.page-about {
  --rail-x: 18px;
  --rail-gap: 52px;
  --stage-pad: 2.4rem;
  overflow-wrap: break-word;
}

.page-about img {
  max-width: 100%;
  height: auto;
  display: block;
}

/* ---------- 首屏 ---------- */
.page-about .about-intro {
  padding: 1.6rem 0 2.2rem;
}

.page-about .breadcrumbs {
  display: flex;
  align-items: center;
  gap: .45rem;
  font-size: .82rem;
  font-weight: 600;
  letter-spacing: .02em;
  color: var(--moss);
}

.page-about .breadcrumbs a {
  color: var(--teal);
  text-decoration: none;
  border-bottom: 2px solid transparent;
  transition: border-color .16s var(--ease);
}

.page-about .breadcrumbs a:hover {
  border-color: var(--orange);
}

.page-about .crumb-sep {
  color: var(--stone);
}

.page-about .intro-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1rem;
  align-items: end;
  margin-top: 1.4rem;
}

.page-about .intro-mark {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(3.4rem, 14vw, 6.4rem);
  font-weight: 700;
  line-height: .85;
  letter-spacing: -.06em;
  color: transparent;
  -webkit-text-stroke: 2px var(--teal);
  margin: 0;
}

.page-about .intro-copy h1 {
  font-size: clamp(1.65rem, 4.6vw, 2.7rem);
  font-weight: 800;
  line-height: 1.18;
  letter-spacing: -.02em;
  color: var(--deep);
  margin: 0 0 .9rem;
}

.page-about .lede {
  font-size: clamp(1.02rem, 2.1vw, 1.2rem);
  line-height: 1.75;
  color: var(--ink);
  max-width: 62ch;
  margin: 0 0 .9rem;
}

.page-about .intro-note {
  font-size: .9rem;
  line-height: 1.75;
  color: var(--moss);
  max-width: 62ch;
  margin: 0;
  padding-left: .9rem;
  border-left: 3px solid var(--light-teal);
}

/* ---------- 轨道标题 ---------- */
.page-about .track-head {
  padding: 1.6rem 0 .4rem;
  border-top: 2px solid var(--stone);
}

.page-about .track-head .section-title {
  font-size: clamp(1.35rem, 3.4vw, 1.9rem);
  font-weight: 800;
  line-height: 1.2;
  letter-spacing: -.02em;
  color: var(--deep);
  margin: 0 0 .5rem;
}

.page-about .track-sub {
  font-size: .95rem;
  line-height: 1.75;
  color: var(--ink);
  max-width: 60ch;
  margin: 0;
}

/* ---------- 筛选 ---------- */
.page-about .filter-bar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: .4rem;
  margin: 1.4rem 0 0;
  padding: .6rem .75rem;
  background: var(--mist);
  border: 2px solid var(--deep);
  border-radius: var(--radius-pill);
}

.page-about .filter-label {
  font-size: .78rem;
  font-weight: 700;
  letter-spacing: .06em;
  color: var(--deep);
  margin-right: .3rem;
}

.page-about .filter-btn {
  font: inherit;
  font-size: .86rem;
  font-weight: 700;
  padding: .38rem .95rem;
  border-radius: var(--radius-pill);
  border: 2px solid transparent;
  background: transparent;
  color: var(--deep);
  cursor: pointer;
  transition: background-color .16s var(--ease), border-color .16s var(--ease), color .16s var(--ease);
}

.page-about .filter-btn:hover {
  border-color: var(--teal);
}

.page-about .filter-btn[aria-pressed="true"] {
  background: var(--teal);
  border-color: var(--deep);
  color: var(--white);
}

.page-about .filter-btn:focus-visible {
  outline: 3px solid var(--orange);
  outline-offset: 2px;
}

/* ---------- 时间轴 ---------- */
.page-about .track {
  position: relative;
  margin-top: 1.6rem;
}

.page-about .track::before {
  content: "";
  position: absolute;
  top: 0;
  bottom: 0;
  left: calc(var(--rail-x) - 1px);
  width: 2px;
  background: var(--stone);
  opacity: .6;
}

.page-about .stage {
  position: relative;
  padding-left: var(--rail-gap);
  padding-top: var(--stage-pad);
  padding-bottom: var(--stage-pad);
}

.page-about .stage::before {
  content: "";
  position: absolute;
  left: calc(var(--rail-x) - 8px);
  top: calc(var(--stage-pad) + .35rem);
  width: 16px;
  height: 16px;
  background: var(--white);
  border: 2px solid var(--teal);
  border-radius: 2px;
  box-shadow: 2px 2px 0 var(--stone);
  transition: background-color .18s var(--ease), transform .18s var(--ease), border-color .18s var(--ease), box-shadow .18s var(--ease);
}

.page-about .stage.is-visible::before {
  background: var(--teal);
  border-color: var(--deep);
  transform: scale(1.16);
  box-shadow: 2px 2px 0 var(--light-teal);
}

.page-about .stage:target::before {
  background: var(--orange);
  border-color: var(--deep);
  transform: scale(1.22);
  box-shadow: 2px 2px 0 var(--stone);
}

.page-about .stage-anchor {
  display: inline-block;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 1.45rem;
  font-weight: 700;
  line-height: 1;
  letter-spacing: -.03em;
  color: var(--orange);
  text-decoration: none;
  margin-bottom: .55rem;
  border-bottom: 2px solid transparent;
  transition: border-color .16s var(--ease), color .16s var(--ease);
}

.page-about .stage-anchor:hover,
.page-about .stage-anchor:focus-visible {
  color: var(--deep);
  border-color: var(--orange);
}

.page-about .stage-title {
  font-size: clamp(1.24rem, 3.1vw, 1.72rem);
  font-weight: 800;
  line-height: 1.22;
  letter-spacing: -.02em;
  color: var(--deep);
  margin: 0 0 .8rem;
}

.page-about .stage-text {
  font-size: 1rem;
  line-height: 1.85;
  color: var(--ink);
  max-width: 64ch;
  margin: 0;
}

.page-about .stage-text--after {
  margin-top: 1.15rem;
}

.page-about .stage-out {
  margin: 1.15rem 0 0;
  padding: .7rem 0 .7rem 1rem;
  border-left: 4px solid var(--orange);
  background: linear-gradient(90deg, rgba(226, 112, 58, .09), rgba(226, 112, 58, 0) 72%);
  font-size: .96rem;
  font-weight: 600;
  line-height: 1.7;
  color: var(--deep);
  max-width: 60ch;
}

.page-about .stage-figure {
  margin: 1.3rem 0 0;
  border: 2px solid var(--deep);
  border-radius: var(--radius-card);
  box-shadow: var(--shadow-hard);
  background: var(--cream);
  overflow: hidden;
}

.page-about .stage-figure img {
  width: 100%;
  object-fit: cover;
  aspect-ratio: 4 / 3;
}

/* ---------- 版本列表 ---------- */
.page-about .ver-list {
  list-style: none;
  margin: 1.2rem 0 0;
  padding: 0;
  display: grid;
  gap: .85rem;
}

.page-about .ver-item {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  align-items: start;
  gap: .3rem .95rem;
  padding: .95rem 1.05rem;
  background: var(--white);
  border: 2px solid var(--deep);
  border-radius: var(--radius-card);
  box-shadow: var(--shadow-soft);
  transition: transform .18s var(--ease), box-shadow .18s var(--ease);
}

.page-about .ver-item:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-hard);
}

.page-about .ver-item--current {
  background: var(--mist);
  border-color: var(--teal);
}

.page-about .ver-tag {
  grid-column: 1;
  grid-row: 1;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: .95rem;
  font-weight: 700;
  color: var(--white);
  background: var(--deep);
  border-radius: 2px;
  padding: .2rem .5rem;
  align-self: start;
}

.page-about .ver-item--current .ver-tag {
  background: var(--orange);
  color: var(--deep);
}

.page-about .ver-badge {
  grid-column: 1;
  grid-row: 2;
  justify-self: start;
  font-size: .72rem;
  padding: .12rem .45rem;
}

.page-about .ver-text {
  grid-column: 2;
  grid-row: 1;
  margin: 0;
  font-size: .97rem;
  line-height: 1.7;
  color: var(--ink);
}

.page-about .ver-note {
  grid-column: 2;
  grid-row: 2;
  font-size: .82rem;
  line-height: 1.65;
  color: var(--moss);
  opacity: 0;
  max-height: 0;
  overflow: hidden;
  transition: opacity .18s var(--ease), max-height .2s var(--ease);
}

.page-about .ver-item:hover .ver-note,
.page-about .ver-item:focus-within .ver-note {
  opacity: 1;
  max-height: 5rem;
}

/* ---------- 团队 ---------- */
.page-about .team-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: .95rem;
  margin-top: 1.25rem;
}

.page-about .team-card {
  padding: 1.1rem 1.15rem 1.2rem;
  background: var(--white);
  border: 2px solid var(--deep);
  border-radius: var(--radius-card);
  box-shadow: var(--shadow-soft);
}

.page-about .team-num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 2.4rem;
  font-weight: 700;
  line-height: 1;
  letter-spacing: -.04em;
  color: var(--teal);
  margin: 0 0 .35rem;
}

.page-about .team-role {
  font-size: 1rem;
  font-weight: 800;
  color: var(--deep);
  margin: 0 0 .45rem;
}

.page-about .team-desc {
  font-size: .9rem;
  line-height: 1.75;
  color: var(--ink);
  margin: 0;
}

/* ---------- 规模横带 ---------- */
.page-about .scale-band {
  margin-top: 1.25rem;
  padding: 1.2rem 1rem;
  background: var(--stone);
  border: 2px solid var(--deep);
  border-radius: var(--radius-card);
  box-shadow: var(--shadow-hard);
}

.page-about .scale-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: .8rem;
}

.page-about .scale-item {
  background: var(--white);
  border: 2px solid var(--deep);
  border-radius: var(--radius-card);
  padding: .85rem .9rem;
  display: flex;
  flex-direction: column;
  gap: .15rem;
}

.page-about .scale-num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(1.6rem, 5vw, 2.1rem);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -.04em;
  color: var(--deep);
}

.page-about .scale-unit {
  font-size: .8rem;
  font-weight: 700;
  color: var(--orange);
}

.page-about .scale-label {
  font-size: .84rem;
  line-height: 1.6;
  color: var(--ink);
  margin-top: .2rem;
}

/* ---------- 三件事 ---------- */
.page-about .steps {
  list-style: none;
  margin: 1.2rem 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: .9rem;
}

.page-about .step {
  padding: 1.05rem 1.1rem 1.15rem;
  background: var(--cream);
  border: 2px solid var(--deep);
  border-radius: var(--radius-card);
  box-shadow: var(--shadow-soft);
}

.page-about .step-num {
  display: block;
  font-family: var(--font-mono);
  font-size: 1.4rem;
  font-weight: 700;
  line-height: 1;
  color: var(--teal);
  margin-bottom: .45rem;
}

.page-about .step-title {
  font-size: 1rem;
  font-weight: 800;
  color: var(--deep);
  margin: 0 0 .4rem;
}

.page-about .step-desc {
  font-size: .9rem;
  line-height: 1.75;
  color: var(--ink);
  margin: 0;
}

/* ---------- 下一站 ---------- */
.page-about .next-links {
  padding: 2.4rem 0 3.2rem;
  border-top: 2px solid var(--stone);
  margin-top: 1.2rem;
}

.page-about .next-links .section-title {
  font-size: clamp(1.3rem, 3.2vw, 1.75rem);
  font-weight: 800;
  letter-spacing: -.02em;
  color: var(--deep);
  margin: 0 0 1.1rem;
}

.page-about .next-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: .7rem;
}

.page-about .next-list a {
  display: flex;
  flex-direction: column;
  gap: .2rem;
  padding: .9rem 1.05rem;
  background: var(--white);
  border: 2px solid var(--deep);
  border-radius: var(--radius-card);
  box-shadow: var(--shadow-soft);
  text-decoration: none;
  transition: transform .18s var(--ease), box-shadow .18s var(--ease), border-color .18s var(--ease);
}

.page-about .next-list a:hover,
.page-about .next-list a:focus-visible {
  transform: translateY(-2px);
  border-color: var(--teal);
  box-shadow: var(--shadow-hard);
}

.page-about .next-name {
  font-size: 1rem;
  font-weight: 800;
  color: var(--deep);
}

.page-about .next-desc {
  font-size: .86rem;
  line-height: 1.6;
  color: var(--moss);
}

/* ---------- 响应式 ---------- */
@media (min-width: 720px) {
  .page-about .team-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .steps {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

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

@media (min-width: 860px) {
  .page-about {
    --rail-x: 22px;
    --rail-gap: 68px;
    --stage-pad: 3rem;
  }

  .page-about .intro-grid {
    grid-template-columns: minmax(160px, 230px) minmax(0, 1fr);
    gap: 2.6rem;
  }

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

  .page-about .stage:nth-child(even) {
    padding-left: calc(var(--rail-gap) + 14px);
  }

  .page-about .stage:nth-child(even)::before {
    left: calc(var(--rail-x) - 8px);
  }
}

@media (max-width: 719px) {
  .page-about {
    --rail-x: 11px;
    --rail-gap: 36px;
    --stage-pad: 1.9rem;
  }

  .page-about .stage::before {
    width: 13px;
    height: 13px;
    left: calc(var(--rail-x) - 6.5px);
    top: calc(var(--stage-pad) + .3rem);
  }

  .page-about .ver-item {
    grid-template-columns: minmax(0, 1fr);
  }

  .page-about .ver-tag,
  .page-about .ver-badge,
  .page-about .ver-text,
  .page-about .ver-note {
    grid-column: 1;
  }

  .page-about .ver-badge {
    grid-row: 2;
  }

  .page-about .ver-text {
    grid-row: 3;
  }

  .page-about .ver-note {
    grid-row: 4;
  }

  .page-about .filter-label {
    width: 100%;
    margin: 0 0 .2rem;
  }
}

@media (hover: none) {
  .page-about .ver-note {
    opacity: 1;
    max-height: 6rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .stage::before,
  .page-about .ver-item,
  .page-about .next-list a {
    transition: none;
  }

  .page-about .stage.is-visible::before {
    transform: none;
  }
}
<<<END>>>