.page-about {
  position: relative;
  overflow-x: clip;
}

.page-about .about-path {
  display: none;
}

@media (min-width: 1280px) {
  .page-about .about-path {
    display: block;
    position: absolute;
    top: 0;
    bottom: 0;
    right: max(12px, calc((100% - var(--container)) / 2 - 30px));
    width: 14px;
    background: linear-gradient(
      180deg,
      color-mix(in srgb, var(--color-primary) 80%, transparent) 0%,
      color-mix(in srgb, var(--color-primary) 26%, transparent) 100%
    );
    clip-path: polygon(0 0, 100% 0, 80% 100%, 64% 100%);
    pointer-events: none;
    z-index: 0;
  }
}

.page-about .crumbs {
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: var(--gutter);
  padding-block: var(--space-4) 0;
  position: relative;
  z-index: 1;
}

.page-about .about-intro,
.page-about .about-band,
.page-about .about-links {
  position: relative;
  z-index: 1;
}

/* ---------- 开篇 ---------- */

.page-about .about-intro {
  padding-block: var(--section-y) var(--section-y-lg);
}

.page-about .about-intro-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-6);
  align-items: start;
}

@media (min-width: 900px) {
  .page-about .about-intro-grid {
    grid-template-columns: minmax(0, 1.02fr) minmax(0, 0.98fr);
    gap: var(--space-8);
    align-items: center;
  }
}

.page-about .about-kicker {
  font-size: var(--text-xs);
  letter-spacing: 0.16em;
  color: var(--color-primary);
  margin: 0 0 var(--space-3);
}

.page-about .about-intro h1 {
  font-size: clamp(var(--text-2xl), 4.6vw, var(--text-4xl));
  line-height: var(--leading-heading);
  font-weight: var(--weight-heading);
  letter-spacing: var(--tracking-heading);
  color: var(--color-ink);
  margin: 0 0 var(--space-3);
  max-width: 16ch;
}

.page-about .about-lede {
  font-size: var(--text-lg);
  line-height: var(--leading-body);
  color: var(--color-ink-soft);
  margin: 0 0 var(--space-3);
  max-width: 46ch;
}

.page-about .about-lede-2 {
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: var(--color-ink-soft);
  margin: 0 0 var(--space-4);
  max-width: var(--measure);
}

.page-about .about-metrics {
  list-style: none;
  margin: 0;
  padding: var(--space-3) 0 0;
  border-top: 1px solid var(--color-line);
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(110px, 1fr));
  gap: var(--space-3);
}

.page-about .about-metrics li {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.page-about .metric-num {
  font-size: var(--text-2xl);
  font-weight: var(--weight-heading);
  line-height: 1;
  color: var(--color-ink);
}

.page-about .metric-lab {
  font-size: var(--text-xs);
  line-height: 1.55;
  color: var(--color-ink-muted);
}

/* ---------- 图框 ---------- */

.page-about .figure-frame {
  margin: 0;
  padding: var(--space-2);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-lg);
  background: var(--color-surface-alt);
}

.page-about .figure-frame img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  border-radius: var(--radius-md);
  object-fit: cover;
}

.page-about .figure-cap {
  margin-top: var(--space-2);
  font-size: var(--text-xs);
  line-height: 1.6;
  color: var(--color-ink-muted);
}

/* ---------- 章节 ---------- */

.page-about .about-band,
.page-about .about-links {
  padding-block: var(--section-y);
}

.page-about .section-head {
  margin-bottom: var(--space-6);
  max-width: var(--measure);
}

.page-about .section-head h2 {
  font-size: clamp(var(--text-xl), 3.4vw, var(--text-3xl));
  line-height: var(--leading-heading);
  font-weight: var(--weight-heading);
  letter-spacing: var(--tracking-heading);
  color: var(--color-ink);
  margin: 0 0 var(--space-2);
}

.page-about .section-lede {
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: var(--color-ink-soft);
  margin: 0;
}

/* ---------- 条目 ---------- */

.page-about .entry-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-6);
}

.page-about .entry {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-2);
  padding-top: var(--space-4);
  border-top: 1px solid var(--color-line);
}

@media (min-width: 800px) {
  .page-about .entry {
    grid-template-columns: 96px minmax(0, 1fr);
    gap: var(--space-4);
    align-items: start;
  }
}

.page-about .entry-num {
  display: block;
  font-size: var(--text-3xl);
  font-weight: var(--weight-heading);
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--color-primary);
}

.page-about .entry-title {
  font-size: clamp(var(--text-lg), 2.4vw, var(--text-xl));
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
  color: var(--color-ink);
  margin: 0 0 var(--space-2);
}

.page-about .entry-body p {
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: var(--color-ink-soft);
  margin: 0 0 var(--space-2);
  max-width: var(--measure);
}

.page-about .entry-body p.entry-fact {
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  letter-spacing: 0.02em;
  color: var(--color-ink-muted);
  border-left: 2px solid var(--color-primary);
  padding-left: var(--space-2);
  margin-top: var(--space-3);
  margin-bottom: 0;
  max-width: var(--measure);
}

.page-about .key-mark {
  background: var(--color-primary-soft);
  color: var(--color-ink);
  padding: 0.1em 0.32em;
  box-decoration-break: clone;
  -webkit-box-decoration-break: clone;
  box-shadow: inset 0 -2px 0 0 color-mix(in srgb, var(--color-primary) 42%, transparent);
}

/* ---------- 悬停注释 ---------- */

.page-about .key-hint {
  position: relative;
  font-family: var(--font-mono);
  color: var(--color-ink);
  border-bottom: 1px dashed color-mix(in srgb, var(--color-primary) 55%, transparent);
  cursor: help;
}

.page-about .key-hint::after {
  content: attr(data-note);
  position: absolute;
  left: 0;
  bottom: calc(100% + 8px);
  max-width: 26ch;
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  font-family: var(--font-body);
  font-size: var(--text-xs);
  line-height: 1.45;
  padding: 6px 10px;
  border-radius: var(--radius-sm);
  opacity: 0;
  visibility: hidden;
  transform: translateY(4px);
  transition: opacity 160ms ease, transform 160ms ease, visibility 160ms;
  pointer-events: none;
  z-index: 5;
}

.page-about .key-hint:hover::after,
.page-about .key-hint:focus-visible::after {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

/* ---------- 原则区配图错位 ---------- */

.page-about .principle-figure {
  margin-block: var(--space-2);
}

@media (min-width: 900px) {
  .page-about .principle-figure {
    margin-left: auto;
    margin-right: 0;
    max-width: 620px;
  }
}

.page-about .stage-figure {
  margin-bottom: var(--space-6);
}

/* ---------- 出口链接 ---------- */

.page-about .link-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-3);
}

@media (min-width: 700px) {
  .page-about .link-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 1080px) {
  .page-about .link-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

.page-about .link-card {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  padding: var(--space-3);
  border: 1px solid var(--color-line);
  border-radius: var(--radius-md);
  background: var(--color-surface);
  color: inherit;
  text-decoration: none;
  transition: border-color 160ms ease, background-color 160ms ease, transform 160ms ease;
}

.page-about .link-card:hover,
.page-about .link-card:focus-visible {
  border-color: var(--color-primary);
  background: var(--color-primary-soft);
  transform: translateY(-2px);
}

.page-about .link-idx {
  font-size: var(--text-xs);
  letter-spacing: 0.14em;
  color: var(--color-primary);
}

.page-about .link-card h3 {
  font-size: var(--text-lg);
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
  color: var(--color-ink);
  margin: 0;
}

.page-about .link-card p {
  font-size: var(--text-sm);
  line-height: 1.65;
  color: var(--color-ink-soft);
  margin: 0;
}

/* ---------- 动效克制 ---------- */

@media (prefers-reduced-motion: reduce) {
  .page-about .key-hint::after,
  .page-about .link-card {
    transition: none;
  }

  .page-about .link-card:hover,
  .page-about .link-card:focus-visible {
    transform: none;
  }
}