.page-about {
  --ab-cut: 34px;
  --ab-hair: 1px solid var(--ba-line);
  position: relative;
  isolation: isolate;
  overflow-x: clip;
}

/* ---------- 面包屑 ---------- */
.page-about .ab-crumb {
  padding-top: clamp(16px, 3vw, 26px);
}

/* ---------- 首屏 ---------- */
.page-about .ab-hero {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(26px, 4vw, 44px);
  padding-top: clamp(24px, 4vw, 46px);
  padding-bottom: clamp(48px, 8vw, 96px);
}

.page-about .ab-hero::before {
  content: "";
  position: absolute;
  z-index: 0;
  top: -70px;
  right: -14vw;
  bottom: 30%;
  left: 34%;
  background:
    linear-gradient(118deg, rgba(53, 211, 199, 0.15) 0%, rgba(53, 211, 199, 0.03) 44%, rgba(230, 184, 74, 0.11) 100%);
  clip-path: polygon(24% 0, 100% 0, 100% 100%, 0 74%);
  pointer-events: none;
}

.page-about .ab-hero__text,
.page-about .ab-hero__media {
  position: relative;
  z-index: 1;
}

.page-about .ab-hero__title {
  margin: 14px 0 0;
  font-family: var(--ba-font-display);
  font-weight: 900;
  font-size: clamp(36px, 8.6vw, 88px);
  line-height: 0.99;
  letter-spacing: -0.022em;
  color: var(--ba-paper);
}

.page-about .ab-hero__title-accent {
  display: block;
  color: var(--ba-gold);
  position: relative;
}

.page-about .ab-hero__title-accent::after {
  content: "";
  position: absolute;
  left: 2px;
  bottom: -8px;
  width: min(58%, 320px);
  height: 2px;
  background: linear-gradient(90deg, var(--ba-gold), rgba(230, 184, 74, 0));
}

.page-about .ab-hero__lede {
  margin: clamp(22px, 3vw, 30px) 0 0;
  max-width: 58ch;
  font-size: clamp(16px, 1.7vw, 18px);
  line-height: 1.8;
  color: var(--ba-steel);
}

.page-about .ab-hero__meta {
  display: flex;
  flex-wrap: wrap;
  gap: 14px 30px;
  margin: clamp(26px, 4vw, 40px) 0 0;
  padding: 0;
}

.page-about .ab-hero__meta > div {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding-left: 14px;
  border-left: 1px solid var(--ba-line);
}

.page-about .ab-hero__meta dt {
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--ba-steel);
}

.page-about .ab-hero__meta dd {
  margin: 0;
  font-family: var(--ba-font-mono);
  font-size: clamp(19px, 2.6vw, 26px);
  line-height: 1;
  color: var(--ba-gold);
}

.page-about .ab-hero__media {
  margin: 0;
  position: relative;
  aspect-ratio: 16 / 9;
  background: var(--ba-panel);
  border: var(--ab-hair);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - var(--ab-cut)), 0 100%);
  overflow: hidden;
}

.page-about .ab-hero__media img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: saturate(0.92) contrast(1.05);
}

.page-about .ab-hero__cap {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 6px 14px;
  align-items: baseline;
  padding: 28px 18px 16px;
  font-size: 12px;
  line-height: 1.6;
  color: var(--ba-paper);
  background: linear-gradient(180deg, rgba(10, 15, 44, 0) 0%, rgba(10, 15, 44, 0.88) 62%);
}

.page-about .ab-hero__cap .ba-mono {
  font-size: 10px;
  letter-spacing: 0.2em;
  color: var(--ba-cyan);
}

/* ---------- 章节索引条 ---------- */
.page-about .ab-toc {
  border-top: var(--ab-hair);
  border-bottom: var(--ab-hair);
  padding: 16px 0;
}

.page-about .ab-toc__list {
  display: flex;
  flex-wrap: wrap;
  gap: 6px 24px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .ab-toc__link {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  padding: 4px 1px;
  font-size: 14px;
  color: var(--ba-steel);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 0.25s var(--ba-ease), border-color 0.25s var(--ba-ease);
}

.page-about .ab-toc__link:hover,
.page-about .ab-toc__link:focus-visible {
  color: var(--ba-gold-hi);
  border-bottom-color: var(--ba-gold-hi);
}

.page-about .ab-toc__link[aria-current="true"] {
  color: var(--ba-gold);
  border-bottom-color: var(--ba-gold);
}

.page-about .ab-toc__num {
  font-family: var(--ba-font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--ba-cyan);
}

/* ---------- 区块骨架 ---------- */
.page-about .ab-section {
  position: relative;
  padding: clamp(52px, 8vw, 104px) 0;
  border-top: var(--ab-hair);
}

.page-about .ab-section--last {
  padding-bottom: clamp(64px, 9vw, 116px);
}

.page-about .ab-sec__head {
  max-width: 760px;
}

.page-about .ab-sec__eyebrow {
  margin: 0;
  font-family: var(--ba-font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--ba-cyan);
}

.page-about .ab-sec__title {
  margin: 12px 0 0;
  font-family: var(--ba-font-display);
  font-weight: 900;
  font-size: clamp(28px, 4.8vw, 46px);
  line-height: 1.1;
  letter-spacing: -0.015em;
  color: var(--ba-paper);
}

.page-about .ab-sec__lede {
  margin: 18px 0 0;
  max-width: 62ch;
  font-size: clamp(15px, 1.6vw, 17px);
  line-height: 1.8;
  color: var(--ba-steel);
}

/* ---------- 01 起点 ---------- */
.page-about .ab-origin {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(28px, 4vw, 46px);
  margin-top: clamp(28px, 4vw, 48px);
}

.page-about .ab-origin__body p {
  margin: 0 0 20px;
  font-size: clamp(15px, 1.65vw, 17px);
  line-height: 1.85;
  color: rgba(244, 241, 232, 0.82);
}

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

.page-about .ab-origin__aside {
  display: grid;
  gap: 22px;
  align-content: start;
}

.page-about .ab-note__k {
  margin: 0 0 8px;
  font-family: var(--ba-font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--ba-gold);
}

.page-about .ab-note__v {
  margin: 0;
  font-size: 16px;
  line-height: 1.75;
  color: var(--ba-paper);
}

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

.page-about .ab-origin__facts li {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding-top: 14px;
  border-top: var(--ab-hair);
  font-size: 14px;
  line-height: 1.65;
  color: var(--ba-steel);
}

.page-about .ab-origin__facts .ba-mono {
  flex: none;
  font-size: 22px;
  line-height: 1;
  color: var(--ba-gold);
}

/* ---------- 02 服务范围 ---------- */
.page-about .ab-stages {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  margin-top: clamp(28px, 4vw, 44px);
  background: var(--ba-line);
  border: var(--ab-hair);
}

.page-about .ab-stage {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 26px 22px 30px;
  background: var(--ba-panel);
  transition: background 0.35s var(--ba-ease);
}

.page-about .ab-stage::before {
  content: "";
  position: absolute;
  inset: 0 0 auto 0;
  height: 2px;
  background: linear-gradient(90deg, var(--ba-cyan), var(--ba-gold));
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform 0.45s var(--ba-ease);
}

.page-about .ab-stage:hover,
.page-about .ab-stage:focus-within {
  background: var(--ba-lift);
}

.page-about .ab-stage:hover::before,
.page-about .ab-stage:focus-within::before {
  transform: scaleX(1);
}

.page-about .ab-stage--hot {
  background: linear-gradient(180deg, rgba(139, 30, 45, 0.26) 0%, var(--ba-panel) 66%);
}

.page-about .ab-stage__idx {
  margin: 0;
  font-family: var(--ba-font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--ba-steel);
}

.page-about .ab-stage--hot .ab-stage__idx {
  color: var(--ba-gold-hi);
}

.page-about .ab-stage__title {
  margin: 0;
  font-size: 19px;
  font-weight: 700;
  line-height: 1.4;
  color: var(--ba-paper);
}

.page-about .ab-stage p:last-child {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--ba-steel);
}

.page-about .ab-scope__strip {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 16px 28px;
  margin-top: clamp(22px, 3vw, 32px);
  padding: 20px 22px;
  background: var(--ba-panel);
  border-left: 3px solid var(--ba-cyan);
}

.page-about .ab-scope__strip-text {
  min-width: 220px;
}

.page-about .ab-scope__strip-k {
  margin: 0 0 6px;
  font-family: var(--ba-font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--ba-cyan);
}

.page-about .ab-scope__strip-v {
  margin: 0;
  font-size: 15px;
  line-height: 1.7;
  color: rgba(244, 241, 232, 0.86);
}

/* ---------- 03 内容生产 ---------- */
.page-about .ab-flow {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(28px, 4vw, 42px);
  margin-top: clamp(28px, 4vw, 44px);
}

.page-about .ab-flow__steps {
  margin: 0;
  padding: 0;
  list-style: none;
  border-top: var(--ab-hair);
}

.page-about .ab-flow__step {
  position: relative;
  padding: 22px 0 24px 56px;
  border-bottom: var(--ab-hair);
}

.page-about .ab-flow__num {
  position: absolute;
  left: 0;
  top: 24px;
  font-family: var(--ba-font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--ba-cyan);
}

.page-about .ab-flow__step h3 {
  margin: 0 0 8px;
  font-size: 17px;
  font-weight: 600;
  line-height: 1.45;
  color: var(--ba-paper);
}

.page-about .ab-flow__step p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--ba-steel);
}

.page-about .ab-flow__media {
  margin: 0;
  position: relative;
  background: var(--ba-panel);
  border: var(--ab-hair);
}

.page-about .ab-flow__media img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 3 / 2;
  object-fit: cover;
}

.page-about .ab-flow__cap {
  padding: 14px 16px 16px;
  font-size: 12.5px;
  line-height: 1.65;
  color: var(--ba-steel);
  border-top: var(--ab-hair);
}

/* ---------- 04 版本演进 ---------- */
.page-about .ab-timeline {
  position: relative;
  margin: clamp(30px, 4vw, 48px) 0 0;
  padding: 0 0 0 26px;
  list-style: none;
}

.page-about .ab-timeline::before {
  content: "";
  position: absolute;
  left: 4px;
  top: 10px;
  bottom: 10px;
  width: 1px;
  background: linear-gradient(180deg, var(--ba-cyan) 0%, var(--ba-gold) 55%, rgba(46, 58, 104, 0.2) 100%);
}

.page-about .ab-timeline__item {
  position: relative;
  padding-bottom: clamp(28px, 3.4vw, 40px);
}

.page-about .ab-timeline__item::before {
  content: "";
  position: absolute;
  left: -26px;
  top: 8px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--ba-night);
  border: 2px solid var(--ba-cyan);
}

.page-about .ab-timeline__item--marked::before {
  border-color: var(--ba-gold);
  background: var(--ba-gold);
}

.page-about .ab-timeline__year {
  display: block;
  font-family: var(--ba-font-mono);
  font-size: clamp(20px, 4vw, 30px);
  line-height: 1;
  letter-spacing: 0.02em;
  color: var(--ba-gold);
}

.page-about .ab-timeline__item--marked .ab-timeline__year {
  color: var(--ba-gold-hi);
}

.page-about .ab-timeline__body h3 {
  margin: 12px 0 8px;
  font-size: 17px;
  font-weight: 600;
  line-height: 1.45;
  color: var(--ba-paper);
}

.page-about .ab-timeline__body p {
  margin: 0;
  max-width: 62ch;
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--ba-steel);
}

.page-about .ab-timeline__media {
  margin: clamp(8px, 2vw, 18px) 0 0;
  border: var(--ab-hair);
  background: var(--ba-panel);
}

.page-about .ab-timeline__media img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 2 / 1;
  object-fit: cover;
}

.page-about .ab-timeline__cap {
  padding: 13px 16px 15px;
  font-size: 12.5px;
  line-height: 1.65;
  color: var(--ba-steel);
  border-top: var(--ab-hair);
}

/* ---------- 05 团队生态 ---------- */
.page-about .ab-team {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(30px, 4vw, 56px);
  align-items: start;
}

.page-about .ab-team__text .ab-sec__title {
  margin-top: 12px;
}

.page-about .ab-team__text .ba-lede {
  margin: 18px 0 0;
  max-width: 58ch;
  font-size: clamp(15px, 1.65vw, 17px);
  line-height: 1.82;
  color: rgba(244, 241, 232, 0.82);
}

.page-about .ab-team__note {
  margin: 18px 0 0;
  max-width: 58ch;
  padding-left: 16px;
  border-left: 2px solid var(--ba-bounty);
  font-size: 14px;
  line-height: 1.78;
  color: var(--ba-steel);
}

.page-about .ab-team__stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 0;
  padding: 0;
  list-style: none;
  background: var(--ba-line);
  border: var(--ab-hair);
}

.page-about .ab-team__stats li {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 22px 18px 24px;
  background: var(--ba-panel);
}

.page-about .ab-team__num {
  font-family: var(--ba-font-mono);
  font-size: clamp(26px, 4.4vw, 36px);
  line-height: 1;
  color: var(--ba-gold);
}

.page-about .ab-team__label {
  font-size: 13px;
  line-height: 1.6;
  color: var(--ba-steel);
}

/* ---------- 06 选择理由 ---------- */
.page-about .ab-why {
  margin: clamp(26px, 3.6vw, 40px) 0 0;
  padding: 0;
  list-style: none;
  border-top: var(--ab-hair);
}

.page-about .ab-why__item {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 8px;
  padding: 22px 0 24px;
  border-bottom: var(--ab-hair);
}

.page-about .ab-why__item h3 {
  margin: 0;
  font-size: 17px;
  font-weight: 600;
  line-height: 1.45;
  color: var(--ba-gold-hi);
}

.page-about .ab-why__item p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--ba-steel);
}

/* ---------- 下一步入口 ---------- */
.page-about .ab-next {
  margin-top: clamp(40px, 6vw, 72px);
  padding-top: clamp(28px, 4vw, 40px);
  border-top: 2px solid var(--ba-gold);
}

.page-about .ab-next__title {
  margin: 12px 0 0;
  font-family: var(--ba-font-display);
  font-weight: 900;
  font-size: clamp(24px, 3.6vw, 34px);
  line-height: 1.15;
  color: var(--ba-paper);
}

.page-about .ab-next__links {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  margin: clamp(24px, 3.4vw, 36px) 0 0;
  padding: 0;
  list-style: none;
  background: var(--ba-line);
}

.page-about .ab-next__link {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 20px 20px 22px;
  background: var(--ba-panel);
  text-decoration: none;
  transition: background 0.3s var(--ba-ease), color 0.3s var(--ba-ease);
}

.page-about .ab-next__link:hover,
.page-about .ab-next__link:focus-visible {
  background: var(--ba-lift);
}

.page-about .ab-next__link-k {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-size: 16px;
  font-weight: 600;
  color: var(--ba-paper);
}

.page-about .ab-next__link-k::after {
  content: "→";
  font-family: var(--ba-font-mono);
  font-size: 14px;
  color: var(--ba-gold);
  transition: transform 0.3s var(--ba-ease);
}

.page-about .ab-next__link:hover .ab-next__link-k::after {
  transform: translateX(4px);
}

.page-about .ab-next__link-v {
  font-size: 13.5px;
  line-height: 1.7;
  color: var(--ba-steel);
}

/* ---------- 响应式 ---------- */
@media (min-width: 640px) {
  .page-about .ab-timeline {
    padding-left: 30px;
  }

  .page-about .ab-timeline__item::before {
    left: -30px;
  }

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

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

@media (min-width: 860px) {
  .page-about .ab-origin {
    grid-template-columns: minmax(0, 1.35fr) minmax(0, 0.65fr);
    column-gap: clamp(36px, 6vw, 84px);
  }

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

  .page-about .ab-why__item {
    grid-template-columns: minmax(0, 0.85fr) minmax(0, 1.15fr);
    gap: 6px 40px;
    align-items: baseline;
  }
}

@media (min-width: 1000px) {
  .page-about .ab-hero {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
    align-items: center;
    column-gap: clamp(36px, 5vw, 72px);
  }

  .page-about .ab-flow {
    grid-template-columns: minmax(0, 1fr) minmax(0, 0.82fr);
    column-gap: clamp(36px, 5vw, 76px);
    align-items: start;
  }

  .page-about .ab-flow__media {
    position: sticky;
    top: 96px;
  }

  .page-about .ab-team {
    grid-template-columns: minmax(0, 1fr) minmax(0, 0.85fr);
    column-gap: clamp(36px, 5vw, 76px);
  }

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

  .page-about .ab-timeline {
    padding-left: 158px;
    margin-top: clamp(36px, 5vw, 56px);
  }

  .page-about .ab-timeline::before {
    left: 118px;
  }

  .page-about .ab-timeline__item {
    display: grid;
    grid-template-columns: minmax(0, 1fr);
    column-gap: 0;
  }

  .page-about .ab-timeline__item::before {
    left: -42px;
  }

  .page-about .ab-timeline__year {
    position: absolute;
    left: -158px;
    top: 0;
    width: 118px;
    text-align: right;
  }

  .page-about .ab-timeline__media {
    margin-left: 158px;
  }
}

@media (min-width: 1240px) {
  .page-about .ab-stages {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-stage::before,
  .page-about .ab-next__link-k::after,
  .page-about .ab-toc__link {
    transition: none;
  }
}
<<<END>>>