.page-about {
  --ab-rail: 132px;
  --ab-line: 1px solid var(--layer);
  padding-bottom: clamp(60px, 9vw, 120px);
}

.page-about .crumbs {
  margin-bottom: clamp(26px, 4vw, 44px);
}

/* ---------- 首屏 ---------- */
.page-about .ab-hero {
  display: grid;
  gap: clamp(18px, 3vw, 28px);
  padding-bottom: clamp(34px, 5vw, 56px);
  border-bottom: var(--ab-line);
}

.page-about .ab-hero__title {
  margin: 0;
  font-family: var(--font-geo);
  font-weight: 300;
  font-size: clamp(34px, 7.4vw, 78px);
  line-height: 1.05;
  letter-spacing: -0.025em;
}

.page-about .ab-hero__title em {
  font-style: normal;
  font-weight: 700;
  color: var(--cyan);
}

.page-about .ab-hero__lead {
  max-width: 64ch;
}

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

.page-about .ab-facts li {
  background: var(--panel);
  padding: 14px 16px;
  display: flex;
  flex-direction: column;
  gap: 3px;
}

.page-about .ab-facts__num {
  font-family: var(--font-geo);
  font-variant-numeric: var(--num);
  font-size: clamp(22px, 3.2vw, 30px);
  font-weight: 600;
  line-height: 1.1;
  color: var(--cyan);
}

.page-about .ab-facts__cap {
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--muted);
}

/* ---------- 章节通用 ---------- */
.page-about .ab-section {
  margin-top: clamp(52px, 8vw, 96px);
}

/* ---------- 01 落地做法 ---------- */
.page-about .ab-practices {
  margin-top: clamp(24px, 3.4vw, 36px);
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(14px, 2vw, 18px);
}

.page-about .ab-card {
  background: var(--panel);
  border-left: 2px solid var(--cyan);
  padding: clamp(20px, 3vw, 26px);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - var(--cut)), calc(100% - var(--cut)) 100%, 0 100%);
  transition: transform 0.3s var(--ease), background 0.3s var(--ease);
}

.page-about .ab-card h3 {
  margin: 10px 0 8px;
  font-size: 19px;
  font-weight: 600;
  color: var(--text);
}

.page-about .ab-card p {
  margin: 0;
  font-size: 15px;
  line-height: 1.75;
  color: var(--muted);
}

.page-about .ab-card:hover {
  transform: translateY(-3px);
  background: var(--layer);
}

/* ---------- 02 时间线 ---------- */
.page-about .ab-timeline__figure {
  margin: clamp(22px, 3vw, 32px) 0 0;
  border: 1px solid var(--layer);
  background: var(--panel);
}

.page-about .ab-timeline__figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 16 / 9;
  object-fit: cover;
}

.page-about .ab-years {
  margin: clamp(20px, 3vw, 28px) 0 0;
}

.page-about .ab-years__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.page-about .ab-years__list a {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 14px;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.16em;
  font-variant-numeric: var(--num);
  color: var(--muted);
  background: var(--panel);
  border: 1px solid var(--layer);
  text-decoration: none;
  transition: color 0.25s var(--ease), border-color 0.25s var(--ease);
}

.page-about .ab-years__list a::before {
  content: "";
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--layer);
  transition: background 0.25s var(--ease), box-shadow 0.25s var(--ease);
}

.page-about .ab-years__list a:hover,
.page-about .ab-years__list a:focus-visible {
  color: var(--cyan-hi);
  border-color: rgba(31, 224, 200, 0.5);
}

.page-about .ab-years__list a:hover::before,
.page-about .ab-years__list a:focus-visible::before {
  background: var(--cyan);
  box-shadow: 0 0 10px var(--cyan);
}

.page-about .ab-stages {
  margin-top: clamp(24px, 3vw, 34px);
}

.page-about .ab-stage {
  display: grid;
  gap: 10px;
  padding: clamp(22px, 3vw, 32px) 0;
  border-top: var(--ab-line);
  scroll-margin-top: 100px;
}

.page-about .ab-stage__rail {
  display: flex;
  align-items: baseline;
  gap: 12px;
}

.page-about .ab-stage__num {
  font-family: var(--font-geo);
  font-size: clamp(38px, 9vw, 64px);
  font-weight: 300;
  line-height: 0.9;
  letter-spacing: -0.03em;
  color: rgba(31, 224, 200, 0.16);
  -webkit-text-stroke: 1px rgba(31, 224, 200, 0.75);
  transition: color 0.3s var(--ease), -webkit-text-stroke-color 0.3s var(--ease);
}

.page-about .ab-stage__year {
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.18em;
  font-variant-numeric: var(--num);
  color: var(--cyan);
}

.page-about .ab-stage__body h3 {
  margin: 0 0 8px;
  font-size: clamp(20px, 2.6vw, 26px);
  font-weight: 600;
  line-height: 1.3;
}

.page-about .ab-stage__body p {
  margin: 0;
  max-width: 62ch;
  font-size: 15.5px;
  line-height: 1.78;
  color: var(--muted);
}

.page-about .ab-stage__marks {
  list-style: none;
  margin: 14px 0 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.page-about .ab-stage__marks li {
  padding: 5px 11px;
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--cyan-hi);
  background: rgba(31, 224, 200, 0.06);
  border: 1px solid rgba(31, 224, 200, 0.3);
}

.page-about .ab-stage:hover .ab-stage__num,
.page-about .ab-stage:focus-within .ab-stage__num {
  color: rgba(31, 224, 200, 0.3);
  -webkit-text-stroke-color: var(--cyan-hi);
}

/* ---------- 03 团队 ---------- */
.page-about .ab-team__grid {
  margin-top: clamp(24px, 3.4vw, 36px);
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(22px, 3vw, 34px);
}

.page-about .ab-team__text .prose {
  margin-top: 0;
}

.page-about .ab-team__list {
  list-style: none;
  margin: clamp(20px, 3vw, 26px) 0 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--layer);
  border: 1px solid var(--layer);
}

.page-about .ab-team__list li {
  background: var(--panel);
  border-left: 2px solid var(--cyan);
  padding: 16px 18px;
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 14px;
  align-items: start;
}

.page-about .ab-team__n {
  font-family: var(--font-geo);
  font-variant-numeric: var(--num);
  font-size: 26px;
  font-weight: 600;
  line-height: 1;
  color: var(--orange);
  min-width: 2ch;
  text-align: right;
}

.page-about .ab-team__list h3 {
  margin: 0 0 4px;
  font-size: 16px;
  font-weight: 600;
}

.page-about .ab-team__list p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.7;
  color: var(--muted);
}

.page-about .ab-team__figure {
  margin: 0;
  border: 1px solid var(--layer);
  background: var(--panel);
}

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

/* ---------- 04 版本与记录 ---------- */
.page-about .ab-versions__grid {
  margin-top: clamp(24px, 3.4vw, 36px);
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(22px, 3vw, 34px);
}

.page-about .ab-versions__figure {
  margin: 0;
  border: 1px solid var(--layer);
  background: var(--panel);
}

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

.page-about .ab-versions__main .prose {
  margin-top: 0;
}

.page-about .ab-ver-list {
  margin-top: clamp(20px, 3vw, 26px);
  border-top: var(--ab-line);
}

.page-about .ab-ver {
  border-bottom: var(--ab-line);
}

.page-about .ab-ver__sum {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
  padding: 14px 4px;
  cursor: pointer;
  list-style: none;
}

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

.page-about .ab-ver__sum::after {
  content: "";
  margin-left: auto;
  width: 9px;
  height: 9px;
  border-right: 2px solid var(--cyan);
  border-bottom: 2px solid var(--cyan);
  transform: rotate(45deg);
  transition: transform 0.25s var(--ease);
}

.page-about .ab-ver[open] .ab-ver__sum::after {
  transform: rotate(-135deg);
}

.page-about .ab-ver__name {
  font-family: var(--font-geo);
  font-variant-numeric: var(--num);
  font-size: 17px;
  font-weight: 600;
  color: var(--text);
  transition: color 0.25s var(--ease);
}

.page-about .ab-ver__sum:hover .ab-ver__name,
.page-about .ab-ver[open] .ab-ver__name {
  color: var(--cyan-hi);
}

.page-about .ab-ver__list {
  list-style: none;
  margin: 0 0 14px;
  padding: 0 0 6px;
}

.page-about .ab-ver__list li {
  display: grid;
  grid-template-columns: 4.6em minmax(0, 1fr);
  gap: 12px;
  padding: 7px 4px;
  font-size: 14.5px;
  line-height: 1.65;
  color: var(--muted);
  border-bottom: 1px dashed rgba(23, 40, 76, 0.9);
}

.page-about .ab-ver__list li:last-child {
  border-bottom: 0;
}

.page-about .ab-ver__no {
  font-family: var(--font-geo);
  font-variant-numeric: var(--num);
  font-weight: 600;
  letter-spacing: 0.02em;
  text-align: right;
  color: var(--blue);
}

/* ---------- 05 服务范围 ---------- */
.page-about .ab-reach__grid {
  margin-top: clamp(24px, 3.4vw, 36px);
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(16px, 2.4vw, 22px);
}

.page-about .ab-reach__card {
  background: var(--panel);
  border-top: 2px solid var(--cyan);
  padding: clamp(20px, 3vw, 28px);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - var(--cut)), calc(100% - var(--cut)) 100%, 0 100%);
}

.page-about .ab-reach__card--jl {
  border-top-color: var(--orange);
}

.page-about .ab-reach__card h3 {
  margin: 10px 0 10px;
  font-size: clamp(19px, 2.4vw, 23px);
  font-weight: 600;
}

.page-about .ab-reach__card p {
  margin: 0;
  font-size: 15px;
  line-height: 1.75;
  color: var(--muted);
}

.page-about .ab-reach__stats {
  margin: clamp(18px, 2.6vw, 24px) 0 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  background: var(--layer);
  border: 1px solid var(--layer);
}

.page-about .ab-reach__stats > div {
  background: var(--ink);
  padding: 12px 14px;
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
}

.page-about .ab-reach__stats dt {
  font-size: 13px;
  color: var(--muted);
}

.page-about .ab-reach__stats dd {
  margin: 0;
  font-family: var(--font-geo);
  font-variant-numeric: var(--num);
  font-size: 18px;
  font-weight: 600;
  color: var(--cyan);
}

/* ---------- 06 合作与认可 ---------- */
.page-about .ab-partners__grid {
  margin-top: clamp(24px, 3.4vw, 36px);
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(14px, 2vw, 18px);
}

.page-about .ab-partner {
  background: var(--panel);
  border-left: 2px solid var(--blue);
  padding: clamp(18px, 2.6vw, 24px);
}

.page-about .ab-partner__num {
  display: block;
  font-family: var(--font-geo);
  font-variant-numeric: var(--num);
  font-size: clamp(30px, 5vw, 44px);
  font-weight: 300;
  line-height: 1;
  color: var(--blue);
}

.page-about .ab-partner h3 {
  margin: 12px 0 6px;
  font-size: 16px;
  font-weight: 600;
}

.page-about .ab-partner p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.72;
  color: var(--muted);
}

/* ---------- 下一步 ---------- */
.page-about .ab-next {
  margin-top: clamp(56px, 8vw, 96px);
  padding: clamp(26px, 4vw, 40px);
  background: linear-gradient(120deg, rgba(31, 224, 200, 0.1), rgba(14, 24, 48, 0) 62%), var(--panel);
  border: 1px solid var(--layer);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - var(--cut)), calc(100% - var(--cut)) 100%, 0 100%);
}

.page-about .ab-next__title {
  margin: 0 0 10px;
  font-size: clamp(22px, 3vw, 30px);
  font-weight: 600;
}

.page-about .ab-next__text {
  margin: 0;
  max-width: 60ch;
  font-size: 15px;
  line-height: 1.75;
  color: var(--muted);
}

.page-about .ab-next__links {
  margin-top: clamp(18px, 2.6vw, 26px);
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

/* ---------- 宽屏 ---------- */
@media (min-width: 880px) {
  .page-about .ab-facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

  .page-about .ab-stage {
    grid-template-columns: var(--ab-rail) minmax(0, 1fr);
    gap: clamp(24px, 4vw, 56px);
    align-items: start;
  }

  .page-about .ab-stage__rail {
    flex-direction: column;
    gap: 6px;
  }

  .page-about .ab-team__grid {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr);
    align-items: start;
  }

  .page-about .ab-versions__grid {
    grid-template-columns: minmax(0, 0.78fr) minmax(0, 1.22fr);
    align-items: start;
  }

  .page-about .ab-reach__grid {
    grid-template-columns: minmax(0, 1.1fr) minmax(0, 0.9fr);
  }

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

@media (min-width: 1100px) {
  .page-about {
    --ab-rail: 156px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-card,
  .page-about .ab-stage__num,
  .page-about .ab-ver__sum::after,
  .page-about .ab-years__list a,
  .page-about .ab-years__list a::before {
    transition: none !important;
  }
}