.page-about {
  background: var(--paper);
  color: var(--ink);
  padding-bottom: 72px;
}

.page-about .about-hero {
  display: grid;
  gap: 26px;
  padding: 20px 0 0;
}

.page-about .about-hero__title {
  font-size: clamp(1.85rem, 7.4vw, 3.05rem);
  font-weight: 900;
  line-height: 1.16;
  letter-spacing: -.02em;
  margin: 10px 0 18px;
  max-width: 22ch;
  color: var(--rock);
}

.page-about .about-hero__text .lede {
  font-size: 1.02rem;
  line-height: 1.8;
  max-width: 50ch;
  color: var(--ink);
  border-left: 3px solid var(--sand);
  padding-left: 16px;
  margin: 0;
}

.page-about .about-hero__figure {
  margin: 0;
  border: var(--hair);
  clip-path: var(--cut-lg);
  background: var(--rock);
  overflow: hidden;
  aspect-ratio: 16 / 9;
}

.page-about .about-hero__figure img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: .82;
  filter: saturate(.72);
}

/* ---------- 主体：左刻度 + 右长文 ---------- */

.page-about .about-body {
  margin-top: 48px;
}

.page-about .about-rail {
  display: none;
}

.page-about .about-rail__list {
  list-style: none;
  margin: 0;
  padding: 0;
  border-left: var(--hair);
}

.page-about .about-rail__item {
  position: relative;
  padding: 7px 0 7px 18px;
}

.page-about .about-rail__item::before {
  content: "";
  position: absolute;
  left: -1px;
  top: 50%;
  width: 8px;
  height: 1px;
  background: rgba(201, 162, 75, .55);
}

.page-about .about-rail__year {
  font-family: var(--mono);
  font-size: .82rem;
  letter-spacing: .06em;
  color: var(--clay);
  transition: color var(--dur) var(--ease);
}

.page-about .about-rail__item.is-now {
  border-left: 3px solid var(--lake);
  margin-left: -2px;
}

.page-about .about-rail__item.is-now .about-rail__year {
  color: var(--lake-deep);
  font-weight: 700;
}

.page-about .about-rail__item:hover .about-rail__year {
  color: var(--sand);
}

.page-about .about-flow {
  display: flex;
  flex-direction: column;
  gap: 52px;
  min-width: 0;
}

.page-about .sec {
  border-top: var(--hair);
  padding-top: 26px;
  min-width: 0;
}

.page-about .sec__no {
  display: block;
  font-size: .76rem;
  letter-spacing: .18em;
  color: var(--sand);
  margin-bottom: 10px;
}

.page-about .sec__title {
  font-size: clamp(1.28rem, 4.6vw, 1.72rem);
  font-weight: 900;
  line-height: 1.32;
  letter-spacing: -.02em;
  color: var(--rock);
  margin: 0 0 16px;
}

.page-about .sec p {
  font-size: 1.02rem;
  line-height: 1.8;
  margin: 0 0 1.2em;
  color: var(--ink);
}

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

.page-about .link {
  color: var(--lake-deep);
  text-decoration: underline;
  text-decoration-color: rgba(46, 126, 123, .45);
  text-underline-offset: 3px;
  transition: color var(--dur) var(--ease), text-decoration-color var(--dur) var(--ease);
}

.page-about .link:hover {
  color: var(--pome);
  text-decoration-color: var(--pome);
}

.page-about .pull {
  border-left: 3px solid var(--sand);
  padding: 4px 0 4px 18px;
  margin: 24px 0 0;
  font-size: 1.12rem;
  line-height: 1.78;
  font-weight: 700;
  color: var(--rock);
}

/* ---------- 折叠 ---------- */

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

.page-about .about-fold .fold__summary {
  cursor: pointer;
  font-size: .92rem;
  font-weight: 700;
  color: var(--lake-deep);
  padding: 10px 0;
  border-top: var(--dash);
}

.page-about .about-fold .fold__body p {
  font-size: .96rem;
  line-height: 1.78;
  color: var(--clay);
  margin: 6px 0 0;
}

/* ---------- 四条主线 ---------- */

.page-about .lanes {
  display: grid;
  gap: 12px;
  margin: 22px 0 0;
}

.page-about .lane {
  border: var(--hair);
  clip-path: var(--cut-shape);
  background: var(--paper);
  transition: background var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .lane:hover {
  border-color: var(--hair-strong);
  background: rgba(228, 206, 151, .18);
}

.page-about .lane[open] {
  background: rgba(228, 206, 151, .26);
  border-color: rgba(201, 162, 75, .62);
}

.page-about .lane__tab {
  list-style: none;
  cursor: pointer;
  display: flex;
  align-items: baseline;
  gap: 10px;
  padding: 15px 16px;
  font-size: 1rem;
  font-weight: 900;
  letter-spacing: -.01em;
  color: var(--rock);
}

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

.page-about .lane__tab::after {
  content: "+";
  margin-left: auto;
  font-family: var(--mono);
  font-size: .95rem;
  color: var(--sand);
}

.page-about .lane[open] .lane__tab::after {
  content: "−";
  color: var(--lake);
}

.page-about .lane__no {
  font-size: .74rem;
  letter-spacing: .1em;
  color: var(--sand);
}

.page-about .lane__body {
  font-size: .94rem;
  line-height: 1.78;
  color: var(--ink);
  margin: 0;
  padding: 0 16px 16px 16px;
  border-top: var(--dash);
  padding-top: 12px;
}

.page-about .note {
  font-size: .86rem;
  line-height: 1.75;
  color: var(--stone);
  border-left: 2px solid rgba(110, 122, 114, .4);
  padding-left: 14px;
  margin: 20px 0 0;
}

/* ---------- 时间线 ---------- */

.page-about .about-figure {
  margin: 22px 0 28px;
  border: var(--hair);
  clip-path: var(--cut-lg);
  background: var(--rock);
  overflow: hidden;
}

.page-about .about-figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 3 / 2;
  object-fit: cover;
  opacity: .9;
  filter: saturate(.7);
}

.page-about .about-figure__cap {
  font-size: .82rem;
  line-height: 1.6;
  letter-spacing: .02em;
  color: var(--clay);
  padding: 10px 14px;
  background: rgba(62, 47, 35, .05);
  border-top: var(--hair);
}

.page-about .timeline__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 18px;
  counter-reset: tl;
}

.page-about .timeline__item {
  position: relative;
  padding-left: 22px;
  border-left: var(--hair);
}

.page-about .timeline__item::before {
  content: "";
  position: absolute;
  left: -4px;
  top: 8px;
  width: 7px;
  height: 7px;
  background: var(--sand);
}

.page-about .timeline__year {
  display: block;
  font-size: .82rem;
  letter-spacing: .08em;
  color: var(--sand);
  margin-bottom: 2px;
}

.page-about .timeline__stage {
  display: block;
  font-size: .98rem;
  font-weight: 900;
  color: var(--rock);
  letter-spacing: -.01em;
  margin-bottom: 4px;
}

.page-about .timeline__desc {
  font-size: .93rem;
  line-height: 1.75;
  color: var(--clay);
  margin: 0;
}

/* ---------- 团队 ---------- */

.page-about .team {
  display: grid;
  gap: 26px;
  margin-top: 20px;
}

.page-about .team__figure {
  margin: 0;
  border: var(--hair);
  clip-path: var(--cut-lg);
  background: var(--rock);
  overflow: hidden;
}

.page-about .team__figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 4 / 3;
  object-fit: cover;
  opacity: .86;
  filter: saturate(.55);
}

.page-about .team-list {
  list-style: none;
  margin: 22px 0 0;
  padding: 0;
  display: grid;
  gap: 16px;
}

.page-about .team-list__item {
  border-top: var(--dash);
  padding-top: 14px;
  display: grid;
  grid-template-columns: 44px minmax(0, 1fr);
  column-gap: 12px;
  align-items: baseline;
}

.page-about .team-list__no {
  grid-row: 1 / span 2;
  font-size: .8rem;
  letter-spacing: .08em;
  color: var(--sand);
}

.page-about .team-list__name {
  font-size: 1rem;
  font-weight: 900;
  letter-spacing: -.01em;
  color: var(--rock);
  margin: 0 0 6px;
}

.page-about .team-list__desc {
  grid-column: 2;
  font-size: .93rem;
  line-height: 1.75;
  color: var(--clay);
  margin: 0;
}

/* ---------- 响应步骤 ---------- */

.page-about .about-steps {
  list-style: none;
  margin: 26px 0 0;
  padding: 0;
  display: grid;
  gap: 14px;
}

.page-about .about-steps__item {
  display: grid;
  grid-template-columns: 38px minmax(0, 1fr);
  column-gap: 12px;
  border-left: 2px solid rgba(201, 162, 75, .5);
  padding: 12px 0 12px 14px;
  background: rgba(201, 162, 75, .07);
  clip-path: var(--cut-shape);
  transition: border-color var(--dur) var(--ease), background var(--dur) var(--ease);
}

.page-about .about-steps__item:hover {
  border-left-color: var(--lake);
  background: rgba(46, 126, 123, .07);
}

.page-about .about-steps__no {
  font-size: .82rem;
  letter-spacing: .08em;
  color: var(--sand);
  padding-top: 2px;
}

.page-about .about-steps__title {
  font-size: .98rem;
  font-weight: 900;
  color: var(--rock);
  letter-spacing: -.01em;
  margin: 0 0 5px;
}

.page-about .about-steps__desc {
  font-size: .92rem;
  line-height: 1.75;
  color: var(--clay);
  margin: 0;
}

/* ---------- 收束入口 ---------- */

.page-about .about-cta__links {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 26px;
}

.page-about .about-cta__links .btn {
  flex: 0 1 auto;
}

/* ---------- 断点 ---------- */

@media (min-width: 640px) {
  .page-about .about-cta__links .btn {
    min-width: 168px;
  }
}

@media (min-width: 768px) {
  .page-about .lanes {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    align-items: start;
  }

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

  .page-about .team-list__item {
    grid-template-columns: 36px minmax(0, 1fr);
  }

  .page-about .about-steps {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 16px;
  }
}

@media (min-width: 1024px) {
  .page-about {
    padding-bottom: 96px;
  }

  .page-about .about-hero {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    align-items: end;
    gap: 44px;
    padding-top: 30px;
  }

  .page-about .about-hero__figure {
    aspect-ratio: 8 / 5;
  }

  .page-about .about-hero__text {
    padding-bottom: 6px;
  }

  .page-about .about-body {
    display: grid;
    grid-template-columns: 118px minmax(0, 1fr);
    column-gap: 56px;
    margin-top: 68px;
    align-items: start;
  }

  .page-about .about-rail {
    display: block;
    position: sticky;
    top: 64px;
  }

  .page-about .about-flow {
    gap: 64px;
  }

  .page-about .lanes {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .lanes .lane__body {
    font-size: .9rem;
  }

  .page-about .timeline__list {
    grid-template-columns: repeat(6, minmax(0, 1fr));
    gap: 0;
    border-top: 2px solid var(--sand);
    padding-top: 0;
  }

  .page-about .timeline__item {
    border-left: 0;
    border-right: var(--hair);
    padding: 26px 16px 0 0;
  }

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

  .page-about .timeline__item::before {
    left: 0;
    top: -5px;
    width: 9px;
    height: 9px;
  }

  .page-about .team {
    grid-template-columns: minmax(0, 1.35fr) minmax(0, 1fr);
    gap: 40px;
    align-items: start;
  }

  .page-about .team-list {
    grid-template-columns: minmax(0, 1fr);
    gap: 14px;
  }
}

@media (min-width: 1280px) {
  .page-about .about-body {
    grid-template-columns: 132px minmax(0, 1fr);
    column-gap: 72px;
  }

  .page-about .about-hero__figure {
    aspect-ratio: 21 / 9;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .lane,
  .page-about .about-steps__item,
  .page-about .about-rail__year,
  .page-about .link {
    transition: none;
  }
}
</main>