:root {
  --color-surface: #fafbfb;
  --color-surface-alt: #f1f2f2;
  --color-surface-deep: #e4e6e6;
  --color-ink: #404a49;
  --color-ink-soft: #647271;
  --color-ink-muted: #788786;
  --color-line: #d9dbdb;
  --color-primary: #36827c;
  --color-primary-ink: #ffffff;
  --color-primary-soft: #dfeae9;
  --color-accent: #1976d2;
  --color-accent-ink: #ffffff;
  --color-highlight: #d2e3f4;
  --color-focus: #0d71d4;
  --color-contrast-surface: #1d2a29;
  --color-contrast-ink: #e4e7e7;
  --color-contrast-line: #495453;
  --color-contrast-accent: #3b92e8;
  --overlay-scrim: linear-gradient(180deg, rgba(29, 42, 41, 0.35) 0%, rgba(29, 42, 41, 0.72) 55%, rgba(29, 42, 41, 0.92) 100%);
  --font-heading: "PingFang SC", "HarmonyOS Sans SC", "Microsoft YaHei", "Source Han Sans SC", sans-serif;
  --font-body: "PingFang SC", "HarmonyOS Sans SC", "Microsoft YaHei", "Source Han Sans SC", sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  --text-xs: 11.4px;
  --text-sm: 14.3px;
  --text-base: 16px;
  --text-lg: 20.0px;
  --text-xl: 25.0px;
  --text-2xl: 31.2px;
  --text-3xl: 39.1px;
  --text-4xl: 48.8px;
  --text-display: clamp(34px, 6.2vw, 79px);
  --text-figure: clamp(28px, 4.5vw, 57px);
  --weight-heading: 790;
  --weight-body: 400;
  --leading-body: 1.83;
  --leading-heading: 1.21;
  --tracking-heading: -0.009em;
  --radius-sm: 14px;
  --radius-md: 15px;
  --radius-lg: 16px;
  --radius-pill: 999px;
  --border-thin: 1px;
  --border-thick: 1px;
  --shadow-1: 0 6px 18px rgba(64, 74, 73, 0.08);
  --shadow-2: 0 18px 44px rgba(64, 74, 73, 0.14);
  --space-1: 8px;
  --space-2: 16px;
  --space-3: 24px;
  --space-4: 32px;
  --space-6: 48px;
  --space-8: 64px;
  --container: 1240px;
  --measure: 70ch;
  --gutter: 16px;
  --section-y: 103px;
  --section-y-lg: 144px;
}

/* ============ reset & base ============ */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body {
  margin: 0;
  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);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
h1, h2, h3, h4, h5 {
  margin: 0;
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  color: var(--color-ink);
}
p { margin: 0; }
ul, ol { margin: 0; padding: 0; list-style: none; }
a { color: var(--color-primary); text-decoration: none; }
a:hover { text-decoration: underline; text-decoration-style: dotted; text-underline-offset: 4px; }
img, svg, video { display: block; max-width: 100%; }
button { font: inherit; color: inherit; }
dl, dd, dt { margin: 0; }
hr { border: 0; }
::selection { background: var(--color-highlight); color: var(--color-ink); }
:focus-visible {
  outline: 2px solid var(--color-focus);
  outline-offset: 3px;
  border-radius: var(--radius-sm);
}
.skip-link {
  position: absolute;
  left: var(--space-2);
  top: -80px;
  z-index: 90;
  padding: 10px 16px;
  border-radius: var(--radius-sm);
  background: var(--color-primary);
  color: var(--color-primary-ink);
  font-size: var(--text-sm);
  box-shadow: var(--shadow-2);
  transition: top 200ms cubic-bezier(0.2, 0.7, 0.2, 1);
}
.skip-link:focus { top: var(--space-2); text-decoration: none; }

/* ============ layout ============ */
.container {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: var(--gutter);
}
.container--narrow { max-width: calc(var(--measure) + var(--space-8)); }
.section { padding-block: var(--section-y); }
.section--lg { padding-block: var(--section-y-lg); }
.section--tight { padding-block: var(--space-6); }
.section-head { display: grid; gap: var(--space-2); max-width: 62ch; margin-bottom: var(--space-6); }
.grid { display: grid; grid-template-columns: repeat(12, minmax(0, 1fr)); gap: var(--gutter); }
.span-3 { grid-column: span 3; }
.span-4 { grid-column: span 4; }
.span-5 { grid-column: span 5; }
.span-6 { grid-column: span 6; }
.span-7 { grid-column: span 7; }
.span-8 { grid-column: span 8; }
.span-9 { grid-column: span 9; }
.span-12 { grid-column: span 12; }
.band {
  background: var(--color-surface-alt);
  border-radius: var(--radius-lg);
  padding: var(--space-4);
}
.band--deep { background: var(--color-surface-deep); }
.band--gradient {
  position: relative;
  overflow: hidden;
  background: linear-gradient(135deg, var(--color-primary-soft) 0%, var(--color-highlight) 48%, var(--color-surface) 100%);
}
.band--gradient::after {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(78% 120% at 100% 0%, color-mix(in srgb, var(--color-primary) 18%, transparent) 0%, transparent 62%);
  pointer-events: none;
}
.band--contrast {
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  border-radius: var(--radius-lg);
  padding: var(--space-4);
}
.band--contrast h1, .band--contrast h2, .band--contrast h3 { color: var(--color-contrast-ink); }
.band--contrast a { color: var(--color-contrast-accent); }

/* ============ 文本层级 ============ */
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--color-accent);
}
.eyebrow::before { content: ""; width: 22px; border-top: var(--border-thin) dotted var(--color-accent); }
.section-title { font-size: var(--text-2xl); }
.section-lede { max-width: var(--measure); color: var(--color-ink-soft); }
.lede { font-size: var(--text-lg); line-height: 1.6; color: var(--color-ink-soft); }
.timestamp {
  font-family: var(--font-mono);
  font-size: calc(var(--text-base) * 0.8);
  color: var(--color-ink-muted);
  letter-spacing: 0.02em;
}
.stamp {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 40px;
  padding: 4px 8px;
  border: var(--border-thin) dashed var(--color-line);
  border-radius: var(--radius-sm);
  background: var(--color-surface-alt);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.12em;
  color: var(--color-ink-muted);
}
.tag {
  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: var(--color-surface-alt);
  color: var(--color-ink-soft);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  text-transform: uppercase;
}
.tag--soft {
  background: var(--color-primary-soft);
  border-color: color-mix(in srgb, var(--color-primary) 34%, transparent);
  color: var(--color-primary);
}
.tag--accent {
  background: var(--color-highlight);
  border-color: color-mix(in srgb, var(--color-accent) 42%, transparent);
  color: var(--color-accent);
}

/* ============ 分隔语言 ============ */
.divider {
  border: 0;
  border-top: var(--border-thin) dashed var(--color-line);
  margin-block: var(--space-4);
}
.divider--block {
  border-top-style: dotted;
  border-top-width: calc(var(--border-thick) * 2);
  border-top-color: var(--color-line);
}
.keyline {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--color-ink-muted);
}
.keyline::before, .keyline::after {
  content: "";
  flex: 1;
  border-top: var(--border-thin) dotted var(--color-line);
}

/* ============ 按钮与链接 ============ */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  padding: 10px 18px;
  border: var(--border-thin) solid transparent;
  border-radius: var(--radius-pill);
  font-size: var(--text-sm);
  font-weight: 600;
  letter-spacing: 0.02em;
  text-decoration: none;
  cursor: pointer;
  transition: transform 240ms cubic-bezier(0.2, 0.7, 0.2, 1), box-shadow 240ms cubic-bezier(0.2, 0.7, 0.2, 1), background-color 240ms cubic-bezier(0.2, 0.7, 0.2, 1), color 240ms cubic-bezier(0.2, 0.7, 0.2, 1);
}
.btn:hover { text-decoration: none; transform: translateY(-1px); }
.btn--primary {
  background: linear-gradient(135deg, var(--color-primary) 0%, color-mix(in srgb, var(--color-primary) 60%, var(--color-accent)) 100%);
  color: var(--color-primary-ink);
  box-shadow: var(--shadow-1);
}
.btn--primary:hover { box-shadow: var(--shadow-2); }
.btn--ghost {
  background: color-mix(in srgb, var(--color-primary-soft) 62%, transparent);
  border: var(--border-thin) dashed var(--color-primary);
  color: var(--color-primary);
}
.btn--ghost:hover { background: var(--color-primary-soft); }
.btn--quiet {
  background: transparent;
  border: var(--border-thin) solid var(--color-line);
  color: var(--color-ink-soft);
}
.btn--quiet:hover { border-color: var(--color-primary); color: var(--color-primary); }
.link-arrow {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--color-primary);
}
.link-arrow::after {
  content: "→";
  color: var(--color-accent);
  transition: transform 240ms cubic-bezier(0.2, 0.7, 0.2, 1);
}
.link-arrow:hover { text-decoration: none; }
.link-arrow:hover::after { transform: translateX(4px); }

/* ============ 面包屑 ============ */
.crumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.06em;
  color: var(--color-ink-muted);
}
.crumbs__item { display: inline-flex; align-items: center; gap: 10px; }
.crumbs__sep { color: var(--color-line); }
.crumbs__link { color: var(--color-ink-soft); }
.crumbs__link:hover { color: var(--color-primary); text-decoration: none; }
.crumbs__current { color: var(--color-ink); border-bottom: var(--border-thin) dotted var(--color-line); }

/* ============ 正文 ============ */
.prose { max-width: var(--measure); color: var(--color-ink); }
.prose > * + * { margin-top: var(--space-3); }
.prose h2 { font-size: var(--text-xl); }
.prose h3 { font-size: var(--text-lg); }
.prose ul, .prose ol { padding-left: 1.2em; list-style: disc; }
.prose ol { list-style: decimal; }
.prose li + li { margin-top: var(--space-1); }
.prose a { text-decoration: underline; text-decoration-style: dotted; text-underline-offset: 4px; }
.prose blockquote {
  margin: 0;
  padding: var(--space-2) var(--space-3);
  border-left: calc(var(--border-thick) * 2) dotted var(--color-primary);
  background: color-mix(in srgb, var(--color-highlight) 40%, transparent);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  color: var(--color-ink-soft);
}

/* ============ 旁注与说明块 ============ */
.note {
  max-width: var(--measure);
  padding: var(--space-2) var(--space-3);
  border-left: calc(var(--border-thick) * 2) dotted var(--color-primary);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  background: color-mix(in srgb, var(--color-highlight) 42%, transparent);
  font-size: var(--text-sm);
  color: var(--color-ink-soft);
}
.note--aside {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.04em;
  background: transparent;
  border-left-style: dashed;
  border-left-color: var(--color-line);
}
.callout {
  padding: var(--space-3);
  border: var(--border-thin) dashed color-mix(in srgb, var(--color-accent) 46%, transparent);
  border-radius: var(--radius-lg);
  background: color-mix(in srgb, var(--color-highlight) 72%, var(--color-surface));
}

/* ============ 图片容器 ============ */
.figure { margin: 0; display: grid; gap: var(--space-1); }
.figure__frame {
  position: relative;
  padding: 10px;
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-lg);
  background: var(--color-surface-deep);
  box-shadow: var(--shadow-1);
}
.figure__media {
  display: block;
  width: 100%;
  height: 100%;
  aspect-ratio: var(--figure-ratio, 4 / 3);
  object-fit: cover;
  border: var(--border-thin) solid color-mix(in srgb, var(--color-line) 72%, transparent);
  border-radius: calc(var(--radius-lg) - 6px);
  background: var(--color-surface-alt);
}
.figure__overlay {
  position: absolute;
  inset: 10px;
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  gap: var(--space-1);
  padding: var(--space-3);
  border-radius: calc(var(--radius-lg) - 6px);
  background: var(--overlay-scrim);
  color: var(--color-contrast-ink);
}
.figure__overlay h3, .figure__overlay p { color: var(--color-contrast-ink); }
.figure__caption {
  display: flex;
  align-items: baseline;
  gap: var(--space-1);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.03em;
  color: var(--color-ink-muted);
}
.figure__caption::before { content: "◻"; color: var(--color-line); }

/* ============ 条目流 ============ */
.entry-list { display: grid; gap: 0; }
.entry {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: var(--space-2);
  padding: var(--space-3) 0;
  border-top: var(--border-thin) dashed var(--color-line);
  align-items: start;
}
.entry:last-child { border-bottom: var(--border-thin) dashed var(--color-line); }
.entry__index {
  padding-top: 6px;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  color: var(--color-ink-muted);
}
.entry__body { display: grid; gap: 6px; }
.entry__title { font-size: var(--text-lg); }
.entry__title a { color: var(--color-ink); }
.entry__title a:hover { color: var(--color-primary); text-decoration: none; }
.entry__meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-sm);
  color: var(--color-ink-soft);
}

/* ============ 页头 ============ */
.site-header {
  position: sticky;
  top: 0;
  z-index: 60;
  background: linear-gradient(180deg, color-mix(in srgb, var(--color-surface) 96%, transparent) 0%, color-mix(in srgb, var(--color-surface) 82%, transparent) 100%);
  -webkit-backdrop-filter: blur(12px);
  backdrop-filter: blur(12px);
  border-bottom: var(--border-thin) dashed var(--color-line);
}
.site-header__inner {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding: var(--space-2) var(--gutter);
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.site-header__bar {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--space-2) var(--space-3);
}
.brand {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  color: var(--color-ink);
}
.brand:hover { text-decoration: none; }
.brand__mark {
  display: grid;
  place-items: center;
  width: 42px;
  height: 42px;
  flex: 0 0 auto;
  border-radius: var(--radius-sm);
  background: linear-gradient(135deg, var(--color-primary) 0%, color-mix(in srgb, var(--color-primary) 52%, var(--color-highlight)) 100%);
  color: var(--color-primary-ink);
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-lg);
  letter-spacing: 0.04em;
  box-shadow: var(--shadow-1);
}
.brand__text { display: grid; gap: 2px; }
.brand__name {
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-lg);
  line-height: 1.2;
  letter-spacing: var(--tracking-heading);
}
.brand__line {
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  color: var(--color-ink-muted);
}
.brand-version {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 5px 12px;
  border: var(--border-thin) dashed var(--color-line);
  border-radius: var(--radius-pill);
  background: color-mix(in srgb, var(--color-surface-alt) 76%, transparent);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.12em;
  color: var(--color-ink-soft);
  white-space: nowrap;
}
.brand-version__key { color: var(--color-accent); letter-spacing: 0.18em; }
.site-header__actions {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: var(--space-1);
}
.nav-toggle {
  display: none;
  align-items: center;
  gap: var(--space-1);
  padding: 9px 14px;
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-pill);
  background: color-mix(in srgb, var(--color-surface-alt) 80%, transparent);
  cursor: pointer;
  transition: border-color 240ms cubic-bezier(0.2, 0.7, 0.2, 1), background-color 240ms cubic-bezier(0.2, 0.7, 0.2, 1);
}
.nav-toggle:hover { border-color: var(--color-primary); }
.nav-toggle__bars {
  width: 16px;
  height: 12px;
  background:
    linear-gradient(var(--color-ink) 0 0) 0 0 / 100% 1.5px no-repeat,
    linear-gradient(var(--color-ink) 0 0) 0 50% / 100% 1.5px no-repeat,
    linear-gradient(var(--color-ink) 0 0) 0 100% / 100% 1.5px no-repeat;
}
.nav-toggle__label {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  color: var(--color-ink-soft);
}

/* ============ 快捷索引导航 ============ */
.site-nav {
  position: relative;
  border-top: var(--border-thin) dashed var(--color-line);
  padding-top: 6px;
}
.site-nav__list {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
}
.site-nav__item { display: flex; }
.site-nav__link {
  position: relative;
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  padding: 8px 14px;
  border: var(--border-thin) dashed transparent;
  border-radius: var(--radius-pill);
  font-size: var(--text-sm);
  color: var(--color-ink-soft);
  white-space: nowrap;
  transition: background-color 240ms cubic-bezier(0.2, 0.7, 0.2, 1), color 240ms cubic-bezier(0.2, 0.7, 0.2, 1), border-color 240ms cubic-bezier(0.2, 0.7, 0.2, 1);
}
.site-nav__link::before {
  content: attr(data-index);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.06em;
  color: var(--color-ink-muted);
}
.site-nav__link::after {
  content: attr(data-path);
  position: absolute;
  top: calc(100% + 8px);
  left: 0;
  z-index: 5;
  padding: 6px 10px;
  border-radius: var(--radius-sm);
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.02em;
  white-space: nowrap;
  opacity: 0;
  visibility: hidden;
  transform: translateY(-4px);
  transition: opacity 240ms cubic-bezier(0.2, 0.7, 0.2, 1), transform 240ms cubic-bezier(0.2, 0.7, 0.2, 1), visibility 240ms;
  pointer-events: none;
}
.site-nav__link:hover {
  background: var(--color-primary-soft);
  border-color: var(--color-primary);
  color: var(--color-ink);
  text-decoration: none;
}
.site-nav__link:hover::after,
.site-nav__link:focus-visible::after {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}
.site-nav__link[aria-current="page"] {
  background: var(--color-primary);
  border-color: var(--color-primary);
  color: var(--color-primary-ink);
  box-shadow: var(--shadow-1);
}
.site-nav__link[aria-current="page"]::before { color: var(--color-primary-ink); opacity: 0.72; }
.site-nav__link[aria-current="page"]:hover { background: var(--color-primary); color: var(--color-primary-ink); }

/* ============ 页脚 ============ */
.site-footer {
  position: relative;
  overflow: hidden;
  margin-top: var(--section-y);
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
}
.site-footer::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background:
    radial-gradient(120% 82% at 10% 0%, color-mix(in srgb, var(--color-primary) 42%, transparent) 0%, transparent 58%),
    radial-gradient(90% 70% at 92% 8%, color-mix(in srgb, var(--color-accent) 26%, transparent) 0%, transparent 62%);
}
.site-footer__inner {
  position: relative;
  z-index: 1;
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding: var(--space-8) var(--gutter) var(--space-6);
}
.site-footer__grid {
  display: grid;
  gap: var(--space-6);
  grid-template-columns: minmax(0, 1fr);
}
.site-footer__lead { display: grid; gap: var(--space-2); max-width: 44ch; align-content: start; }
.site-footer__kicker {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--color-contrast-accent);
}
.site-footer__title { font-size: var(--text-2xl); color: var(--color-contrast-ink); }
.site-footer__note {
  font-size: var(--text-sm);
  color: color-mix(in srgb, var(--color-contrast-ink) 74%, transparent);
}
.path-map { position: relative; display: grid; gap: 0; }
.path-map__node {
  position: relative;
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 6px var(--space-2);
  padding: var(--space-2) 0 var(--space-2) var(--space-3);
  border-left: var(--border-thin) dashed var(--color-contrast-line);
}
.path-map__node--child { padding-left: calc(var(--space-3) + var(--space-3)); }
.path-map__dot {
  position: absolute;
  left: -4.5px;
  top: calc(var(--space-2) + 7px);
  width: 9px;
  height: 9px;
  border-radius: var(--radius-pill);
  background: var(--color-contrast-accent);
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--color-contrast-accent) 24%, transparent);
}
.path-map__node--child .path-map__dot {
  width: 6px;
  height: 6px;
  left: -3px;
  background: var(--color-contrast-line);
  box-shadow: none;
}
.path-map__label {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--color-contrast-accent);
  min-width: 42px;
}
.path-map__node--child .path-map__label { color: color-mix(in srgb, var(--color-contrast-ink) 60%, transparent); }
.path-map__link {
  font-size: var(--text-base);
  font-weight: 600;
  color: var(--color-contrast-ink);
  border-bottom: var(--border-thin) dashed var(--color-contrast-line);
  padding-bottom: 1px;
}
.path-map__link:hover {
  color: var(--color-contrast-accent);
  border-bottom-color: var(--color-contrast-accent);
  text-decoration: none;
}
.path-map__aside {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.02em;
  color: color-mix(in srgb, var(--color-contrast-ink) 58%, transparent);
}
.site-footer__meta {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-4) var(--space-6);
  margin-top: var(--space-6);
  padding-top: var(--space-4);
  border-top: var(--border-thin) dashed var(--color-contrast-line);
}
.footer-contact { display: grid; gap: var(--space-2); flex: 1 1 340px; }
.footer-contact__title {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--color-contrast-accent);
}
.footer-contact__list { display: grid; gap: var(--space-1); }
.footer-contact__row {
  display: grid;
  grid-template-columns: 56px minmax(0, 1fr);
  gap: var(--space-2);
  align-items: baseline;
}
.footer-contact__key {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  color: color-mix(in srgb, var(--color-contrast-ink) 60%, transparent);
}
.footer-contact__value {
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  color: var(--color-contrast-ink);
  word-break: break-word;
}
.footer-contact__note {
  max-width: 46ch;
  font-size: var(--text-xs);
  line-height: 1.72;
  color: color-mix(in srgb, var(--color-contrast-ink) 66%, transparent);
}
.site-footer__legal { display: grid; gap: var(--space-2); align-content: start; flex: 0 1 220px; }
.legal-list { display: grid; gap: var(--space-1); }
.legal-link {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  font-size: var(--text-sm);
  color: var(--color-contrast-ink);
  border-bottom: var(--border-thin) dotted var(--color-contrast-line);
}
.legal-link::after { content: "→"; color: var(--color-contrast-accent); font-size: var(--text-xs); }
.legal-link:hover { color: var(--color-contrast-accent); text-decoration: none; }
.site-footer__base {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-1) var(--space-4);
  align-items: baseline;
  justify-content: space-between;
  margin-top: var(--space-4);
  padding-top: var(--space-3);
  border-top: var(--border-thin) dashed var(--color-contrast-line);
  font-size: var(--text-xs);
  color: color-mix(in srgb, var(--color-contrast-ink) 68%, transparent);
}
.site-footer__sig { letter-spacing: 0.02em; }
.site-footer__copy { font-family: var(--font-mono); letter-spacing: 0.04em; }

/* ============ 滚动进度与回顶 ============ */
.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  z-index: 95;
  width: 100%;
  height: 2px;
  transform: scaleX(0);
  transform-origin: 0 50%;
  background: linear-gradient(90deg, var(--color-primary) 0%, var(--color-accent) 100%);
  pointer-events: none;
}
.to-top {
  position: fixed;
  right: var(--space-3);
  bottom: var(--space-3);
  z-index: 80;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 10px 14px;
  border: var(--border-thin) solid color-mix(in srgb, var(--color-contrast-accent) 55%, transparent);
  border-radius: var(--radius-pill);
  background: color-mix(in srgb, var(--color-contrast-surface) 92%, transparent);
  color: var(--color-contrast-ink);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  box-shadow: var(--shadow-2);
  cursor: pointer;
}
.to-top:hover { background: var(--color-contrast-surface); color: var(--color-contrast-accent); }
.to-top[hidden] { display: none; }

/* ============ 显现动效协议 ============ */
[data-motion="on"] [data-reveal] {
  opacity: 0;
  transform: translateY(16px);
  transition:
    opacity 340ms cubic-bezier(0.2, 0.7, 0.2, 1),
    transform 340ms cubic-bezier(0.2, 0.7, 0.2, 1);
  transition-delay: var(--reveal-delay, 0ms);
  will-change: opacity, transform;
}
[data-motion="on"] [data-reveal].is-visible { opacity: 1; transform: none; }

/* ============ 响应式 ============ */
@media (max-width: 1023px) {
  .nav-toggle { display: inline-flex; }
  .brand__line { display: none; }
  .site-nav { border-top: var(--border-thin) dashed var(--color-line); padding-top: 6px; }
  .site-nav__list {
    flex-wrap: nowrap;
    overflow-x: auto;
    padding-bottom: 4px;
    scrollbar-width: none;
    -webkit-overflow-scrolling: touch;
  }
  .site-nav__list::-webkit-scrollbar { display: none; }
  .site-nav__item { flex: 0 0 auto; }
  .site-nav__link::after { display: none; }
  .site-nav[data-open] {
    position: absolute;
    left: var(--gutter);
    right: var(--gutter);
    top: calc(100% + 6px);
    max-height: 70vh;
    overflow: auto;
    padding: var(--space-2);
    border: var(--border-thin) solid var(--color-line);
    border-radius: var(--radius-lg);
    background-color: var(--color-surface);
    background-image: linear-gradient(160deg, color-mix(in srgb, var(--color-highlight) 62%, transparent) 0%, transparent 62%);
    box-shadow: var(--shadow-2);
  }
  .site-nav[data-open] .site-nav__list {
    flex-direction: column;
    flex-wrap: nowrap;
    overflow: visible;
    gap: 2px;
  }
  .site-nav[data-open] .site-nav__item { width: 100%; }
  .site-nav[data-open] .site-nav__link {
    width: 100%;
    justify-content: flex-start;
    padding: 12px 14px;
    border-radius: var(--radius-sm);
  }
  .span-3, .span-4 { grid-column: span 6; }
  .span-5, .span-6, .span-7, .span-8, .span-9 { grid-column: span 12; }
  .site-header__bar { gap: var(--space-1) var(--space-2); }
}
@media (min-width: 900px) {
  .site-footer__grid { grid-template-columns: minmax(0, 0.85fr) minmax(0, 1.35fr); align-items: start; }
}
@media (max-width: 719px) {
  .span-3, .span-4, .span-5, .span-6, .span-7, .span-8, .span-9, .span-12 { grid-column: 1 / -1; }
  .brand__mark { width: 36px; height: 36px; font-size: var(--text-base); }
  .brand__name { font-size: var(--text-base); }
  .site-header__actions { width: 100%; justify-content: space-between; }
  .site-footer__meta { flex-direction: column; }
  .to-top { right: var(--space-2); bottom: var(--space-2); }
}

@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;
  }
  [data-motion="on"] [data-reveal] { opacity: 1; transform: none; }
  .btn:hover { transform: none; }
}