.page-about {
  --about-index-w: 208px;
  --about-gap: clamp(40px, 7vw, 88px);
  position: relative;
  padding-bottom: clamp(40px, 7vw, 84px);
}

/* ---------- 面包屑 ---------- */
.page-about .breadcrumb {
  padding-top: clamp(12px, 3vw, 24px);
}

.page-about .breadcrumb ol {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
  margin: 0;
  padding: 0;
  list-style: none;
  font-size: 0.8125rem;
  letter-spacing: 0.02em;
  color: var(--mist);
}

.page-about .breadcrumb li + li::before {
  content: "/";
  margin-right: 6px;
  color: var(--stone);
}

.page-about .breadcrumb a {
  color: var(--mist);
  text-decoration: none;
  border-bottom: 1px solid var(--line-soft);
}

.page-about .breadcrumb a:hover {
  color: var(--paper);
  border-bottom-color: var(--away);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  padding-top: clamp(18px, 4vw, 34px);
}

.page-about .about-hero h1 {
  margin: 10px 0 0;
  max-width: 17ch;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(2.1rem, 6.4vw, 3.5rem);
  line-height: 1.06;
  letter-spacing: -0.02em;
  color: var(--paper);
}

.page-about .about-hero__lede {
  margin-top: 18px;
  max-width: 64ch;
  color: var(--paper-dim);
}

.page-about .about-hero__facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 20px 22px;
  margin: clamp(26px, 5vw, 42px) 0 0;
}

.page-about .about-hero__fact {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding-left: 12px;
  border-left: 2px solid var(--line);
}

.page-about .about-hero__fact--accent {
  border-left-color: var(--away);
}

.page-about .about-hero__k {
  font-size: 0.8125rem;
  letter-spacing: 0.04em;
  color: var(--mist);
}

.page-about .about-hero__v {
  display: flex;
  align-items: baseline;
  gap: 6px;
  margin: 0;
  font-family: var(--font-data);
  font-variant-numeric: tabular-nums;
  font-size: clamp(1.35rem, 4vw, 1.7rem);
  font-weight: 600;
  letter-spacing: 0.01em;
  color: var(--paper);
}

.page-about .about-hero__fact--accent .about-hero__v {
  color: var(--away);
}

.page-about .about-hero__unit {
  font-family: var(--font-body);
  font-size: 0.8125rem;
  font-weight: 400;
  color: var(--mist);
}

.page-about .about-hero__figure {
  margin: clamp(28px, 5vw, 52px) 0 0;
}

/* ---------- 主体骨架 ---------- */
.page-about .about-shell {
  padding-top: clamp(38px, 7vw, 76px);
}

.page-about .about-flow {
  display: grid;
  gap: var(--about-gap);
}

/* ---------- 章节索引 ---------- */
.page-about .about-index {
  padding: 14px 16px;
  border-radius: var(--radius);
  margin-bottom: 28px;
}

.page-about .about-index__title {
  margin: 0 0 10px;
  font-family: var(--font-data);
  font-size: 0.75rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--mist);
}

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

.page-about .about-index__link {
  display: inline-flex;
  align-items: baseline;
  gap: 6px;
  padding: 5px 10px;
  border: 1px solid var(--line-soft);
  border-radius: var(--radius);
  font-size: 0.8125rem;
  color: var(--paper-dim);
  text-decoration: none;
  white-space: nowrap;
  transition: color 180ms ease, border-color 180ms ease;
}

.page-about .about-index__no {
  font-family: var(--font-data);
  font-size: 0.75rem;
  color: var(--mist);
}

.page-about .about-index__link:hover,
.page-about .about-index__link.is-current {
  color: var(--paper);
  border-color: var(--away);
}

.page-about .about-index__link.is-current .about-index__no {
  color: var(--away);
}

/* ---------- 章节 ---------- */
.page-about .about-chapter {
  scroll-margin-top: calc(var(--header-h-sm) + 28px);
}

.page-about .about-chapter h2 {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(1.4rem, 3.6vw, 2rem);
  line-height: 1.16;
  letter-spacing: -0.02em;
  color: var(--paper);
}

.page-about .about-copy {
  max-width: 68ch;
  margin-top: 20px;
  font-size: 16.5px;
  line-height: 1.75;
  color: var(--paper-dim);
}

.page-about .about-copy p + p {
  margin-top: 14px;
}

.page-about .about-copy a {
  color: var(--paper);
  text-decoration: none;
  border-bottom: 1px solid var(--away);
}

.page-about .about-copy a:hover {
  color: var(--away);
}

/* ---------- 口径清单 ---------- */
.page-about .standard-grid {
  display: grid;
  gap: 26px;
}

.page-about .standard-grid__terms .about-copy {
  margin-top: 0;
}

.page-about .terms {
  display: grid;
  gap: 10px;
  margin-top: 22px;
}

.page-about .term {
  border: 1px solid var(--line-soft);
  border-left: 2px solid var(--stone);
  border-radius: var(--radius);
  background: rgba(18, 58, 49, 0.42);
  transition: border-left-color 180ms ease;
}

.page-about .term[open] {
  border-left-color: var(--away);
}

.page-about .term__head {
  display: flex;
  align-items: baseline;
  gap: 10px;
  padding: 13px 14px;
  cursor: pointer;
  list-style: none;
}

.page-about .term__head::-webkit-details-marker {
  display: none;
}

.page-about .term__idx {
  font-family: var(--font-data);
  font-size: 0.78rem;
  letter-spacing: 0.06em;
  color: var(--stone);
}

.page-about .term__name {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.0625rem;
  letter-spacing: -0.01em;
  color: var(--paper);
}

.page-about .term__hint {
  margin-left: auto;
  font-size: 0.75rem;
  color: var(--mist);
}

.page-about .term__hint::after {
  content: "+";
  margin-left: 6px;
  font-family: var(--font-data);
  color: var(--away);
}

.page-about .term[open] .term__hint::after {
  content: "\2212";
}

.page-about .term__body {
  padding: 0 14px 15px 14px;
  border-top: 1px solid var(--line-soft);
  margin-top: 2px;
}

.page-about .term__body p {
  margin: 12px 0 0;
  font-size: 0.9375rem;
  line-height: 1.75;
  color: var(--paper-dim);
}

.page-about .standard-grid__figure {
  margin: 0;
}

/* ---------- 版本沿革 ---------- */
.page-about .timeline {
  position: relative;
  margin: clamp(24px, 4vw, 36px) 0 0;
  padding: 0 0 0 30px;
  list-style: none;
}

.page-about .timeline::before {
  content: "";
  position: absolute;
  left: 8px;
  top: 8px;
  bottom: 8px;
  width: 2px;
  border-radius: 2px;
  background: linear-gradient(180deg, var(--gold) 0%, var(--gold) 34%, var(--away) 72%, var(--away) 100%);
}

.page-about .timeline__item {
  position: relative;
  padding-bottom: 28px;
}

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

.page-about .timeline__item::before {
  content: "";
  position: absolute;
  left: -27px;
  top: 7px;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--green-void);
  border: 2px solid var(--gold);
}

.page-about .timeline__item:nth-child(3)::before,
.page-about .timeline__item:nth-child(4)::before {
  border-color: var(--away);
}

.page-about .timeline__item--current::before {
  background: var(--away);
  border-color: var(--away);
}

.page-about .timeline__tag {
  display: inline-block;
  font-family: var(--font-data);
  font-size: 0.75rem;
  letter-spacing: 0.06em;
  color: var(--mist);
}

.page-about .timeline__item--current .timeline__tag {
  color: var(--away);
}

.page-about .timeline__item h3 {
  margin: 6px 0 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.125rem;
  letter-spacing: -0.01em;
  color: var(--paper);
}

.page-about .timeline__item p {
  margin: 8px 0 0;
  max-width: 62ch;
  font-size: 0.9375rem;
  line-height: 1.75;
  color: var(--paper-dim);
}

/* ---------- 编辑分工 ---------- */
.page-about .desk-grid {
  display: grid;
  gap: 22px;
  margin-top: clamp(24px, 4vw, 36px);
}

.page-about .desk-card {
  padding-top: 14px;
  border-top: 2px solid var(--green-mid);
}

.page-about .desk-card:nth-child(2) {
  border-top-color: var(--indigo);
}

.page-about .desk-card:nth-child(3) {
  border-top-color: var(--wine);
}

.page-about .desk-card:nth-child(4) {
  border-top-color: var(--gold);
}

.page-about .desk-card__count {
  display: flex;
  align-items: baseline;
  gap: 5px;
  margin: 0;
  font-family: var(--font-data);
  font-variant-numeric: tabular-nums;
  font-size: 1.6rem;
  font-weight: 600;
  color: var(--paper);
}

.page-about .desk-card__unit {
  font-family: var(--font-body);
  font-size: 0.8125rem;
  color: var(--mist);
}

.page-about .desk-card h3 {
  margin: 6px 0 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.0625rem;
  color: var(--paper);
}

.page-about .desk-card p {
  margin: 8px 0 0;
  font-size: 0.9375rem;
  line-height: 1.72;
  color: var(--paper-dim);
}

.page-about .deskmap-scroll {
  margin-top: clamp(28px, 5vw, 44px);
  overflow-x: auto;
  padding-bottom: 6px;
}

.page-about .deskmap {
  display: block;
  width: 100%;
  min-width: 560px;
  height: auto;
}

.page-about .deskmap__line {
  stroke: var(--line);
}

.page-about .deskmap__node rect {
  fill: rgba(18, 58, 49, 0.86);
  stroke: var(--line-soft);
}

.page-about .deskmap__node .deskmap__node--core {
  stroke: var(--away);
}

.page-about .deskmap__node .deskmap__node--out {
  stroke: var(--gold);
}

.page-about .deskmap__label text {
  font-family: var(--font-display);
  font-size: 15px;
  font-weight: 700;
  fill: var(--paper);
}

.page-about .deskmap__label .deskmap__meta {
  font-family: var(--font-data);
  font-size: 11px;
  font-weight: 400;
  letter-spacing: 0.02em;
  fill: var(--mist);
}

.page-about .deskmap__cap {
  margin: 12px 0 0;
  max-width: 62ch;
  font-size: 0.8125rem;
  line-height: 1.7;
  color: var(--mist);
}

/* ---------- 工作台图 ---------- */
.page-about .about-workbench {
  margin: 0;
}

/* ---------- 复核流程 ---------- */
.page-about .steps {
  counter-reset: rev;
  margin: clamp(22px, 4vw, 32px) 0 0;
  padding: 0;
  list-style: none;
}

.page-about .steps > li {
  counter-increment: rev;
  position: relative;
  padding: 15px 0 15px 48px;
  border-bottom: 1px dashed var(--line-soft);
  font-size: 0.9375rem;
  line-height: 1.72;
  color: var(--paper-dim);
}

.page-about .steps > li:first-child {
  border-top: 1px dashed var(--line-soft);
}

.page-about .steps > li::before {
  content: counter(rev, decimal-leading-zero);
  position: absolute;
  left: 0;
  top: 16px;
  font-family: var(--font-data);
  font-variant-numeric: tabular-nums;
  font-size: 0.8125rem;
  letter-spacing: 0.04em;
  color: var(--away);
}

/* ---------- 读者画像 ---------- */
.page-about .readplan {
  display: grid;
  gap: 1px;
  margin: clamp(24px, 4vw, 34px) 0 0;
  padding: 0;
  list-style: none;
  background: var(--line-soft);
}

.page-about .readplan__item {
  display: flex;
  gap: 16px;
  padding: 18px 0;
  background: var(--green-void);
}

.page-about .readplan__no {
  flex: 0 0 auto;
  font-family: var(--font-data);
  font-variant-numeric: tabular-nums;
  font-size: 0.8125rem;
  letter-spacing: 0.06em;
  color: var(--gold);
  padding-top: 3px;
}

.page-about .readplan__item h3 {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.0625rem;
  color: var(--paper);
}

.page-about .readplan__item p {
  margin: 6px 0 0;
  font-size: 0.9375rem;
  line-height: 1.72;
  color: var(--paper-dim);
}

/* ---------- 内容边界 ---------- */
.page-about .limits-list {
  display: grid;
  gap: 18px;
  margin: clamp(24px, 4vw, 34px) 0 0;
  padding: 0;
  list-style: none;
}

.page-about .limits-list__item {
  display: flex;
  flex-direction: column;
  gap: 9px;
  padding-left: 14px;
  border-left: 1px solid var(--line);
}

.page-about .limits-list__item .chip {
  align-self: flex-start;
}

.page-about .limits-list__item p {
  margin: 0;
  max-width: 60ch;
  font-size: 0.9375rem;
  line-height: 1.72;
  color: var(--paper-dim);
}

.page-about .about-cta {
  margin-top: clamp(30px, 5vw, 46px);
  padding-top: 22px;
  border-top: 1px solid var(--line);
}

.page-about .about-cta p {
  margin: 0;
  max-width: 60ch;
  font-size: 0.9375rem;
  line-height: 1.72;
  color: var(--paper-dim);
}

.page-about .about-cta__links {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 18px;
}

/* ---------- 桌面端 ---------- */
@media (min-width: 720px) {
  .page-about .about-hero__facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

  .page-about .limits-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 24px 32px;
  }
}

@media (min-width: 960px) {
  .page-about .about-shell {
    display: grid;
    grid-template-columns: var(--about-index-w) minmax(0, 1fr);
    gap: clamp(32px, 4vw, 64px);
    align-items: start;
  }

  .page-about .about-index {
    position: sticky;
    top: calc(var(--header-h-sm) + 22px);
    margin-bottom: 0;
  }

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

  .page-about .about-index__link {
    display: flex;
    justify-content: flex-start;
    padding: 9px 0;
    border: 0;
    border-bottom: 1px solid var(--line-soft);
    border-radius: 0;
  }

  .page-about .about-index__link.is-current {
    border-bottom-color: var(--away);
  }

  .page-about .standard-grid {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr);
    gap: clamp(26px, 3vw, 44px);
  }

  .page-about .standard-grid__figure {
    position: sticky;
    top: calc(var(--header-h-sm) + 30px);
  }
}

@media (min-width: 1100px) {
  .page-about .desk-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

/* ---------- 降低动效 ---------- */
@media (prefers-reduced-motion: reduce) {
  .page-about .about-index__link,
  .page-about .term {
    transition: none;
  }
}
<<<END>>>