4vw, 32px);
  z-index: 70;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 14px;
  font-family: var(--f-mono);
  font-size: 11.5px;
  line-height: 1;
  letter-spacing: 0.12em;
  color: var(--c-void);
  background: var(--c-paper);
  border: 2px solid var(--c-void);
  border-radius: 2px;
  box-shadow: var(--shadow-soft);
  opacity: 0;
  transform: translateY(10px);
  pointer-events: none;
  transition: opacity var(--dur) var(--ease), transform var(--dur) var(--ease), background-color var(--dur) var(--ease);
}

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

.to-top:hover { background: var(--c-cyan); }

.to-top__arrow { font-size: 14px; }

html.js [data-reveal] {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 520ms var(--ease), transform 520ms var(--ease);
}

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

/* ---------- 13. 断点 ---------- */
@media (max-width: 1080px) {
  .site-footer__inner { grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); }
  .footer-contact { grid-column: 1 / -1; }
}

@media (max-width: 1000px) {
  .site-header__inner {
    grid-template-columns: minmax(0, 1fr) auto;
    padding-block: 12px;
  }

  .site-nav {
    position: absolute;
    left: 0;
    right: 0;
    top: 100%;
    display: block;
    max-height: 0;
    overflow: hidden;
    visibility: hidden;
    pointer-events: none;
    background-color: var(--c-orbit);
    border-bottom: 3px solid var(--c-stand);
    box-shadow: 0 26px 44px -22px rgba(2, 9, 20, 0.95);
    transition: max-height 300ms var(--ease), visibility 0s linear 300ms;
  }

  .site-nav[data-open] {
    max-height: min(72vh, 560px);
    overflow-y: auto;
    visibility: visible;
    pointer-events: auto;
    transition: max-height 300ms var(--ease), visibility 0s linear 0s;
  }

  .site-nav__list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 6px var(--pad-x) 18px;
  }

  .site-nav__item { border-bottom: 1px solid var(--c-stand); }
  .site-nav__item:last-child { border-bottom: 0; }

  .site-nav__link {
    width: 100%;
    height: auto;
    padding: 15px 2px;
    font-size: 16px;
    justify-content: flex-start;
  }

  .site-nav__link::after {
    left: 2px;
    right: auto;
    width: 26px;
    bottom: 8px;
  }

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

@media (max-width: 760px) {
  .site-footer__inner { grid-template-columns: minmax(0, 1fr); }

  .footer-nav {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 22px 24px;
  }

  .footer-contact { grid-column: auto; }

  .header__meta-item:last-child { display: none; }

  .brand__note { font-size: 10px; letter-spacing: 0.1em; }
}

@media (max-width: 520px) {
  .header__cta {
    height: 38px;
    padding-inline: 12px;
    font-size: 13px;
  }

  .nav-toggle {
    height: 38px;
    padding-inline: 10px;
    font-size: 11px;
  }

  .nav-toggle__label { display: none; }

  .brand__mark { width: 36px; height: 36px; font-size: 18px; }

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

  .footer-base__note { margin-inline-start: 0; }
}

/* ---------- 14. 减少动效 ---------- */
@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;
  }

  .site-progress__bar { transition: none; }
  .to-top { transition: none; }

  html.js [data-reveal] {
    opacity: 1 !important;
    transform: none !important;
  }
}