:root {
  --color-surface: #fdfdfd;
  --color-surface-alt: #f3f3f3;
  --color-surface-deep: #e5e5e4;
  --color-ink: #37342f;
  --color-ink-soft: #646159;
  --color-ink-muted: #807d74;
  --color-line: #d9d9d8;
  --color-primary: #946d0f;
  --color-primary-ink: #ffffff;
  --color-primary-soft: #eee9dc;
  --color-accent: #147dae;
  --color-accent-ink: #ffffff;
  --color-highlight: #d3e6ef;
  --color-focus: #0a7aae;
  --color-contrast-surface: #201b0f;
  --color-contrast-ink: #e7e6e4;
  --color-contrast-line: #4c483e;
  --color-contrast-accent: #1ba4e4;
  --overlay-scrim: linear-gradient(180deg, rgba(32, 27, 15, 0.35) 0%, rgba(32, 27, 15, 0.72) 55%, rgba(32, 27, 15, 0.92) 100%);
  --font-heading: "Source Han Sans SC", "Noto Sans SC", SimHei, "Microsoft YaHei", sans-serif;
  --font-body: "PingFang SC", "Microsoft YaHei", "Source Han Sans SC", sans-serif;
  --font-mono: ui-monospace, Menlo, Consolas, monospace;
  --text-xs: 9.3px;
  --text-sm: 13.9px;
  --text-base: 17px;
  --text-lg: 25.5px;
  --text-xl: 38.2px;
  --text-2xl: 57.4px;
  --text-3xl: 86.1px;
  --text-4xl: 129.1px;
  --text-display: clamp(62px, 12.8vw, 164px);
  --text-figure: clamp(52px, 9.2vw, 118px);
  --weight-heading: 770;
  --weight-body: 400;
  --leading-body: 1.75;
  --leading-heading: 1.2;
  --tracking-heading: -0.022em;
  --radius-sm: 0px;
  --radius-md: 0px;
  --radius-lg: 1px;
  --radius-pill: 1px;
  --border-thin: 1px;
  --border-thick: 2px;
  --shadow-1: none;
  --shadow-2: none;
  --space-1: 8px;
  --space-2: 16px;
  --space-3: 24px;
  --space-4: 32px;
  --space-6: 48px;
  --space-8: 64px;
  --container: 1220px;
  --measure: 66ch;
  --gutter: 24px;
  --section-y: 77px;
  --section-y-lg: 108px;
}

/* ============================================================
   1. 重置与基础
   ============================================================ */
*, *::before, *::after { box-sizing: border-box; }

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

@media (prefers-reduced-motion: no-preference) {
  html { scroll-behavior: smooth; }
}

body {
  margin: 0;
  min-height: 100vh;
  background: var(--color-surface);
  color: var(--color-ink);
  font-family: var(--font-body);
  font-size: var(--text-base);
  font-weight: var(--weight-body);
  line-height: var(--leading-body);
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

h1, h2, h3, h4, h5, h6 {
  margin: 0;
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
}

p { margin: 0; }
ul, ol { margin: 0; padding: 0; list-style: none; }
figure { margin: 0; }
img, svg, video, canvas { display: block; max-width: 100%; }
button { font: inherit; color: inherit; background: none; border: 0; padding: 0; }
a { color: inherit; text-decoration: none; }
strong, b { font-weight: var(--weight-heading); }
table { border-collapse: collapse; width: 100%; }

main { display: block; }

::selection {
  background: var(--color-primary);
  color: var(--color-primary-ink);
}

:focus-visible {
  outline: var(--border-thick) solid var(--color-focus);
  outline-offset: 3px;
  border-radius: var(--radius-sm);
}

/* ============================================================
   2. 跳转链接
   ============================================================ */
.skip-link {
  position: fixed;
  top: var(--space-2);
  left: var(--space-2);
  z-index: 300;
  padding: 12px var(--space-3);
  background: var(--color-primary);
  color: var(--color-primary-ink);
  font-family: var(--font-heading);
  font-size: var(--text-sm);
  font-weight: var(--weight-heading);
  letter-spacing: 0.14em;
  transform: translateY(-220%);
  transition: transform 0.2s ease;
}

.skip-link:focus {
  transform: translateY(0);
}

/* ============================================================
   3. 容器 / 分节 / 色块反转
   ============================================================ */
.shell {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: var(--space-3);
}

.slab {
  position: relative;
  padding-block: var(--section-y);
}

.slab--tall { padding-block: var(--section-y-lg); }
.slab--tight { padding-block: var(--space-6); }
.slab--flat-top { padding-block-start: 0; }
.slab--flat-bottom { padding-block-end: 0; }
.slab--lead { padding-block-start: calc(var(--space-8) + var(--space-8)); }

.slab--surface  { background: var(--color-surface);          color: var(--color-ink); }
.slab--alt      { background: var(--color-surface-alt);      color: var(--color-ink); }
.slab--deep     { background: var(--color-surface-deep);     color: var(--color-ink); }
.slab--soft     { background: var(--color-primary-soft);     color: var(--color-ink); }
.slab--primary  { background: var(--color-primary);          color: var(--color-primary-ink); }
.slab--accent   { background: var(--color-accent);           color: var(--color-accent-ink); }
.slab--contrast { background: var(--color-contrast-surface); color: var(--color-contrast-ink); }

.slab--primary .u-muted,
.slab--accent .u-muted,
.slab--contrast .u-muted {
  color: color-mix(in srgb, currentColor 70%, transparent);
}

.slab--primary a,
.slab--accent a {
  text-underline-offset: 4px;
}

.slab--contrast a { color: var(--color-contrast-accent); }

/* ============================================================
   4. 栅格与排列
   ============================================================ */
.grid--11 {
  display: grid;
  grid-template-columns: repeat(11, minmax(0, 1fr));
  gap: var(--gutter);
}

.grid--11 > * {
  grid-column: span var(--span, 11);
  min-width: 0;
}

.stack { display: grid; gap: var(--space-3); }
.stack--lg { gap: var(--space-6); }
.stack--xl { gap: var(--space-8); }
.stack--sm { gap: var(--space-2); }

.cluster {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-2);
}

.cluster--lg { gap: var(--space-4); }

@media (max-width: 1000px) {
  .grid--11 { grid-template-columns: repeat(6, minmax(0, 1fr)); }
  .grid--11 > * { grid-column: span var(--span-md, 6); }
}

@media (max-width: 640px) {
  .grid--11 { grid-template-columns: 1fr; }
  .grid--11 > * { grid-column: 1 / -1; }
}

/* ============================================================
   5. 标题与文字
   ============================================================ */
.sec-head {
  display: grid;
  gap: var(--space-2);
}

.sec-head__idx {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: 700;
  letter-spacing: 0.34em;
  text-transform: uppercase;
  color: var(--color-ink-muted);
}

.slab--primary .sec-head__idx,
.slab--accent .sec-head__idx {
  color: color-mix(in srgb, currentColor 68%, transparent);
}

.slab--contrast .sec-head__idx {
  color: var(--color-contrast-accent);
}

.sec-head__title {
  font-size: var(--text-xl);
  text-transform: uppercase;
  max-width: 22ch;
}

.sec-head__lead {
  max-width: var(--measure);
  font-size: var(--text-base);
  color: var(--color-ink-soft);
}

.slab--primary .sec-head__lead,
.slab--accent .sec-head__lead,
.slab--contrast .sec-head__lead {
  color: color-mix(in srgb, currentColor 80%, transparent);
}

.eyebrow {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: 700;
  letter-spacing: 0.3em;
  text-transform: uppercase;
  color: var(--color-accent);
}

.slab--primary .eyebrow,
.slab--accent .eyebrow {
  color: color-mix(in srgb, currentColor 78%, transparent);
}

.slab--contrast .eyebrow { color: var(--color-contrast-accent); }

.lede {
  max-width: var(--measure);
  font-size: var(--text-lg);
  line-height: 1.5;
  font-weight: var(--weight-body);
}

.note {
  max-width: var(--measure);
  font-size: var(--text-sm);
  line-height: var(--leading-body);
  color: var(--color-ink-muted);
}

.mono {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-feature-settings: "tnum" 1;
}

.u-muted { color: var(--color-ink-muted); }

.display {
  display: block;
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-display);
  line-height: 0.88;
  letter-spacing: -0.035em;
  text-transform: uppercase;
  margin: 0;
}

.figure {
  display: block;
  font-family: var(--font-mono);
  font-weight: var(--weight-heading);
  font-size: var(--text-figure);
  line-height: 0.9;
  letter-spacing: -0.03em;
  font-variant-numeric: tabular-nums;
}

/* ============================================================
   6. 按钮
   ============================================================ */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  padding: 15px var(--space-3);
  background: var(--color-primary);
  color: var(--color-primary-ink);
  font-family: var(--font-heading);
  font-size: var(--text-sm);
  font-weight: var(--weight-heading);
  letter-spacing: 0.16em;
  text-transform: uppercase;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: background-color 0.2s ease, color 0.2s ease;
}

.btn:hover { background: var(--color-contrast-surface); color: var(--color-contrast-ink); }

.btn--accent { background: var(--color-accent); color: var(--color-accent-ink); }
.btn--accent:hover { background: var(--color-contrast-surface); color: var(--color-contrast-ink); }

.btn--ghost {
  background: color-mix(in srgb, currentColor 12%, transparent);
  color: inherit;
}
.btn--ghost:hover { background: currentColor; color: var(--color-surface); }

.slab--contrast .btn--ghost:hover { color: var(--color-contrast-surface); }

/* ============================================================
   7. 面包屑 / 标签 / 索引 / 数据
   ============================================================ */
.crumbs {
  font-size: var(--text-sm);
  color: var(--color-ink-muted);
}

.crumbs ol {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-2);
}

.crumbs li {
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.crumbs li + li::before {
  content: "/";
  opacity: 0.45;
}

.crumbs a:hover { color: var(--color-accent); }

.tag-row {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-1);
}

.tag {
  display: inline-block;
  padding: 6px 12px;
  background: var(--color-highlight);
  color: color-mix(in srgb, var(--color-accent) 82%, var(--color-ink));
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: 700;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  border-radius: var(--radius-sm);
}

.slab--primary .tag,
.slab--accent .tag,
.slab--contrast .tag {
  background: color-mix(in srgb, currentColor 16%, transparent);
  color: inherit;
}

.stat-row {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: var(--space-3);
}

.stat {
  display: grid;
  gap: var(--space-1);
  padding: var(--space-3) 0;
}

.stat__value {
  font-family: var(--font-mono);
  font-size: var(--text-2xl);
  font-weight: var(--weight-heading);
  line-height: 1;
  letter-spacing: -0.02em;
  font-variant-numeric: tabular-nums;
  color: var(--color-accent);
}

.slab--primary .stat__value,
.slab--accent .stat__value,
.slab--contrast .stat__value {
  color: var(--color-contrast-accent);
}

.slab--primary .stat__value { color: var(--color-primary-ink); }

.stat__label {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: 700;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--color-ink-muted);
}

.slab--primary .stat__label,
.slab--accent .stat__label,
.slab--contrast .stat__label {
  color: color-mix(in srgb, currentColor 66%, transparent);
}

.index-list {
  display: grid;
  gap: 0;
}

.index-list__item { display: block; }

.index-list__link {
  display: grid;
  grid-template-columns: 4ch 1fr;
  gap: var(--space-2);
  align-items: baseline;
  padding: var(--space-2) 0;
  transition: color 0.18s ease, padding-inline-start 0.18s ease;
}

.index-list__link:hover {
  color: var(--color-accent);
  padding-inline-start: var(--space-1);
}

.slab--contrast .index-list__link:hover { color: var(--color-contrast-accent); }

.index-list__no {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: 700;
  letter-spacing: 0.14em;
  color: var(--color-ink-muted);
}

.slab--contrast .index-list__no { color: var(--color-contrast-accent); }

/* ============================================================
   8. 图片容器
   ============================================================ */
.media {
  position: relative;
  display: block;
  overflow: hidden;
  aspect-ratio: 3 / 2;
  background: var(--color-surface-deep);
  border-radius: var(--radius-lg);
}

.media > img,
.media > picture > img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
  border-radius: inherit;
}

.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--duotone::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 1;
  background: var(--color-primary);
  mix-blend-mode: color;
  opacity: 0.62;
  pointer-events: none;
}

.media--scrim::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 2;
  background: var(--overlay-scrim);
  pointer-events: none;
}

.media__caption {
  position: absolute;
  z-index: 3;
  left: 0;
  right: 0;
  bottom: 0;
  padding: var(--space-3);
  color: var(--color-contrast-ink);
  font-size: var(--text-sm);
  line-height: 1.5;
}

.media__caption .mono {
  display: block;
  font-size: var(--text-xs);
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--color-contrast-accent);
  margin-bottom: 6px;
}

/* ============================================================
   9. 折叠面板
   ============================================================ */
.acc {
  background: var(--color-surface-alt);
  border-radius: var(--radius-sm);
}

.acc__q {
  display: flex;
  align-items: baseline;
  gap: var(--space-2);
  padding: var(--space-3);
  cursor: pointer;
  list-style: none;
  font-family: var(--font-heading);
  font-size: var(--text-base);
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
  transition: background-color 0.2s ease, color 0.2s ease;
}

.acc__q::-webkit-details-marker { display: none; }
.acc__q::marker { content: ""; }

.acc__q::after {
  content: "+";
  margin-inline-start: auto;
  font-family: var(--font-mono);
  font-size: var(--text-lg);
  line-height: 1;
  color: var(--color-accent);
}

.acc[open] > .acc__q {
  background: var(--color-primary);
  color: var(--color-primary-ink);
}

.acc[open] > .acc__q::after {
  content: "−";
  color: var(--color-primary-ink);
}

.acc__a {
  padding: var(--space-3);
  max-width: var(--measure);
  color: var(--color-ink-soft);
}

.slab--contrast .acc { background: color-mix(in srgb, var(--color-contrast-ink) 8%, transparent); }
.slab--contrast .acc__q { color: var(--color-contrast-ink); }
.slab--contrast .acc__a { color: color-mix(in srgb, var(--color-contrast-ink) 76%, transparent); }

/* ============================================================
   10. 头部
   ============================================================ */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  color: var(--color-ink);
}

.site-header__bar {
  background: color-mix(in srgb, var(--color-surface) 90%, transparent);
  transition: background-color 0.28s ease, color 0.28s ease;
}

.site-header.is-solid .site-header__bar {
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
}

.site-header__inner {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding: var(--space-2) var(--space-3);
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

/* 品牌 */
.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  flex: 0 0 auto;
  min-width: 0;
}

.brand__mark {
  display: inline-grid;
  place-items: center;
  width: 38px;
  height: 38px;
  background: var(--color-primary);
  color: var(--color-primary-ink);
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  font-weight: 700;
  letter-spacing: 0.02em;
  border-radius: var(--radius-sm);
}

.site-header.is-solid .brand__mark {
  background: var(--color-contrast-accent);
  color: var(--color-contrast-surface);
}

.brand__text {
  display: grid;
  gap: 1px;
  min-width: 0;
}

.brand__name {
  font-family: var(--font-heading);
  font-size: var(--text-base);
  font-weight: var(--weight-heading);
  letter-spacing: 0.06em;
  line-height: 1.15;
  white-space: nowrap;
}

.brand__tag {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.14em;
  color: var(--color-ink-muted);
  line-height: 1.4;
  white-space: nowrap;
}

.site-header.is-solid .brand__tag {
  color: color-mix(in srgb, var(--color-contrast-ink) 60%, transparent);
}

/* 主导航 */
.primary-nav {
  margin-inline-start: auto;
}

.nav-list {
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.nav-list__item { display: block; }

.nav-link {
  display: inline-flex;
  align-items: baseline;
  gap: 6px;
  padding: 8px 10px;
  font-family: var(--font-heading);
  font-size: var(--text-sm);
  font-weight: var(--weight-heading);
  letter-spacing: 0.06em;
  line-height: 1.2;
  white-space: nowrap;
  border-radius: var(--radius-sm);
  transition: background-color 0.2s ease, color 0.2s ease;
}

.nav-link__idx {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: 700;
  letter-spacing: 0.1em;
  color: var(--color-ink-muted);
  transition: color 0.2s ease;
}

.nav-link:hover { background: color-mix(in srgb, var(--color-primary) 16%, transparent); }

.site-header.is-solid .nav-link:hover {
  background: color-mix(in srgb, var(--color-contrast-ink) 14%, transparent);
}

.site-header.is-solid .nav-link__idx {
  color: var(--color-contrast-accent);
}

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

.nav-link[aria-current="page"] .nav-link__idx {
  color: color-mix(in srgb, var(--color-primary-ink) 62%, var(--color-primary));
}

.site-header.is-solid .nav-link[aria-current="page"] {
  background: var(--color-contrast-accent);
  color: var(--color-contrast-surface);
}

.site-header.is-solid .nav-link[aria-current="page"] .nav-link__idx {
  color: color-mix(in srgb, var(--color-contrast-surface) 62%, var(--color-contrast-accent));
}

/* 移动端按钮 */
.nav-toggle {
  display: none;
  align-items: center;
  gap: var(--space-1);
  margin-inline-start: auto;
  padding: 10px var(--space-2);
  position: relative;
  z-index: 120;
  cursor: pointer;
  border-radius: var(--radius-sm);
  transition: background-color 0.2s ease;
}

.nav-toggle:hover { background: color-mix(in srgb, var(--color-primary) 18%, transparent); }

.nav-toggle__bars {
  display: grid;
  gap: 4px;
  width: 20px;
}

.nav-toggle__bars span {
  display: block;
  height: var(--border-thick);
  background: currentColor;
}

.nav-toggle__text {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: 700;
  letter-spacing: 0.2em;
  text-transform: uppercase;
}

/* 滚动进度 */
.header-progress {
  height: var(--border-thick);
  background: color-mix(in srgb, var(--color-ink) 12%, transparent);
}

.site-header.is-solid .header-progress {
  background: color-mix(in srgb, var(--color-contrast-ink) 14%, transparent);
}

.header-progress__bar {
  display: block;
  width: 0;
  height: 100%;
  background: var(--color-accent);
  transition: width 0.08s linear;
}

.site-header.is-solid .header-progress__bar {
  background: var(--color-contrast-accent);
}

/* 移动端导航 */
@media (max-width: 1000px) {
  .nav-toggle { display: inline-flex; }

  .primary-nav {
    position: fixed;
    inset: 0;
    z-index: 90;
    margin: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: calc(var(--space-8) + var(--space-4)) var(--space-3) var(--space-8);
    background: var(--color-contrast-surface);
    color: var(--color-contrast-ink);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-1.25rem);
    transition: opacity 0.24s ease, transform 0.24s ease, visibility 0.24s;
    overflow-y: auto;
  }

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

  .nav-list {
    flex-direction: column;
    align-items: stretch;
    gap: 2px;
    width: min(460px, 100%);
  }

  .nav-link {
    display: flex;
    align-items: baseline;
    gap: var(--space-2);
    padding: var(--space-2) var(--space-3);
    font-size: var(--text-lg);
    letter-spacing: 0.02em;
  }

  .nav-link__idx {
    color: var(--color-contrast-accent);
    font-size: var(--text-sm);
  }

  .site-header.is-solid .nav-link__idx { color: var(--color-contrast-accent); }

  .nav-link:hover { background: color-mix(in srgb, var(--color-contrast-ink) 12%, transparent); }
  .site-header.is-solid .nav-link:hover { background: color-mix(in srgb, var(--color-contrast-ink) 12%, transparent); }

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

  .nav-link[aria-current="page"] .nav-link__idx {
    color: color-mix(in srgb, var(--color-primary-ink) 64%, var(--color-primary));
  }

  body.nav-open { overflow: hidden; }
}

@media (max-width: 460px) {
  .brand__tag { display: none; }
  .site-header__inner { padding-inline: var(--space-2); }
}

/* ============================================================
   11. 页脚
   ============================================================ */
.site-footer {
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  padding-block: var(--section-y);
}

.site-footer__inner {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: var(--space-3);
  display: grid;
  gap: var(--space-8);
}

.footer-tier {
  display: grid;
  gap: var(--space-3);
}

.footer-tier__label {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: 700;
  letter-spacing: 0.34em;
  text-transform: uppercase;
  color: var(--color-contrast-accent);
}

.footer-index__list {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(168px, 1fr));
  gap: 2px var(--space-3);
}

.footer-index__link {
  display: flex;
  align-items: baseline;
  gap: var(--space-1);
  padding: 10px 0;
  font-size: var(--text-sm);
  line-height: 1.4;
  transition: color 0.18s ease;
}

.footer-index__link:hover { color: var(--color-contrast-accent); }

.footer-index__no {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: 700;
  letter-spacing: 0.1em;
  color: color-mix(in srgb, var(--color-contrast-ink) 44%, transparent);
  flex: 0 0 auto;
}

.footer-notes__line {
  max-width: var(--measure);
  font-size: var(--text-sm);
  line-height: var(--leading-body);
  color: color-mix(in srgb, var(--color-contrast-ink) 76%, transparent);
}

.footer-notes__line + .footer-notes__line { margin-block-start: var(--space-1); }

.footer-meta {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(255px, 1fr));
  gap: var(--space-1) var(--space-4);
}

.footer-meta__row {
  display: flex;
  align-items: baseline;
  gap: var(--space-2);
  font-size: var(--text-sm);
  line-height: 1.6;
}

.footer-meta__key {
  flex: 0 0 auto;
  min-width: 68px;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: 700;
  letter-spacing: 0.2em;
  color: color-mix(in srgb, var(--color-contrast-ink) 44%, transparent);
}

.footer-meta__val { color: var(--color-contrast-ink); }

.footer-meta__link {
  color: var(--color-contrast-accent);
  border-bottom: var(--border-thin) solid color-mix(in srgb, var(--color-contrast-accent) 55%, transparent);
  transition: color 0.18s ease, border-color 0.18s ease;
}

.footer-meta__link:hover {
  color: var(--color-contrast-ink);
  border-color: var(--color-contrast-ink);
}

.footer-copyright {
  margin-block-start: var(--space-4);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.16em;
  color: color-mix(in srgb, var(--color-contrast-ink) 48%, transparent);
}

/* ============================================================
   12. 显现动效
   ============================================================ */
.js-motion [data-reveal] {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 0.5s ease, transform 0.5s ease;
}

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

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }

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

  .header-progress__bar,
  .site-header__bar,
  .nav-link,
  .btn,
  .primary-nav,
  .skip-link {
    transition: none;
  }
}

@media (max-width: 640px) {
  .sec-head__title { font-size: var(--text-lg); }
  .lede { font-size: var(--text-base); }
  .stat__value { font-size: var(--text-xl); }
  .footer-index__list { grid-template-columns: repeat(auto-fill, minmax(140px, 1fr)); }
  .footer-meta { grid-template-columns: 1fr; }
}