.page-about {
  --rail-w: 168px;
  --about-gap: 56px;
  background: var(--paper);
  color: var(--text-1);
  padding-bottom: 64px;
}

.page-about .about-hero {
  padding: 8px 0 36px;
}

.page-about .about-hero__title {
  font-family: var(--font-display);
  font-size: 28px;
  font-weight: 600;
  letter-spacing: 0.01em;
  line-height: 1.3;
  color: var(--text-1);
  margin: 10px 0 16px;
  max-width: 20ch;
}

.page-about .about-hero__lede {
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.85;
  color: var(--text-2);
  max-width: 68ch;
  margin: 0 0 28px;
}

.page-about .about-meta {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 20px 40px;
}

.page-about .about-meta__item {
  display: flex;
  flex-direction: column;
  gap: 4px;
  border-top: 2px solid var(--ink);
  padding-top: 10px;
  min-width: 120px;
}

.page-about .about-meta__num {
  font-family: var(--font-mono);
  font-size: 22px;
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.06em;
  color: var(--ink);
}

.page-about .about-meta__label {
  font-size: 12px;
  line-height: 1.5;
  color: var(--text-2);
}

/* 左侧刻度栏：移动端为横向滑动条 */
.page-about .about-body {
  display: block;
}

.page-about .year-rail {
  border-top: 1px solid var(--rule);
  border-bottom: 1px solid var(--rule);
  padding: 16px 0 14px;
  margin-bottom: 32px;
}

.page-about .year-rail__title {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--text-2);
  margin: 0 0 10px;
}

.page-about .year-rail__title--sub {
  margin-top: 18px;
}

.page-about .year-rail__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  gap: 4px;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

.page-about .year-link {
  display: flex;
  flex-direction: column;
  gap: 2px;
  padding: 6px 14px 6px 0;
  text-decoration: none;
  white-space: nowrap;
  border-bottom: 2px solid transparent;
  transition: border-color 200ms var(--ease), color 200ms var(--ease);
}

.page-about .year-link__num {
  font-family: var(--font-mono);
  font-size: 13px;
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.08em;
  color: var(--ink);
}

.page-about .year-link__label {
  font-size: 11px;
  line-height: 1.4;
  color: var(--text-2);
}

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

.page-about .year-link:focus-visible {
  outline: 2px solid var(--amber);
  outline-offset: 2px;
}

/* 内容区块 */
.page-about .about-sec {
  padding: 34px 0;
  border-top: 1px solid var(--rule);
}

.page-about .about-sec:first-child {
  border-top: 0;
  padding-top: 4px;
}

.page-about .about-sec--end {
  border-top: 1px solid var(--rule);
  padding: 56px 0 0;
}

.page-about .about-sec .section-head {
  margin-bottom: 24px;
}

.page-about .about-sec .section-title {
  font-size: 22px;
  line-height: 1.35;
}

.page-about .about-sec .section-lede {
  font-family: var(--font-body);
  font-size: 15px;
  line-height: 1.8;
  color: var(--text-2);
  max-width: 62ch;
}

/* 时间线 */
.page-about .about-timeline__figure {
  margin: 0 0 26px;
}

.page-about .timeline {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .timeline__item {
  display: grid;
  grid-template-columns: 72px minmax(0, 1fr);
  gap: 14px;
  padding: 18px 0;
  border-top: 1px solid var(--rule);
}

.page-about .timeline__item:last-child {
  border-bottom: 1px solid var(--rule);
}

.page-about .timeline__item--now {
  border-left: 3px solid var(--alert);
  padding-left: 14px;
  margin-left: -17px;
}

.page-about .timeline__year {
  font-family: var(--font-mono);
  font-size: 14px;
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.06em;
  color: var(--teal);
  padding-top: 2px;
}

.page-about .timeline__title {
  font-family: var(--font-display);
  font-size: 16px;
  font-weight: 600;
  line-height: 1.4;
  color: var(--text-1);
  margin: 0 0 6px;
}

.page-about .timeline__body p {
  font-family: var(--font-body);
  font-size: 15px;
  line-height: 1.8;
  color: var(--text-2);
  margin: 0;
  max-width: 60ch;
}

.page-about .about-archive {
  display: grid;
  gap: 20px;
  margin-top: 28px;
}

.page-about .about-archive__title {
  font-family: var(--font-display);
  font-size: 16px;
  font-weight: 600;
  color: var(--text-1);
  margin: 0 0 8px;
}

.page-about .about-archive__text p {
  font-family: var(--font-body);
  font-size: 15px;
  line-height: 1.8;
  color: var(--text-2);
  margin: 0;
}

/* 三组分工 */
.page-about .about-teams {
  gap: 16px;
}

.page-about .about-team {
  background: var(--paper-2);
  border: 1px solid var(--rule);
  padding: 18px 16px;
}

.page-about .about-team .card__index {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--teal);
  display: block;
  margin-bottom: 10px;
}

.page-about .about-team .card__title {
  font-family: var(--font-display);
  font-size: 16px;
  font-weight: 600;
  color: var(--text-1);
  margin: 0 0 8px;
}

.page-about .about-team .card__text {
  font-family: var(--font-body);
  font-size: 14px;
  line-height: 1.8;
  color: var(--text-2);
  margin: 0;
}

/* 五步流程 */
.page-about .flow-steps {
  list-style: none;
  margin: 0 0 24px;
  padding: 0;
  display: grid;
  gap: 12px;
}

.page-about .flow-step {
  position: relative;
  background: var(--paper-2);
  border: 1px solid var(--rule);
  padding: 16px 14px;
}

.page-about .flow-step__num {
  display: block;
  font-family: var(--font-mono);
  font-size: 12px;
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.12em;
  color: var(--teal);
  margin-bottom: 8px;
}

.page-about .flow-step__title {
  font-family: var(--font-display);
  font-size: 15px;
  font-weight: 600;
  color: var(--text-1);
  margin: 0 0 6px;
}

.page-about .flow-step__text {
  font-family: var(--font-body);
  font-size: 13px;
  line-height: 1.75;
  color: var(--text-2);
  margin: 0;
}

.page-about .about-workflow__figure {
  max-width: 520px;
}

/* 版本对照表 */
.page-about .about-versions-table {
  min-width: 620px;
}

.page-about .about-versions-table th[scope="row"] {
  font-family: var(--font-display);
  font-size: 13px;
  font-weight: 600;
  line-height: 1.5;
  color: var(--text-1);
  text-align: left;
  white-space: nowrap;
}

.page-about .about-versions-table th[scope="row"] .mono {
  font-size: 11px;
  color: var(--text-2);
  font-weight: 400;
}

.page-about .about-versions-table tbody tr {
  transition: background-color 120ms var(--ease);
}

.page-about .about-versions-table tbody tr:hover {
  background: var(--sand);
}

.page-about .about-table-note {
  font-family: var(--font-body);
  font-size: 12.5px;
  line-height: 1.7;
  color: var(--text-2);
  margin: 12px 0 0;
}

/* 服务地区 */
.page-about .about-reach {
  display: grid;
  gap: 24px;
}

.page-about .about-reach__prose p {
  font-family: var(--font-body);
  font-size: 15px;
  line-height: 1.85;
  color: var(--text-2);
  margin: 0 0 14px;
}

.page-about .reach-list {
  margin: 0;
  border-top: 1px solid var(--rule);
}

.page-about .reach-list > div {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
  padding: 11px 0;
  border-bottom: 1px solid var(--rule);
}

.page-about .reach-list dt {
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.1em;
  color: var(--text-2);
}

.page-about .reach-list dd {
  font-family: var(--font-mono);
  font-size: 13.5px;
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.04em;
  color: var(--ink);
  margin: 0;
  text-align: right;
}

/* 联系与反馈：留白放大 */
.page-about .about-contact {
  max-width: 720px;
}

.page-about .about-contact__prose {
  margin: 20px 0 24px;
}

.page-about .about-contact__prose p {
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.9;
  color: var(--text-2);
  margin: 0 0 20px;
}

.page-about .about-contact__mail {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px 16px;
  padding: 16px 0;
  border-top: 1px solid var(--rule);
  border-bottom: 1px solid var(--rule);
}

.page-about .about-contact__addr {
  font-family: var(--font-mono);
  font-size: 13.5px;
  letter-spacing: 0.04em;
  color: var(--ink);
  word-break: break-all;
}

.page-about .about-contact__note {
  font-family: var(--font-body);
  font-size: 12.5px;
  line-height: 1.7;
  color: var(--text-2);
  margin: 12px 0 0;
}

.page-about .about-contact__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 28px;
}

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

@media (min-width: 700px) {
  .page-about .about-hero__title {
    font-size: 36px;
  }

  .page-about .about-sec .section-title {
    font-size: 26px;
  }

  .page-about .timeline__item {
    grid-template-columns: 92px minmax(0, 1fr);
    gap: 20px;
  }

  .page-about .about-archive {
    grid-template-columns: minmax(0, 1.1fr) minmax(0, 1fr);
    align-items: center;
    gap: 28px;
  }

  .page-about .flow-steps {
    grid-template-columns: repeat(5, minmax(0, 1fr));
    gap: 10px;
  }

  .page-about .flow-step {
    padding: 14px 12px;
  }

  .page-about .flow-step:not(:last-child)::after {
    content: "";
    position: absolute;
    top: 14px;
    bottom: 14px;
    right: -6px;
    width: 1px;
    background: var(--rule);
    transform: skewX(-8deg);
  }

  .page-about .about-reach {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr);
    gap: 32px;
    align-items: start;
  }
}

@media (min-width: 960px) {
  .page-about .about-hero {
    padding: 12px 0 48px;
  }

  .page-about .about-hero__title {
    font-size: 44px;
    max-width: 24ch;
  }

  .page-about .about-body {
    display: grid;
    grid-template-columns: var(--rail-w) minmax(0, 1fr);
    gap: var(--about-gap);
    align-items: start;
  }

  .page-about .year-rail {
    position: sticky;
    top: 88px;
    border-top: 1px solid var(--rule);
    border-bottom: 0;
    margin: 0;
    padding: 14px 0 0;
  }

  .page-about .year-rail__list {
    flex-direction: column;
    overflow: visible;
    gap: 0;
  }

  .page-about .year-link {
    flex-direction: row;
    align-items: baseline;
    gap: 10px;
    padding: 10px 0 10px 14px;
    border-bottom: 0;
    border-left: 1px solid var(--rule);
    position: relative;
  }

  .page-about .year-link::before {
    content: "";
    position: absolute;
    left: 0;
    top: 50%;
    width: 6px;
    height: 1px;
    background: var(--rule);
    transition: width 200ms var(--ease), background-color 200ms var(--ease);
  }

  .page-about .year-link:hover,
  .page-about .year-link:focus-visible {
    border-left-color: var(--amber);
  }

  .page-about .year-link:hover::before,
  .page-about .year-link:focus-visible::before {
    width: 12px;
    background: var(--amber);
  }

  .page-about .about-sec {
    padding: 44px 0;
  }

  .page-about .about-sec:first-child {
    padding-top: 8px;
  }

  .page-about .about-sec--end {
    padding: 72px 0 0;
  }

  .page-about .about-contact__prose p {
    font-size: 17px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .year-link,
  .page-about .year-link::before,
  .page-about .about-versions-table tbody tr {
    transition: none;
  }

  .page-about .flow-step:not(:last-child)::after {
    transform: none;
  }
}
<<<END>>>