/* ============================================================
   星空体育主站 · 共享样式表 /assets/site.css
   深空底 + 暖纸承托面 · 展览画册式骨架 · 锐利直角与精密网格
   ============================================================ */

/* ---------- 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, li, figure, figcaption,
blockquote, dl, dt, dd, fieldset, legend {
  margin: 0;
  padding: 0;
}

ul, ol { list-style: none; }

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

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

button { background: none; border: 0; }

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

table { border-collapse: collapse; width: 100%; }

/* ---------- 2. 变量 ---------- */
:root {
  /* 色彩 */
  --deep:        #070B1E;
  --nebula:      #111B3E;
  --orbit:       #26356B;
  --paper:       #F4EFE4;
  --paper-line:  #D6CEBC;
  --violet:      #8B5CF6;
  --pulse:       #35E0D0;
  --orange:      #FF7A2F;
  --starlight:   #F7F9FF;
  --ink:         #14161C;
  --ink-soft:    #4C5265;
  --obs:         #9AA4C4;

  /* 字体 */
  --font-sans: system-ui, -apple-system, "Segoe UI", "PingFang SC",
               "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas,
               "DejaVu Sans Mono", monospace;

  /* 字号阶差 1.25 */
  --fs-xs:  0.8rem;
  --fs-sm:  1rem;
  --fs-md:  1.25rem;
  --fs-lg:  1.5625rem;
  --fs-xl:  1.9531rem;
  --fs-2xl: 2.4414rem;
  --fs-3xl: 3.0518rem;
  --fs-4xl: 3.8147rem;

  /* 度量 */
  --shell:  1240px;
  --gutter: clamp(1.25rem, 4vw, 2.5rem);
  --ease:   cubic-bezier(0.22, 0.61, 0.36, 1);
}

/* ---------- 3. 中文排版与文档基调 ---------- */
body {
  min-height: 100vh;
  background: var(--deep);
  color: var(--starlight);
  font-family: var(--font-sans);
  font-size: var(--fs-sm);
  line-height: 1.85;
  letter-spacing: 0.01em;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

h1, h2, h3, h4, h5, h6 {
  font-weight: 900;
  line-height: 1.15;
  letter-spacing: 0.04em;
}

p { overflow-wrap: break-word; }

::selection {
  background: var(--violet);
  color: var(--starlight);
}

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

/* ---------- 4. 跳转链接 ---------- */
.skip-link {
  position: absolute;
  left: 50%;
  top: 0;
  z-index: 200;
  transform: translate(-50%, -140%);
  padding: 0.7rem 1.3rem;
  background: var(--orange);
  color: var(--ink);
  font-size: var(--fs-xs);
  font-weight: 800;
  letter-spacing: 0.16em;
  text-indent: 0.16em;
  transition: transform 0.2s var(--ease);
}

.skip-link:focus {
  transform: translate(-50%, 0);
}

/* ---------- 5. 布局容器与网格 ---------- */
.shell {
  width: min(calc(100% - var(--gutter) * 2), var(--shell));
  margin-inline: auto;
}

.shell--narrow { max-width: 880px; }

.grid {
  display: grid;
  gap: clamp(1rem, 2.4vw, 1.75rem);
}

.grid--2 { grid-template-columns: repeat(auto-fit, minmax(min(100%, 20rem), 1fr)); }
.grid--3 { grid-template-columns: repeat(auto-fit, minmax(min(100%, 16rem), 1fr)); }
.grid--4 { grid-template-columns: repeat(auto-fit, minmax(min(100%, 12rem), 1fr)); }

.grid--split {
  grid-template-columns: minmax(0, 1.35fr) minmax(0, 1fr);
}

.rule {
  height: 1px;
  border: 0;
  background: var(--orbit);
}

.rule--paper { background: var(--paper-line); }

.mono { font-family: var(--font-mono); letter-spacing: 0.04em; }

/* ---------- 6. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.55rem;
  padding: 0.8rem 1.5rem;
  border: 1px solid transparent;
  font-size: var(--fs-sm);
  font-weight: 800;
  letter-spacing: 0.1em;
  text-indent: 0.1em;
  cursor: pointer;
  transition: background-color 0.18s var(--ease),
              color 0.18s var(--ease),
              border-color 0.18s var(--ease);
}

.btn--primary {
  background: var(--orange);
  color: var(--ink);
  border-color: var(--orange);
}

.btn--primary:hover {
  background: transparent;
  color: var(--orange);
}

.btn--ghost {
  background: transparent;
  color: var(--starlight);
  border-color: var(--orbit);
}

.btn--ghost:hover {
  background: var(--paper);
  color: var(--ink);
  border-color: var(--paper);
}

.btn--ink {
  background: transparent;
  color: var(--ink);
  border-color: rgba(20, 22, 28, 0.35);
}

.btn--ink:hover {
  background: var(--ink);
  color: var(--paper);
  border-color: var(--ink);
}

.copy-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.2rem 0.6rem;
  background: transparent;
  border: 1px solid var(--orbit);
  color: var(--obs);
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  letter-spacing: 0.08em;
  cursor: pointer;
  transition: color 0.18s var(--ease),
              background-color 0.18s var(--ease),
              border-color 0.18s var(--ease);
}

.copy-btn:hover {
  background: var(--pulse);
  border-color: var(--pulse);
  color: var(--deep);
}

/* ---------- 7. 面包屑 ---------- */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.5rem;
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  letter-spacing: 0.1em;
  color: var(--obs);
}

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

.breadcrumb a:hover {
  color: var(--pulse);
  border-bottom-color: var(--pulse);
}

.breadcrumb__sep { color: var(--orbit); }

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

/* ---------- 8. 每页首块 ---------- */
.section-head {
  display: grid;
  gap: 0.8rem;
  padding-block: clamp(2rem, 5vw, 3.5rem) clamp(1.25rem, 3vw, 2rem);
}

.section-head__index {
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  letter-spacing: 0.3em;
  color: var(--violet);
}

.section-head__title {
  font-size: clamp(1.95rem, 1.2rem + 2.4vw, var(--fs-3xl));
  letter-spacing: 0.04em;
  color: var(--starlight);
}

.section-head__lead {
  max-width: 46ch;
  color: var(--obs);
  line-height: 1.85;
}

/* ---------- 9. 正文容器 ---------- */
.prose {
  background: var(--paper);
  color: var(--ink);
  border: 1px solid var(--paper-line);
  padding: clamp(1.5rem, 4vw, 3.25rem);
  line-height: 1.85;
}

.prose > * + * { margin-top: 1.15em; }

.prose p {
  font-size: clamp(1rem, 0.96rem + 0.2vw, 1.125rem);
  color: var(--ink);
}

.prose h2 {
  font-size: var(--fs-md);
  letter-spacing: 0.06em;
  color: var(--ink);
}

.prose h3 {
  font-size: var(--fs-sm);
  letter-spacing: 0.1em;
  color: var(--ink);
}

.prose a {
  color: var(--ink);
  text-decoration: underline;
  text-decoration-color: var(--violet);
  text-underline-offset: 0.25em;
  transition: color 0.18s var(--ease);
}

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

.prose strong { font-weight: 800; }

.prose code {
  font-family: var(--font-mono);
  font-size: 0.9em;
  color: var(--ink);
  background: rgba(214, 206, 188, 0.5);
  padding: 0.1em 0.35em;
}

.prose ul,
.prose ol {
  display: grid;
  gap: 0.6rem;
}

.prose li {
  position: relative;
  padding-left: 1.4rem;
  font-size: clamp(1rem, 0.96rem + 0.2vw, 1.125rem);
}

.prose li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.82em;
  width: 0.55rem;
  height: 1px;
  background: var(--violet);
}

.prose blockquote {
  border-left: 2px solid var(--violet);
  padding-left: 1.1rem;
  color: var(--ink-soft);
}

/* ---------- 10. 卡片 ---------- */
.card {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  padding: clamp(1.25rem, 2.6vw, 1.9rem);
  background: var(--nebula);
  border: 1px solid var(--orbit);
  color: var(--starlight);
  transition: border-color 0.18s var(--ease), background-color 0.18s var(--ease);
}

.card:hover { border-color: var(--pulse); }

.card--paper {
  background: var(--paper);
  color: var(--ink);
  border-color: var(--paper-line);
}

.card--paper:hover { border-color: var(--violet); }

.card__index {
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  letter-spacing: 0.2em;
  color: var(--violet);
}

.card__title {
  font-size: var(--fs-md);
  font-weight: 900;
  letter-spacing: 0.05em;
}

.card__text {
  color: var(--obs);
  line-height: 1.85;
}

.card--paper .card__text { color: var(--ink-soft); }

/* ---------- 11. 标签 ---------- */
.tag {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.22rem 0.6rem;
  border: 1px solid var(--orbit);
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  letter-spacing: 0.1em;
  color: var(--obs);
}

.tag--pulse  { color: var(--pulse);  border-color: rgba(53, 224, 208, 0.42); }
.tag--violet { color: #B79BFF;       border-color: rgba(139, 92, 246, 0.45); }
.tag--orange { color: var(--orange); border-color: rgba(255, 122, 47, 0.45); }

.tag--paper {
  background: var(--paper);
  color: var(--ink);
  border-color: var(--paper-line);
}

/* ---------- 12. 图例 ---------- */
.legend {
  display: flex;
  flex-wrap: wrap;
  gap: 0.65rem 1.5rem;
  padding: 0.9rem 0;
  border-top: 1px solid var(--orbit);
  border-bottom: 1px solid var(--orbit);
  font-size: var(--fs-xs);
  letter-spacing: 0.08em;
  color: var(--obs);
}

.legend__item {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
}

.legend__swatch {
  width: 0.65rem;
  height: 0.65rem;
  flex: none;
  border: 1px solid currentColor;
}

.legend__swatch--pulse  { background: var(--pulse);  color: var(--pulse); }
.legend__swatch--violet { background: var(--violet); color: var(--violet); }
.legend__swatch--orange { background: var(--orange); color: var(--orange); }
.legend__swatch--orbit  { background: transparent;   color: var(--orbit); }

/* ---------- 13. 图片容器 ---------- */
.figure {
  position: relative;
  display: block;
  overflow: hidden;
  margin: 0;
  background: var(--nebula);
  border: 1px solid var(--orbit);
}

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

.figure--banner { aspect-ratio: 21 / 9; }
.figure--wide   { aspect-ratio: 16 / 9; }
.figure--square { aspect-ratio: 1 / 1; }
.figure--tall   { aspect-ratio: 3 / 4; }

.figure__overlay {
  position: absolute;
  inset: auto 0 0 0;
  padding: 1rem 1.1rem;
  background: linear-gradient(to top, rgba(7, 11, 30, 0.92), rgba(7, 11, 30, 0));
  color: var(--starlight);
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  letter-spacing: 0.08em;
}

.figure__caption {
  margin-top: 0.6rem;
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  letter-spacing: 0.06em;
  color: var(--obs);
}

/* ---------- 14. 折叠面板 ---------- */
.accordion { border-top: 1px solid var(--orbit); }

.accordion__item { border-bottom: 1px solid var(--orbit); }

.accordion__trigger {
  display: flex;
  align-items: center;
  gap: 1rem;
  width: 100%;
  padding: 1.05rem 0;
  background: none;
  border: 0;
  color: var(--starlight);
  font-family: inherit;
  font-size: var(--fs-sm);
  font-weight: 800;
  letter-spacing: 0.08em;
  text-align: left;
  cursor: pointer;
  transition: color 0.18s var(--ease);
}

.accordion__trigger:hover { color: var(--pulse); }

.accordion__index {
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  font-weight: 400;
  letter-spacing: 0.2em;
  color: var(--violet);
}

.accordion__sign {
  position: relative;
  width: 0.8rem;
  height: 0.8rem;
  margin-left: auto;
  flex: none;
}

.accordion__sign::before,
.accordion__sign::after {
  content: "";
  position: absolute;
  background: currentColor;
  transition: transform 0.18s var(--ease), opacity 0.18s var(--ease);
}

.accordion__sign::before {
  left: 0;
  top: 50%;
  width: 100%;
  height: 1px;
  transform: translateY(-50%);
}

.accordion__sign::after {
  top: 0;
  left: 50%;
  width: 1px;
  height: 100%;
  transform: translateX(-50%);
}

.accordion__trigger[aria-expanded="true"] .accordion__sign::after {
  opacity: 0;
  transform: translateX(-50%) scaleY(0);
}

.accordion__panel {
  padding: 0 0 1.3rem;
  color: var(--obs);
  line-height: 1.85;
}

.accordion__panel[hidden] { display: none; }

.accordion--paper { border-top-color: var(--paper-line); }
.accordion--paper .accordion__item { border-bottom-color: var(--paper-line); }
.accordion--paper .accordion__trigger { color: var(--ink); }
.accordion--paper .accordion__panel { color: var(--ink-soft); }

/* ---------- 15. 滚动显现 ---------- */
html.js [data-reveal] {
  opacity: 0;
  transform: translateY(12px);
  transition: opacity 0.24s var(--ease), transform 0.24s var(--ease);
}

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

/* ---------- 16. 页头 ---------- */
.site-header {
  position: relative;
  z-index: 60;
  background: var(--deep);
  border-bottom: 1px solid var(--orbit);
}

.header-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto minmax(0, 1fr);
  align-items: center;
  gap: clamp(1rem, 3vw, 2.5rem);
  width: min(calc(100% - var(--gutter) * 2), var(--shell));
  margin-inline: auto;
  padding: clamp(1.1rem, 2.4vw, 1.7rem) 0 clamp(1rem, 2vw, 1.4rem);
}

.coord-mark {
  display: flex;
  flex-direction: column;
  gap: 0.15rem;
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  letter-spacing: 0.1em;
  line-height: 1.5;
}

.coord-mark__code { color: var(--violet); }
.coord-mark__value { color: var(--obs); }

.brand-lockup {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.4rem;
  text-align: center;
}

.brand-mark {
  font-size: clamp(1.5rem, 1.1rem + 1.6vw, 2rem);
  font-weight: 900;
  line-height: 1.1;
  letter-spacing: 0.2em;
  text-indent: 0.2em;
  color: var(--starlight);
  transition: color 0.18s var(--ease);
}

.brand-mark:hover { color: var(--pulse); }

.brand-tagline {
  font-size: var(--fs-xs);
  letter-spacing: 0.4em;
  text-indent: 0.4em;
  color: var(--obs);
}

.header-status {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: 0.7rem;
}

.status-pill {
  display: inline-flex;
  align-items: center;
  gap: 0.55rem;
  padding: 0.32rem 0.75rem;
  border: 1px solid var(--orbit);
  font-size: var(--fs-xs);
  letter-spacing: 0.08em;
  color: var(--obs);
  transition: border-color 0.18s var(--ease);
}

.header-status:hover .status-pill { border-color: rgba(53, 224, 208, 0.5); }

.status-dot {
  width: 0.4rem;
  height: 0.4rem;
  flex: none;
  border-radius: 50%;
  background: var(--pulse);
  animation: statusPulse 2.4s ease-out infinite;
}

@keyframes statusPulse {
  0%   { box-shadow: 0 0 0 0 rgba(53, 224, 208, 0.55); }
  70%  { box-shadow: 0 0 0 0.5rem rgba(53, 224, 208, 0); }
  100% { box-shadow: 0 0 0 0 rgba(53, 224, 208, 0); }
}

.status-text { color: var(--starlight); }

.status-version {
  font-family: var(--font-mono);
  letter-spacing: 0.04em;
  color: var(--pulse);
}

.status-tip {
  position: absolute;
  top: 100%;
  right: 0;
  z-index: 5;
  margin-top: 0.4rem;
  padding: 0.45rem 0.7rem;
  background: var(--nebula);
  border: 1px solid var(--orbit);
  color: var(--obs);
  font-size: var(--fs-xs);
  letter-spacing: 0.06em;
  white-space: nowrap;
  opacity: 0;
  visibility: hidden;
  transform: translateY(-4px);
  pointer-events: none;
  transition: opacity 0.18s var(--ease),
              transform 0.18s var(--ease),
              visibility 0.18s;
}

.header-status:hover .status-tip,
.header-status:focus-within .status-tip {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.header-cta {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.5rem 1rem;
  background: var(--orange);
  border: 1px solid var(--orange);
  color: var(--ink);
  font-size: var(--fs-xs);
  font-weight: 800;
  letter-spacing: 0.14em;
  text-indent: 0.14em;
  transition: background-color 0.18s var(--ease),
              color 0.18s var(--ease);
}

.header-cta:hover {
  background: transparent;
  color: var(--orange);
}

/* ---------- 17. 栏目条 ---------- */
.site-nav {
  background: var(--nebula);
  border-top: 1px solid var(--orbit);
}

.nav-coord { display: none; }

.nav-list {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: clamp(0.25rem, 2vw, 2rem);
  width: min(calc(100% - var(--gutter) * 2), var(--shell));
  margin-inline: auto;
}

.nav-link {
  position: relative;
  display: inline-flex;
  align-items: baseline;
  gap: 0.5rem;
  padding: 0.85rem 0.2rem;
  color: var(--obs);
  font-size: var(--fs-sm);
  letter-spacing: 0.12em;
  transition: color 0.18s var(--ease);
}

.nav-link::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0.5rem;
  width: 100%;
  height: 1px;
  background: currentColor;
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.18s var(--ease), background-color 0.18s var(--ease);
}

.nav-link:hover { color: var(--starlight); }
.nav-link:hover::after { transform: scaleX(1); }

.nav-link[aria-current="page"] { color: var(--starlight); }

.nav-link[aria-current="page"]::after {
  height: 2px;
  background: var(--orange);
  transform: scaleX(1);
}

.nav-index {
  font-family: var(--font-mono);
  font-size: 0.72em;
  letter-spacing: 0.1em;
  color: var(--violet);
  transition: color 0.18s var(--ease);
}

.nav-link[aria-current="page"] .nav-index { color: var(--orange); }

.nav-toggle { display: none; }

/* ---------- 18. 页脚 ---------- */
.site-footer {
  margin-top: clamp(3rem, 8vw, 6rem);
  background: var(--deep);
  border-top: 1px solid var(--orbit);
  color: var(--obs);
}

.footer-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.4fr) repeat(3, minmax(0, 1fr));
  gap: clamp(1.5rem, 4vw, 3rem);
  width: min(calc(100% - var(--gutter) * 2), var(--shell));
  margin-inline: auto;
  padding: clamp(2.5rem, 6vw, 4rem) 0 clamp(1.5rem, 3vw, 2.5rem);
}

.footer-brand__mark {
  font-size: var(--fs-md);
  font-weight: 900;
  letter-spacing: 0.2em;
  text-indent: 0.2em;
  color: var(--starlight);
}

.footer-brand__coord {
  margin-top: 0.6rem;
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  letter-spacing: 0.1em;
  color: var(--violet);
}

.footer-col__title {
  margin-bottom: 0.9rem;
  font-size: var(--fs-xs);
  font-weight: 800;
  letter-spacing: 0.28em;
  color: var(--starlight);
}

.footer-list {
  display: grid;
  gap: 0.55rem;
}

.footer-list a {
  position: relative;
  display: inline-block;
  color: var(--obs);
  transition: color 0.18s var(--ease);
}

.footer-list a::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -2px;
  width: 100%;
  height: 1px;
  background: var(--pulse);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.18s var(--ease);
}

.footer-list a:hover { color: var(--starlight); }
.footer-list a:hover::after { transform: scaleX(1); }

.footer-contact {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(100%, 15rem), 1fr));
  gap: 1.25rem 2rem;
  width: min(calc(100% - var(--gutter) * 2), var(--shell));
  margin-inline: auto;
  padding: clamp(1.5rem, 3vw, 2rem) 0;
  border-top: 1px solid var(--orbit);
  border-bottom: 1px solid var(--orbit);
}

.footer-contact__item {
  display: flex;
  flex-direction: column;
  gap: 0.2rem;
}

.footer-contact__key {
  font-size: var(--fs-xs);
  letter-spacing: 0.24em;
  color: var(--violet);
}

.footer-contact__value {
  font-family: var(--font-mono);
  font-size: var(--fs-sm);
  color: var(--starlight);
  overflow-wrap: anywhere;
}

.footer-contact__note {
  grid-column: 1 / -1;
  max-width: 64ch;
  color: var(--obs);
  line-height: 1.85;
}

.footer-signoff {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 1rem 1.5rem;
  width: min(calc(100% - var(--gutter) * 2), var(--shell));
  margin-inline: auto;
  padding: clamp(1.5rem, 3vw, 2.25rem) 0 clamp(2rem, 4vw, 3rem);
}

.signoff-scale {
  position: relative;
  flex: 1 1 8rem;
  height: 1px;
  background: repeating-linear-gradient(
    to right,
    var(--orbit) 0 1px,
    transparent 1px 12px
  );
}

.signoff-scale::after {
  content: "";
  position: absolute;
  right: 0;
  top: -2px;
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--pulse);
  animation: statusPulse 2.4s ease-out infinite;
}

.footer-signoff__tagline {
  font-size: var(--fs-sm);
  font-weight: 900;
  letter-spacing: 0.2em;
  color: var(--starlight);
}

.footer-signoff__legal {
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  letter-spacing: 0.06em;
  color: var(--obs);
}

/* ---------- 19. 平板 ---------- */
@media (max-width: 1080px) {
  .footer-grid {
    grid-template-columns: minmax(0, 1fr) repeat(3, minmax(0, 1fr));
    gap: 1.5rem;
  }
}

@media (max-width: 900px) {
  .footer-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .footer-brand { grid-column: 1 / -1; }
}

/* ---------- 20. 移动 ---------- */
@media (max-width: 880px) {
  .header-grid {
    grid-template-columns: 1fr;
    justify-items: center;
    gap: 0.85rem;
    padding: 1.15rem 0 1rem;
  }

  .coord-mark { display: none; }

  .header-status {
    align-items: center;
    gap: 0.6rem;
  }

  .status-tip { display: none; }

  .nav-toggle {
    display: flex;
    align-items: center;
    gap: 0.7rem;
    width: min(calc(100% - var(--gutter) * 2), var(--shell));
    margin-inline: auto;
    padding: 0.9rem 0;
    border-top: 1px solid var(--orbit);
    color: var(--starlight);
    font-size: var(--fs-xs);
    font-weight: 800;
    letter-spacing: 0.3em;
    text-indent: 0.3em;
    cursor: pointer;
  }

  .nav-toggle__bars {
    display: flex;
    flex-direction: column;
    gap: 0.28rem;
    width: 1.35rem;
    flex: none;
  }

  .nav-toggle__bars span {
    display: block;
    height: 1px;
    background: var(--pulse);
    transition: transform 0.2s var(--ease);
  }

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

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

  .site-nav {
    max-height: 0;
    overflow: hidden;
    visibility: hidden;
    border-top: 0;
    transition: max-height 0.26s var(--ease), visibility 0.26s;
  }

  .site-nav[data-open] {
    max-height: 36rem;
    visibility: visible;
    border-top: 1px solid var(--orbit);
  }

  .nav-coord {
    display: block;
    width: min(calc(100% - var(--gutter) * 2), var(--shell));
    margin-inline: auto;
    padding: 0.9rem 0 0;
    font-family: var(--font-mono);
    font-size: var(--fs-xs);
    letter-spacing: 0.12em;
    color: var(--obs);
  }

  .nav-list {
    flex-direction: column;
    flex-wrap: nowrap;
    gap: 0;
    padding-bottom: 1rem;
  }

  .nav-link {
    display: flex;
    align-items: center;
    gap: 0.85rem;
    width: 100%;
    padding: 0.95rem 0;
    border-bottom: 1px solid rgba(38, 53, 107, 0.55);
  }

  .nav-link::after { display: none; }

  .nav-link[aria-current="page"] { color: var(--pulse); }
}

@media (max-width: 600px) {
  .footer-grid { grid-template-columns: 1fr; }

  .footer-signoff__legal { width: 100%; }

  .figure--banner { aspect-ratio: 16 / 9; }
  .figure--wide   { aspect-ratio: 4 / 3; }
  .figure--tall   { aspect-ratio: 4 / 5; }
}

/* ---------- 21. 动效克制 ---------- */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
    scroll-behavior: auto !important;
  }

  .status-dot,
  .signoff-scale::after { animation: none; }

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

  .site-nav { transition: none; }
}