:root {
  --color-surface: #fcfcfc;
  --color-surface-alt: #f3f3f4;
  --color-surface-deep: #e6e7e8;
  --color-ink: #464a53;
  --color-ink-soft: #6a707b;
  --color-ink-muted: #787d87;
  --color-line: #dbdcde;
  --color-primary: #416abe;
  --color-primary-ink: #ffffff;
  --color-primary-soft: #e2e8f3;
  --color-accent: #e5156b;
  --color-accent-ink: #ffffff;
  --color-highlight: #f8d2e2;
  --color-focus: #de0760;
  --color-contrast-surface: #101319;
  --color-contrast-ink: #e4e5e7;
  --color-contrast-line: #3f4146;
  --color-contrast-accent: #ec2878;
  --overlay-scrim: linear-gradient(180deg, rgba(16, 19, 25, 0.35) 0%, rgba(16, 19, 25, 0.72) 55%, rgba(16, 19, 25, 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: 10.7px;
  --text-sm: 13.4px;
  --text-base: 15px;
  --text-lg: 18.8px;
  --text-xl: 23.4px;
  --text-2xl: 29.3px;
  --text-3xl: 36.6px;
  --text-4xl: 45.8px;
  --text-display: clamp(34px, 5.4vw, 69px);
  --text-figure: clamp(28px, 3.9vw, 50px);
  --weight-heading: 600;
  --weight-body: 400;
  --leading-body: 1.67;
  --leading-heading: 1.21;
  --tracking-heading: -0.004em;
  --radius-sm: 4px;
  --radius-md: 6px;
  --radius-lg: 9px;
  --radius-pill: 999px;
  --border-thin: 1px;
  --border-thick: 1px;
  --shadow-1: 0 1px 0 rgba(70, 74, 83, 0.12);
  --shadow-2: 0 2px 0 rgba(70, 74, 83, 0.18);
  --space-1: 8px;
  --space-2: 16px;
  --space-3: 24px;
  --space-4: 32px;
  --space-6: 48px;
  --space-8: 64px;
  --container: 1120px;
  --measure: 73ch;
  --gutter: 16px;
  --section-y: 77px;
  --section-y-lg: 108px;
}

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

html { -webkit-text-size-adjust: 100%; }
@media (prefers-reduced-motion: no-preference) {
  html { 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);
  letter-spacing: 0.01em;
  -webkit-font-smoothing: antialiased;
  word-break: break-word;
  overflow-wrap: anywhere;
}

img, svg, video { display: block; max-width: 100%; height: auto; }
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;
  text-wrap: balance;
}
p, figure, blockquote, dl, dd { margin: 0; }
ul, ol { margin: 0; padding: 0; list-style: none; }
a { color: var(--color-primary); text-decoration: none; }
a:hover { text-decoration: underline; }
button { font: inherit; color: inherit; background: none; border: 0; padding: 0; cursor: pointer; }
table { border-collapse: collapse; width: 100%; }
[hidden] { display: none !important; }

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

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

/* ---------- 骨架 ---------- */
.wrap {
  width: 100%;
  max-width: calc(var(--container) + var(--space-4));
  margin-inline: auto;
  padding-inline: var(--space-2);
}

.grid-12 { display: grid; grid-template-columns: repeat(12, minmax(0, 1fr)); gap: var(--gutter); }
@media (max-width: 1000px) { .grid-12 { grid-template-columns: repeat(6, minmax(0, 1fr)); } }
@media (max-width: 640px) { .grid-12 { grid-template-columns: repeat(2, minmax(0, 1fr)); } }

.section { padding-block: var(--section-y); position: relative; }
.section--lg { padding-block: var(--section-y-lg); }
.section--tight { padding-block: calc(var(--section-y) / 2); }

.band-contrast {
  background-color: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
}
.band-contrast a { color: var(--color-contrast-accent); }
.band-contrast .eyebrow { color: color-mix(in srgb, var(--color-contrast-ink) 62%, transparent); }
.band-contrast .lede { color: color-mix(in srgb, var(--color-contrast-ink) 80%, transparent); }
.band-contrast .rule-dotted { border-top-color: var(--color-contrast-line); }
.band-contrast .prose li::before { background-color: var(--color-contrast-line); }
.band-contrast .tag {
  background-color: transparent;
  border-color: var(--color-contrast-line);
  color: var(--color-contrast-ink);
}
.band-contrast .timeline__rail {
  background-image: repeating-linear-gradient(180deg, var(--color-contrast-line) 0 4px, transparent 4px 8px);
}

/* ---------- 文字 ---------- */
.eyebrow {
  display: block;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.24em;
  text-transform: uppercase;
  color: var(--color-ink-muted);
  line-height: 1.6;
}
.display-title {
  font-family: var(--font-heading);
  font-size: var(--text-display);
  font-weight: var(--weight-heading);
  line-height: 0.98;
  letter-spacing: 0.01em;
}
.section-title {
  font-size: var(--text-3xl);
  letter-spacing: 0.06em;
  transition: color 0.24s ease-out;
}
[data-section].is-current .section-title { color: var(--color-primary); }
.band-contrast[data-section].is-current .section-title,
.band-contrast [data-section].is-current .section-title { color: var(--color-contrast-accent); }
.lede {
  font-size: var(--text-lg);
  line-height: 1.55;
  color: var(--color-ink-soft);
  max-width: var(--measure);
}
.mono { font-family: var(--font-mono); font-variant-numeric: tabular-nums; }

.prose { max-width: var(--measure); font-size: var(--text-base); line-height: var(--leading-body); }
.prose > * + * { margin-top: var(--space-2); }
.prose h2 { font-size: var(--text-xl); letter-spacing: 0.04em; margin-top: var(--space-4); }
.prose h3 { font-size: var(--text-lg); letter-spacing: 0.04em; margin-top: var(--space-3); }
.prose li { position: relative; padding-left: 18px; }
.prose li + li { margin-top: 6px; }
.prose li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.72em;
  width: 6px;
  height: 1px;
  background-color: var(--color-line);
}

.link-inline { border-bottom: 1px dashed color-mix(in srgb, var(--color-primary) 60%, transparent); }
.link-inline:hover { text-decoration: none; border-bottom-style: solid; }

.rule-dotted {
  border: 0;
  border-top: 1px dashed var(--color-line);
  margin-block: var(--space-4);
}
.rule-dotted--tight { margin-block: var(--space-2); }

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  padding: 10px 18px;
  border: 1px solid transparent;
  border-radius: var(--radius-sm);
  font-family: var(--font-heading);
  font-size: var(--text-sm);
  font-weight: var(--weight-heading);
  letter-spacing: 0.1em;
  text-decoration: none;
  transition: background-color 0.18s ease-out, color 0.18s ease-out, border-color 0.18s ease-out;
}
.btn:hover { text-decoration: none; }
.btn--primary { background-color: var(--color-primary); color: var(--color-primary-ink); }
.btn--primary:hover { background-color: color-mix(in srgb, var(--color-primary) 84%, var(--color-contrast-surface)); }
.btn--accent { background-color: var(--color-accent); color: var(--color-accent-ink); }
.btn--accent:hover { background-color: var(--color-focus); }
.btn--ghost { background-color: transparent; border-color: var(--color-line); color: var(--color-ink); }
.btn--ghost:hover { border-color: var(--color-primary); color: var(--color-primary); }

.copy-btn {
  padding: 3px 10px;
  border: 1px solid var(--color-line);
  border-radius: var(--radius-pill);
  background-color: transparent;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  color: var(--color-ink-soft);
  transition: background-color 0.18s ease-out, color 0.18s ease-out, border-color 0.18s ease-out;
}
.copy-btn:hover { border-color: var(--color-primary); color: var(--color-primary); }
.copy-btn.is-done {
  background-color: var(--color-accent);
  border-color: var(--color-accent);
  color: var(--color-accent-ink);
}

/* ---------- 面板 / 标签 / 数字 ---------- */
.panel {
  background-color: var(--color-surface);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-lg);
  padding: var(--space-3);
}
.panel--soft { background-color: var(--color-surface-alt); border-color: transparent; }
.panel--deep { background-color: var(--color-surface-deep); border-color: transparent; }
.panel--contrast {
  background-color: var(--color-contrast-surface);
  border-color: var(--color-contrast-line);
  color: var(--color-contrast-ink);
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 3px 9px;
  border: 1px solid var(--color-line);
  border-radius: var(--radius-pill);
  background-color: var(--color-surface-alt);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  color: var(--color-ink-soft);
}
.tag--data { background-color: var(--color-primary-soft); border-color: transparent; color: var(--color-primary); }
.tag--rule { background-color: var(--color-accent); border-color: var(--color-accent); color: var(--color-accent-ink); }
.tag--focus { background-color: var(--color-highlight); border-color: transparent; color: var(--color-focus); }
.tag--muted { background-color: transparent; border-style: dashed; color: var(--color-ink-muted); }

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

.stat-strip { display: grid; gap: var(--space-3); grid-template-columns: repeat(auto-fit, minmax(140px, 1fr)); }
.stat {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding-left: var(--space-2);
  border-left: 1px dashed var(--color-line);
}
.band-contrast .stat { border-left-color: var(--color-contrast-line); }
.stat__num {
  font-family: var(--font-mono);
  font-size: var(--text-2xl);
  font-weight: var(--weight-heading);
  line-height: 1.1;
  font-variant-numeric: tabular-nums;
}
.stat__label {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.16em;
  color: var(--color-ink-muted);
}
.band-contrast .stat__label { color: color-mix(in srgb, var(--color-contrast-ink) 62%, transparent); }

/* ---------- 时间轴 ---------- */
.timeline { position: relative; display: flex; flex-direction: column; gap: var(--space-4); }
.timeline__rail {
  position: absolute;
  left: 7px;
  top: 6px;
  bottom: 6px;
  width: 1px;
  background-image: repeating-linear-gradient(180deg, var(--color-line) 0 4px, transparent 4px 8px);
}
.tl-item { position: relative; padding-left: var(--space-4); }
.tl-item__marker {
  position: absolute;
  left: 0;
  top: 3px;
  width: 15px;
  height: 15px;
  display: grid;
  place-items: center;
  border: 1px solid var(--color-primary);
  border-radius: var(--radius-pill);
  background-color: var(--color-surface);
  transition: background-color 0.24s ease-out, border-color 0.24s ease-out, transform 0.24s ease-out;
}
.tl-item__marker::after {
  content: "";
  width: 7px;
  height: 7px;
  border-radius: var(--radius-pill);
  background-color: var(--color-primary);
  transition: background-color 0.24s ease-out;
}
.tl-item__marker--square { border-radius: var(--radius-sm); }
.tl-item__marker--square::after { border-radius: 1px; background-color: var(--color-accent); }
.tl-item.is-lit .tl-item__marker { background-color: var(--color-primary-soft); transform: scale(1.08); }
.tl-item.is-lit .tl-item__marker--square { background-color: var(--color-highlight); }
.band-contrast .tl-item__marker { background-color: var(--color-contrast-surface); border-color: var(--color-contrast-accent); }
.band-contrast .tl-item__marker::after { background-color: var(--color-contrast-accent); }
.band-contrast .tl-item.is-lit .tl-item__marker { background-color: color-mix(in srgb, var(--color-contrast-accent) 26%, transparent); }
.tl-item__meta {
  display: block;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.16em;
  color: var(--color-ink-muted);
  margin-bottom: 4px;
}
.band-contrast .tl-item__meta { color: color-mix(in srgb, var(--color-contrast-ink) 62%, transparent); }
.tl-item__title { font-size: var(--text-lg); letter-spacing: 0.03em; }
.tl-item__text { margin-top: 6px; color: var(--color-ink-soft); max-width: var(--measure); }
.band-contrast .tl-item__text { color: color-mix(in srgb, var(--color-contrast-ink) 80%, transparent); }

/* ---------- 图片容器 ---------- */
.media-frame {
  position: relative;
  overflow: hidden;
  border-radius: var(--radius-lg);
  background-color: var(--color-surface-deep);
}
.media-frame img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: saturate(0.62) contrast(1.06);
}
.media-frame--16x9 { aspect-ratio: 16 / 9; }
.media-frame--4x3 { aspect-ratio: 4 / 3; }
.media-frame--1x1 { aspect-ratio: 1 / 1; }
.media-frame__scrim { position: absolute; inset: 0; background-image: var(--overlay-scrim); pointer-events: none; }
.media-frame__caption {
  position: absolute;
  left: var(--space-2);
  right: var(--space-2);
  bottom: var(--space-2);
  color: var(--color-contrast-ink);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  line-height: 1.6;
}

/* ---------- 展开 / 筛选 / 显现 ---------- */
.expand { border-top: 1px dashed var(--color-line); }
.expand__toggle {
  display: flex;
  align-items: center;
  gap: var(--space-1);
  width: 100%;
  padding: 14px 0;
  text-align: left;
  font-family: var(--font-heading);
  font-size: var(--text-lg);
  font-weight: var(--weight-heading);
  letter-spacing: 0.04em;
  color: var(--color-ink);
}
.expand__toggle::after {
  content: "+";
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: var(--text-lg);
  color: var(--color-accent);
  transition: transform 0.18s ease-out;
}
.expand[data-open="true"] .expand__toggle::after { content: "−"; }
.expand__panel {
  max-height: 0;
  overflow: hidden;
  opacity: 0;
  transition: max-height 0.26s ease-out, opacity 0.26s ease-out;
}
.expand[data-open="true"] .expand__panel { max-height: var(--expand-max, 420px); opacity: 1; }
.expand__panel > * { padding-bottom: var(--space-3); }

.filter-bar { display: flex; flex-wrap: wrap; gap: var(--space-1); }
.filter-chip {
  padding: 5px 12px;
  border: 1px solid var(--color-line);
  border-radius: var(--radius-pill);
  background-color: transparent;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.12em;
  color: var(--color-ink-soft);
  transition: background-color 0.18s ease-out, color 0.18s ease-out, border-color 0.18s ease-out;
}
.filter-chip[aria-pressed="true"] {
  background-color: var(--color-primary);
  border-color: var(--color-primary);
  color: var(--color-primary-ink);
}
.band-contrast .filter-chip { border-color: var(--color-contrast-line); color: var(--color-contrast-ink); }
.band-contrast .filter-chip[aria-pressed="true"] {
  background-color: var(--color-contrast-accent);
  border-color: var(--color-contrast-accent);
  color: var(--color-contrast-surface);
}

.reveal {
  opacity: 0;
  transform: translateY(10px);
  transition: opacity 0.24s ease-out, transform 0.24s ease-out;
}
.reveal.is-in { opacity: 1; transform: none; }

/* ---------- 面包屑 ---------- */
.breadcrumb {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.12em;
  color: var(--color-ink-muted);
}
.breadcrumb ol { display: flex; flex-wrap: wrap; align-items: center; gap: 6px; }
.breadcrumb li + li::before { content: "/"; margin-right: 6px; color: var(--color-line); }
.breadcrumb a { color: inherit; }
.breadcrumb a:hover { color: var(--color-primary); text-decoration: none; }

/* ---------- 头部 ---------- */
.site-header { position: relative; z-index: 60; }

.skip-link {
  position: fixed;
  top: var(--space-1);
  left: var(--space-2);
  z-index: 90;
  padding: 8px 14px;
  border-radius: var(--radius-sm);
  background-color: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  font-size: var(--text-sm);
  letter-spacing: 0.08em;
  transform: translateY(-220%);
  transition: transform 0.18s ease-out;
}
.skip-link:focus { transform: none; text-decoration: none; }

.nav-dock {
  position: fixed;
  left: var(--space-1);
  right: var(--space-1);
  bottom: var(--space-1);
  z-index: 60;
  display: flex;
  align-items: center;
  gap: var(--space-1);
  padding: 6px;
  background-color: color-mix(in srgb, var(--color-surface) 96%, transparent);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-pill);
  box-shadow: var(--shadow-2);
  backdrop-filter: blur(10px);
}

.nav-island { display: flex; align-items: center; gap: var(--space-1); flex: 1 1 auto; min-width: 0; }
.nav-island__head { flex: 1 1 auto; min-width: 0; }

.brand { display: flex; align-items: center; gap: 8px; min-width: 0; color: var(--color-ink); text-decoration: none; }
.brand:hover { text-decoration: none; }
.brand__mark {
  display: grid;
  place-items: center;
  flex: none;
  width: 30px;
  height: 30px;
  border-radius: var(--radius-sm);
  background-color: var(--color-primary);
  color: var(--color-primary-ink);
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  letter-spacing: 0.02em;
}
.brand__name {
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.brand__tag { display: none; }

.nav-island__nav {
  position: absolute;
  left: 0;
  right: 0;
  bottom: calc(100% + var(--space-1));
  padding: var(--space-2);
  background-color: var(--color-surface);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-2);
  opacity: 0;
  visibility: hidden;
  transform: translateY(6px);
  transition: opacity 0.18s ease-out, transform 0.18s ease-out, visibility 0.18s;
}
.nav-island[data-open="true"] .nav-island__nav { opacity: 1; visibility: visible; transform: none; }

.nav-list { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 4px; }
.nav-list__item { display: flex; }
.nav-link {
  display: block;
  width: 100%;
  padding: 9px 10px;
  border-radius: var(--radius-md);
  font-size: var(--text-sm);
  letter-spacing: 0.06em;
  color: var(--color-ink);
  transition: background-color 0.18s ease-out, color 0.18s ease-out;
}
.nav-link:hover { background-color: var(--color-primary-soft); color: var(--color-primary); text-decoration: none; }
.nav-link[aria-current="page"] { background-color: var(--color-primary); color: var(--color-primary-ink); }

.nav-island__foot { display: flex; align-items: center; flex: none; }
.nav-cta {
  display: inline-flex;
  align-items: center;
  padding: 7px 12px;
  border-radius: var(--radius-pill);
  background-color: var(--color-accent);
  color: var(--color-accent-ink);
  font-size: var(--text-xs);
  font-weight: var(--weight-heading);
  letter-spacing: 0.08em;
  white-space: nowrap;
  transition: background-color 0.18s ease-out;
}
.nav-cta:hover { background-color: var(--color-focus); text-decoration: none; }

.nav-toggle {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  flex: none;
  padding: 8px 10px;
  border: 1px solid var(--color-line);
  border-radius: var(--radius-pill);
  background-color: var(--color-surface-alt);
  color: var(--color-ink);
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
}
.nav-toggle__bars { position: relative; display: block; width: 14px; height: 2px; border-radius: 2px; background-color: currentColor; }
.nav-toggle__bars::before,
.nav-toggle__bars::after {
  content: "";
  position: absolute;
  left: 0;
  width: 14px;
  height: 2px;
  border-radius: 2px;
  background-color: currentColor;
  transition: transform 0.18s ease-out, top 0.18s ease-out;
}
.nav-toggle__bars::before { top: -5px; }
.nav-toggle__bars::after { top: 5px; }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars { background-color: transparent; }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars::before { top: 0; transform: rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars::after { top: 0; transform: rotate(-45deg); }

.progress-rail {
  position: fixed;
  left: 0;
  right: 0;
  bottom: 0;
  height: 3px;
  z-index: 55;
  background-color: color-mix(in srgb, var(--color-ink) 14%, transparent);
}
.progress-rail__fill {
  display: block;
  width: 100%;
  height: 100%;
  background-color: var(--color-accent);
  transform: scaleX(0);
  transform-origin: 0 50%;
}

@media (min-width: 1080px) {
  body { padding-left: 96px; }
  .nav-dock {
    left: 20px;
    right: auto;
    top: 50%;
    bottom: auto;
    transform: translateY(-50%);
    flex-direction: column;
    gap: var(--space-1);
    width: 60px;
    max-height: calc(100vh - 24px);
    overflow-y: auto;
    padding: var(--space-1) 6px;
    scrollbar-width: none;
  }
  .nav-dock::-webkit-scrollbar { display: none; }
  .nav-island { flex-direction: column; gap: var(--space-2); width: 100%; }
  .nav-island__head { width: 100%; }
  .brand { flex-direction: column; gap: 6px; justify-content: center; }
  .brand__name {
    writing-mode: vertical-rl;
    text-orientation: upright;
    font-size: var(--text-xs);
    letter-spacing: 0.16em;
    white-space: normal;
    text-align: center;
    overflow: visible;
  }
  .brand__tag {
    display: block;
    writing-mode: vertical-rl;
    text-orientation: upright;
    font-family: var(--font-mono);
    font-size: var(--text-xs);
    letter-spacing: 0.12em;
    color: var(--color-ink-muted);
  }
  .nav-island__nav {
    position: static;
    opacity: 1;
    visibility: visible;
    transform: none;
    padding: 0;
    border: 0;
    border-radius: 0;
    box-shadow: none;
    background-color: transparent;
    width: 100%;
  }
  .nav-list { display: flex; flex-direction: column; align-items: center; gap: 2px; }
  .nav-list__item { display: block; }
  .nav-link {
    writing-mode: vertical-rl;
    text-orientation: upright;
    width: auto;
    padding: 8px 5px;
    font-size: var(--text-sm);
    letter-spacing: 0.14em;
    text-align: center;
  }
  .nav-island__foot { width: 100%; }
  .nav-cta {
    writing-mode: vertical-rl;
    text-orientation: upright;
    justify-content: center;
    width: 100%;
    padding: 12px 5px;
    font-size: var(--text-xs);
    letter-spacing: 0.14em;
  }
  .nav-toggle { display: none; }
}

@media (min-width: 1080px) and (max-height: 840px) {
  .nav-island { gap: var(--space-1); }
  .nav-link { padding: 6px 4px; letter-spacing: 0.1em; }
  .brand__tag { display: none; }
}

/* ---------- 页脚 ---------- */
.site-footer {
  margin-top: var(--section-y);
  padding-block: var(--space-6) calc(var(--space-3) + 76px);
  background-color: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  font-size: var(--text-sm);
}
.footer-brand {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding-bottom: var(--space-3);
  border-bottom: 1px dashed var(--color-contrast-line);
}
.footer-brand__mark {
  display: grid;
  place-items: center;
  flex: none;
  width: 40px;
  height: 40px;
  border-radius: var(--radius-sm);
  background-color: var(--color-contrast-accent);
  color: var(--color-contrast-surface);
  font-family: var(--font-mono);
  font-size: var(--text-lg);
}
.footer-brand__name {
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-lg);
  letter-spacing: 0.2em;
  color: var(--color-contrast-ink);
}
.footer-brand__tag {
  margin-top: 2px;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.16em;
  color: color-mix(in srgb, var(--color-contrast-ink) 62%, transparent);
}
.footer-panels {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-2);
  padding-block: var(--space-4);
}
.footer-panel {
  background-color: color-mix(in srgb, var(--color-contrast-ink) 6%, transparent);
  border: 1px solid var(--color-contrast-line);
  border-radius: var(--radius-lg);
  padding: var(--space-3);
}
.footer-panel__title {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: var(--weight-body);
  letter-spacing: 0.24em;
  text-transform: uppercase;
  color: var(--color-contrast-accent);
  margin-bottom: var(--space-2);
}
.footer-nav { display: flex; flex-direction: column; gap: 8px; }
.footer-nav a {
  color: var(--color-contrast-ink);
  font-size: var(--text-sm);
  letter-spacing: 0.06em;
}
.footer-nav a:hover { color: var(--color-contrast-accent); text-decoration: none; }
.footer-contact { display: flex; flex-direction: column; gap: 10px; }
.footer-contact__row { display: flex; flex-wrap: wrap; align-items: center; gap: 8px; }
.footer-contact__key {
  min-width: 32px;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.12em;
  color: color-mix(in srgb, var(--color-contrast-ink) 58%, transparent);
}
.footer-contact__val {
  font-size: var(--text-sm);
  color: var(--color-contrast-ink);
  line-height: 1.6;
}
.footer-panel .copy-btn { border-color: var(--color-contrast-line); color: var(--color-contrast-ink); }
.footer-panel .copy-btn:hover { border-color: var(--color-contrast-accent); color: var(--color-contrast-accent); }
.footer-panel .copy-btn.is-done {
  background-color: var(--color-contrast-accent);
  border-color: var(--color-contrast-accent);
  color: var(--color-contrast-surface);
}
.footer-note {
  margin-top: var(--space-2);
  font-size: var(--text-xs);
  line-height: 1.7;
  color: color-mix(in srgb, var(--color-contrast-ink) 68%, transparent);
}
.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-2);
  padding-top: var(--space-3);
  border-top: 1px dashed var(--color-contrast-line);
}
.footer-fine {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  color: color-mix(in srgb, var(--color-contrast-ink) 62%, transparent);
}
.back-top {
  margin-left: auto;
  padding: 6px 14px;
  border: 1px solid var(--color-contrast-line);
  border-radius: var(--radius-pill);
  color: var(--color-contrast-ink);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.12em;
  transition: border-color 0.18s ease-out, color 0.18s ease-out;
}
.back-top:hover { border-color: var(--color-contrast-accent); color: var(--color-contrast-accent); }

@media (min-width: 720px) {
  .footer-panels { grid-template-columns: repeat(3, minmax(0, 1fr)); gap: var(--space-3); }
}
@media (min-width: 1080px) {
  .site-footer { padding-bottom: var(--space-3); }
}

@media (max-width: 420px) {
  .nav-list { grid-template-columns: 1fr; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
  .reveal { opacity: 1; transform: none; }
}