/* ==========================================================================
   壹号官网 · 共享样式表 /assets/site.css
   覆盖：设计变量 / 重置 / 中文排版 / 头部 / 页脚 / 通用组件 / 响应式
   ========================================================================== */

/* --- 1. 设计变量（定稿，逐字保留） --- */
:root {
  --color-surface: #fbfbfb;
  --color-surface-alt: #f2f2f2;
  --color-surface-deep: #e5e6e5;
  --color-ink: #434c43;
  --color-ink-soft: #667066;
  --color-ink-muted: #7a857b;
  --color-line: #dadcda;
  --color-primary: #1a891f;
  --color-primary-ink: #ffffff;
  --color-primary-soft: #dcebdc;
  --color-accent: #1622e9;
  --color-accent-ink: #ffffff;
  --color-highlight: #d2d4f8;
  --color-focus: #0917f6;
  --color-contrast-surface: #142515;
  --color-contrast-ink: #e4e7e4;
  --color-contrast-line: #425043;
  --color-contrast-accent: #787ff2;
  --overlay-scrim: linear-gradient(180deg, rgba(20, 37, 21, 0.35) 0%, rgba(20, 37, 21, 0.72) 55%, rgba(20, 37, 21, 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: 12.2px;
  --text-sm: 15.2px;
  --text-base: 17px;
  --text-lg: 21.2px;
  --text-xl: 26.6px;
  --text-2xl: 33.2px;
  --text-3xl: 41.5px;
  --text-4xl: 51.9px;
  --text-display: clamp(52px, 10.6vw, 136px);
  --text-figure: clamp(43px, 7.7vw, 98px);
  --weight-heading: 866;
  --weight-body: 400;
  --leading-body: 1.69;
  --leading-heading: 1.21;
  --tracking-heading: -0.001em;
  --radius-sm: 9px;
  --radius-md: 10px;
  --radius-lg: 10px;
  --radius-pill: 999px;
  --border-thin: 2px;
  --border-thick: 2px;
  --shadow-1: 0 1px 0 rgba(67, 76, 67, 0.12);
  --shadow-2: 0 2px 0 rgba(67, 76, 67, 0.18);
  --space-1: 8px;
  --space-2: 16px;
  --space-3: 24px;
  --space-4: 32px;
  --space-6: 48px;
  --space-8: 64px;
  --container: 1260px;
  --measure: 73ch;
  --gutter: 24px;
  --section-y: 88px;
  --section-y-lg: 123px;
}

/* --- 2. 重置 --- */
*,
*::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;
  text-rendering: optimizeLegibility;
}

h1, h2, h3, h4, h5, h6, p, figure, blockquote, dl, dd, pre { margin: 0; }
ul, ol { margin: 0; padding: 0; }
img, svg, video, canvas { display: block; max-width: 100%; }
button, input, select, textarea { font: inherit; color: inherit; }
button { background: none; border: 0; }
hr { border: 0; border-top: var(--border-thin) solid var(--color-line); margin: var(--space-4) 0; }
summary { display: list-item; }

a {
  color: var(--color-accent);
  text-decoration-thickness: 2px;
  text-underline-offset: 3px;
}
a:hover { color: color-mix(in srgb, var(--color-accent) 76%, var(--color-ink)); }

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

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

/* --- 3. 中文排版 --- */
h1, h2, h3, h4 {
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  color: inherit;
  text-wrap: balance;
}
h5, h6 {
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  line-height: 1.3;
  color: inherit;
}
p { text-wrap: pretty; }
strong, b { font-weight: var(--weight-heading); }

.title-display {
  font-size: var(--text-display);
  line-height: 0.92;
  letter-spacing: -0.022em;
  margin: 0;
}
.title-page { font-size: var(--text-4xl); margin: 0; }
.title-section { font-size: var(--text-3xl); margin: 0; }
.title-block { font-size: var(--text-xl); margin: 0; }
.title-sub { font-size: var(--text-lg); margin: 0; }

.figure-num {
  display: block;
  font-family: var(--font-mono);
  font-weight: var(--weight-heading);
  font-size: var(--text-figure);
  line-height: 0.88;
  letter-spacing: -0.03em;
  font-variant-numeric: tabular-nums;
}

.mono,
code,
kbd {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  letter-spacing: -0.01em;
}

.small { font-size: var(--text-sm); }
.tiny { font-size: var(--text-xs); }

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.14em;
  color: var(--color-ink-muted);
}
.eyebrow::before {
  content: "";
  flex: 0 0 auto;
  width: 18px;
  height: 3px;
  border-radius: 2px;
  background-color: var(--color-primary);
}

.lede {
  max-width: var(--measure);
  font-size: var(--text-lg);
  line-height: 1.55;
  color: var(--color-ink-soft);
}

.prose { max-width: var(--measure); }
.prose > * + * { margin-top: var(--space-2); }
.prose h2, .prose h3 { margin-top: var(--space-4); }

.mark {
  background-color: var(--color-highlight);
  color: var(--color-accent);
  padding: 0 5px;
  border-radius: 4px;
}

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

.section { padding-block: var(--section-y); }
.section--lg { padding-block: var(--section-y-lg); }
.section--tight { padding-block: var(--space-6); }

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

.section--deep h1,
.section--deep h2,
.section--deep h3,
.section--deep h4,
.section--deep h5,
.section--deep h6 { color: var(--color-contrast-ink); }

.section--deep a { color: var(--color-contrast-accent); }
.section--deep a:hover { color: var(--color-contrast-ink); }
.section--deep .lede,
.section--deep .prose { color: color-mix(in srgb, var(--color-contrast-ink) 82%, var(--color-contrast-surface)); }
.section--deep .eyebrow { color: color-mix(in srgb, var(--color-contrast-ink) 66%, var(--color-contrast-surface)); }
.section--deep .eyebrow::before { background-color: var(--color-contrast-accent); }
.section--deep .field-key,
.section--deep .frame__caption { color: color-mix(in srgb, var(--color-contrast-ink) 58%, var(--color-contrast-surface)); }
.section--deep .field-row { border-top-color: var(--color-contrast-line); }
.section--deep hr { border-top-color: var(--color-contrast-line); }
.section--deep :focus-visible { outline-color: var(--color-contrast-accent); }

.grid-9 {
  display: grid;
  grid-template-columns: repeat(9, 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-9 { grid-column: span 9; }

.stack > * + * { margin-top: var(--space-3); }
.stack--tight > * + * { margin-top: var(--space-1); }
.stack--loose > * + * { margin-top: var(--space-4); }

.cluster {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-2);
}
.cluster--tight { gap: var(--space-1); }

/* --- 5. 通用组件 --- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 11px 20px;
  border: var(--border-thick) solid var(--color-ink);
  border-radius: var(--radius-md);
  background-color: var(--color-surface);
  color: var(--color-ink);
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-sm);
  line-height: 1.2;
  text-decoration: none;
  box-shadow: 4px 4px 0 var(--color-ink);
  transition: transform 0.15s ease, box-shadow 0.15s ease, background-color 0.15s ease, color 0.15s ease;
}
.btn:hover {
  transform: translate(-2px, -2px);
  box-shadow: 6px 6px 0 var(--color-ink);
  color: var(--color-ink);
}
.btn:active {
  transform: translate(2px, 2px);
  box-shadow: 1px 1px 0 var(--color-ink);
}
.btn--primary {
  background-color: var(--color-primary);
  border-color: var(--color-primary);
  color: var(--color-primary-ink);
}
.btn--primary:hover { color: var(--color-primary-ink); }
.btn--accent {
  background-color: var(--color-accent);
  border-color: var(--color-accent);
  color: var(--color-accent-ink);
}
.btn--accent:hover { color: var(--color-accent-ink); }

.chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px;
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-pill);
  background-color: var(--color-surface);
  color: var(--color-ink-soft);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  line-height: 1.5;
  white-space: nowrap;
}
.chip--primary {
  background-color: var(--color-primary);
  border-color: var(--color-primary);
  color: var(--color-primary-ink);
}
.chip--accent {
  background-color: var(--color-accent);
  border-color: var(--color-accent);
  color: var(--color-accent-ink);
}
.chip--invert {
  background-color: var(--color-highlight);
  border-color: var(--color-accent);
  color: var(--color-accent);
}
.chip--soft {
  background-color: var(--color-primary-soft);
  border-color: var(--color-primary);
  color: var(--color-primary);
}
.chip--deep {
  background-color: var(--color-contrast-surface);
  border-color: var(--color-contrast-line);
  color: var(--color-contrast-ink);
}
.section--deep .chip {
  background-color: transparent;
  border-color: var(--color-contrast-line);
  color: var(--color-contrast-ink);
}
.section--deep .chip--accent {
  background-color: var(--color-contrast-accent);
  border-color: var(--color-contrast-accent);
  color: var(--color-contrast-surface);
}

.index-card {
  position: relative;
  display: block;
  padding: var(--space-3);
  background-color: var(--color-surface);
  border: var(--border-thick) solid var(--color-line);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-2);
  transition: transform 0.15s ease, box-shadow 0.15s ease, border-color 0.15s ease;
}
.index-card:hover,
.index-card:focus-within {
  transform: translate(-3px, -3px);
  border-color: var(--color-accent);
  box-shadow: 5px 5px 0 var(--color-line), 9px 9px 0 var(--color-primary-soft);
}
.index-card__no {
  display: block;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-ink-muted);
  letter-spacing: 0.02em;
}
.index-card__title {
  margin-top: var(--space-1);
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-lg);
  line-height: 1.25;
}
.index-card__title a { color: inherit; text-decoration: none; }
.index-card__title a:hover { color: var(--color-accent); text-decoration: underline; }
.index-card__note {
  margin-top: var(--space-1);
  font-size: var(--text-sm);
  color: var(--color-ink-soft);
}
.section--deep .index-card {
  background-color: color-mix(in srgb, var(--color-contrast-surface) 88%, var(--color-contrast-ink));
  border-color: var(--color-contrast-line);
  color: var(--color-contrast-ink);
}
.section--deep .index-card:hover {
  border-color: var(--color-contrast-accent);
  box-shadow: 5px 5px 0 var(--color-contrast-line), 9px 9px 0 color-mix(in srgb, var(--color-contrast-accent) 42%, var(--color-contrast-surface));
}
.section--deep .index-card__no,
.section--deep .index-card__note { color: color-mix(in srgb, var(--color-contrast-ink) 66%, var(--color-contrast-surface)); }

.breadcrumb { margin-bottom: var(--space-3); }
.breadcrumb__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  list-style: none;
  padding: 0;
  margin: 0;
  font-size: var(--text-xs);
}
.breadcrumb__list li {
  display: inline-flex;
  align-items: center;
  font-family: var(--font-mono);
  color: var(--color-ink-muted);
}
.breadcrumb__list li + li::before {
  content: "/";
  margin: 0 var(--space-1);
  color: var(--color-line);
}
.breadcrumb__list a {
  color: var(--color-accent);
  text-decoration: none;
  border-bottom: var(--border-thin) solid var(--color-highlight);
}
.breadcrumb__list a:hover { background-color: var(--color-highlight); }
.breadcrumb__list [aria-current="page"] { color: var(--color-ink-soft); }

.field-row {
  display: flex;
  flex-wrap: wrap;
  gap: 4px var(--space-2);
  padding: 10px 0;
  border-top: var(--border-thin) solid var(--color-line);
  align-items: baseline;
}
.field-key {
  flex: 0 0 auto;
  min-width: 92px;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-ink-muted);
  letter-spacing: 0.02em;
}
.field-val {
  flex: 1 1 240px;
  font-size: var(--text-sm);
  color: var(--color-ink);
}
.section--deep .field-val { color: var(--color-contrast-ink); }

.table-scroll {
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-sm);
  background-color: var(--color-surface);
}
.data-table {
  width: 100%;
  min-width: 560px;
  border-collapse: collapse;
  font-size: var(--text-sm);
}
.data-table th {
  padding: 11px 14px;
  text-align: left;
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-sm);
  background-color: var(--color-surface-deep);
  color: var(--color-ink);
  border-bottom: var(--border-thin) solid var(--color-ink);
  white-space: nowrap;
}
.data-table td {
  padding: 11px 14px;
  border-bottom: var(--border-thin) solid var(--color-line);
  vertical-align: top;
}
.data-table tbody tr:last-child td { border-bottom: 0; }
.data-table tbody tr:hover td { background-color: var(--color-surface-alt); }
.section--deep .table-scroll {
  background-color: color-mix(in srgb, var(--color-contrast-surface) 90%, var(--color-contrast-ink));
  border-color: var(--color-contrast-line);
}
.section--deep .data-table th {
  background-color: color-mix(in srgb, var(--color-contrast-surface) 78%, var(--color-contrast-ink));
  color: var(--color-contrast-ink);
  border-bottom-color: var(--color-contrast-line);
}
.section--deep .data-table td { border-bottom-color: var(--color-contrast-line); color: var(--color-contrast-ink); }
.section--deep .data-table tbody tr:hover td { background-color: color-mix(in srgb, var(--color-contrast-surface) 82%, var(--color-contrast-accent)); }

.fold {
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-sm);
  background-color: var(--color-surface);
  overflow: hidden;
}
.fold + .fold { margin-top: var(--space-1); }
.fold > summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-2);
  padding: 12px var(--space-3);
  cursor: pointer;
  list-style: none;
  background-color: var(--color-surface-deep);
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-sm);
  color: var(--color-ink);
}
.fold > summary::-webkit-details-marker { display: none; }
.fold > summary::after {
  content: "+";
  font-family: var(--font-mono);
  font-size: var(--text-lg);
  line-height: 1;
  color: var(--color-accent);
}
.fold[open] > summary::after { content: "–"; }
.fold[open] > summary { border-bottom: var(--border-thin) solid var(--color-line); }
.fold__body { padding: var(--space-3); }
.fold > summary:hover { background-color: var(--color-primary-soft); }

.timeline {
  display: flex;
  gap: var(--space-1);
  overflow-x: auto;
  padding-bottom: var(--space-1);
  scrollbar-width: thin;
}
.timeline__node {
  flex: 0 0 auto;
  padding: 9px 13px;
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-sm);
  background-color: var(--color-surface);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-ink-soft);
  text-decoration: none;
  transition: background-color 0.15s ease, color 0.15s ease, border-color 0.15s ease, transform 0.15s ease;
}
.timeline__node:hover {
  transform: translateY(-2px);
  border-color: var(--color-accent);
  color: var(--color-accent);
}
.timeline__node[aria-current="true"] {
  background-color: var(--color-primary);
  border-color: var(--color-primary);
  color: var(--color-primary-ink);
}

.frame {
  position: relative;
  padding: 10px;
  background-color: var(--color-surface-deep);
  border: var(--border-thick) solid var(--color-ink);
  border-radius: var(--radius-sm);
  box-shadow: 5px 5px 0 var(--color-primary-soft);
}
.frame__media {
  position: relative;
  display: block;
  overflow: hidden;
  aspect-ratio: 16 / 9;
  border-radius: calc(var(--radius-sm) - 4px);
  background-color: color-mix(in srgb, var(--color-surface-deep) 62%, var(--color-surface));
}
.frame__media > img,
.frame__media > svg,
.frame__media > picture > img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.frame__overlay {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  gap: 6px;
  padding: var(--space-2);
  background: var(--overlay-scrim);
  color: var(--color-contrast-ink);
  font-size: var(--text-sm);
}
.frame__overlay .mono { font-size: var(--text-xs); color: var(--color-contrast-ink); }
.frame__caption {
  margin-top: var(--space-1);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-ink-muted);
}
.frame--wide .frame__media { aspect-ratio: 21 / 9; }
.frame--tall .frame__media { aspect-ratio: 4 / 3; }
.section--deep .frame {
  background-color: color-mix(in srgb, var(--color-contrast-surface) 86%, var(--color-contrast-ink));
  border-color: var(--color-contrast-line);
  box-shadow: 5px 5px 0 color-mix(in srgb, var(--color-contrast-accent) 40%, var(--color-contrast-surface));
}

.deco-host { position: relative; }
.deco { position: absolute; z-index: 0; pointer-events: none; }
.deco-dot {
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background-color: var(--color-accent);
}
.deco-bar {
  width: 46px;
  height: 10px;
  border-radius: var(--radius-pill);
  background-color: var(--color-primary);
  transform: rotate(-12deg);
}
.deco-notch {
  width: 26px;
  height: 26px;
  background-color: var(--color-highlight);
  border: var(--border-thin) solid var(--color-accent);
  border-radius: 4px;
  transform: rotate(14deg);
}
.deco-square {
  width: 14px;
  height: 14px;
  background-color: var(--color-primary-soft);
  border: var(--border-thin) solid var(--color-primary);
}
.section--deep .deco-dot { background-color: var(--color-contrast-accent); }
.section--deep .deco-bar { background-color: var(--color-contrast-accent); }
.section--deep .deco-notch { background-color: transparent; border-color: var(--color-contrast-line); }

/* --- 6. 头部 --- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 60;
  background-color: var(--color-surface);
  border-bottom: var(--border-thick) solid var(--color-contrast-surface);
}

.scroll-progress {
  position: absolute;
  left: 0;
  bottom: 0;
  height: 3px;
  width: 0;
  background-color: var(--color-accent);
  pointer-events: none;
  z-index: 4;
  transition: width 0.1s linear;
}

.skip-link {
  position: fixed;
  top: -140px;
  left: var(--gutter);
  z-index: 200;
  padding: 11px 18px;
  background-color: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-sm);
  text-decoration: none;
  border-radius: 0 0 var(--radius-sm) var(--radius-sm);
  transition: top 0.18s ease;
}
.skip-link:focus { top: 0; color: var(--color-contrast-ink); }

.header-bar {
  position: relative;
  background-color: var(--color-surface);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-3);
  min-height: 78px;
  padding-block: var(--space-2);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  color: var(--color-ink);
  text-decoration: none;
}
.brand:hover { color: var(--color-ink); }
.brand-mark {
  display: grid;
  place-items: center;
  width: 46px;
  height: 46px;
  flex: 0 0 auto;
  background-color: var(--color-primary);
  color: var(--color-primary-ink);
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-lg);
  line-height: 1;
  border-radius: var(--radius-sm);
  box-shadow: 4px 4px 0 var(--color-accent);
}
.brand-text { display: flex; flex-direction: column; gap: 1px; }
.brand-name {
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-lg);
  line-height: 1.1;
  letter-spacing: var(--tracking-heading);
}
.brand-domain {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-ink-muted);
  letter-spacing: 0.02em;
}

.nav-toggle {
  display: none;
  align-items: center;
  gap: 9px;
  padding: 9px 14px;
  border: var(--border-thin) solid var(--color-ink);
  border-radius: var(--radius-sm);
  background-color: var(--color-surface-deep);
  color: var(--color-ink);
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-sm);
  line-height: 1.2;
  cursor: pointer;
  box-shadow: var(--shadow-2);
}
.nav-toggle[aria-expanded="true"] {
  background-color: var(--color-accent);
  border-color: var(--color-accent);
  color: var(--color-accent-ink);
  box-shadow: 4px 4px 0 var(--color-highlight);
}
.nav-toggle-icon {
  display: inline-flex;
  flex-direction: column;
  gap: 3px;
  width: 18px;
}
.nav-toggle-icon i {
  display: block;
  height: 2px;
  background-color: currentColor;
  border-radius: 2px;
}
.nav-toggle-icon i:nth-child(2) { width: 74%; }
.nav-toggle-icon i:nth-child(3) { width: 48%; }

.site-nav { display: block; }
.nav-list {
  display: flex;
  align-items: center;
  gap: 4px;
  list-style: none;
}
.nav-link {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 9px 12px;
  border: var(--border-thin) solid transparent;
  border-radius: var(--radius-sm);
  color: var(--color-ink-soft);
  font-family: var(--font-heading);
  font-weight: 600;
  font-size: var(--text-sm);
  line-height: 1.2;
  text-decoration: none;
  transition: transform 0.15s ease, box-shadow 0.15s ease, background-color 0.15s ease, border-color 0.15s ease, color 0.15s ease;
}
.nav-index {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-ink-muted);
  letter-spacing: 0.02em;
}
.nav-link:hover {
  color: var(--color-ink);
  background-color: var(--color-surface-alt);
  border-color: var(--color-line);
  transform: translateY(-2px);
  box-shadow: var(--shadow-2);
}
.nav-link[aria-current="page"] {
  background-color: var(--color-accent);
  border-color: var(--color-accent);
  color: var(--color-accent-ink);
  box-shadow: 4px 4px 0 var(--color-highlight), inset 0 -3px 0 var(--color-primary);
}
.nav-link[aria-current="page"]:hover { color: var(--color-accent-ink); }
.nav-link[aria-current="page"] .nav-index { color: var(--color-highlight); }

.status-bar {
  background-color: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  border-top: var(--border-thin) solid var(--color-contrast-line);
}
.status-inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 4px var(--space-3);
  min-height: 42px;
  padding-block: 9px;
  font-size: var(--text-xs);
}
.status-item {
  display: inline-flex;
  align-items: baseline;
  gap: 7px;
}
.status-key {
  color: color-mix(in srgb, var(--color-contrast-ink) 56%, var(--color-contrast-surface));
  letter-spacing: 0.06em;
}
.status-val {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-weight: 700;
  color: var(--color-contrast-ink);
  letter-spacing: -0.01em;
}
.status-dot {
  align-self: center;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background-color: var(--color-contrast-accent);
}

/* --- 7. 页脚 --- */
.site-footer {
  background-color: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  border-top: var(--border-thick) solid var(--color-contrast-line);
}
.footer-inner {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
  padding-block: var(--space-3);
}
.footer-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px var(--space-3);
}
.footer-mark {
  flex: 0 0 auto;
  width: 12px;
  height: 12px;
  background-color: var(--color-primary);
  border-radius: 3px;
  transform: rotate(12deg);
}
.footer-brand {
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-sm);
  color: var(--color-contrast-ink);
}
.footer-links {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 4px 18px;
}
.footer-links a {
  color: color-mix(in srgb, var(--color-contrast-ink) 78%, var(--color-contrast-surface));
  font-size: var(--text-sm);
  text-decoration: none;
  padding-bottom: 2px;
  border-bottom: var(--border-thin) solid transparent;
}
.footer-links a:hover {
  color: var(--color-contrast-ink);
  border-bottom-color: var(--color-contrast-accent);
}
.footer-shape {
  flex: 0 0 auto;
  width: 22px;
  height: 8px;
  border-radius: var(--radius-pill);
  background-color: var(--color-contrast-accent);
  transform: rotate(-10deg);
}
.footer-icp {
  font-size: var(--text-xs);
  color: color-mix(in srgb, var(--color-contrast-ink) 62%, var(--color-contrast-surface));
  margin-left: auto;
}
.footer-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px;
  font-size: var(--text-xs);
  color: color-mix(in srgb, var(--color-contrast-ink) 58%, var(--color-contrast-surface));
}
.footer-sep { color: var(--color-contrast-line); }
.site-footer :focus-visible { outline-color: var(--color-contrast-accent); }

/* --- 8. 无障碍与通用工具类 --- */
.visually-hidden {
  position: absolute !important;
  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;
}

.text-soft { color: var(--color-ink-soft); }
.text-muted { color: var(--color-ink-muted); }
.text-accent { color: var(--color-accent); }

/* --- 9. 渐显（仅在脚本可用时生效） --- */
html.js [data-reveal] {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity 0.35s ease, transform 0.35s ease;
}
html.js [data-reveal].is-revealed {
  opacity: 1;
  transform: none;
}

/* --- 10. 响应式 --- */
@media (max-width: 1080px) {
  .header-inner { min-height: 70px; }
  .nav-link { font-size: var(--text-xs); padding: 8px 9px; }
  .brand-domain { display: none; }
}

@media (max-width: 1020px) {
  .nav-toggle { display: inline-flex; }
  .site-nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    display: none;
    max-height: 72vh;
    overflow-y: auto;
    padding: var(--space-2) var(--gutter) var(--space-3);
    background-color: var(--color-surface);
    border-bottom: var(--border-thick) solid var(--color-contrast-surface);
    box-shadow: 0 8px 0 rgba(67, 76, 67, 0.1);
  }
  .site-nav[data-open] { display: block; }
  .nav-list {
    flex-direction: column;
    align-items: stretch;
    gap: 2px;
  }
  .nav-link {
    justify-content: flex-start;
    font-size: var(--text-base);
    padding: 12px;
    border-color: var(--color-line);
    background-color: var(--color-surface);
  }
  .nav-link[aria-current="page"] {
    box-shadow: inset 0 -3px 0 var(--color-primary);
  }
  .grid-9 { grid-template-columns: repeat(6, minmax(0, 1fr)); }
  .col-3, .col-4, .col-5, .col-6, .col-9 { grid-column: span 6; }
}

@media (max-width: 760px) {
  :root {
    --section-y: 56px;
    --section-y-lg: 72px;
    --gutter: 18px;
  }
  .brand-mark { width: 40px; height: 40px; font-size: var(--text-base); }
  .brand-name { font-size: var(--text-base); }
  .status-inner { font-size: var(--text-xs); gap: 3px var(--space-2); }
  .footer-icp { margin-left: 0; }
  .footer-row { gap: 6px var(--space-2); }
  .fold__body { padding: var(--space-2); }
}

@media (max-width: 560px) {
  .grid-9 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .col-3, .col-4, .col-5, .col-6, .col-9 { grid-column: span 2; }
  .index-card { padding: var(--space-2); }
  .btn { width: 100%; justify-content: center; }
}

/* --- 11. 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;
  }
  html.js [data-reveal] {
    opacity: 1;
    transform: none;
  }
  .index-card:hover,
  .index-card:focus-within,
  .btn:hover,
  .btn:active,
  .nav-link:hover,
  .timeline__node:hover { transform: none; }
  .scroll-progress { transition: none; }
}