:root {
  --color-surface: #f4f4f3;
  --color-surface-alt: #ecebea;
  --color-surface-deep: #e0dfdd;
  --color-ink: #4b443f;
  --color-ink-soft: #736963;
  --color-ink-muted: #887e77;
  --color-line: #d6d4d3;
  --color-primary: #a86538;
  --color-primary-ink: #ffffff;
  --color-primary-soft: #e9e0d9;
  --color-accent: #177da0;
  --color-accent-ink: #ffffff;
  --color-highlight: #ccdfe4;
  --color-focus: #0d769b;
  --color-contrast-surface: #1f1814;
  --color-contrast-ink: #e7e5e4;
  --color-contrast-line: #4b4542;
  --color-contrast-accent: #20addf;
  --overlay-scrim: linear-gradient(180deg, rgba(31, 24, 20, 0.35) 0%, rgba(31, 24, 20, 0.72) 55%, rgba(31, 24, 20, 0.92) 100%);
  --font-heading: "Songti SC", "Source Han Serif SC", "Noto Serif SC", SimSun, serif;
  --font-body: "PingFang SC", "Microsoft YaHei", "Source Han Sans SC", sans-serif;
  --font-mono: ui-monospace, Menlo, Consolas, monospace;
  --text-xs: 11.0px;
  --text-sm: 14.7px;
  --text-base: 17px;
  --text-lg: 22.7px;
  --text-xl: 30.2px;
  --text-2xl: 40.3px;
  --text-3xl: 53.7px;
  --text-4xl: 71.5px;
  --text-display: clamp(39px, 8.0vw, 102px);
  --text-figure: clamp(32px, 5.7vw, 73px);
  --weight-heading: 653;
  --weight-body: 400;
  --leading-body: 1.76;
  --leading-heading: 1.19;
  --tracking-heading: 0.003em;
  --radius-sm: 0px;
  --radius-md: 0px;
  --radius-lg: 1px;
  --radius-pill: 1px;
  --border-thin: 1px;
  --border-thick: 1px;
  --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: 1140px;
  --measure: 61ch;
  --gutter: 24px;
  --section-y: 92px;
  --section-y-lg: 129px;
}

/* =========================================================
   九洲平台 · 共享样式 /assets/site.css
   编辑部衬线刊物 × 高原夜航档案室
   ========================================================= */

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

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

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

ul, ol { padding: 0; list-style: none; }
img, svg, video { display: block; max-width: 100%; }
button { font: inherit; color: inherit; background: none; border: 0; padding: 0; cursor: pointer; }
a { color: inherit; text-decoration: none; }
table { border-collapse: collapse; width: 100%; }
hr { border: 0; }

/* ---------- 2. 基础排版与纸面 ---------- */
body {
  font-family: var(--font-body);
  font-size: var(--text-base);
  font-weight: var(--weight-body);
  line-height: var(--leading-body);
  color: var(--color-ink);
  background-color: var(--color-surface);
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

/* 纸面纤维质感：极淡的经纬细纹，不参与交互 */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background-image:
    repeating-linear-gradient(0deg,
      color-mix(in srgb, var(--color-ink) 5%, transparent) 0 1px,
      transparent 1px 5px),
    repeating-linear-gradient(90deg,
      color-mix(in srgb, var(--color-ink) 3%, transparent) 0 1px,
      transparent 1px 9px);
  opacity: 0.55;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  color: var(--color-ink);
  text-wrap: balance;
}

h1 { font-size: var(--text-3xl); }
h2 { font-size: var(--text-2xl); }
h3 { font-size: var(--text-xl); }
h4 { font-size: var(--text-lg); }
h5, h6 { font-size: var(--text-base); }

strong, b { font-weight: var(--weight-heading); }
code, kbd, samp, pre { font-family: var(--font-mono); font-size: 0.92em; }

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

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

:where([id]) { scroll-margin-top: 168px; }

/* ---------- 3. 跳转链接 ---------- */
.skip-link {
  position: absolute;
  left: -9999px;
  top: auto;
  width: 1px;
  height: 1px;
  overflow: hidden;
  z-index: 200;
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  letter-spacing: 0.08em;
}

.skip-link:focus {
  position: fixed;
  left: 8px;
  top: 8px;
  width: auto;
  height: auto;
  overflow: visible;
  padding: 12px 18px;
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  border: 1px solid var(--color-contrast-accent);
}

/* ---------- 4. 布局容器与栅格 ---------- */
.container {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.grid {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: var(--gutter);
}

.col-3 { grid-column: span 3; }
.col-4 { grid-column: span 4; }
.col-5 { grid-column: span 5; }
.col-6 { grid-column: span 6; }
.col-7 { grid-column: span 7; }
.col-8 { grid-column: span 8; }
.col-9 { grid-column: span 9; }
.col-12 { grid-column: span 12; }

/* 非对称双栏：窄旁注栏 + 宽正文栏 */
.split {
  display: grid;
  grid-template-columns: minmax(0, 4fr) minmax(0, 8fr);
  gap: var(--space-6) var(--gutter);
  align-items: start;
}

.split__head { grid-column: 1 / -1; }
.split__aside { grid-column: 1 / 2; }
.split__main { grid-column: 2 / 3; min-width: 0; }

/* ---------- 5. 章节分区（靠底色交替，不用边框） ---------- */
.section { padding-block: var(--section-y); }
.section--lg { padding-block: var(--section-y-lg); }
.section--tight { padding-block: var(--space-6); }
.section--alt { background: var(--color-surface-alt); }
.section--deep {
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
}
.section--deep h1,
.section--deep h2,
.section--deep h3,
.section--deep h4 { color: var(--color-contrast-ink); }
.section--deep .prose,
.section--deep .prose p { color: var(--color-contrast-ink); }
.section--deep .note { color: var(--color-contrast-ink); border-top-color: var(--color-contrast-line); }
.section--deep .note__title { color: var(--color-contrast-accent); }
.section--deep a { color: var(--color-contrast-accent); }

.section__head { grid-column: 1 / -1; }
.section__head h2 { margin-top: var(--space-2); }

/* ---------- 6. 正文与刊物组件 ---------- */
.prose {
  max-width: var(--measure);
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: var(--color-ink);
}

.prose > * + * { margin-top: var(--space-2); }
.prose p { max-width: none; }
.prose h2 { margin-top: var(--space-6); }
.prose h3 { margin-top: var(--space-4); }
.prose ul, .prose ol { max-width: none; padding-left: var(--space-3); }
.prose ul li { list-style: none; position: relative; }
.prose ul li::before {
  content: "";
  position: absolute;
  left: calc(-1 * var(--space-3));
  top: 0.72em;
  width: 12px;
  height: 1px;
  background: var(--color-primary);
}
.prose ol { list-style: decimal; }
.prose li + li { margin-top: var(--space-1); }

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 0.6em;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--color-primary);
}

.label {
  display: inline-flex;
  align-items: center;
  gap: 0.6em;
  padding: 4px 9px;
  background: var(--color-surface-deep);
  color: var(--color-ink-soft);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  line-height: 1.45;
  letter-spacing: 0.16em;
  text-transform: uppercase;
}

.label--primary { background: var(--color-primary); color: var(--color-primary-ink); }
.label--accent { background: var(--color-accent); color: var(--color-accent-ink); }
.label--outline {
  background: transparent;
  border: var(--border-thin) solid var(--color-line);
  color: var(--color-ink-muted);
}

.tag {
  display: inline-block;
  padding: 3px 8px;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  line-height: 1.5;
  letter-spacing: 0.1em;
  background: var(--color-surface-deep);
  color: var(--color-ink-soft);
}

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

.note {
  border-top: 3px double var(--color-line);
  padding-top: var(--space-2);
  font-size: var(--text-sm);
  line-height: 1.72;
  color: var(--color-ink-soft);
}

.note__title {
  display: block;
  margin-bottom: 6px;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--color-primary);
}

.quote {
  border-left: 3px solid var(--color-primary);
  background: var(--color-primary-soft);
  padding: var(--space-3);
  font-family: var(--font-heading);
  font-size: var(--text-lg);
  line-height: 1.5;
  color: var(--color-ink);
}

.quote cite,
.quote__source {
  display: block;
  margin-top: var(--space-2);
  font-family: var(--font-mono);
  font-style: normal;
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  color: var(--color-ink-muted);
}

.timestamp {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  color: var(--color-ink-muted);
}

/* ---------- 7. 分隔语言 ---------- */
.rule { border: 0; border-top: var(--border-thin) solid var(--color-line); }
.rule--double { border-top: 3px double var(--color-line); }
.rule--primary { border-top: var(--border-thin) solid var(--color-primary); }

/* ---------- 8. 按钮与行动 ---- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.6em;
  padding: 11px 18px;
  font-family: var(--font-body);
  font-size: var(--text-sm);
  line-height: 1.2;
  letter-spacing: 0.04em;
  color: var(--color-ink);
  background: transparent;
  border: var(--border-thin) solid var(--color-ink);
  border-radius: var(--radius-sm);
  transition: background-color 0.18s ease-out, color 0.18s ease-out, border-color 0.18s ease-out;
}

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

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

.btn--primary:hover,
.btn--primary:focus-visible {
  background: var(--color-contrast-surface);
  border-color: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
}

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

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

/* ---------- 9. 面包屑 ---------- */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.5em;
  padding-block: var(--space-2);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  color: var(--color-ink-muted);
}

.breadcrumb a {
  color: var(--color-accent);
  border-bottom: 3px double transparent;
  transition: border-color 0.18s ease-out;
}

.breadcrumb a:hover { border-bottom-color: var(--color-accent); }
.breadcrumb__sep { color: var(--color-line); }

/* ---------- 10. 索引条目 ---------- */
.index-list { border-top: 3px double var(--color-line); }

.index-item {
  display: grid;
  grid-template-columns: 92px minmax(0, 1fr) auto;
  gap: var(--space-2);
  align-items: baseline;
  padding: var(--space-2) var(--space-1);
  border-bottom: var(--border-thin) solid var(--color-line);
  transition: background-color 0.18s ease-out;
}

.index-item:hover { background: var(--color-surface-alt); }

.index-item__num {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.06em;
  color: var(--color-primary);
}

.index-item__title {
  font-family: var(--font-heading);
  font-size: var(--text-lg);
  font-weight: var(--weight-heading);
  line-height: 1.35;
  color: var(--color-ink);
}

.index-item__desc {
  grid-column: 2 / 3;
  font-size: var(--text-sm);
  line-height: 1.7;
  color: var(--color-ink-soft);
}

.index-item__meta {
  grid-row: 1 / 2;
  grid-column: 3 / 4;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.06em;
  color: var(--color-ink-muted);
  white-space: nowrap;
}

/* ---------- 11. 数字带 ---------- */
.stat { display: block; }

.stat__value {
  font-family: var(--font-mono);
  font-size: var(--text-figure);
  font-weight: 600;
  line-height: 1;
  letter-spacing: -0.01em;
  color: var(--color-ink);
}

.stat__unit {
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  letter-spacing: 0.15em;
  margin-left: 0.15em;
  color: var(--color-ink-muted);
}

.stat__label {
  margin-top: var(--space-1);
  font-size: var(--text-xs);
  letter-spacing: 0.16em;
  color: var(--color-ink-muted);
}

.section--deep .stat__value { color: var(--color-contrast-ink); }
.section--deep .stat__unit { color: var(--color-contrast-accent); }
.section--deep .stat__label { color: color-mix(in srgb, var(--color-contrast-ink) 70%, transparent); }

/* ---------- 12. 图片容器与展签 ---------- */
.figure { margin: 0; }

.figure__frame {
  position: relative;
  overflow: hidden;
  background: var(--color-surface-deep);
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-sm);
  aspect-ratio: 4 / 3;
}

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

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

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

.figure__plate {
  position: absolute;
  left: 0;
  bottom: 0;
  z-index: 1;
  max-width: 100%;
  padding: 7px 11px;
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  line-height: 1.55;
  letter-spacing: 0.08em;
}

.figure__plate span { display: block; }
.figure__plate span + span { color: color-mix(in srgb, var(--color-contrast-ink) 72%, transparent); }

.figure__cap {
  margin-top: var(--space-1);
  font-size: var(--text-xs);
  line-height: 1.6;
  letter-spacing: 0.04em;
  color: var(--color-ink-muted);
}

/* ---------- 13. 站点页头 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 80;
  background: var(--color-surface);
  border-bottom: 3px double var(--color-line);
}

.header-top__inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-2) var(--space-3);
  padding-block: var(--space-2);
  transition: padding 0.2s ease-out;
}

.site-header[data-scrolled="true"] .header-top__inner { padding-block: var(--space-1); }

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

.brand__mark {
  display: inline-block;
  padding: 6px 8px;
  background: var(--color-primary);
  color: var(--color-primary-ink);
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-sm);
  line-height: 1;
  letter-spacing: 0.1em;
  border-radius: var(--radius-sm);
  transition: background-color 0.18s ease-out;
}

.brand:hover .brand__mark,
.brand:focus-visible .brand__mark { background: var(--color-accent); }

.brand__name {
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-lg);
  line-height: 1;
  letter-spacing: 0.02em;
  color: var(--color-ink);
}

.brand__line {
  padding-left: var(--space-3);
  border-left: var(--border-thin) solid var(--color-line);
  font-size: var(--text-xs);
  line-height: 1.6;
  letter-spacing: 0.14em;
  color: var(--color-ink-muted);
}

.header-utility {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.util-link,
.util-time {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  white-space: nowrap;
}

.util-link {
  color: var(--color-accent);
  padding-bottom: 1px;
  border-bottom: 3px double transparent;
  transition: border-color 0.18s ease-out, color 0.18s ease-out;
}

.util-link:hover,
.util-link:focus-visible { border-bottom-color: var(--color-accent); }

.util-time { color: var(--color-ink-muted); }
.util-time__k { margin-right: 0.45em; color: var(--color-primary); }

.cta {
  display: inline-flex;
  align-items: center;
  gap: 0.5em;
  padding: 9px 15px;
  font-size: var(--text-sm);
  line-height: 1.2;
  letter-spacing: 0.06em;
  color: var(--color-primary-ink);
  background: var(--color-primary);
  border: var(--border-thin) solid var(--color-primary);
  border-radius: var(--radius-sm);
  transition: background-color 0.18s ease-out, color 0.18s ease-out, border-color 0.18s ease-out;
}

.cta:hover,
.cta:focus-visible {
  background: var(--color-contrast-surface);
  border-color: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
}

/* 移动导航按钮 */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 9px;
  padding: 8px 12px;
  background: var(--color-surface-alt);
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-sm);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.14em;
  color: var(--color-ink);
  transition: background-color 0.18s ease-out, color 0.18s ease-out;
}

.nav-toggle:hover { background: var(--color-primary-soft); }

.nav-toggle__bars {
  position: relative;
  display: inline-block;
  width: 16px;
  height: 9px;
}

.nav-toggle__bars::before,
.nav-toggle__bars::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  height: 1px;
  background: currentColor;
  transition: transform 0.18s ease-out;
}

.nav-toggle__bars::before { top: 0; }
.nav-toggle__bars::after { bottom: 0; }

.site-header[data-open="true"] .nav-toggle {
  background: var(--color-primary);
  border-color: var(--color-primary);
  color: var(--color-primary-ink);
}

.site-header[data-open="true"] .nav-toggle__bars::before { transform: translateY(4px) rotate(45deg); }
.site-header[data-open="true"] .nav-toggle__bars::after { transform: translateY(-4px) rotate(-45deg); }

/* 主导航：印刷标签横排 */
.header-nav {
  background: var(--color-surface-alt);
  border-top: var(--border-thin) solid var(--color-line);
}

.nav__list {
  display: flex;
  flex-wrap: wrap;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.nav__link {
  position: relative;
  display: inline-flex;
  align-items: baseline;
  gap: 0.55em;
  padding: 12px 16px;
  font-size: var(--text-sm);
  letter-spacing: 0.04em;
  color: var(--color-ink);
  transition: background-color 0.18s ease-out, color 0.18s ease-out;
}

.nav__num {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.06em;
  color: var(--color-ink-muted);
  transition: color 0.18s ease-out;
}

.nav__link::after {
  content: "";
  position: absolute;
  left: 16px;
  right: 16px;
  bottom: 0;
  height: 0;
  border-bottom: 3px double transparent;
  transition: border-color 0.18s ease-out;
}

.nav__link:hover { background: var(--color-primary-soft); }
.nav__link:hover .nav__num { color: var(--color-primary); }
.nav__link:hover::after { border-bottom-color: var(--color-primary); }

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

.nav__link[aria-current="page"] .nav__num {
  color: var(--color-primary-ink);
  opacity: 0.72;
}

/* 阅读进度脊线 */
.progress {
  height: 3px;
  background: var(--color-surface-deep);
}

.progress__bar {
  display: block;
  width: 0;
  height: 100%;
  background: var(--color-primary);
  transition: width 0.12s linear;
}

/* ---------- 14. 站点页脚：三块并列面板 ---------- */
.site-footer {
  margin-top: var(--section-y);
  padding-block: var(--space-8) var(--space-4);
  background: var(--color-surface-alt);
  border-top: 3px double var(--color-line);
}

.footer-head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: var(--space-3) var(--space-4);
  padding-bottom: var(--space-3);
  border-bottom: var(--border-thin) solid var(--color-line);
}

.footer-brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
}

.footer-brand__name {
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-xl);
  line-height: 1;
  color: var(--color-ink);
}

.footer-note {
  max-width: 56ch;
  font-size: var(--text-sm);
  line-height: 1.72;
  color: var(--color-ink-soft);
}

.footer-panels {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  margin-top: var(--space-4);
  border: var(--border-thin) solid var(--color-line);
}

.panel {
  padding: var(--space-4) var(--space-3);
  background: var(--color-surface);
  border-right: 3px double var(--color-line);
}

.panel:last-child { border-right: 0; }

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

.panel--index { background: var(--color-surface-alt); }
.panel--note { background: var(--color-surface-deep); }

.panel__title {
  padding-bottom: 10px;
  margin-bottom: var(--space-2);
  border-bottom: var(--border-thin) solid var(--color-line);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: var(--weight-body);
  line-height: 1.5;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--color-primary);
}

.panel--contrast .panel__title {
  color: var(--color-contrast-accent);
  border-bottom-color: var(--color-contrast-line);
}

.panel--note .panel__title { color: var(--color-ink-muted); }

.panel__list { display: block; }

.panel__item {
  padding: 5px 0;
  font-size: var(--text-sm);
  line-height: 1.7;
  color: var(--color-ink-soft);
}

.panel--contrast .panel__item { color: var(--color-contrast-ink); }

.panel__link {
  color: var(--color-accent);
  border-bottom: 3px double transparent;
  transition: border-color 0.18s ease-out, color 0.18s ease-out;
}

.panel__link:hover,
.panel__link:focus-visible { border-bottom-color: var(--color-accent); }

.panel--contrast .panel__link { color: var(--color-contrast-accent); }
.panel--contrast .panel__link:hover,
.panel--contrast .panel__link:focus-visible { border-bottom-color: var(--color-contrast-accent); }

.footer-base {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-2);
  margin-top: var(--space-4);
  padding-top: var(--space-3);
  border-top: 3px double var(--color-line);
}

.legal-line,
.copyright {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  line-height: 1.7;
  letter-spacing: 0.06em;
  color: var(--color-ink-muted);
  max-width: none;
}

/* ---------- 15. 响应式 ---------- */
@media (max-width: 1024px) {
  .split { grid-template-columns: minmax(0, 5fr) minmax(0, 7fr); }
  .brand__line { display: none; }
}

@media (max-width: 900px) {
  .split {
    grid-template-columns: minmax(0, 1fr);
    gap: var(--space-6);
  }
  .split__aside { grid-column: 1 / -1; }
  .split__main { grid-column: 1 / -1; }
  .col-3, .col-4, .col-5, .col-6, .col-7 { grid-column: span 12; }
  .col-8, .col-9 { grid-column: span 12; }
}

@media (max-width: 860px) {
  :where([id]) { scroll-margin-top: 132px; }

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

  .header-utility {
    margin-left: auto;
    gap: var(--space-2);
  }

  .util-link { display: none; }

  .nav { display: none; }

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

  .nav__list {
    flex-direction: column;
    flex-wrap: nowrap;
    padding-block: var(--space-1);
  }

  .nav__item { border-bottom: var(--border-thin) solid var(--color-line); }
  .nav__item:last-child { border-bottom: 0; }

  .nav__link {
    width: 100%;
    padding: 13px 0;
    font-size: var(--text-base);
  }

  .nav__link::after { left: 0; right: 0; bottom: 0; }

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

  .panel {
    border-right: 0;
    border-bottom: 3px double var(--color-line);
  }

  .panel:last-child { border-bottom: 0; }

  .index-item {
    grid-template-columns: 72px minmax(0, 1fr);
  }

  .index-item__meta {
    grid-row: 2 / 3;
    grid-column: 2 / 3;
    padding-top: 4px;
  }
}

@media (max-width: 640px) {
  :root { --gutter: 18px; }

  .site-header[data-scrolled="true"] .header-top__inner { padding-block: var(--space-1); }

  .brand__name { font-size: var(--text-base); }
  .footer-brand__name { font-size: var(--text-lg); }

  .cta { padding: 8px 12px; font-size: var(--text-xs); letter-spacing: 0.08em; }

  .footer-base { flex-direction: column; align-items: flex-start; }

  .figure__plate { padding: 6px 9px; }
}

/* ---------- 16. 动效降级 ---------- */
@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;
  }
}