:root {
  --color-surface: #fafafa;
  --color-surface-alt: #f1f1f1;
  --color-surface-deep: #e5e4e5;
  --color-ink: #4f454c;
  --color-ink-soft: #776973;
  --color-ink-muted: #867982;
  --color-line: #dbd9db;
  --color-primary: #d912a3;
  --color-primary-ink: #ffffff;
  --color-primary-soft: #f5daee;
  --color-accent: #5c7f0f;
  --color-accent-ink: #ffffff;
  --color-highlight: #dee4d0;
  --color-focus: #587d08;
  --color-contrast-surface: #261120;
  --color-contrast-ink: #e7e4e6;
  --color-contrast-line: #503f4c;
  --color-contrast-accent: #a5e41b;
  --overlay-scrim: linear-gradient(180deg, rgba(38, 17, 32, 0.35) 0%, rgba(38, 17, 32, 0.72) 55%, rgba(38, 17, 32, 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(46px, 9.4vw, 120px);
  --text-figure: clamp(38px, 6.7vw, 86px);
  --weight-heading: 702;
  --weight-body: 400;
  --leading-body: 1.71;
  --leading-heading: 1.2;
  --tracking-heading: 0.003em;
  --radius-sm: 12px;
  --radius-md: 16px;
  --radius-lg: 21px;
  --radius-pill: 999px;
  --border-thin: 2px;
  --border-thick: 2px;
  --shadow-1: 0 1px 0 rgba(79, 69, 76, 0.12);
  --shadow-2: 0 2px 0 rgba(79, 69, 76, 0.18);
  --space-1: 8px;
  --space-2: 16px;
  --space-3: 24px;
  --space-4: 32px;
  --space-6: 48px;
  --space-8: 64px;
  --container: 1240px;
  --measure: 74ch;
  --gutter: 24px;
  --section-y: 69px;
  --section-y-lg: 97px;
}

/* ============ RESET & 基础 ============ */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body {
  margin: 0;
  min-height: 100vh;
  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);
  overflow-wrap: break-word;
}
img, svg, video, picture { display: block; max-width: 100%; }
button { font: inherit; color: inherit; }
[hidden] { display: none !important; }
::selection { background-color: var(--color-primary); color: var(--color-primary-ink); }

a {
  color: var(--color-ink);
  text-decoration: underline;
  text-decoration-color: color-mix(in srgb, var(--color-primary) 55%, transparent);
  text-decoration-thickness: var(--border-thin);
  text-underline-offset: 4px;
}
a:hover { color: var(--color-primary); text-decoration-color: var(--color-primary); }

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

/* ============ 中文排版 ============ */
h1, h2, h3, h4, h5, h6 {
  margin: 0 0 var(--space-2);
  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-4xl); }
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); letter-spacing: 0.02em; }
p { margin: 0 0 var(--space-2); }
p:last-child { margin-bottom: 0; }

.display {
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-display);
  line-height: 0.94;
  letter-spacing: -0.01em;
  margin: 0;
}
.figure {
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-figure);
  line-height: 1;
  letter-spacing: -0.01em;
}
.mono, .index-num, .stamp, .kicker, .ledger-index, .ledger-meta { font-family: var(--font-mono); }

.kicker {
  display: inline-block;
  font-size: var(--text-xs);
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--color-ink-muted);
}
.index-num {
  display: inline-block;
  font-size: var(--text-xs);
  font-weight: 600;
  letter-spacing: 0.08em;
  color: var(--color-primary);
}
.stamp {
  display: inline-block;
  font-size: var(--text-xs);
  letter-spacing: 0.06em;
  color: var(--color-ink-muted);
}
.mark {
  background-image: linear-gradient(transparent 62%, var(--color-highlight) 62%);
  padding: 0 0.12em;
  color: inherit;
}
.mark--primary { background-image: linear-gradient(transparent 62%, var(--color-primary-soft) 62%); }
.mark--dark {
  background-color: var(--color-contrast-accent);
  color: var(--color-contrast-surface);
  border-radius: 3px;
  padding: 0 0.2em;
}

/* ============ 布局工具 ============ */
.container {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: var(--space-3);
}
.stack > * + * { margin-top: var(--space-3); }
.cluster { display: flex; flex-wrap: wrap; align-items: center; gap: var(--space-2); }
.grid { display: grid; gap: var(--gutter); }
.grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid--4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }
.grid--7 { grid-template-columns: repeat(7, minmax(0, 1fr)); }
.col-span-2 { grid-column: span 2; }
.col-span-3 { grid-column: span 3; }
.col-span-4 { grid-column: span 4; }
.col-span-5 { grid-column: span 5; }
.col-span-6 { grid-column: span 6; }
.col-span-7 { grid-column: span 7; }
.col-start-2 { grid-column-start: 2; }
.col-start-3 { grid-column-start: 3; }
.col-start-4 { grid-column-start: 4; }
.col-start-5 { grid-column-start: 5; }
.col-start-6 { grid-column-start: 6; }
.col-start-7 { grid-column-start: 7; }

/* ============ 分节底色轮换 ============ */
.band { padding-block: var(--section-y); background-color: var(--color-surface); }
.band--alt { background-color: var(--color-surface-alt); }
.band--deep { background-color: var(--color-surface-deep); }
.band--tint { background-color: var(--color-primary-soft); }
.band--contrast {
  background-color: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
}
.band--contrast h1, .band--contrast h2, .band--contrast h3,
.band--contrast h4, .band--contrast h5, .band--contrast h6 { color: var(--color-contrast-ink); }
.band--contrast .kicker,
.band--contrast .index-num { color: var(--color-contrast-accent); }
.band--contrast .stamp,
.band--contrast .ledger-meta { color: color-mix(in srgb, var(--color-contrast-ink) 72%, transparent); }
.band--contrast a { color: var(--color-contrast-ink); text-decoration-color: var(--color-contrast-accent); }
.band--contrast a:hover { color: var(--color-contrast-accent); }
.band--contrast .tag {
  background-color: transparent;
  border-color: var(--color-contrast-line);
  color: var(--color-contrast-ink);
}
.band--contrast .card {
  background-color: color-mix(in srgb, var(--color-contrast-ink) 8%, transparent);
  border-color: var(--color-contrast-line);
  color: var(--color-contrast-ink);
}
.band--contrast .btn {
  background-color: var(--color-contrast-accent);
  color: var(--color-contrast-surface);
  border-color: var(--color-contrast-accent);
}
.band--contrast .ledger,
.band--contrast .ledger-row { border-color: var(--color-contrast-line); }
.band--contrast .ledger-row:hover { background-color: color-mix(in srgb, var(--color-contrast-ink) 10%, transparent); }

.rule-thick {
  border: 0;
  border-top: var(--border-thick) solid var(--color-ink);
  margin-block: var(--space-3);
}
.rule-double {
  border: 0;
  border-top: var(--border-thick) solid var(--color-ink);
  border-bottom: var(--border-thick) solid var(--color-ink);
  height: calc(var(--border-thick) * 3);
  margin-block: var(--space-4);
}
.band--contrast .rule-thick,
.band--contrast .rule-double { border-color: var(--color-contrast-line); }

.section-head {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-end;
  justify-content: space-between;
  gap: var(--space-2);
  margin-bottom: var(--space-4);
  padding-bottom: var(--space-2);
  border-bottom: var(--border-thin) solid var(--color-line);
}
.section-title { margin: 0; font-size: var(--text-2xl); }

/* ============ 装饰形状 ============ */
.shape { display: block; position: absolute; }
.shape--circle {
  width: 18px; height: 18px;
  border-radius: 50%;
  background-color: var(--color-primary);
  border: var(--border-thin) solid var(--color-ink);
}
.shape--square {
  width: 16px; height: 16px;
  border-radius: 4px;
  background-color: var(--color-accent);
  border: var(--border-thin) solid var(--color-ink);
  transform: rotate(24deg);
}
.shape--wedge {
  width: 0; height: 0;
  border-left: 11px solid transparent;
  border-right: 11px solid transparent;
  border-bottom: 18px solid var(--color-primary-soft);
}

/* ============ 头部 ============ */
.site-header {
  position: sticky;
  top: 0;
  z-index: 60;
  padding-block: var(--space-2);
  background-color: color-mix(in srgb, var(--color-surface) 86%, transparent);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
  border-bottom: var(--border-thin) solid transparent;
  transition: padding-block 0.2s ease, border-color 0.2s ease, background-color 0.2s ease;
}
.site-header[data-scrolled] {
  padding-block: 6px;
  border-bottom-color: var(--color-line);
  background-color: color-mix(in srgb, var(--color-surface) 96%, transparent);
}
.skip-link {
  position: absolute;
  left: var(--space-3);
  top: -120px;
  z-index: 90;
  padding: 10px 20px;
  background-color: var(--color-primary);
  color: var(--color-primary-ink);
  border: var(--border-thick) solid var(--color-ink);
  border-radius: var(--radius-pill);
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-sm);
  text-decoration: none;
  transition: top 0.18s ease;
}
.skip-link:focus { top: var(--space-2); color: var(--color-primary-ink); }

.header-shell {
  position: relative;
  display: flex;
  align-items: center;
  gap: var(--space-2);
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: var(--space-3);
}
.header-shapes { position: absolute; inset: 0; pointer-events: none; z-index: 0; }
.header-shapes .shape--circle { top: -4px; left: 44%; }
.header-shapes .shape--square { bottom: -6px; left: 58%; }
.header-shapes .shape--wedge { top: -8px; right: 16%; }

.brand-island {
  position: relative;
  z-index: 1;
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: 6px 18px 6px 8px;
  background-color: var(--color-surface);
  border: var(--border-thick) solid var(--color-ink);
  border-radius: var(--radius-pill);
  box-shadow: var(--shadow-2);
}
.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: var(--color-ink);
}
.brand:hover { color: var(--color-primary); }
.brand-mark {
  position: relative;
  display: grid;
  place-items: center;
  width: 36px;
  height: 36px;
  border-radius: var(--radius-sm);
  background-color: var(--color-primary);
  color: var(--color-primary-ink);
  border: var(--border-thick) solid var(--color-ink);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: 700;
  letter-spacing: 0.06em;
}
.brand-mark::after {
  content: "";
  position: absolute;
  right: -5px;
  bottom: -5px;
  width: 12px;
  height: 12px;
  border-radius: 3px;
  background-color: var(--color-accent);
  border: var(--border-thin) solid var(--color-ink);
  transform: rotate(20deg);
}
.brand-text { display: flex; flex-direction: column; line-height: 1.15; }
.brand-name {
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-lg);
  letter-spacing: 0.04em;
}
.brand-slogan {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  color: var(--color-ink-muted);
}
.brand-domain {
  padding-left: var(--space-2);
  border-left: var(--border-thin) solid var(--color-line);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.04em;
  color: var(--color-ink-muted);
}

.nav-island { position: relative; z-index: 1; margin-left: auto; }
.nav-list {
  display: flex;
  align-items: center;
  gap: 2px;
  margin: 0;
  padding: 5px;
  list-style: none;
  background-color: var(--color-surface);
  border: var(--border-thick) solid var(--color-ink);
  border-radius: var(--radius-pill);
  box-shadow: var(--shadow-2);
}
.nav-link {
  display: block;
  padding: 7px 14px;
  border-radius: var(--radius-pill);
  font-family: var(--font-heading);
  font-weight: 600;
  font-size: var(--text-sm);
  letter-spacing: 0.02em;
  color: var(--color-ink);
  text-decoration: none;
  white-space: nowrap;
  transition: background-color 0.16s ease, color 0.16s ease, transform 0.16s ease;
}
.nav-link:hover {
  background-color: var(--color-primary-soft);
  color: var(--color-primary);
  transform: translateY(-1px);
}
.nav-link[aria-current="page"] {
  background-color: var(--color-primary);
  color: var(--color-primary-ink);
}

.header-meta {
  position: relative;
  z-index: 1;
  flex: 0 0 auto;
  display: flex;
  align-items: center;
  gap: var(--space-2);
}
.header-update {
  padding: 5px 12px;
  background-color: var(--color-surface-deep);
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-pill);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.06em;
  color: var(--color-ink-soft);
  white-space: nowrap;
}
.nav-toggle {
  display: none;
  align-items: center;
  gap: 8px;
  padding: 8px 16px;
  background-color: var(--color-primary);
  color: var(--color-primary-ink);
  border: var(--border-thick) solid var(--color-ink);
  border-radius: var(--radius-pill);
  box-shadow: var(--shadow-2);
  cursor: pointer;
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-sm);
  letter-spacing: 0.06em;
}
.nav-toggle:hover { background-color: color-mix(in srgb, var(--color-primary) 80%, var(--color-contrast-surface)); }
.nav-toggle-bars { position: relative; display: inline-block; width: 18px; height: 12px; }
.nav-toggle-bars::before,
.nav-toggle-bars::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  height: var(--border-thin);
  border-radius: var(--radius-pill);
  background-color: currentColor;
}
.nav-toggle-bars::before { top: 0; }
.nav-toggle-bars::after { bottom: 0; }
.nav-toggle-label { line-height: 1; }

/* ============ 页脚 ============ */
.site-footer {
  position: relative;
  margin-top: var(--section-y-lg);
  background-color: var(--color-surface-alt);
  border-top: var(--border-thick) solid var(--color-ink);
}
.site-footer::before {
  content: "";
  position: absolute;
  top: 6px;
  left: 0;
  right: 0;
  height: var(--border-thin);
  background-color: var(--color-primary);
}
.footer-shell {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding: var(--space-4) var(--space-3) var(--space-3);
}
.footer-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px var(--space-3);
  font-size: var(--text-sm);
  color: var(--color-ink-soft);
}
.footer-brand {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-lg);
  letter-spacing: 0.04em;
  color: var(--color-ink);
}
.footer-mark {
  display: inline-block;
  width: 12px;
  height: 12px;
  border-radius: 3px;
  background-color: var(--color-primary);
  border: var(--border-thin) solid var(--color-ink);
  transform: rotate(20deg);
}
.footer-links { display: flex; flex-wrap: wrap; align-items: center; gap: var(--space-3); }
.footer-link {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.06em;
  color: var(--color-ink-soft);
  text-decoration: none;
  border-bottom: var(--border-thin) solid transparent;
}
.footer-link:hover { color: var(--color-primary); border-bottom-color: var(--color-primary); }
.footer-note {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.04em;
  color: var(--color-ink-soft);
}
.footer-legal {
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.04em;
  color: var(--color-ink-muted);
}

/* ============ 按钮 ============ */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 20px;
  background-color: var(--color-surface);
  color: var(--color-ink);
  border: var(--border-thick) solid var(--color-ink);
  border-radius: var(--radius-pill);
  box-shadow: var(--shadow-2);
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-sm);
  letter-spacing: 0.04em;
  text-decoration: none;
  cursor: pointer;
  transition: transform 0.16s ease, box-shadow 0.16s ease, background-color 0.16s ease, color 0.16s ease;
}
.btn:hover {
  transform: translate(-2px, -2px);
  box-shadow: 4px 4px 0 color-mix(in srgb, var(--color-ink) 22%, transparent);
}
.btn--primary { background-color: var(--color-primary); color: var(--color-primary-ink); border-color: var(--color-ink); }
.btn--accent { background-color: var(--color-accent); color: var(--color-accent-ink); border-color: var(--color-ink); }
.btn--ghost { background-color: transparent; box-shadow: none; }
.btn--ghost:hover { background-color: var(--color-primary-soft); }

/* ============ 标签 ============ */
.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px;
  background-color: var(--color-surface-deep);
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-pill);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.06em;
  color: var(--color-ink-soft);
  text-decoration: none;
}
.tag--primary { background-color: var(--color-primary); border-color: var(--color-primary); color: var(--color-primary-ink); }
.tag--accent { background-color: var(--color-accent); border-color: var(--color-accent); color: var(--color-accent-ink); }
.tag--soft {
  background-color: var(--color-primary-soft);
  border-color: color-mix(in srgb, var(--color-primary) 32%, var(--color-line));
  color: color-mix(in srgb, var(--color-primary) 74%, var(--color-ink));
}
.tag--outline { background-color: transparent; border-color: var(--color-ink); color: var(--color-ink); }

/* ============ 卡片 ============ */
.card {
  padding: var(--space-3);
  background-color: var(--color-surface);
  border: var(--border-thick) solid var(--color-ink);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-2);
}
.card--alt { background-color: var(--color-surface-deep); }
.card--deep {
  background-color: var(--color-contrast-surface);
  border-color: var(--color-contrast-line);
  color: var(--color-contrast-ink);
}
.card--deep h2, .card--deep h3, .card--deep h4 { color: var(--color-contrast-ink); }
.card--deep .index-num { color: var(--color-contrast-accent); }

/* ============ 编号条目流 ============ */
.ledger { margin: 0; padding: 0; list-style: none; border-top: var(--border-thin) solid var(--color-line); }
.ledger-row {
  display: grid;
  grid-template-columns: 92px minmax(0, 1fr) auto;
  align-items: baseline;
  gap: var(--space-2);
  padding: var(--space-2) 0;
  border-bottom: var(--border-thin) solid var(--color-line);
  transition: background-color 0.16s ease;
}
.ledger-row:hover { background-color: var(--color-surface-alt); }
.ledger-index { font-size: var(--text-xs); letter-spacing: 0.06em; color: var(--color-primary); }
.ledger-title {
  font-family: var(--font-heading);
  font-weight: 600;
  font-size: var(--text-base);
}
.ledger-meta { font-size: var(--text-xs); letter-spacing: 0.06em; color: var(--color-ink-muted); }

/* ============ 图片容器 ============ */
.media {
  position: relative;
  display: block;
  overflow: hidden;
  background-color: var(--color-surface-deep);
  border: var(--border-thick) solid var(--color-ink);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-2);
}
.media > img,
.media > picture > img,
.media > .media-fill {
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.media--wide { aspect-ratio: 16 / 9; }
.media--band { aspect-ratio: 21 / 9; }
.media--tall { aspect-ratio: 3 / 4; }
.media--square { aspect-ratio: 1 / 1; }
.media--fill { aspect-ratio: auto; height: 100%; }
.media--offset { border-radius: var(--radius-lg); }
.media-caption {
  position: absolute;
  inset: auto 0 0 0;
  padding: var(--space-3);
  background-image: var(--overlay-scrim);
  color: var(--color-contrast-ink);
  font-size: var(--text-sm);
  line-height: 1.5;
}
.media-caption .index-num { color: var(--color-contrast-accent); }
.media-tag { position: absolute; top: var(--space-2); left: var(--space-2); }

/* ============ 面包屑 ============ */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin: 0 0 var(--space-2);
  padding: 0;
  list-style: none;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.06em;
  color: var(--color-ink-muted);
}
.breadcrumb a {
  color: var(--color-ink-soft);
  text-decoration: none;
  border-bottom: var(--border-thin) solid var(--color-line);
}
.breadcrumb a:hover { color: var(--color-primary); border-bottom-color: var(--color-primary); }
.breadcrumb-sep { color: var(--color-ink-muted); }

/* ============ 正文容器 ============ */
.prose { max-width: var(--measure); }
.prose > * + * { margin-top: calc(var(--text-base) * 1.5); }
.prose h2 { margin-top: calc(var(--text-base) * 2.4); font-size: var(--text-2xl); }
.prose h3 { margin-top: calc(var(--text-base) * 1.8); font-size: var(--text-xl); }
.prose ul, .prose ol { padding-left: 1.2em; }
.prose li + li { margin-top: var(--space-1); }
.prose blockquote {
  margin: 0;
  padding: var(--space-2) var(--space-3);
  background-color: var(--color-surface-deep);
  border-left: var(--border-thick) solid var(--color-primary);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  color: var(--color-ink-soft);
}
.prose code {
  padding: 2px 6px;
  background-color: var(--color-surface-deep);
  border-radius: 4px;
  font-family: var(--font-mono);
  font-size: var(--text-sm);
}

/* ============ 章节目录 ============ */
.toc { position: sticky; top: 104px; padding-left: var(--space-2); border-left: var(--border-thick) solid var(--color-line); }
.toc-title {
  margin: 0 0 var(--space-2);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.16em;
  color: var(--color-ink-muted);
}
.toc-list { display: flex; flex-direction: column; gap: 2px; margin: 0; padding: 0; list-style: none; }
.toc-link {
  display: block;
  padding: 6px 10px;
  border-left: var(--border-thin) solid transparent;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  font-size: var(--text-sm);
  color: var(--color-ink-soft);
  text-decoration: none;
  transition: background-color 0.16s ease, color 0.16s ease;
}
.toc-link:hover { background-color: var(--color-primary-soft); color: var(--color-primary); }
.toc-link.is-active {
  background-color: var(--color-primary-soft);
  border-left-color: var(--color-primary);
  color: var(--color-primary);
  font-weight: 600;
}

/* ============ 标签筛选 ============ */
.filter-bar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  padding: var(--space-2);
  background-color: var(--color-surface-deep);
  border: var(--border-thick) solid var(--color-ink);
  border-radius: var(--radius-lg);
}
.filter-chip {
  padding: 6px 14px;
  background-color: var(--color-surface);
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-pill);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.06em;
  color: var(--color-ink-soft);
  cursor: pointer;
  transition: background-color 0.16s ease, color 0.16s ease, border-color 0.16s ease;
}
.filter-chip:hover { border-color: var(--color-primary); color: var(--color-primary); }
.filter-chip[aria-pressed="true"] {
  background-color: var(--color-primary);
  border-color: var(--color-primary);
  color: var(--color-primary-ink);
}
.filter-count { margin-left: auto; font-family: var(--font-mono); font-size: var(--text-xs); color: var(--color-ink-muted); }

/* ============ 返回顶部 ============ */
.to-top {
  position: fixed;
  right: var(--space-3);
  bottom: var(--space-3);
  z-index: 70;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 18px;
  background-color: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  border: var(--border-thick) solid var(--color-contrast-accent);
  border-radius: var(--radius-pill);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.12em;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition: opacity 0.2s ease, transform 0.2s ease, visibility 0.2s ease;
}
.to-top[data-visible] { opacity: 1; visibility: visible; transform: none; }
.to-top-mark { color: var(--color-contrast-accent); font-size: var(--text-sm); line-height: 1; }
.to-top-text { line-height: 1; }

/* ============ 显现 ============ */
.reveal { transition: opacity 0.45s ease, transform 0.45s ease; }
html[data-reveal="on"] .reveal { opacity: 0; transform: translateY(16px); }
html[data-reveal="on"] .reveal.is-visible { opacity: 1; transform: none; }

/* ============ 响应式 ============ */
@media (max-width: 1024px) {
  .grid--7 { grid-template-columns: repeat(4, minmax(0, 1fr)); }
  .grid--7 > .col-span-4,
  .grid--7 > .col-span-5,
  .grid--7 > .col-span-6,
  .grid--7 > .col-span-7 { grid-column: span 4; }
  .grid--7 > .col-span-3 { grid-column: span 3; }
  .grid--4 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 960px) {
  .brand-domain { display: none; }
  .header-update { display: none; }
  .nav-toggle { display: inline-flex; }
  .nav-island {
    position: absolute;
    top: calc(100% + 10px);
    left: var(--space-3);
    right: var(--space-3);
    margin-left: 0;
    display: none;
  }
  .nav-island[data-open] { display: block; }
  .nav-list {
    flex-direction: column;
    align-items: stretch;
    gap: 4px;
    padding: var(--space-2);
    border-radius: var(--radius-lg);
  }
  .nav-link { padding: 12px 14px; border-radius: var(--radius-sm); font-size: var(--text-base); }
  .toc { position: static; top: auto; }
}

@media (max-width: 720px) {
  .grid--7 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .grid--7 > .col-span-2,
  .grid--7 > .col-span-3,
  .grid--7 > .col-span-4,
  .grid--7 > .col-span-5,
  .grid--7 > .col-span-6,
  .grid--7 > .col-span-7 { grid-column: span 2; }
  .grid--7 > .col-start-2,
  .grid--7 > .col-start-3,
  .grid--7 > .col-start-4,
  .grid--7 > .col-start-5,
  .grid--7 > .col-start-6,
  .grid--7 > .col-start-7 { grid-column-start: auto; }
  .grid--2, .grid--3, .grid--4 { grid-template-columns: minmax(0, 1fr); }
  .band { padding-block: var(--section-y); }
  .ledger-row { grid-template-columns: 72px minmax(0, 1fr); }
  .ledger-meta { grid-column: 2; }
  .footer-legal { margin-left: 0; flex-basis: 100%; }
  .footer-links { gap: var(--space-2); }
  .media--tall { aspect-ratio: 4 / 5; }
  .to-top { right: var(--space-2); bottom: var(--space-2); }
}

/* ============ 动效克制 ============ */
@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;
  }
  .site-header[data-scrolled] { padding-block: var(--space-2); }
  .btn:hover { transform: none; }
  html[data-reveal="on"] .reveal { opacity: 1; transform: none; }
}