/* ==========================================================================
   KU游官网 · /assets/site.css
   共享外壳：reset、变量、中文排版、页头轨道导航、页脚、通用组件
   ========================================================================== */

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

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: 84px;
}

body {
  margin: 0;
  background: var(--ink);
  color: var(--white);
  font-family: var(--font-body);
  font-size: 17px;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

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, canvas { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
button { font: inherit; color: inherit; background: none; border: 0; padding: 0; cursor: pointer; }
table { border-collapse: collapse; width: 100%; }
main { display: block; }
hr { border: 0; }

::selection { background: var(--aurora); color: #04202b; }

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

/* ---------- 2. 变量 ---------- */
:root {
  --ink: #061726;
  --panel: #0D2A44;
  --grid: #1C4560;
  --aurora: #2FE3C6;
  --aurora-soft: #A6F6E9;
  --amber: #FF7A33;
  --lime: #E4FF4F;
  --muted: #93AEC6;
  --white: #F4FAFF;
  --glow: #0A3A47;

  --rail: 88px;
  --rail-open: 268px;
  --bar: 64px;
  --maxw: 1280px;
  --gutter: clamp(20px, 4vw, 56px);
  --radius: 2px;

  --ease: cubic-bezier(.22, .61, .36, 1);
  --dur: 200ms;

  --font-display: "Inter Tight", "Source Han Sans SC", "Noto Sans SC", system-ui, -apple-system, "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-body: system-ui, -apple-system, "PingFang SC", "Microsoft YaHei", "Noto Sans SC", "Helvetica Neue", sans-serif;
  --font-mono: ui-monospace, "SFMono-Regular", "JetBrains Mono", Menlo, Consolas, "Liberation Mono", monospace;
}

/* ---------- 3. 中文排版基础 ---------- */
.display,
.section__title,
.page-title {
  font-family: var(--font-display);
  font-weight: 300;
  letter-spacing: -.02em;
  line-height: 1.05;
}

.display { font-size: clamp(40px, 7vw, 112px); }
.section__title { font-size: clamp(30px, 4.6vw, 58px); }

p { max-width: 68ch; }

.mono,
.kpi,
time {
  font-family: var(--font-mono);
  font-size: 14px;
  letter-spacing: .04em;
}

.eyebrow {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .2em;
  text-transform: uppercase;
  color: var(--lime);
}

.sr-only {
  position: absolute;
  width: 1px; height: 1px;
  margin: -1px; padding: 0;
  overflow: hidden;
  clip: rect(0 0 0 0);
  clip-path: inset(50%);
  white-space: nowrap;
  border: 0;
}

/* ---------- 4. 跳转链接 ---------- */
.skip-link {
  position: fixed;
  top: 10px;
  left: 10px;
  z-index: 999;
  padding: 10px 18px;
  background: var(--lime);
  color: #10200a;
  font-size: 14px;
  font-weight: 600;
  border-radius: var(--radius);
  transform: translateY(-180%);
  transition: transform var(--dur) var(--ease);
}
.skip-link:focus { transform: translateY(0); }

/* ---------- 5. 容器与网格 ---------- */
.container {
  width: 100%;
  max-width: var(--maxw);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.grid-12 {
  display: grid;
  gap: clamp(18px, 2.6vw, 32px);
  grid-template-columns: repeat(12, minmax(0, 1fr));
}

.stack > * + * { margin-top: var(--stack-gap, 16px); }

@media (max-width: 960px) {
  .grid-12 { grid-template-columns: repeat(4, minmax(0, 1fr)); }
}
@media (max-width: 600px) {
  .grid-12 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

/* ---------- 6. 章节节奏 ---------- */
.section { padding-block: clamp(56px, 8vw, 104px); }

.section__head {
  display: flex;
  flex-direction: column;
  gap: 14px;
  margin-bottom: clamp(26px, 4vw, 46px);
  max-width: 900px;
}

.section__index {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .22em;
  color: var(--lime);
}

.section__lead { color: var(--muted); }

.rule-band {
  height: 4px;
  width: 100%;
  border: 0;
  margin: 0;
  background: linear-gradient(90deg, var(--aurora) 0%, var(--glow) 34%, var(--amber) 70%, var(--lime) 100%);
  opacity: .9;
}

/* ---------- 7. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 13px 22px;
  border: 1px solid var(--grid);
  border-radius: var(--radius);
  background: var(--panel);
  color: var(--white);
  font-size: 14px;
  font-weight: 600;
  letter-spacing: .02em;
  line-height: 1.2;
  text-align: center;
  transition: transform var(--dur) var(--ease),
              border-color var(--dur) var(--ease),
              background-color var(--dur) var(--ease),
              color var(--dur) var(--ease);
}
.btn:hover,
.btn:focus-visible {
  transform: translateY(-4px);
  border-color: var(--aurora);
}
.btn--cta {
  background: linear-gradient(135deg, var(--aurora) 0%, #1FB8A4 100%);
  border-color: transparent;
  color: #04202b;
}
.btn--cta:hover,
.btn--cta:focus-visible {
  background: linear-gradient(135deg, var(--aurora-soft) 0%, var(--aurora) 100%);
  color: #04202b;
}
.btn--ghost { background: transparent; }

/* ---------- 8. 标签 ---------- */
.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px;
  border: 1px solid var(--grid);
  border-radius: var(--radius);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .06em;
  line-height: 1.6;
  color: var(--muted);
  background: rgba(13, 42, 68, .55);
  transition: color var(--dur) var(--ease),
              border-color var(--dur) var(--ease),
              background-color var(--dur) var(--ease);
}
.tag:hover { color: var(--aurora-soft); border-color: var(--aurora); }
.tag--aurora { color: var(--aurora); border-color: rgba(47, 227, 198, .5); }
.tag--amber { color: var(--amber); border-color: rgba(255, 122, 51, .5); }
.tag--lime { color: var(--lime); border-color: rgba(228, 255, 79, .45); }
.tag[aria-pressed="true"],
.tag.is-active {
  background: var(--lime);
  border-color: var(--lime);
  color: #10200a;
  font-weight: 600;
}

/* ---------- 9. 卡片 ---------- */
.card {
  position: relative;
  display: block;
  padding: 26px 24px;
  background: var(--panel);
  border: 1px solid var(--grid);
  border-radius: var(--radius);
  transition: transform var(--dur) var(--ease),
              border-color var(--dur) var(--ease),
              background-color var(--dur) var(--ease);
}
.card:hover,
.card:focus-within {
  transform: translateY(-4px);
  border-color: var(--aurora);
  background: #10314F;
}
.card__title {
  font-size: 20px;
  font-weight: 600;
  line-height: 1.3;
  margin-bottom: 10px;
}
.card__meta {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--lime);
  margin-bottom: 14px;
}
.card__body { color: var(--muted); font-size: 15px; }
.card__tags { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 18px; }

/* ---------- 10. 专题研究板 ---------- */
.board {
  border: 1px solid var(--grid);
  border-radius: var(--radius);
  background: linear-gradient(180deg, rgba(13, 42, 68, .92) 0%, rgba(6, 23, 38, .92) 100%);
  overflow: hidden;
}
.board__summary {
  padding: 22px 24px;
  border-bottom: 1px solid var(--grid);
  font-size: 17px;
  color: var(--white);
}
.board__grid { display: grid; grid-template-columns: 1fr; }
@media (min-width: 780px) {
  .board__grid { grid-template-columns: 1.15fr .85fr; }
}
.board__cell {
  padding: 22px 24px;
  border-bottom: 1px solid var(--grid);
}
@media (min-width: 780px) {
  .board__grid .board__cell:first-child { border-right: 1px solid var(--grid); }
}
.board__cell:last-child { border-bottom: 0; }
.board__label {
  display: block;
  margin-bottom: 12px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .2em;
  text-transform: uppercase;
  color: var(--lime);
}
.board__evidence li {
  position: relative;
  padding-left: 20px;
  font-size: 15px;
  color: var(--muted);
}
.board__evidence li + li { margin-top: 8px; }
.board__evidence li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .78em;
  width: 10px;
  height: 1px;
  background: var(--aurora);
}
.board__terms { display: flex; flex-wrap: wrap; gap: 8px; }
.board__more { margin-top: 18px; font-size: 14px; }
.board__more a { color: var(--aurora); border-bottom: 1px solid rgba(47, 227, 198, .35); }
.board__more a:hover { color: var(--aurora-soft); border-bottom-color: var(--aurora-soft); }

/* ---------- 11. 面包屑 ---------- */
.crumbs {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--muted);
}
.crumbs ol { display: flex; flex-wrap: wrap; align-items: center; }
.crumbs li { display: inline-flex; align-items: center; }
.crumbs li + li::before {
  content: "/";
  margin: 0 10px;
  color: var(--grid);
}
.crumbs a { transition: color var(--dur) var(--ease); }
.crumbs a:hover,
.crumbs a:focus-visible { color: var(--aurora-soft); }
.crumbs [aria-current="page"] { color: var(--white); }

/* ---------- 12. 正文排版 ---------- */
.prose { max-width: 68ch; }
.prose > * + * { margin-top: 1.05em; }
.prose h2 { font-size: clamp(22px, 2.6vw, 30px); font-weight: 600; line-height: 1.3; margin-top: 2em; }
.prose h3 { font-size: 19px; font-weight: 600; margin-top: 1.6em; }
.prose p,
.prose li { color: #D6E5F1; }
.prose strong { color: var(--white); }
.prose a { color: var(--aurora); border-bottom: 1px solid rgba(47, 227, 198, .35); }
.prose a:hover { color: var(--aurora-soft); }
.prose ul li,
.prose ol li { position: relative; padding-left: 20px; }
.prose ul li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .78em;
  width: 10px;
  height: 1px;
  background: var(--aurora);
}
.prose ol { counter-reset: prose-ol; }
.prose ol li::before {
  counter-increment: prose-ol;
  content: counter(prose-ol, decimal-leading-zero);
  position: absolute;
  left: 0;
  top: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--lime);
}
.prose blockquote {
  padding: 18px 22px;
  border-left: 3px solid var(--aurora);
  background: rgba(13, 42, 68, .6);
  color: var(--muted);
}

/* ---------- 13. 图片容器基础规则 ---------- */
.media {
  position: relative;
  display: block;
  width: 100%;
  overflow: hidden;
  border: 1px solid var(--grid);
  border-radius: var(--radius);
  background:
    linear-gradient(155deg, rgba(47, 227, 198, .16) 0%, rgba(10, 58, 71, 0) 58%),
    linear-gradient(20deg, var(--glow) 0%, var(--panel) 100%);
  transition: border-color var(--dur) var(--ease);
}
.media:hover { border-color: var(--aurora); }
.media > img,
.media > svg,
.media > picture > img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}
.media--wide { aspect-ratio: 16 / 9; }
.media--tall { aspect-ratio: 3 / 4; }
.media--square { aspect-ratio: 1 / 1; }
.media--banner { aspect-ratio: 21 / 9; }
.media__caption {
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--muted);
}
.media__badge {
  position: absolute;
  left: 12px;
  top: 12px;
  z-index: 1;
  padding: 3px 9px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .1em;
  background: rgba(6, 23, 38, .82);
  border: 1px solid var(--grid);
  color: var(--lime);
}

/* ---------- 14. 数据与索引 ---------- */
.kpi {
  font-size: clamp(30px, 4vw, 48px);
  line-height: 1.1;
  color: var(--lime);
}
.kpi-label {
  display: block;
  margin-top: 6px;
  font-size: 13px;
  letter-spacing: .06em;
  color: var(--muted);
  font-family: var(--font-body);
}

/* ---------- 15. 显现动效协议 ---------- */
.js-reveal [data-reveal] {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 600ms var(--ease), transform 600ms var(--ease);
}
.js-reveal [data-reveal].is-visible {
  opacity: 1;
  transform: none;
}

/* ---------- 16. 页头 - 轨道导航 ---------- */
.site-header {
  position: relative;
  z-index: 120;
}

.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  z-index: 200;
  pointer-events: none;
}
.scroll-progress__bar {
  display: block;
  width: 100%;
  height: 100%;
  transform: scaleX(0);
  transform-origin: 0 50%;
  background: linear-gradient(90deg, var(--aurora) 0%, var(--lime) 58%, var(--amber) 100%);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  color: var(--white);
  transition: color var(--dur) var(--ease);
}
.brand:hover { color: var(--aurora-soft); }
.brand__mark {
  display: grid;
  place-items: center;
  width: 36px;
  height: 36px;
  flex: none;
  color: var(--aurora);
}
.brand__text { display: flex; flex-direction: column; line-height: 1.15; }
.brand__name { font-size: 16px; font-weight: 600; letter-spacing: .02em; white-space: nowrap; }
.brand__sub {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .16em;
  color: var(--muted);
  white-space: nowrap;
}

/* 移动端菜单按钮 */
.nav-toggle {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 10px 12px;
  border: 1px solid var(--grid);
  border-radius: var(--radius);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--white);
  transition: border-color var(--dur) var(--ease), color var(--dur) var(--ease);
}
.nav-toggle:hover { border-color: var(--aurora); color: var(--aurora); }
.nav-toggle__bars {
  display: inline-flex;
  flex-direction: column;
  gap: 4px;
  width: 18px;
}
.nav-toggle__bars span {
  display: block;
  height: 1.5px;
  width: 100%;
  background: currentColor;
  transition: transform var(--dur) var(--ease), opacity var(--dur) var(--ease);
}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:nth-child(1) { transform: translateY(5.5px) 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(-5.5px) rotate(-45deg); }

/* 移动端/平板：吸顶栏 + 抽屉 */
.site-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  min-height: var(--bar);
  padding: 10px var(--gutter);
  background: #071E30;
  border-bottom: 1px solid var(--grid);
}

.rail-nav {
  position: fixed;
  top: var(--bar);
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 130;
  display: flex;
  flex-direction: column;
  padding: 22px var(--gutter) 56px;
  background: linear-gradient(180deg, #082034 0%, var(--ink) 62%);
  border-top: 1px solid var(--grid);
  overflow-y: auto;
  overscroll-behavior: contain;
  opacity: 0;
  visibility: hidden;
  transform: translateY(-10px);
  transition: opacity 220ms var(--ease),
              transform 220ms var(--ease),
              visibility 0ms linear 220ms;
}
.rail-nav[data-open] {
  opacity: 1;
  visibility: visible;
  transform: none;
  transition: opacity 220ms var(--ease),
              transform 220ms var(--ease),
              visibility 0ms;
}
body.is-nav-open { overflow: hidden; }

.rail-nav__list { display: flex; flex-direction: column; }
.rail-nav__link {
  position: relative;
  display: flex;
  align-items: baseline;
  gap: 16px;
  padding: 18px 4px;
  border-bottom: 1px solid var(--grid);
  font-size: 20px;
  font-weight: 600;
  color: var(--white);
  transition: color var(--dur) var(--ease), padding-left var(--dur) var(--ease);
}
.rail-nav__link:hover,
.rail-nav__link:focus-visible { color: var(--aurora); padding-left: 12px; }
.rail-nav__link[aria-current="page"] { color: var(--aurora); }
.rail-nav__idx {
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 400;
  letter-spacing: .1em;
  color: var(--lime);
  flex: none;
}
.rail-nav__label { opacity: 1; }

.rail-nav__extra {
  margin-top: 28px;
  padding-top: 22px;
  border-top: 1px solid var(--grid);
}
.rail-nav__caption {
  margin-bottom: 12px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .2em;
  color: var(--lime);
}
.rail-tools { display: flex; flex-direction: column; gap: 4px; }
.rail-tools__link {
  display: block;
  padding: 8px 0;
  font-size: 15px;
  color: var(--muted);
  transition: color var(--dur) var(--ease), padding-left var(--dur) var(--ease);
}
.rail-tools__link:hover,
.rail-tools__link:focus-visible { color: var(--aurora-soft); padding-left: 8px; }
.rail-cta { margin-top: 20px; width: 100%; }

/* 桌面端：固定 88px 轨道，悬停/聚焦展开 */
@media (min-width: 1080px) {
  body { padding-left: var(--rail); }

  .site-header {
    position: fixed;
    top: 0;
    left: 0;
    height: 100vh;
    width: var(--rail);
    background: #071E30;
    border-right: 1px solid var(--grid);
    overflow: hidden;
    transition: width 260ms var(--ease), box-shadow 260ms var(--ease);
  }
  .site-header:hover,
  .site-header:focus-within {
    width: var(--rail-open);
    box-shadow: 28px 0 64px rgba(2, 10, 18, .55);
  }

  .site-header__inner {
    display: flex;
    flex-direction: column;
    align-items: stretch;
    justify-content: flex-start;
    width: var(--rail-open);
    height: 100%;
    min-height: 0;
    padding: 0;
    background: transparent;
    border-bottom: 0;
  }

  .brand {
    height: var(--rail);
    min-height: var(--rail);
    padding-left: 26px;
    border-bottom: 1px solid var(--grid);
  }
  .brand__text {
    opacity: 0;
    transition: opacity 180ms var(--ease);
  }
  .site-header:hover .brand__text,
  .site-header:focus-within .brand__text { opacity: 1; }

  .nav-toggle { display: none; }

  .rail-nav {
    position: static;
    inset: auto;
    flex: 1 1 auto;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    padding: 10px 0 0;
    background: transparent;
    border-top: 0;
    overflow-y: auto;
    overflow-x: hidden;
    opacity: 1;
    visibility: visible;
    transform: none;
    transition: none;
  }
  .rail-nav[data-open] { opacity: 1; visibility: visible; transform: none; }

  .rail-nav__link {
    height: 58px;
    align-items: center;
    gap: 14px;
    padding: 0 24px 0 30px;
    border-bottom: 0;
    font-size: 15px;
    font-weight: 500;
    color: var(--muted);
    white-space: nowrap;
    transition: color var(--dur) var(--ease), background-color var(--dur) var(--ease);
  }
  .rail-nav__link::before {
    content: "";
    position: absolute;
    left: 0;
    top: 50%;
    width: 3px;
    height: 0;
    transform: translateY(-50%);
    background: var(--aurora);
    transition: height var(--dur) var(--ease);
  }
  .rail-nav__link:hover,
  .rail-nav__link:focus-visible {
    color: var(--white);
    background: rgba(13, 42, 68, .55);
    padding-left: 30px;
  }
  .rail-nav__link:hover::before,
  .rail-nav__link:focus-visible::before,
  .rail-nav__link[aria-current="page"]::before { height: 26px; }
  .rail-nav__link[aria-current="page"] {
    color: var(--aurora);
    padding-left: 30px;
    background: rgba(13, 42, 68, .4);
  }

  .rail-nav__idx { width: 28px; }
  .rail-nav__label {
    font-size: 15px;
    opacity: 0;
    transition: opacity 180ms var(--ease);
  }
  .site-header:hover .rail-nav__label,
  .site-header:focus-within .rail-nav__label { opacity: 1; }

  .rail-nav__extra {
    margin-top: 0;
    padding: 18px 0 22px;
    border-top: 1px solid var(--grid);
    opacity: 0;
    transition: opacity 180ms var(--ease);
  }
  .site-header:hover .rail-nav__extra,
  .site-header:focus-within .rail-nav__extra { opacity: 1; }

  .rail-nav__caption { padding-left: 30px; margin-bottom: 8px; }
  .rail-tools__link {
    padding: 6px 24px 6px 30px;
    font-size: 13px;
    white-space: nowrap;
  }
  .rail-tools__link:hover,
  .rail-tools__link:focus-visible { padding-left: 30px; }
  .rail-cta { margin: 16px 24px 0 30px; width: auto; }

  html { scroll-padding-top: 28px; }
}

/* ---------- 17. 页脚 ---------- */
.site-footer {
  position: relative;
  margin-top: clamp(56px, 8vw, 104px);
  border-top: 1px solid var(--grid);
  background:
    linear-gradient(180deg, rgba(10, 58, 71, .55) 0%, rgba(6, 23, 38, 0) 46%),
    var(--ink);
}
.site-footer::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(var(--grid) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid) 1px, transparent 1px);
  background-size: 80px 80px;
  opacity: .16;
  -webkit-mask-image: linear-gradient(180deg, #000 0%, transparent 78%);
  mask-image: linear-gradient(180deg, #000 0%, transparent 78%);
}
.site-footer__inner {
  position: relative;
  z-index: 1;
  width: 100%;
  max-width: var(--maxw);
  margin-inline: auto;
  padding: clamp(44px, 6vw, 84px) var(--gutter) 30px;
}

.site-footer__top {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(30px, 5vw, 56px);
  padding-bottom: clamp(30px, 4vw, 52px);
  border-bottom: 1px solid var(--grid);
}
@media (min-width: 900px) {
  .site-footer__top {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 1.55fr);
  }
}

.brand--footer { margin-bottom: 18px; }
.site-footer__blurb {
  font-size: 15px;
  color: var(--muted);
  max-width: 36ch;
}
.site-footer__meta { margin-top: 20px; }
.site-footer__meta li {
  display: flex;
  gap: 12px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .02em;
  color: #C3D6E6;
}
.site-footer__meta li + li { margin-top: 8px; }
.site-footer__meta-key {
  flex: none;
  min-width: 68px;
  color: var(--muted);
}

.site-footer__cols {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 28px;
}
@media (min-width: 620px) {
  .site-footer__cols { grid-template-columns: repeat(3, minmax(0, 1fr)); }
}
.site-footer__col-title {
  margin-bottom: 14px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .2em;
  color: var(--lime);
  max-width: none;
}
.site-footer__list li + li { margin-top: 10px; }
.site-footer__list a {
  font-size: 15px;
  color: var(--muted);
  transition: color var(--dur) var(--ease), padding-left var(--dur) var(--ease);
}
.site-footer__list a:hover,
.site-footer__list a:focus-visible { color: var(--aurora); padding-left: 6px; }

.site-footer__notice {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-start;
  gap: 14px;
  margin-top: clamp(26px, 3.5vw, 40px);
  padding: 18px 22px;
  border: 1px solid var(--grid);
  border-left: 3px solid var(--amber);
  border-radius: var(--radius);
  background: rgba(13, 42, 68, .6);
}
.site-footer__notice-tag {
  flex: none;
  padding: 3px 9px;
  border: 1px solid rgba(255, 122, 51, .55);
  border-radius: var(--radius);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .12em;
  color: var(--amber);
}
.site-footer__notice p {
  flex: 1 1 320px;
  font-size: 14px;
  color: #C3D6E6;
  max-width: 76ch;
}

.site-footer__bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px 28px;
  margin-top: clamp(24px, 3vw, 34px);
  padding-top: 20px;
  border-top: 1px solid var(--grid);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .04em;
  color: var(--muted);
}
.site-footer__bottom p { max-width: none; }
.site-footer__contact { flex: 1 1 340px; }
.site-footer__copy { margin-left: auto; }
@media (max-width: 720px) {
  .site-footer__copy { margin-left: 0; }
}

/* ---------- 18. 降低动效偏好 ---------- */
@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-reveal [data-reveal] { opacity: 1 !important; transform: none !important; }
  .btn:hover,
  .btn:focus-visible,
  .card:hover,
  .card:focus-within { transform: none; }
}