.page-about {
  --ab-text: #C4D4E1;
  --ab-line: rgba(34, 224, 214, .18);
  --ab-line-soft: rgba(34, 224, 214, .14);
  position: relative;
  padding-bottom: clamp(40px, 6vw, 88px);
}

.page-about .breadcrumbs {
  margin-bottom: 26px;
  font-size: 13px;
  letter-spacing: .02em;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  padding-top: clamp(18px, 3vw, 40px);
  padding-bottom: clamp(44px, 7vw, 88px);
}

.page-about .about-hero__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(26px, 4vw, 48px);
  align-items: end;
}

.page-about .about-hero__eyebrow {
  margin: 0 0 20px;
  font-size: 12px;
  letter-spacing: .18em;
  color: var(--cyan);
}

.page-about .about-hero__title {
  margin: 0 0 24px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(2.35rem, 7.6vw, 4.9rem);
  line-height: .97;
  letter-spacing: -.035em;
  color: var(--ink);
}

.page-about .about-hero__title span {
  display: block;
  color: var(--cyan);
}

.page-about .about-hero__lede {
  margin: 0;
  max-width: 34em;
}

.page-about .about-hero__figure {
  margin: 0;
  border-radius: var(--radius-card);
  overflow: hidden;
  border: 1px solid var(--ab-line);
  clip-path: polygon(0 4%, 100% 0, 100% 96%, 0 100%);
}

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

/* ---------- 入口定位 ---------- */
.page-about .about-what {
  padding-block: clamp(40px, 7vw, 84px);
  border-top: 1px solid var(--ab-line-soft);
}

.page-about .about-what__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(20px, 3vw, 34px);
  margin-top: 28px;
}

.page-about .about-what__lead {
  margin: 0;
  font-family: var(--font-serif);
  font-weight: 500;
  font-size: clamp(1.15rem, 2.4vw, 1.55rem);
  line-height: 1.5;
  color: var(--ink);
  max-width: 22em;
}

.page-about .about-what__body p {
  margin: 0 0 16px;
  max-width: 34em;
  color: var(--ab-text);
}

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

/* ---------- 版本时间线 ---------- */
.page-about .about-timeline {
  padding-block: clamp(44px, 7vw, 88px);
}

.page-about .tl {
  list-style: none;
  margin: 34px 0 0;
  padding: 0;
}

.page-about .tl__item {
  position: relative;
  padding: 0 0 38px 26px;
  border-left: 2px solid var(--ab-line);
}

.page-about .tl__item::before {
  content: "";
  position: absolute;
  left: -7px;
  top: 8px;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--deep);
  border: 2px solid var(--cyan);
}

.page-about .tl__item:last-child {
  padding-bottom: 0;
  border-left-color: transparent;
}

.page-about .tl__year {
  display: flex;
  align-items: baseline;
  gap: 12px;
  margin-bottom: 10px;
}

.page-about .tl__year .mono {
  font-size: clamp(1.4rem, 3vw, 1.95rem);
  font-weight: 600;
  letter-spacing: -.02em;
  color: var(--cyan);
  line-height: 1;
}

.page-about .tl__ver {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--muted);
}

.page-about .tl__body h3 {
  margin: 0 0 10px;
  font-family: var(--font-serif);
  font-weight: 500;
  font-size: clamp(1.1rem, 2.2vw, 1.4rem);
  line-height: 1.35;
  color: var(--ink);
}

.page-about .tl__body p {
  margin: 0;
  max-width: 34em;
  color: var(--ab-text);
  font-size: 16px;
  line-height: 1.8;
}

.page-about .tl__extra {
  max-height: 0;
  overflow: hidden;
  opacity: 0;
  margin-top: 0;
  color: var(--cyan-mist);
  font-size: 15px;
  transition: max-height .35s var(--ease), opacity .28s var(--ease), margin-top .35s var(--ease);
}

.page-about .tl__item:hover .tl__extra,
.page-about .tl__item:focus-within .tl__extra {
  max-height: 220px;
  opacity: 1;
  margin-top: 12px;
}

/* ---------- 团队分工 ---------- */
.page-about .about-team {
  padding-block: clamp(44px, 7vw, 92px);
  background: linear-gradient(158deg, rgba(46, 35, 82, .92) 0%, rgba(10, 27, 46, .5) 68%);
  border-top: 1px solid var(--ab-line);
  border-bottom: 1px solid var(--ab-line);
}

.page-about .about-team__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(26px, 4vw, 46px);
  margin-top: 26px;
  align-items: start;
}

.page-about .about-team__lede {
  margin: 0 0 28px;
  max-width: 34em;
}

.page-about .team-bar {
  display: flex;
  gap: 6px;
  margin-bottom: 26px;
}

.page-about .team-bar__seg {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 8px;
  border-radius: var(--radius-pill);
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: .02em;
  color: var(--abyss);
  white-space: nowrap;
}

.page-about .team-bar__seg--a { flex: 7; background: var(--cyan); }
.page-about .team-bar__seg--b { flex: 6; background: var(--cyan-mist); }
.page-about .team-bar__seg--c { flex: 5; background: rgba(34, 224, 214, .42); color: var(--ink); }

.page-about .team-note {
  border-top: 1px solid var(--ab-line-soft);
  padding-block: 16px;
}

.page-about .team-note:last-of-type {
  border-bottom: 1px solid var(--ab-line-soft);
}

.page-about .team-note summary {
  display: flex;
  align-items: baseline;
  gap: 12px;
  list-style: none;
  cursor: pointer;
  font-family: var(--font-serif);
  font-weight: 500;
  font-size: clamp(1rem, 2vw, 1.24rem);
  color: var(--ink);
}

.page-about .team-note summary::-webkit-details-marker {
  display: none;
}

.page-about .team-note summary::after {
  content: "+";
  margin-left: auto;
  font-family: var(--font-mono);
  font-weight: 600;
  font-size: 18px;
  line-height: 1;
  color: var(--cyan);
}

.page-about .team-note[open] summary::after {
  content: "\2212";
}

.page-about .team-note summary .mono {
  font-size: 13px;
  color: var(--cyan-mist);
}

.page-about .team-note p {
  margin: 12px 0 0;
  max-width: 34em;
  color: var(--ab-text);
  font-size: 16px;
  line-height: 1.8;
}

.page-about .about-team__figure {
  margin: 0;
  border-radius: var(--radius-card);
  overflow: hidden;
  border: 1px solid var(--ab-line);
}

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

/* ---------- 更新节奏 ---------- */
.page-about .about-cadence {
  padding-block: clamp(44px, 7vw, 92px);
}

.page-about .about-cadence__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(26px, 4vw, 48px);
  align-items: start;
}

.page-about .about-cadence__copy .lede {
  margin: 0;
  max-width: 34em;
}

.page-about .cadence-list {
  list-style: none;
  margin: 28px 0 0;
  padding: 0;
}

.page-about .cadence-list__row {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 8px;
  padding: 18px 0;
  border-top: 1px solid var(--ab-line-soft);
}

.page-about .cadence-list__row:last-child {
  border-bottom: 1px solid var(--ab-line-soft);
}

.page-about .cadence-list__row h3 {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: .1em;
  color: var(--cyan);
}

.page-about .cadence-list__row p {
  margin: 0;
  max-width: 34em;
  color: var(--ab-text);
  font-size: 16px;
  line-height: 1.8;
}

.page-about .about-cadence__figure {
  margin: 0;
  border-radius: var(--radius-card);
  overflow: hidden;
  border: 1px solid var(--ab-line);
}

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

/* ---------- 覆盖与响应 ---------- */
.page-about .about-reach {
  padding-block: clamp(44px, 7vw, 92px);
  background: linear-gradient(152deg, rgba(74, 27, 46, .9) 0%, rgba(10, 27, 46, .55) 72%);
  border-top: 1px solid var(--ab-line);
  border-bottom: 1px solid var(--ab-line);
}

.page-about .about-reach__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(28px, 4vw, 52px);
  margin-top: 30px;
  align-items: start;
}

.page-about .about-reach__figures {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 22px;
}

.page-about .reach-fig {
  padding-left: 16px;
  border-left: 2px solid var(--ab-line);
}

.page-about .reach-fig__num {
  display: block;
  font-size: clamp(2.1rem, 5.4vw, 3.2rem);
  font-weight: 600;
  line-height: 1;
  letter-spacing: -.03em;
  color: var(--ink);
}

.page-about .reach-fig__num em {
  font-style: normal;
  font-size: .42em;
  margin-left: 4px;
  color: var(--cyan);
}

.page-about .reach-fig p {
  margin: 10px 0 0;
  font-size: 14px;
  color: var(--muted);
}

.page-about .about-reach__body p {
  margin: 0 0 16px;
  max-width: 34em;
  color: var(--ab-text);
}

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

/* ---------- 后续入口 ---------- */
.page-about .about-next {
  padding-block: clamp(44px, 7vw, 88px);
}

.page-about .about-next .lede {
  margin: 0;
  max-width: 34em;
}

.page-about .about-next__pills {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 28px;
}

.page-about .about-next__pill {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 12px 22px;
  border-radius: var(--radius-pill);
  border: 1px solid var(--ab-line);
  color: var(--ink);
  font-size: 15px;
  text-decoration: none;
  transition: border-color .25s var(--ease), background .25s var(--ease), transform .25s var(--ease);
}

.page-about .about-next__pill::after {
  content: "\2192";
  font-size: 14px;
  color: var(--cyan);
}

.page-about .about-next__pill:hover {
  border-color: var(--cyan);
  background: rgba(34, 224, 214, .1);
  transform: translateY(-2px);
}

.page-about .about-next__pill:active {
  transform: scale(.97);
}

/* ---------- 触屏降级：时间线附加说明常驻可见 ---------- */
@media (hover: none), (pointer: coarse) {
  .page-about .tl__extra {
    max-height: none;
    opacity: 1;
    margin-top: 12px;
  }
}

/* ---------- 中等屏幕 ---------- */
@media (min-width: 720px) {
  .page-about .about-what__grid {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    gap: clamp(28px, 4vw, 56px);
    align-items: start;
  }

  .page-about .cadence-list__row {
    grid-template-columns: 132px minmax(0, 1fr);
    gap: 26px;
    align-items: baseline;
  }

  .page-about .about-reach__figures {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 18px;
  }

  .page-about .team-bar__seg {
    font-size: 13px;
    min-height: 48px;
  }
}

/* ---------- 桌面端 ---------- */
@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: clamp(32px, 4vw, 56px);
  }

  .page-about .about-hero__figure {
    margin-bottom: 6px;
  }

  .page-about .tl__item {
    grid-template-columns: 150px minmax(0, 1fr);
    column-gap: 40px;
    padding-left: 40px;
  }

  .page-about .tl__year {
    flex-direction: column;
    align-items: flex-start;
    gap: 6px;
    margin-bottom: 0;
    padding-top: 2px;
  }

  .page-about .about-team__grid {
    grid-template-columns: minmax(0, 1.12fr) minmax(0, .88fr);
  }

  .page-about .about-cadence__grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: clamp(32px, 4vw, 60px);
  }

  .page-about .about-reach__grid {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    gap: clamp(32px, 4vw, 64px);
  }

  .page-about .about-reach__figures {
    grid-template-columns: minmax(0, 1fr);
    gap: 26px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .tl__extra,
  .page-about .about-next__pill {
    transition: none;
  }
  .page-about .about-next__pill:hover {
    transform: none;
  }
}
<<<END>>>