.page-about {
  background: var(--color-surface);
}

.page-about .st-wrap {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

/* ---------- 面包屑 ---------- */
.page-about .st-crumbs {
  padding-top: var(--space-3);
}

.page-about .st-crumbs ol {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0 var(--space-1);
  margin: 0;
  padding: 0;
  list-style: none;
  font-size: var(--text-xs);
  color: var(--color-ink-muted);
}

.page-about .st-crumbs li + li::before {
  content: "/";
  margin-inline-end: var(--space-1);
  color: var(--color-line);
}

.page-about .st-crumbs a {
  color: var(--color-ink-soft);
  text-decoration: none;
}

.page-about .st-crumbs a:hover {
  color: var(--color-primary);
}

/* ---------- 开篇 ---------- */
.page-about .st-open {
  padding-top: var(--space-6);
  padding-bottom: var(--space-6);
  display: grid;
  gap: var(--space-6);
}

.page-about .st-eyebrow {
  margin: 0 0 var(--space-2);
  font-size: var(--text-xs);
  font-weight: var(--weight-heading);
  letter-spacing: 0.16em;
  color: var(--color-primary);
}

.page-about .st-open__title {
  margin: 0 0 var(--space-4);
  font-family: var(--font-heading);
  font-size: var(--text-4xl);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  font-weight: var(--weight-heading);
  color: var(--color-ink);
}

.page-about .st-open__lede {
  margin: 0 0 var(--space-3);
  max-width: var(--measure);
  font-size: var(--text-xl);
  line-height: 1.62;
  color: var(--color-ink);
}

.page-about .st-open__lede:last-child {
  margin-bottom: 0;
}

.page-about .st-open__figure {
  margin: 0;
}

.page-about .st-open__figure img {
  display: block;
  width: 100%;
  height: auto;
  background: var(--color-surface-deep);
}

.page-about .st-open__figure figcaption {
  margin-top: var(--space-2);
  font-size: var(--text-xs);
  line-height: 1.7;
  color: var(--color-ink-muted);
}

/* ---------- 章节索引 ---------- */
.page-about .st-toc {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: var(--space-1) var(--space-4);
  padding-top: var(--space-3);
  padding-bottom: var(--space-3);
  border-top: var(--border-thin) solid var(--color-line);
  border-bottom: var(--border-thin) solid var(--color-line);
}

.page-about .st-toc__title {
  margin: 0;
  font-size: var(--text-xs);
  letter-spacing: 0.16em;
  color: var(--color-ink-muted);
}

.page-about .st-toc__list {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-1) var(--space-3);
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .st-toc__link {
  display: inline-block;
  padding-bottom: 2px;
  font-size: var(--text-sm);
  color: var(--color-ink-soft);
  text-decoration: none;
  border-bottom: var(--border-thin) solid transparent;
  transition: color 180ms ease, border-color 180ms ease;
}

.page-about .st-toc__link:hover {
  color: var(--color-primary);
}

.page-about .st-toc__link[aria-current="true"] {
  color: var(--color-accent);
  border-bottom-color: var(--color-accent);
}

/* ---------- 章节色带与错位边界 ---------- */
.page-about .st-band {
  padding-block: var(--section-y);
}

.page-about .st-band--flow {
  background: var(--color-surface);
}

.page-about .st-band--calm {
  background: var(--color-surface-alt);
}

@media (min-width: 900px) {
  .page-about .st-band--flow {
    margin-inline-start: var(--space-4);
  }

  .page-about .st-band--calm {
    margin-inline-end: var(--space-4);
  }
}

/* ---------- 叙事段落 ---------- */
.page-about .st-chapter__num {
  margin: 0 0 var(--space-1);
  font-size: var(--text-sm);
  font-weight: var(--weight-heading);
  letter-spacing: 0.1em;
  color: var(--color-primary);
}

.page-about .st-chapter__title {
  margin: 0 0 var(--space-4);
  font-family: var(--font-heading);
  font-size: var(--text-3xl);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  font-weight: var(--weight-heading);
  color: var(--color-ink);
}

.page-about .st-prose {
  max-width: var(--measure);
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: var(--color-ink);
}

.page-about .st-prose p {
  margin: 0 0 var(--space-2);
}

.page-about .st-prose p:last-child {
  margin-bottom: 0;
}

/* ---------- 术语悬停解释 ---------- */
.page-about .st-term {
  position: relative;
  display: inline-block;
  border-bottom: var(--border-thin) dashed var(--color-primary);
  color: var(--color-primary);
  cursor: help;
}

.page-about .st-term:focus-visible {
  outline: 2px solid var(--color-focus);
  outline-offset: 2px;
}

.page-about .st-term__tip {
  position: absolute;
  left: 0;
  bottom: calc(100% + var(--space-1));
  z-index: 6;
  width: max-content;
  max-width: min(280px, 72vw);
  padding: var(--space-2);
  font-size: var(--text-xs);
  font-weight: var(--weight-body);
  line-height: 1.65;
  color: var(--color-contrast-ink);
  background: var(--color-contrast-surface);
  border-radius: var(--radius-sm);
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transition: opacity 180ms ease;
}

.page-about .st-term:hover .st-term__tip,
.page-about .st-term:focus-visible .st-term__tip {
  opacity: 1;
  visibility: visible;
}

/* ---------- 插图 ---------- */
.page-about .st-figure {
  margin: var(--space-4) 0 0;
}

.page-about .st-figure img {
  display: block;
  width: 100%;
  height: auto;
  background: var(--color-surface-deep);
}

.page-about .st-figure figcaption {
  margin-top: var(--space-2);
  font-size: var(--text-xs);
  line-height: 1.7;
  color: var(--color-ink-muted);
}

/* ---------- 数字窄条 ---------- */
.page-about .st-figures {
  padding-block: var(--space-6);
  padding-inline: var(--gutter);
  background: var(--color-surface);
}

.page-about .st-figures__inner {
  width: 100%;
  max-width: calc(var(--container) - var(--space-4));
  margin-inline: auto;
  padding: var(--space-4) var(--space-3);
  background: var(--color-surface-deep);
  border-radius: var(--radius-lg);
  display: grid;
  gap: var(--space-4);
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.page-about .st-figure-item__num {
  display: block;
  font-family: var(--font-mono);
  font-size: var(--text-3xl);
  font-weight: var(--weight-heading);
  line-height: 1.05;
  font-variant-numeric: tabular-nums;
  color: var(--color-primary);
}

.page-about .st-figure-item__label {
  display: block;
  margin-top: var(--space-1);
  font-size: var(--text-sm);
  line-height: 1.65;
  color: var(--color-ink-soft);
}

@media (min-width: 900px) {
  .page-about .st-figures__inner {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    padding: var(--space-4);
  }

  .page-about .st-figures--shift-end .st-figures__inner {
    margin-inline-start: 0;
    margin-inline-end: var(--space-3);
  }
}

/* ---------- 收束带 ---------- */
.page-about .st-close {
  margin-top: var(--space-4);
  padding-block: var(--section-y-lg);
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
}

.page-about .st-eyebrow--deep {
  color: var(--color-contrast-accent);
}

.page-about .st-close__title {
  margin: 0 0 var(--space-2);
  font-family: var(--font-heading);
  font-size: var(--text-3xl);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  font-weight: var(--weight-heading);
  color: var(--color-contrast-ink);
}

.page-about .st-close__note {
  margin: 0;
  max-width: var(--measure);
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: var(--color-contrast-ink);
}

.page-about .st-close__note a {
  color: var(--color-contrast-accent);
  text-underline-offset: 3px;
}

.page-about .st-exits {
  margin: var(--space-6) 0 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: var(--space-3);
  grid-template-columns: repeat(2, minmax(0, 1fr));
  align-items: start;
}

.page-about .st-exit a {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  padding: var(--space-3);
  border: var(--border-thin) solid var(--color-contrast-line);
  border-radius: var(--radius-md);
  color: var(--color-contrast-ink);
  text-decoration: none;
  transition: border-color 180ms ease, background-color 180ms ease;
}

.page-about .st-exit a:hover {
  border-color: var(--color-contrast-accent);
  background: color-mix(in srgb, var(--color-contrast-accent) 8%, transparent);
}

.page-about .st-exit a:focus-visible {
  outline: 2px solid var(--color-contrast-accent);
  outline-offset: 2px;
}

.page-about .st-exit__label {
  font-family: var(--font-heading);
  font-size: var(--text-lg);
  font-weight: var(--weight-heading);
  color: var(--color-contrast-ink);
}

.page-about .st-exit__desc {
  font-size: var(--text-sm);
  line-height: 1.7;
  color: var(--color-contrast-ink);
  opacity: 0.78;
}

.page-about .st-exit__go {
  font-family: var(--font-mono);
  font-size: var(--text-base);
  color: var(--color-contrast-accent);
}

@keyframes st-rise {
  from {
    opacity: 0;
    transform: translateY(16px);
  }
  to {
    opacity: 1;
    transform: none;
  }
}

@media (min-width: 720px) and (prefers-reduced-motion: no-preference) {
  .page-about .st-exit.is-in {
    animation: st-rise 420ms cubic-bezier(0.22, 0.8, 0.3, 1) both;
  }

  .page-about .st-exit:nth-child(2).is-in {
    animation-delay: 70ms;
  }

  .page-about .st-exit:nth-child(3).is-in {
    animation-delay: 140ms;
  }

  .page-about .st-exit:nth-child(4).is-in {
    animation-delay: 210ms;
  }
}

@media (min-width: 900px) {
  .page-about .st-open {
    grid-template-columns: minmax(0, 1.4fr) minmax(0, 0.85fr);
    align-items: start;
    gap: var(--space-8);
    padding-top: var(--space-8);
    padding-bottom: var(--space-8);
  }

  .page-about .st-exits {
    grid-template-columns: 1.15fr 0.9fr 1.35fr 1fr;
    gap: var(--space-4);
  }

  .page-about .st-exit:nth-child(2) {
    margin-top: var(--space-4);
  }

  .page-about .st-exit:nth-child(3) {
    margin-top: var(--space-2);
  }

  .page-about .st-exit:nth-child(4) {
    margin-top: var(--space-6);
  }
}

@media (max-width: 480px) {
  .page-about .st-exits {
    grid-template-columns: minmax(0, 1fr);
  }
}
</｜｜DSML｜｜ parameter>
</invoke>