.page-about {
  --about-rule: 1px solid var(--line);
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-body);
}

/* ── 页首 ───────────────────────────── */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  background: var(--sand);
  border-bottom: var(--about-rule);
  isolation: isolate;
}

.page-about .about-hero__bg {
  position: absolute;
  inset: 0;
  z-index: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center;
  opacity: 0.3;
  pointer-events: none;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 0;
  background: linear-gradient(180deg, rgba(251, 247, 240, 0.45) 0%, rgba(251, 247, 240, 0.9) 78%);
  pointer-events: none;
}

.page-about .about-hero__inner {
  position: relative;
  z-index: 1;
  padding-block: clamp(26px, 6vw, 74px);
}

.page-about .about-hero__title {
  margin: 16px 0 0;
  font-size: clamp(30px, 5.6vw, 58px);
  line-height: 1.1;
  letter-spacing: -0.02em;
  font-weight: 300;
  max-width: 15em;
  color: var(--ink);
}

.page-about .about-hero__lede {
  margin: 20px 0 0;
  max-width: 640px;
  font-size: clamp(15px, 1.6vw, 17px);
  line-height: 1.78;
  color: var(--graphite);
}

.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 26px;
}

/* ── 主体版式 ───────────────────────── */
.page-about .about-body {
  padding-block: clamp(22px, 4vw, 52px) clamp(34px, 6vw, 72px);
}

.page-about .about-index__label {
  margin: 0 0 10px;
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--graphite);
}

.page-about .about-index__list {
  list-style: none;
  margin: 0;
  padding: 0 0 6px;
  display: flex;
  gap: 8px;
  overflow-x: auto;
  scrollbar-width: thin;
}

.page-about .about-index__link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  white-space: nowrap;
  padding: 6px 12px 6px 10px;
  border: var(--about-rule);
  background: var(--paper);
  color: var(--indigo);
  font-size: 13px;
  text-decoration: none;
  transition: border-color var(--dur) var(--ease), color var(--dur) var(--ease), background-color var(--dur) var(--ease);
}

.page-about .about-index__link .mono {
  color: var(--brick);
  font-size: 12px;
}

.page-about .about-index__link:hover,
.page-about .about-index__link:focus-visible {
  border-color: var(--brick);
  color: var(--brick-deep);
  background: var(--sand);
}

/* ── 章节 ───────────────────────────── */
.page-about .about-sections {
  min-width: 0;
  margin-top: 22px;
}

.page-about .about-section {
  padding-block: clamp(26px, 4vw, 46px);
  padding-inline: clamp(14px, 2.5vw, 28px);
  border-top: var(--about-rule);
}

.page-about .about-section:first-child {
  border-top: 0;
  padding-top: 0;
}

.page-about .about-section--sand {
  background: var(--sand);
}

.page-about .about-section h2 {
  margin: 0 0 16px;
  font-size: clamp(21px, 2.8vw, 30px);
  line-height: 1.28;
  letter-spacing: -0.01em;
  font-weight: 500;
  color: var(--ink);
}

.page-about .about-section p {
  margin: 0 0 14px;
  font-size: 16px;
  line-height: 1.78;
  color: var(--ink);
  max-width: 62ch;
}

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

/* ── 三件日常 ───────────────────────── */
.page-about .duty-list {
  list-style: none;
  margin: 22px 0 20px;
  padding: 0;
  display: grid;
  gap: 18px;
}

.page-about .duty-list__item {
  display: grid;
  grid-template-columns: 32px minmax(0, 1fr);
  gap: 12px;
  align-items: start;
}

.page-about .duty-list__idx {
  padding-top: 3px;
  font-size: 15px;
  color: var(--brick);
}

.page-about .duty-list__title {
  margin: 0 0 4px;
  font-size: 17px;
  font-weight: 600;
  line-height: 1.4;
  color: var(--ink);
}

.page-about .duty-list__item p {
  margin: 0;
  font-size: 15.5px;
  color: var(--graphite);
}

/* ── 时间线 ─────────────────────────── */
.page-about .timeline {
  list-style: none;
  margin: 26px 0 24px;
  padding: 0 0 0 26px;
  border-left: 1px solid var(--line);
}

.page-about .timeline__item {
  position: relative;
  padding-bottom: 26px;
}

.page-about .timeline__item:last-child {
  padding-bottom: 0;
}

.page-about .timeline__item::before {
  content: "";
  position: absolute;
  left: calc(-26px - 4.5px);
  top: 14px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--brick);
  transition: transform var(--dur) var(--ease);
}

.page-about .timeline__item:hover::before {
  transform: scale(1.35);
}

.page-about .timeline__year {
  display: block;
  font-size: clamp(26px, 3.6vw, 42px);
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--indigo);
}

.page-about .timeline__title {
  margin: 8px 0 6px;
  font-size: 16px;
  font-weight: 600;
  line-height: 1.5;
  color: var(--ink);
}

.page-about .timeline__item p:last-child {
  font-size: 15.5px;
  color: var(--graphite);
}

/* ── 覆盖与规模 ─────────────────────── */
.page-about .reach-stats {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0;
  margin: 20px 0 22px;
  border-top: var(--about-rule);
  border-left: var(--about-rule);
}

.page-about .reach-stats__cell {
  display: flex;
  align-items: baseline;
  gap: 10px;
  padding: 14px 16px;
  border-right: var(--about-rule);
  border-bottom: var(--about-rule);
  background: var(--paper);
}

.page-about .reach-stats__num {
  font-size: 26px;
  line-height: 1.1;
  color: var(--brick);
  letter-spacing: -0.01em;
}

.page-about .reach-stats__unit {
  font-size: 13.5px;
  color: var(--graphite);
}

.page-about .reach-chips {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 0 0 8px;
  padding: 0;
}

.page-about .reach-chips li {
  padding: 4px 11px;
  border: 1px solid var(--line);
  background: var(--paper);
  font-size: 13.5px;
  color: var(--indigo);
}

.page-about .quote-band {
  margin: 24px 0 0;
  padding: 16px 20px;
  background: var(--sand);
  border-left: 4px solid var(--indigo);
}

.page-about .quote-band p {
  margin: 0;
  font-size: 16px;
  line-height: 1.75;
  color: var(--ink);
}

/* ── 栏目说明 ───────────────────────── */
.page-about .columns-wrap {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0;
}

.page-about .column-list {
  list-style: none;
  margin: 20px 0 20px;
  padding: 0;
  display: grid;
  gap: 16px;
}

.page-about .column-list__title {
  margin: 0 0 4px;
  font-size: 16.5px;
  font-weight: 600;
  line-height: 1.4;
  color: var(--ink);
  padding-left: 12px;
  border-left: 3px solid var(--brick-soft);
}

.page-about .column-list p {
  margin: 0;
  font-size: 15.5px;
  color: var(--graphite);
  padding-left: 15px;
}

/* ── 图 ─────────────────────────────── */
.page-about .fig {
  margin: 26px 0 0;
}

.page-about .fig__frame {
  border: var(--about-rule);
  background: var(--paper);
  overflow: hidden;
  box-shadow: 4px 4px 0 rgba(185, 199, 222, 0.4);
}

.page-about .fig__frame img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: cover;
}

.page-about .fig__caption {
  margin-top: 10px;
  font-size: 13px;
  line-height: 1.65;
  color: var(--graphite);
}

/* ── 联系 ───────────────────────────── */
.page-about .support-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
  margin: 22px 0 24px;
}

.page-about .support-card {
  padding: 15px 17px;
  background: var(--paper);
  border: var(--about-rule);
  border-top: 3px solid var(--indigo);
}

.page-about .support-card__label {
  margin: 0 0 8px;
  font-size: 11.5px;
  letter-spacing: 0.16em;
  color: var(--graphite);
}

.page-about .support-card__value {
  margin: 0;
  font-size: 16.5px;
  line-height: 1.5;
  color: var(--ink);
  word-break: break-word;
}

.page-about .support-card__value.mono {
  font-size: 18px;
  letter-spacing: 0.02em;
}

.page-about .support-card__note {
  margin: 8px 0 0;
  font-size: 13px;
  line-height: 1.65;
  color: var(--graphite);
}

.page-about .support-card:last-child {
  border-top-color: var(--brick-soft);
}

.page-about .fold {
  margin-top: 12px;
}

.page-about .support-tail {
  margin-top: 22px;
  font-size: 15px;
  color: var(--graphite);
}

.page-about .tail-link {
  color: var(--indigo-mid);
  text-decoration: none;
  border-bottom: 1px solid var(--line);
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .tail-link:hover,
.page-about .tail-link:focus-visible {
  color: var(--brick);
  border-bottom-color: var(--brick);
}

/* ── 断点 ───────────────────────────── */
@media (min-width: 600px) {
  .page-about .reach-stats {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .support-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 820px) {
  .page-about .columns-wrap {
    grid-template-columns: minmax(0, 1fr) 300px;
    column-gap: 28px;
    align-items: start;
  }

  .page-about .fig--side {
    margin-top: 22px;
  }
}

@media (min-width: 960px) {
  .page-about .about-layout {
    display: grid;
    grid-template-columns: 208px minmax(0, 1fr);
    column-gap: clamp(28px, 4vw, 60px);
    align-items: start;
  }

  .page-about .about-index {
    position: sticky;
    top: 24px;
  }

  .page-about .about-index__list {
    display: block;
    overflow: visible;
    padding-bottom: 0;
  }

  .page-about .about-index__list li {
    margin-bottom: 2px;
  }

  .page-about .about-index__link {
    display: flex;
    width: 100%;
    padding: 8px 10px;
    border: 0;
    border-left: 2px solid transparent;
    background: transparent;
    color: var(--graphite);
    font-size: 14px;
    white-space: normal;
  }

  .page-about .about-index__link:hover,
  .page-about .about-index__link:focus-visible {
    border-left-color: var(--brick);
    background: var(--sand);
    color: var(--brick-deep);
  }

  .page-about .about-sections {
    margin-top: 0;
  }

  .page-about .about-section:first-child {
    padding-top: 0;
  }

  .page-about .duty-list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 22px;
  }

  .page-about .duty-list__item {
    grid-template-columns: minmax(0, 1fr);
    gap: 6px;
  }

  .page-about .duty-list__idx {
    padding-top: 0;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-index__link,
  .page-about .tail-link,
  .page-about .timeline__item::before {
    transition: none;
  }

  .page-about .timeline__item:hover::before {
    transform: none;
  }
}