.page-about {
  --about-rail: 34em;
  --tl-pad: 26px;
}

.page-about .crumbs__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin: 0;
  padding: 0;
  list-style: none;
  font-family: var(--font-mono);
  font-size: var(--fs-6);
  letter-spacing: 0.08em;
}

.page-about .crumbs {
  padding-top: 20px;
}

.page-about .crumbs__link {
  color: var(--sky);
  text-decoration: none;
}

.page-about .crumbs__link:hover,
.page-about .crumbs__link:focus-visible {
  text-decoration: underline;
}

.page-about .crumbs__sep {
  color: var(--line-sand);
}

.page-about .crumbs__current {
  color: var(--ink-soft);
}

/* 首屏 */
.page-about .about-masthead {
  display: grid;
  gap: 32px;
  padding: 28px 0 56px;
  border-bottom: 1px solid var(--line);
}

.page-about .about-title {
  margin: 14px 0 0;
  font-family: var(--font-body);
  font-weight: 900;
  font-size: var(--fs-1);
  line-height: 1.04;
  letter-spacing: -0.02em;
  color: var(--night);
}

.page-about .about-lede {
  max-width: var(--about-rail);
  margin-top: 22px;
  color: var(--ink-soft);
}

.page-about .about-jumprow {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 14px;
  margin-top: 26px;
}

.page-about .about-jump {
  display: inline-block;
  padding: 10px 18px;
  border: 1px solid var(--line-sand);
  border-left: 4px solid var(--sand);
  background: var(--paper);
  color: var(--night);
  font-size: var(--fs-5);
  font-weight: 700;
  text-decoration: none;
  transition: background var(--dur) var(--ease), color var(--dur) var(--ease);
}

.page-about .about-jump:hover,
.page-about .about-jump:focus-visible {
  background: var(--night);
  color: var(--paper);
}

.page-about .about-jumprow__hint {
  font-family: var(--font-mono);
  font-size: var(--fs-6);
  letter-spacing: 0.08em;
  color: var(--ink-soft);
}

.page-about .about-masthead__media {
  margin: 0;
  position: relative;
}

.page-about .about-masthead__media::after {
  content: "";
  position: absolute;
  top: 0;
  right: 0;
  width: 46%;
  height: 14px;
  background: var(--sand);
}

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

.page-about .about-masthead__media .media__img {
  aspect-ratio: 4 / 5;
  max-height: 380px;
  filter: saturate(0.92);
}

.page-about .media__caption {
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: var(--fs-6);
  letter-spacing: 0.08em;
  color: var(--ink-soft);
}

/* 通用标题 */
.page-about .about-h2 {
  margin: 0;
  font-size: var(--fs-2);
  font-weight: 900;
  line-height: 1.14;
  letter-spacing: -0.02em;
  color: var(--night);
}

.page-about .about-head {
  max-width: 40em;
  margin-bottom: 40px;
}

.page-about .about-head .lede {
  margin-top: 16px;
  color: var(--ink-soft);
}

/* 自述 */
.page-about .about-note {
  padding-top: 72px;
}

.page-about .about-note__grid {
  display: grid;
  gap: 36px;
}

.page-about .about-note__body p {
  max-width: var(--about-rail);
  margin-top: 20px;
  font-size: var(--fs-5);
  line-height: 1.9;
  color: var(--ink);
}

.page-about .about-note__body p:first-of-type {
  margin-top: 24px;
}

.page-about .about-note__margin {
  display: grid;
  gap: 1px;
  align-content: start;
  background: var(--line);
  border-top: 1px solid var(--line);
}

.page-about .about-annot {
  position: relative;
  display: grid;
  grid-template-columns: auto 1fr;
  align-items: baseline;
  gap: 12px;
  margin: 0;
  padding: 12px 14px;
  background: var(--paper);
  font-family: var(--font-mono);
  font-size: var(--fs-6);
  letter-spacing: 0.06em;
  outline: none;
}

.page-about .about-annot__key {
  color: var(--ink-soft);
}

.page-about .about-annot__val {
  color: var(--night);
  font-weight: 600;
  font-variant-numeric: tabular-nums;
}

.page-about .about-annot__more {
  grid-column: 1 / -1;
  max-height: 0;
  overflow: hidden;
  color: var(--ink-soft);
  line-height: 1.6;
  transition: max-height var(--dur) var(--ease), padding-top var(--dur) var(--ease);
}

.page-about .about-annot:hover .about-annot__more,
.page-about .about-annot:focus .about-annot__more,
.page-about .about-annot:focus-within .about-annot__more {
  max-height: 4em;
  padding-top: 6px;
}

/* 沙色带 */
.page-about .about-band {
  margin: 72px 0;
  padding: 40px 0;
  background: var(--sand-pale);
  border-top: 1px solid var(--line-sand);
  border-bottom: 1px solid var(--line-sand);
  color: var(--night);
}

.page-about .about-band__text {
  max-width: 30em;
  margin: 0;
  font-size: var(--fs-3);
  font-weight: 700;
  line-height: 1.5;
  letter-spacing: -0.01em;
  border-left: 6px solid var(--sand);
  padding-left: 20px;
}

/* 六类 */
.page-about .about-taxonomy__list {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 1px;
  background: var(--line);
  border-top: 1px solid var(--line);
}

.page-about .about-taxonomy__item {
  display: grid;
  grid-template-columns: 44px 1fr;
  gap: 4px 14px;
  padding: 20px 16px;
  background: var(--paper);
}

.page-about .about-taxonomy__num {
  grid-row: 1 / span 2;
  color: var(--sand);
  font-size: var(--fs-6);
  letter-spacing: 0.08em;
  padding-top: 6px;
}

.page-about .about-taxonomy__title {
  margin: 0;
  font-size: var(--fs-4);
  font-weight: 900;
  letter-spacing: -0.01em;
  color: var(--night);
}

.page-about .about-taxonomy__text {
  margin: 0;
  font-size: var(--fs-5);
  line-height: 1.8;
  color: var(--ink-soft);
}

/* 时间线 */
.page-about .about-timeline__list {
  position: relative;
  margin: 0;
  padding: 0 0 0 var(--tl-pad);
  list-style: none;
  border-left: 1px dashed var(--line-sand);
}

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

.page-about .about-timeline__item::before {
  content: "";
  position: absolute;
  top: 10px;
  left: calc(var(--tl-pad) * -1);
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--sand);
  transform: translateX(-50%);
  box-shadow: 0 0 0 3px var(--paper);
}

.page-about .about-timeline__item:last-child::before {
  background: var(--poplar);
}

.page-about .about-node {
  background: var(--paper);
  border: 1px solid var(--line);
}

.page-about .about-node[open] {
  border-color: var(--line-sand);
  box-shadow: 0 10px 26px rgba(18, 49, 79, 0.06);
}

.page-about .about-node__summary {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 6px 14px;
  padding: 16px 18px;
  cursor: pointer;
  list-style: none;
}

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

.page-about .about-node__summary::marker {
  content: "";
}

.page-about .about-node__summary:focus-visible {
  outline: 2px solid var(--sky);
  outline-offset: -2px;
}

.page-about .about-node__year {
  color: var(--deep);
  font-size: var(--fs-6);
  letter-spacing: 0.08em;
  font-variant-numeric: tabular-nums;
}

.page-about .about-node__title {
  font-size: var(--fs-4);
  font-weight: 900;
  letter-spacing: -0.01em;
  color: var(--night);
}

.page-about .about-node[open] .about-node__title {
  color: var(--deep);
}

.page-about .about-node__body {
  padding: 0 18px 18px;
}

.page-about .about-node__points {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 10px;
}

.page-about .about-node__points li {
  position: relative;
  padding-left: 16px;
  font-size: var(--fs-5);
  line-height: 1.8;
  color: var(--ink-soft);
}

.page-about .about-node__points li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.72em;
  width: 6px;
  height: 6px;
  background: var(--sky);
}

.page-about .about-slice {
  margin: 36px 0 0;
}

.page-about .about-slice .media__img {
  aspect-ratio: 35 / 12;
  max-height: 260px;
}

/* 四步 */
.page-about .about-flow {
  padding-top: 72px;
}

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

.page-about .about-flow__step {
  position: relative;
  padding: 22px 20px 22px 22px;
  background: var(--paper);
  border-left: 4px solid var(--sand);
  box-shadow: 0 1px 0 var(--line);
}

.page-about .about-flow__num {
  display: block;
  color: var(--clay);
  font-size: var(--fs-6);
  letter-spacing: 0.08em;
  margin-bottom: 6px;
}

.page-about .about-flow__title {
  margin: 0 0 8px;
  font-size: var(--fs-4);
  font-weight: 900;
  color: var(--night);
  letter-spacing: -0.01em;
}

.page-about .about-flow__step p {
  margin: 0;
  font-size: var(--fs-5);
  line-height: 1.85;
  color: var(--ink-soft);
}

/* 团队 */
.page-about .about-teams {
  padding-top: 80px;
}

.page-about .about-teams__layout {
  display: grid;
  gap: 28px;
}

.page-about .about-teams__bars {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.page-about .about-team {
  padding: 20px;
  color: var(--paper);
  background: var(--night);
}

.page-about .about-team--wide {
  flex: 3 1 0;
}

.page-about .about-team--narrow {
  flex: 2 1 0;
  background: var(--deep);
}

.page-about .about-team__count {
  margin: 0 0 6px;
  color: var(--sand);
  font-size: var(--fs-6);
  letter-spacing: 0.08em;
}

.page-about .about-team__title {
  margin: 0 0 8px;
  font-size: var(--fs-4);
  font-weight: 900;
  color: var(--paper);
}

.page-about .about-team p:last-child {
  margin: 0;
  font-size: var(--fs-5);
  line-height: 1.8;
  color: var(--on-night);
}

.page-about .about-teams__figure {
  margin: 0;
}

.page-about .about-teams__figure .media__img {
  aspect-ratio: 10 / 7;
  background: var(--sand-pale);
}

.page-about .about-teams__foot {
  max-width: 38em;
  margin-top: 30px;
  padding-top: 20px;
  border-top: 1px solid var(--line-sand);
  font-size: var(--fs-5);
  line-height: 1.9;
  color: var(--ink-soft);
}

/* 反馈 */
.page-about .about-feedback {
  padding-top: 80px;
}

.page-about .about-feedback__grid {
  display: grid;
  gap: 30px;
}

.page-about .about-feedback__main p {
  max-width: var(--about-rail);
  margin-top: 18px;
  font-size: var(--fs-5);
  line-height: 1.9;
  color: var(--ink-soft);
}

.page-about .about-feedback__side {
  display: grid;
  gap: 1px;
  background: var(--line);
  align-self: start;
}

.page-about .about-feedback__stat {
  margin: 0;
  padding: 16px;
  background: var(--sand-pale);
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.page-about .about-feedback__statnum {
  font-family: var(--font-mono);
  font-size: var(--fs-2);
  font-weight: 600;
  color: var(--night);
  font-variant-numeric: tabular-nums;
  line-height: 1;
}

.page-about .about-feedback__statlabel {
  font-family: var(--font-mono);
  font-size: var(--fs-6);
  letter-spacing: 0.08em;
  color: var(--ink-soft);
}

.page-about .about-feedback__tail {
  max-width: 38em;
  margin-top: 26px;
  font-size: var(--fs-5);
  line-height: 1.85;
  color: var(--ink);
}

/* 后续入口 */
.page-about .about-next {
  padding: 80px 0 96px;
}

.page-about .about-next__list {
  margin: 26px 0 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 1px;
  background: var(--line);
}

.page-about .about-next__link {
  display: grid;
  grid-template-columns: 32px 1fr;
  gap: 2px 12px;
  padding: 18px 16px;
  background: var(--paper);
  color: var(--night);
  font-size: var(--fs-4);
  font-weight: 900;
  text-decoration: none;
  transition: background var(--dur) var(--ease), color var(--dur) var(--ease);
}

.page-about .about-next__link:hover,
.page-about .about-next__link:focus-visible {
  background: var(--night);
  color: var(--paper);
}

.page-about .about-next__num {
  grid-row: 1 / span 2;
  color: var(--sand);
  font-size: var(--fs-6);
  letter-spacing: 0.08em;
  padding-top: 8px;
}

.page-about .about-next__desc {
  font-family: var(--font-body);
  font-size: var(--fs-6);
  font-weight: 400;
  letter-spacing: 0;
  color: var(--ink-soft);
}

.page-about .about-next__link:hover .about-next__desc,
.page-about .about-next__link:focus-visible .about-next__desc {
  color: var(--on-night);
}

/* 平板 */
@media (min-width: 720px) {
  .page-about .about-taxonomy__list {
    grid-template-columns: 1fr 1fr;
  }

  .page-about .about-flow__list {
    grid-template-columns: 1fr 1fr;
    gap: 24px;
  }

  .page-about .about-flow__step:nth-child(2n) {
    transform: translateY(20px);
  }

  .page-about .about-next__list {
    grid-template-columns: 1fr 1fr;
  }

  .page-about .about-teams__bars {
    flex-direction: row;
    align-items: stretch;
    min-height: 240px;
  }

  .page-about .about-teams__bars .about-team {
    display: flex;
    flex-direction: column;
    justify-content: flex-end;
  }

  .page-about .about-team--narrow {
    margin-top: 28px;
  }
}

/* 桌面 */
@media (min-width: 960px) {
  .page-about {
    --tl-pad: 54px;
  }

  .page-about .about-masthead {
    grid-template-columns: minmax(0, 1.4fr) minmax(220px, 0.6fr);
    gap: 48px;
    padding: 40px 0 72px;
    align-items: start;
  }

  .page-about .about-title {
    margin-top: 18px;
  }

  .page-about .about-masthead__media .media__img {
    aspect-ratio: 8 / 11;
    max-height: 460px;
  }

  .page-about .about-note {
    padding-top: 96px;
  }

  .page-about .about-note__grid {
    grid-template-columns: minmax(0, 1fr) 240px;
    gap: 64px;
  }

  .page-about .about-note__margin {
    position: sticky;
    top: 96px;
    border-top: none;
    border-left: 1px solid var(--line);
  }

  .page-about .about-band {
    margin: 96px 0;
    padding: 56px 0;
  }

  .page-about .about-taxonomy__item {
    grid-template-columns: 52px 1fr;
    padding: 26px 24px;
  }

  .page-about .about-flow {
    padding-top: 96px;
  }

  .page-about .about-flow__list {
    grid-template-columns: repeat(4, 1fr);
    gap: 18px;
  }

  .page-about .about-flow__step:nth-child(2n) {
    transform: translateY(30px);
  }

  .page-about .about-teams,
  .page-about .about-feedback {
    padding-top: 104px;
  }

  .page-about .about-teams__layout {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr);
    gap: 40px;
    align-items: start;
  }

  .page-about .about-feedback__grid {
    grid-template-columns: minmax(0, 1fr) 260px;
    gap: 56px;
  }

  .page-about .about-next {
    padding: 96px 0 120px;
  }

  .page-about .about-next__list {
    grid-template-columns: 1fr 1fr;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-flow__step:nth-child(2n) {
    transform: none;
  }

  .page-about .about-jump,
  .page-about .about-annot__more,
  .page-about .about-next__link {
    transition: none;
  }
}
<<<END>>>