:root {
  --color-surface: #f9fafa;
  --color-surface-alt: #eff0f0;
  --color-surface-deep: #e1e2e3;
  --color-ink: #2e3238;
  --color-ink-soft: #595f69;
  --color-ink-muted: #747b86;
  --color-line: #d4d6d7;
  --color-primary: #1064ef;
  --color-primary-ink: #ffffff;
  --color-primary-soft: #d8e5f8;
  --color-accent: #7c19e6;
  --color-accent-ink: #ffffff;
  --color-highlight: #e2d2f6;
  --color-focus: #7b0cf3;
  --color-contrast-surface: #121b2a;
  --color-contrast-ink: #e4e5e7;
  --color-contrast-line: #404754;
  --color-contrast-accent: #a663ee;
  --overlay-scrim: linear-gradient(180deg, rgba(18, 27, 42, 0.35) 0%, rgba(18, 27, 42, 0.72) 55%, rgba(18, 27, 42, 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: 10.4px;
  --text-sm: 13.9px;
  --text-base: 16px;
  --text-lg: 21.3px;
  --text-xl: 28.4px;
  --text-2xl: 37.9px;
  --text-3xl: 50.5px;
  --text-4xl: 67.3px;
  --text-display: clamp(47px, 9.6vw, 123px);
  --text-figure: clamp(39px, 7.0vw, 89px);
  --weight-heading: 889;
  --weight-body: 400;
  --leading-body: 1.8;
  --leading-heading: 1.27;
  --tracking-heading: -0.026em;
  --radius-sm: 0px;
  --radius-md: 0px;
  --radius-lg: 0px;
  --radius-pill: 0px;
  --border-thin: 2px;
  --border-thick: 3px;
  --shadow-1: 4px 4px 0 #2e3238;
  --shadow-2: 8px 8px 0 #2e3238;
  --space-1: 8px;
  --space-2: 16px;
  --space-3: 24px;
  --space-4: 32px;
  --space-6: 48px;
  --space-8: 64px;
  --container: 1180px;
  --measure: 73ch;
  --gutter: 16px;
  --section-y: 88px;
  --section-y-lg: 123px;
}

/* ==========================================================================
   1. Reset 与基础排版
   ========================================================================== */

*,
*::before,
*::after { box-sizing: border-box; }

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

body {
  margin: 0;
  background-color: 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);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

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

button,
input,
select,
textarea {
  font: inherit;
  color: inherit;
  margin: 0;
}

ul,
ol { margin: 0; padding: 0; }

li { list-style: none; }

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);
  color: inherit;
}

h1 { font-size: clamp(var(--text-2xl), 5vw, var(--text-4xl)); }
h2 { font-size: clamp(var(--text-xl), 3.2vw, var(--text-3xl)); }
h3 { font-size: var(--text-lg); }
h4 { font-size: var(--text-base); }

p { margin: 0 0 var(--space-3); }
p:last-child { margin-bottom: 0; }

a {
  color: var(--color-primary);
  text-decoration-thickness: var(--border-thin);
  text-underline-offset: 3px;
}

a:hover { color: var(--color-focus); }

strong,
b { font-weight: var(--weight-heading); }

hr {
  border: 0;
  height: 0;
  margin: 0;
}

:focus { outline: none; }

:focus-visible {
  outline: var(--border-thick) solid var(--color-focus);
  outline-offset: 2px;
}

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

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

/* ==========================================================================
   2. 布局容器与栅格
   ========================================================================== */

.container {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.container--wide {
  max-width: none;
  padding-inline: var(--gutter);
}

.grid {
  display: grid;
  grid-template-columns: repeat(6, minmax(0, 1fr));
  gap: var(--space-3);
}

.span-2 { grid-column: span 2; }
.span-3 { grid-column: span 3; }
.span-4 { grid-column: span 4; }
.span-5 { grid-column: span 5; }
.span-6 { grid-column: span 6; }

.stack > * + * { margin-top: var(--space-3); }
.stack-lg > * + * { margin-top: var(--space-6); }

.prose { max-width: var(--measure); }
.prose > * { margin-top: 0; margin-bottom: var(--space-3); }
.prose > *:last-child { margin-bottom: 0; }

.section { padding-block: var(--section-y); }
.section--lg { padding-block: var(--section-y-lg); }
.section--tight { padding-block: var(--space-6); }
.section--alt { background-color: var(--color-surface-alt); }
.section--deep {
  background-color: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
}
.section--primary {
  background-color: var(--color-primary);
  color: var(--color-primary-ink);
}
.section--primary a { color: var(--color-primary-ink); }
.section--deep a { color: var(--color-contrast-accent); }
.section--deep a:hover { color: var(--color-contrast-ink); }

.sec-head {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  margin-bottom: var(--space-6);
}

.sec-head--tight { margin-bottom: var(--space-4); }

.sec-head__kicker {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.26em;
  color: var(--color-ink-muted);
  margin: 0;
}

.section--deep .sec-head__kicker { color: var(--color-contrast-accent); }
.section--primary .sec-head__kicker { color: var(--color-primary-ink); }

.sec-head__title {
  font-size: clamp(var(--text-xl), 4vw, var(--text-3xl));
  letter-spacing: 0.02em;
  margin: 0;
}

.sec-head__desc {
  max-width: var(--measure);
  font-size: var(--text-base);
  color: var(--color-ink-soft);
  margin: 0;
}

.section--deep .sec-head__desc { color: var(--color-contrast-ink); }
.section--primary .sec-head__desc { color: var(--color-primary-ink); }

/* ==========================================================================
   3. 贯通整行的色带
   ========================================================================== */

.band {
  width: 100%;
  background-color: var(--color-primary);
  color: var(--color-primary-ink);
  border-top: var(--border-thick) solid var(--color-ink);
  border-bottom: var(--border-thick) solid var(--color-ink);
}

.band--accent {
  background-color: var(--color-accent);
  color: var(--color-accent-ink);
}

.band--deep {
  background-color: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  border-color: var(--color-contrast-line);
}

.band__inner {
  max-width: var(--container);
  margin-inline: auto;
  padding: var(--space-4) var(--gutter);
}

.band a { color: inherit; }

/* ==========================================================================
   4. 块体：粗边框 + 硬投影
   ========================================================================== */

.panel {
  position: relative;
  background-color: var(--color-surface);
  color: var(--color-ink);
  border: var(--border-thick) solid var(--color-ink);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-2);
  padding: var(--space-4);
  transition: transform 140ms linear, box-shadow 140ms linear;
}

.panel--flush { padding: 0; }
.panel--sm { padding: var(--space-3); box-shadow: var(--shadow-1); }

.panel--deep {
  background-color: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  border-color: var(--color-contrast-line);
}

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

.panel--primary a { color: var(--color-primary-ink); }

.panel--accent {
  background-color: var(--color-accent);
  color: var(--color-accent-ink);
}

.panel--accent a { color: var(--color-accent-ink); }

.panel--quiet {
  background-color: var(--color-surface-alt);
  box-shadow: var(--shadow-1);
}

a.panel:hover,
button.panel:hover,
.panel--hover:hover {
  transform: translate(-4px, -4px);
  box-shadow: var(--shadow-2), 0 0 0 var(--color-ink);
  border-color: var(--color-focus);
}

.panel__title {
  font-size: var(--text-lg);
  letter-spacing: 0.02em;
  margin: 0 0 var(--space-1);
}

.panel__meta {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.18em;
  color: var(--color-ink-muted);
  margin: 0;
}

.panel--deep .panel__meta,
.panel--primary .panel__meta,
.panel--accent .panel__meta { color: currentColor; opacity: 0.78; }

.panel__text {
  font-size: var(--text-base);
  color: var(--color-ink-soft);
  margin: var(--space-2) 0 0;
}

.panel--deep .panel__text { color: var(--color-contrast-ink); }
.panel--primary .panel__text,
.panel--accent .panel__text { color: currentColor; }

/* 大编号压在区块左上角并与边框重叠 */
.block-num {
  position: absolute;
  top: 0;
  left: 0;
  z-index: 2;
  transform: translate(-3px, -50%);
  display: inline-block;
  padding: var(--space-1) var(--space-2);
  background-color: var(--color-primary);
  color: var(--color-primary-ink);
  border: var(--border-thick) solid var(--color-ink);
  border-radius: var(--radius-sm);
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  font-weight: 700;
  line-height: 1;
  letter-spacing: 0.16em;
}

.block-num--accent {
  background-color: var(--color-accent);
  color: var(--color-accent-ink);
}

.block-num--plain {
  background-color: var(--color-surface);
  color: var(--color-ink);
}

/* ==========================================================================
   5. 强调、标签与数字
   ========================================================================== */

.hl {
  text-decoration: underline;
  text-decoration-color: var(--color-accent);
  text-decoration-thickness: var(--border-thick);
  text-underline-offset: 4px;
}

.hl-box {
  background-color: var(--color-highlight);
  color: var(--color-ink);
  padding: 0 4px;
  box-decoration-break: clone;
  -webkit-box-decoration-break: clone;
}

.section--primary .hl-box,
.panel--primary .hl-box { color: var(--color-primary-ink); }

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 2px var(--space-1);
  border: var(--border-thin) solid var(--color-ink);
  border-radius: var(--radius-sm);
  background-color: transparent;
  color: var(--color-ink);
  font-size: var(--text-xs);
  letter-spacing: 0.12em;
  line-height: 1.5;
  white-space: nowrap;
}

.tag--red {
  background-color: var(--color-accent);
  color: var(--color-accent-ink);
  border-color: var(--color-ink);
}

.tag--yellow {
  background-color: transparent;
  color: var(--color-primary);
  border: var(--border-thick) solid var(--color-primary);
}

.tag--solid {
  background-color: var(--color-primary);
  color: var(--color-primary-ink);
}

.tag--deep {
  background-color: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  border-color: var(--color-contrast-line);
}

.figure {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
  padding: var(--space-3) var(--space-4);
  background-color: var(--color-primary);
  color: var(--color-primary-ink);
  border: var(--border-thick) solid var(--color-ink);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-2);
}

.figure--accent {
  background-color: var(--color-accent);
  color: var(--color-accent-ink);
}

.figure--deep {
  background-color: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  border-color: var(--color-contrast-line);
}

.figure__num {
  font-family: var(--font-mono);
  font-size: var(--text-figure);
  font-weight: 700;
  line-height: 0.92;
  letter-spacing: -0.05em;
  font-variant-numeric: tabular-nums;
  font-feature-settings: "tnum" 1;
}

.figure__label {
  font-size: var(--text-sm);
  letter-spacing: 0.2em;
  line-height: 1.4;
}

.num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-feature-settings: "tnum" 1;
  letter-spacing: 0.02em;
}

.display-title {
  font-size: var(--text-display);
  line-height: 1.02;
  letter-spacing: 0.04em;
  margin: 0;
}

/* ==========================================================================
   6. 图片容器（页面阶段放置图片占位）
   ========================================================================== */

.media-frame {
  position: relative;
  display: block;
  overflow: hidden;
  aspect-ratio: 16 / 9;
  background-color: var(--color-surface-deep);
  border: var(--border-thick) solid var(--color-ink);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-2);
}

.media-frame--wide { aspect-ratio: 21 / 9; }
.media-frame--tall { aspect-ratio: 3 / 4; }
.media-frame--square { aspect-ratio: 1 / 1; }
.media-frame--flat { box-shadow: none; }

.media-frame > img,
.media-frame > picture,
.media-frame > picture > img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: saturate(0.55) contrast(1.06);
}

.media-frame__scrim {
  position: absolute;
  inset: 0;
  background-image: var(--overlay-scrim);
  pointer-events: none;
}

.media-frame__body {
  position: absolute;
  inset: auto 0 0 0;
  z-index: 2;
  padding: var(--space-3);
  color: var(--color-contrast-ink);
}

.media-frame__eyebrow {
  display: block;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.24em;
  color: var(--color-contrast-accent);
  margin-bottom: var(--space-1);
}

.media-frame__title {
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-lg);
  line-height: var(--leading-heading);
  letter-spacing: 0.02em;
  margin: 0;
}

.media-frame__note {
  margin: var(--space-1) 0 0;
  font-size: var(--text-sm);
  line-height: 1.6;
  color: var(--color-contrast-ink);
}

/* ==========================================================================
   7. 按钮与筛选
   ========================================================================== */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-1);
  padding: var(--space-2) var(--space-3);
  background-color: var(--color-surface);
  color: var(--color-ink);
  border: var(--border-thick) solid var(--color-ink);
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-1);
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-sm);
  letter-spacing: 0.1em;
  line-height: 1.4;
  text-decoration: none;
  cursor: pointer;
  transition: transform 140ms linear, box-shadow 140ms linear, background-color 140ms linear, color 140ms linear;
}

.btn:hover {
  transform: translate(-4px, -4px);
  box-shadow: var(--shadow-2);
  background-color: var(--color-surface-alt);
  color: var(--color-ink);
}

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

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

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

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

.btn--ghost {
  background-color: transparent;
  box-shadow: none;
}

.btn--ghost:hover {
  transform: none;
  box-shadow: var(--shadow-1);
  background-color: var(--color-primary-soft);
}

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

.filter-bar {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  align-items: center;
  margin-bottom: var(--space-4);
}

.filter-bar__label {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.24em;
  color: var(--color-ink-muted);
  margin: 0;
}

.filter-btn {
  display: inline-flex;
  align-items: center;
  padding: var(--space-1) var(--space-2);
  background-color: var(--color-primary-soft);
  color: var(--color-ink);
  border: var(--border-thick) solid var(--color-ink);
  border-radius: var(--radius-sm);
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-sm);
  letter-spacing: 0.1em;
  line-height: 1.4;
  cursor: pointer;
  transition: background-color 120ms linear, color 120ms linear;
}

.filter-btn:hover {
  background-color: var(--color-highlight);
  color: var(--color-ink);
}

.filter-btn[aria-pressed="true"] {
  background-color: var(--color-primary);
  color: var(--color-primary-ink);
}

.filter-status {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.16em;
  color: var(--color-ink-muted);
  margin: 0 0 var(--space-3);
}

[data-cat][hidden] { display: none !important; }

/* ==========================================================================
   8. 横向数据带
   ========================================================================== */

.strip {
  position: relative;
  margin-block: var(--space-4);
}

.strip__head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-2);
  margin-bottom: var(--space-2);
}

.strip__title {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.24em;
  color: var(--color-ink-muted);
  margin: 0;
}

.strip__controls {
  display: flex;
  gap: var(--space-1);
}

.strip__btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  background-color: var(--color-surface);
  color: var(--color-ink);
  border: var(--border-thick) solid var(--color-ink);
  border-radius: var(--radius-sm);
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  line-height: 1;
  cursor: pointer;
  transition: background-color 120ms linear, color 120ms linear;
}

.strip__btn:hover {
  background-color: var(--color-primary);
  color: var(--color-primary-ink);
}

.strip__track {
  display: flex;
  gap: var(--space-2);
  overflow-x: auto;
  overflow-y: hidden;
  scroll-snap-type: x proximity;
  scrollbar-width: thin;
  padding-bottom: var(--space-2);
  overscroll-behavior-x: contain;
}

.strip__item {
  flex: 0 0 clamp(200px, 24vw, 280px);
  scroll-snap-align: start;
}

.strip__item--wide { flex-basis: clamp(260px, 34vw, 400px); }

/* ==========================================================================
   9. 面包屑
   ========================================================================== */

.crumbs {
  padding-block: var(--space-3);
}

.crumbs__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-1) var(--space-2);
  margin: 0;
  padding: 0;
  font-size: var(--text-sm);
}

.crumbs__item {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  color: var(--color-ink-muted);
  letter-spacing: 0.06em;
}

.crumbs__item + .crumbs__item::before {
  content: "/";
  font-family: var(--font-mono);
  color: var(--color-line);
}

.crumbs__link {
  color: var(--color-ink-soft);
  text-decoration: none;
}

.crumbs__link:hover {
  color: var(--color-focus);
  text-decoration: underline;
}

.crumbs__current {
  color: var(--color-ink);
  font-weight: var(--weight-heading);
}

/* ==========================================================================
   10. 头部：框架式导航
   ========================================================================== */

.skip-link {
  position: absolute;
  top: -120px;
  left: var(--space-2);
  z-index: 200;
  padding: var(--space-2) var(--space-3);
  background-color: var(--color-primary);
  color: var(--color-primary-ink);
  border: var(--border-thick) solid var(--color-ink);
  border-radius: var(--radius-sm);
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-sm);
  letter-spacing: 0.12em;
  text-decoration: none;
  transition: top 120ms linear;
}

.skip-link:focus {
  top: var(--space-2);
  color: var(--color-primary-ink);
}

.site-header {
  position: relative;
  z-index: 60;
  width: 100%;
  background-color: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  border-bottom: var(--border-thick) solid var(--color-ink);
}

.site-header__inner {
  display: flex;
  align-items: stretch;
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: var(--gutter);
  min-height: 78px;
}

.site-header__brand {
  display: flex;
  align-items: center;
  flex: 0 0 auto;
  padding-block: var(--space-2);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  text-decoration: none;
  color: var(--color-contrast-ink);
}

.brand:hover { color: var(--color-contrast-ink); }

.brand__mark {
  display: grid;
  place-items: center;
  width: 46px;
  height: 46px;
  background-color: var(--color-primary);
  color: var(--color-primary-ink);
  border: var(--border-thin) solid var(--color-contrast-ink);
  border-radius: var(--radius-sm);
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-lg);
  line-height: 1;
}

.brand__text { display: block; }

.brand__name {
  display: block;
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-lg);
  letter-spacing: 0.1em;
  line-height: 1.15;
}

.brand__sub {
  display: block;
  margin-top: 2px;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.18em;
  color: var(--color-contrast-accent);
}

.nav-toggle {
  display: none;
  align-items: center;
  gap: var(--space-1);
  margin-block: var(--space-2);
  padding: var(--space-2) var(--space-3);
  background-color: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  border: var(--border-thin) solid var(--color-contrast-line);
  border-radius: var(--radius-sm);
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-sm);
  letter-spacing: 0.16em;
  line-height: 1.4;
  cursor: pointer;
  transition: background-color 120ms linear, color 120ms linear, border-color 120ms linear;
}

.nav-toggle:hover { background-color: var(--color-contrast-line); }

.nav-toggle__bars {
  display: grid;
  gap: 3px;
  width: 18px;
}

.nav-toggle__bars span {
  display: block;
  height: 3px;
  background-color: currentColor;
}

.nav-toggle[aria-expanded="true"] {
  background-color: var(--color-primary);
  color: var(--color-primary-ink);
  border-color: var(--color-primary);
}

.site-nav {
  display: none;
  align-items: stretch;
  margin-left: auto;
}

.site-nav[data-open="true"] { display: flex; }

.site-nav__list {
  display: flex;
  align-items: stretch;
  margin: 0;
  padding: 0;
}

.site-nav__item { display: flex; }

.site-nav__link {
  display: flex;
  align-items: center;
  padding-inline: var(--space-3);
  border-left: var(--border-thin) solid var(--color-contrast-line);
  color: var(--color-contrast-ink);
  font-size: var(--text-sm);
  letter-spacing: 0.1em;
  line-height: 1.4;
  text-decoration: none;
  transition: background-color 120ms linear, color 120ms linear;
}

.site-nav__link:hover {
  background-color: var(--color-contrast-line);
  color: var(--color-contrast-ink);
}

.site-nav__link[aria-current="page"] {
  background-color: var(--color-primary);
  color: var(--color-primary-ink);
  border-left-color: var(--color-primary);
}

.site-nav__cta {
  display: flex;
  align-items: center;
  padding-inline: var(--space-4);
  background-color: var(--color-accent);
  color: var(--color-accent-ink);
  border-left: var(--border-thick) solid var(--color-contrast-surface);
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-sm);
  letter-spacing: 0.12em;
  line-height: 1.4;
  text-decoration: none;
  white-space: nowrap;
  transition: background-color 120ms linear;
}

.site-nav__cta:hover {
  background-color: var(--color-focus);
  color: var(--color-accent-ink);
}

/* ==========================================================================
   11. 页脚：深色同色延续
   ========================================================================== */

.site-footer {
  width: 100%;
  background-color: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  border-top: var(--border-thick) solid var(--color-ink);
  padding-block: var(--space-8) var(--space-4);
}

.site-footer__inner {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.site-footer__top {
  display: grid;
  grid-template-columns: minmax(240px, 1fr) minmax(0, 2fr);
  gap: var(--space-6);
  padding-bottom: var(--space-6);
  border-bottom: var(--border-thin) solid var(--color-contrast-line);
}

.site-footer__lead { display: block; }

.footer-brand {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  text-decoration: none;
  color: var(--color-contrast-ink);
}

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

.footer-brand__mark {
  display: grid;
  place-items: center;
  width: 42px;
  height: 42px;
  background-color: var(--color-primary);
  color: var(--color-primary-ink);
  border: var(--border-thin) solid var(--color-contrast-ink);
  border-radius: var(--radius-sm);
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-lg);
  line-height: 1;
}

.footer-brand__name {
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-lg);
  letter-spacing: 0.1em;
}

.footer-brand__line {
  margin: var(--space-3) 0 var(--space-2);
  font-size: var(--text-sm);
  line-height: 1.8;
  color: var(--color-contrast-ink);
  max-width: 40ch;
}

.footer-brand__note {
  margin: 0;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.2em;
  color: var(--color-contrast-accent);
}

.footer-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: var(--space-4);
}

.footer-col__title {
  margin: 0 0 var(--space-2);
  padding-bottom: var(--space-1);
  border-bottom: var(--border-thin) solid var(--color-contrast-line);
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-sm);
  letter-spacing: 0.26em;
  color: var(--color-contrast-ink);
}

.footer-col__list {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
  margin: 0;
  padding: 0;
}

.footer-link {
  display: inline-block;
  color: var(--color-contrast-ink);
  font-size: var(--text-sm);
  line-height: 1.7;
  text-decoration: none;
  border-bottom: var(--border-thin) solid transparent;
  transition: color 120ms linear, border-color 120ms linear;
}

.footer-link:hover {
  color: var(--color-contrast-accent);
  border-bottom-color: var(--color-contrast-accent);
}

.footer-link--strong {
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  letter-spacing: 0.12em;
  border-bottom-color: var(--color-contrast-accent);
}

.site-footer__meta {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2) var(--space-6);
  padding-block: var(--space-4);
  border-bottom: var(--border-thin) solid var(--color-contrast-line);
  font-size: var(--text-sm);
}

.footer-meta {
  display: inline-flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: var(--space-1);
  margin: 0;
}

.footer-meta__label {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.2em;
  color: color-mix(in srgb, var(--color-contrast-ink) 62%, var(--color-contrast-surface));
}

.footer-meta__value {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  color: var(--color-contrast-ink);
  word-break: break-all;
}

.site-footer__legal {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: var(--space-2) var(--space-6);
  padding-top: var(--space-4);
}

.footer-legal {
  margin: 0;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.14em;
  color: color-mix(in srgb, var(--color-contrast-ink) 58%, var(--color-contrast-surface));
}

/* ==========================================================================
   12. 显现动效
   ========================================================================== */

.js-ready .reveal {
  opacity: 0;
  transform: translateY(12px);
  transition: opacity 200ms linear, transform 200ms linear;
}

.js-ready .reveal.is-in {
  opacity: 1;
  transform: translateY(0);
}

/* ==========================================================================
   13. 响应式
   ========================================================================== */

@media (max-width: 1024px) {
  .grid { grid-template-columns: repeat(4, minmax(0, 1fr)); }
  .span-5,
  .span-6 { grid-column: span 4; }
  .site-footer__top { grid-template-columns: minmax(0, 1fr); gap: var(--space-4); }
}

@media (max-width: 900px) {
  .site-header__inner {
    flex-wrap: wrap;
    align-items: center;
    padding-block: var(--space-2);
    min-height: 0;
  }

  .site-header__brand { padding-block: 0; }

  .nav-toggle {
    display: inline-flex;
    margin-left: auto;
  }

  .site-nav {
    flex-basis: 100%;
    flex-direction: column;
    align-items: stretch;
    margin-left: 0;
    margin-top: var(--space-2);
    max-height: 72vh;
    overflow-y: auto;
    border-top: var(--border-thick) solid var(--color-contrast-line);
  }

  .site-nav[data-open="true"] { display: flex; }

  .site-nav__list {
    flex-direction: column;
    align-items: stretch;
  }

  .site-nav__item { width: 100%; }

  .site-nav__link {
    padding: var(--space-3);
    border-left: 0;
    border-bottom: var(--border-thin) solid var(--color-contrast-line);
  }

  .site-nav__link[aria-current="page"] { border-left: 0; }

  .site-nav__cta {
    justify-content: center;
    padding: var(--space-3);
    border-left: 0;
    border-top: var(--border-thick) solid var(--color-ink);
  }

  .footer-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .section { padding-block: var(--space-8); }
  .section--lg { padding-block: var(--section-y); }
}

@media (max-width: 720px) {
  .grid { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: var(--space-2); }
  .span-2,
  .span-3,
  .span-4,
  .span-5,
  .span-6 { grid-column: span 2; }

  .panel { padding: var(--space-3); box-shadow: var(--shadow-1); }
  .panel--flush { padding: 0; }

  .sec-head { margin-bottom: var(--space-4); }

  .strip__item { flex: 0 0 78%; }
  .strip__item--wide { flex-basis: 88%; }

  .site-footer__meta { flex-direction: column; gap: var(--space-2); }
  .site-footer__legal { flex-direction: column; }
}

@media (max-width: 480px) {
  .grid { grid-template-columns: minmax(0, 1fr); }
  .span-2,
  .span-3,
  .span-4,
  .span-5,
  .span-6 { grid-column: span 1; }

  .brand__sub { display: none; }
  .footer-grid { grid-template-columns: minmax(0, 1fr); }

  .btn { width: 100%; }
  .filter-bar { gap: var(--space-1); }
  .filter-btn { flex: 1 1 auto; justify-content: center; }
}

/* ==========================================================================
   14. 无障碍与动效偏好
   ========================================================================== */

@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;
    scroll-behavior: auto !important;
  }

  .js-ready .reveal {
    opacity: 1;
    transform: none;
  }

  a.panel:hover,
  button.panel:hover,
  .panel--hover:hover,
  .btn:hover {
    transform: none;
  }
}

@media print {
  .site-header,
  .site-footer,
  .skip-link,
  .strip__controls { display: none; }
  .panel { box-shadow: none; }
}