.page-about {
  --about-rule: 1px solid var(--line);
  --about-side-w: 300px;
  color: var(--white);
  background: var(--bg);
}

.page-about .breadcrumb {
  margin: 26px 0 18px;
}

/* ---------- 首屏框景 ---------- */
.page-about .about-hero {
  border: 1px solid var(--line);
  background: var(--panel);
  padding: 26px 20px 24px;
  position: relative;
}

.page-about .about-hero .eyebrow {
  margin: 0 0 14px;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--cyan);
  text-transform: uppercase;
}

.page-about .about-hero h1 {
  margin: 0 0 16px;
  font-size: clamp(28px, 7vw, 52px);
  font-weight: 900;
  line-height: 1.14;
  letter-spacing: 0.05em;
  max-width: 14em;
}

.page-about .about-hero__lead {
  margin: 0;
  max-width: 40em;
  font-size: 15px;
  line-height: 1.8;
  color: var(--muted);
}

.page-about .about-hero__facts {
  list-style: none;
  margin: 22px 0 0;
  padding: 18px 0 0;
  border-top: var(--about-rule);
  display: flex;
  flex-wrap: wrap;
  gap: 12px 30px;
}

.page-about .about-hero__facts li {
  display: flex;
  align-items: baseline;
  gap: 8px;
  font-size: 13px;
  color: var(--muted);
}

.page-about .about-hero__facts b {
  font-family: var(--mono);
  font-size: 22px;
  font-weight: 700;
  color: var(--cyan);
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.02em;
}

/* ---------- 主区骨架 ---------- */
.page-about .about-body {
  display: grid;
  gap: 30px;
  margin-top: 32px;
}

.page-about .about-flow {
  display: block;
}

.page-about .about-section {
  padding: 26px 0;
  border-top: var(--about-rule);
}

.page-about .about-section:first-child {
  border-top: 1px solid var(--line);
  padding-top: 0;
}

.page-about .about-section__title {
  display: flex;
  align-items: center;
  gap: 10px;
  margin: 0 0 14px;
  font-size: clamp(20px, 4.6vw, 28px);
  font-weight: 800;
  letter-spacing: 0.06em;
  line-height: 1.3;
}

.page-about .about-section__title::before {
  content: "";
  flex: none;
  width: 2px;
  height: 0.92em;
  background: var(--cyan);
}

.page-about .about-section__lead {
  margin: 0 0 10px;
  font-size: 16px;
  font-weight: 600;
  line-height: 1.7;
  color: var(--white);
  max-width: 34em;
}

.page-about .about-section p {
  margin: 0 0 10px;
  max-width: 36em;
  font-size: 15px;
  line-height: 1.8;
  color: var(--muted);
}

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

/* ---------- 分工条目 ---------- */
.page-about .duty-list {
  list-style: none;
  margin: 18px 0 0;
  padding: 0;
}

.page-about .duty {
  display: grid;
  grid-template-columns: 58px minmax(0, 1fr);
  gap: 2px 16px;
  padding: 16px 0;
  border-top: var(--about-rule);
  scroll-margin-top: 120px;
}

.page-about .duty__num {
  grid-row: 1 / span 2;
  font-family: var(--mono);
  font-size: 30px;
  font-weight: 700;
  line-height: 1.05;
  color: var(--cyan);
  font-variant-numeric: tabular-nums;
}

.page-about .duty__role {
  font-size: 15px;
  font-weight: 700;
  letter-spacing: 0.03em;
}

.page-about .duty__text {
  font-size: 14px;
  line-height: 1.75;
  color: var(--muted);
}

/* ---------- 四步流程 ---------- */
.page-about .flow-grid {
  display: grid;
  gap: 22px;
  margin-top: 18px;
}

.page-about .media-frame {
  display: block;
  margin: 0;
  border: 1px solid var(--line);
  background: var(--bg-deep);
  overflow: hidden;
}

.page-about .media-frame__img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 3 / 2;
  object-fit: cover;
}

.page-about .media-frame--wide .media-frame__img {
  aspect-ratio: 16 / 9;
}

.page-about .media-frame__caption {
  display: block;
  padding: 9px 12px;
  border-top: var(--about-rule);
  font-size: 12px;
  line-height: 1.6;
  color: var(--muted);
  font-family: var(--mono);
  letter-spacing: 0.04em;
}

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

.page-about .step {
  display: grid;
  grid-template-columns: 34px minmax(0, 1fr);
  gap: 3px 14px;
  padding: 13px 0;
  border-top: var(--about-rule);
}

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

.page-about .step__index {
  grid-row: 1 / span 2;
  padding-top: 3px;
  font-family: var(--mono);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.1em;
  color: var(--orange);
}

.page-about .step__title {
  font-size: 15px;
  font-weight: 700;
  letter-spacing: 0.03em;
}

.page-about .step__text {
  font-size: 14px;
  line-height: 1.7;
  color: var(--muted);
}

/* ---------- 右侧旁注 ---------- */
.page-about .about-side {
  display: grid;
  align-content: start;
  gap: 18px;
}

.page-about .side-card {
  border: 1px solid var(--line);
  background: var(--panel);
  padding: 18px 16px;
}

.page-about .side-card__title {
  margin: 0 0 12px;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  color: var(--muted);
}

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

.page-about .team-scale__link {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  align-items: baseline;
  gap: 14px;
  padding: 11px 0;
  border-top: var(--about-rule);
  color: inherit;
  text-decoration: none;
  transition: border-color var(--t-fast) ease;
}

.page-about .team-scale li:first-child .team-scale__link {
  border-top: 0;
  padding-top: 0;
}

.page-about .team-scale__num {
  font-family: var(--mono);
  font-size: 32px;
  font-weight: 700;
  line-height: 1;
  color: var(--white);
  font-variant-numeric: tabular-nums;
  transition: color var(--t-fast) ease;
}

.page-about .team-scale__link--lead .team-scale__num {
  color: var(--cyan);
}

.page-about .team-scale__label {
  font-size: 13px;
  line-height: 1.55;
  color: var(--muted);
}

.page-about .team-scale__link:hover .team-scale__num,
.page-about .team-scale__link:focus-visible .team-scale__num {
  color: var(--cyan-deep);
}

.page-about .team-scale__link:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 3px;
}

.page-about .side-card__foot {
  margin: 14px 0 0;
  padding-top: 12px;
  border-top: var(--about-rule);
  font-size: 12px;
  color: var(--muted);
  letter-spacing: 0.02em;
}

/* ---------- 版本时间线 ---------- */
.page-about .about-timeline {
  padding-top: 26px;
  border-top: var(--about-rule);
}

.page-about .about-timeline__figure {
  margin: 6px 0 26px;
}

.page-about .timeline-track {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0;
}

.page-about .tl-node {
  position: relative;
  padding: 22px 16px 16px 0;
  border-top: 1px solid var(--line);
  outline-offset: 4px;
}

.page-about .tl-node::before {
  content: "";
  position: absolute;
  top: -5px;
  left: 0;
  width: 9px;
  height: 9px;
  background: var(--line);
  transition: background var(--t-fast) ease;
}

.page-about .tl-node--now::before {
  background: var(--cyan);
  box-shadow: 0 0 0 3px rgba(53, 242, 198, 0.16);
}

.page-about .tl-node__year {
  display: block;
  font-family: var(--mono);
  font-size: 22px;
  font-weight: 700;
  letter-spacing: 0.06em;
  color: var(--white);
  font-variant-numeric: tabular-nums;
}

.page-about .tl-node--now .tl-node__year {
  color: var(--cyan);
}

.page-about .tl-node__name {
  display: block;
  margin-top: 4px;
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.02em;
}

.page-about .tl-node__note {
  display: grid;
  grid-template-rows: 1fr;
  transition: grid-template-rows var(--t-mid) ease;
}

.page-about .tl-node__note > span {
  overflow: hidden;
  display: block;
  font-size: 13px;
  line-height: 1.7;
  color: var(--muted);
  padding-top: 6px;
}

.page-about .tl-node:hover::before,
.page-about .tl-node:focus-within::before {
  background: var(--cyan);
}

/* ---------- 主场标准 ---------- */
.page-about .about-standards {
  padding-top: 26px;
  border-top: var(--about-rule);
  display: grid;
  gap: 24px;
}

.page-about .std-list {
  list-style: none;
  margin: 16px 0 0;
  padding: 0;
}

.page-about .std {
  display: grid;
  grid-template-columns: 40px minmax(0, 1fr);
  gap: 3px 14px;
  padding: 15px 0;
  border-top: var(--about-rule);
}

.page-about .std__mark {
  grid-row: 1 / span 2;
  padding-top: 2px;
  font-family: var(--mono);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.1em;
  color: var(--purple);
}

.page-about .std__title {
  font-size: 15px;
  font-weight: 700;
  letter-spacing: 0.04em;
}

.page-about .std__text {
  font-size: 14px;
  line-height: 1.75;
  color: var(--muted);
  max-width: 34em;
}

.page-about .std-contact {
  margin-top: 18px;
  padding-top: 14px;
  border-top: var(--about-rule);
  display: flex;
  flex-wrap: wrap;
  gap: 6px 26px;
}

.page-about .std-contact__line {
  margin: 0;
  font-family: var(--mono);
  font-size: 13px;
  letter-spacing: 0.03em;
}

.page-about .std-contact__line a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid var(--line);
  padding-bottom: 2px;
  transition: border-color var(--t-fast) ease, color var(--t-fast) ease;
}

.page-about .std-contact__line a:hover,
.page-about .std-contact__line a:focus-visible {
  border-color: var(--cyan);
  color: var(--white);
}

.page-about .about-standards__figure {
  align-self: start;
}

/* ---------- 结尾指引 ---------- */
.page-about .about-cta {
  padding: 24px 0 8px;
  border-top: var(--about-rule);
}

.page-about .about-cta__lead {
  margin: 0 0 16px;
  max-width: 34em;
  font-size: 15px;
  line-height: 1.75;
  color: var(--muted);
}

.page-about .about-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

/* ---------- 平板及以上 ---------- */
@media (min-width: 700px) {
  .page-about .about-hero {
    padding: 34px 32px 30px;
  }

  .page-about .flow-grid {
    grid-template-columns: minmax(0, 0.85fr) minmax(0, 1.15fr);
    align-items: start;
    gap: 26px;
  }

  .page-about .duty {
    grid-template-columns: 78px minmax(0, 1fr);
  }

  .page-about .duty__num {
    font-size: 36px;
  }
}

@media (min-width: 860px) {
  .page-about .timeline-track {
    grid-template-columns: repeat(5, minmax(0, 1fr));
  }

  .page-about .tl-node {
    padding-right: 20px;
  }

  .page-about .tl-node__note {
    grid-template-rows: 0fr;
  }

  .page-about .tl-node:hover .tl-node__note,
  .page-about .tl-node:focus-within .tl-node__note {
    grid-template-rows: 1fr;
  }

  .page-about .about-standards {
    grid-template-columns: minmax(0, 1.45fr) minmax(0, 1fr);
    gap: 34px;
  }
}

/* ---------- 桌面：左内容 + 右旁注 ---------- */
@media (min-width: 1000px) {
  .page-about .about-body {
    grid-template-columns: minmax(0, 1fr) var(--about-side-w);
    gap: 40px 44px;
    margin-top: 40px;
  }

  .page-about .about-side {
    grid-column: 2;
    grid-row: 1;
    position: sticky;
    top: 96px;
    align-self: start;
  }

  .page-about .about-timeline,
  .page-about .about-standards,
  .page-about .about-cta {
    grid-column: 1 / -1;
  }

  .page-about .about-standards {
    grid-template-columns: minmax(0, 1.5fr) minmax(0, 0.9fr);
    gap: 44px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .tl-node__note,
  .page-about .team-scale__num,
  .page-about .team-scale__link,
  .page-about .tl-node::before {
    transition: none;
  }
}
<<<END>>>