.page-about {
  --ab-rail-w: 84px;
  --ab-body-max: 44rem;
  --ab-gap: 22px;
}

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

.page-about .ab-hero {
  position: relative;
  padding: 22px 0 10px;
  overflow: hidden;
}

.page-about .ab-hero::before {
  content: "";
  position: absolute;
  top: -140px;
  right: -180px;
  width: min(860px, 92vw);
  height: min(560px, 64vw);
  background: var(--grad-highland);
  opacity: .34;
  transform: rotate(-11deg);
  clip-path: polygon(16% 0, 100% 0, 100% 74%, 0 100%);
  pointer-events: none;
  z-index: 0;
}

.page-about .ab-hero__head {
  position: relative;
  z-index: 1;
}

.page-about .breadcrumb ol {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 0 0 24px;
  padding: 0;
  list-style: none;
  font-size: var(--fs-7);
  color: var(--muted);
}

.page-about .breadcrumb li + li::before {
  content: "/";
  margin-right: 8px;
  color: var(--line);
}

.page-about .breadcrumb a {
  color: var(--blue);
  text-decoration: none;
}

.page-about .breadcrumb a:hover {
  color: var(--gold);
}

.page-about .ab-hero__eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  margin: 0 0 16px;
  font-family: var(--font-mono);
  font-size: var(--fs-7);
  letter-spacing: .06em;
  color: var(--yellow);
}

.page-about .ab-hero__dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--red);
  box-shadow: 0 0 0 4px rgba(214, 58, 76, .18);
}

.page-about .ab-hero h1 {
  margin: 0 0 20px;
  max-width: 17em;
  font-family: var(--font-head);
  font-weight: 900;
  font-size: var(--fs-1);
  line-height: 1.16;
  letter-spacing: -.01em;
  color: var(--paper);
}

.page-about .ab-hero__lede {
  max-width: 36em;
  margin: 0;
  font-size: var(--fs-5);
  line-height: 1.75;
  color: rgba(242, 246, 252, .8);
}

.page-about .ab-hero__facts {
  display: flex;
  flex-wrap: wrap;
  gap: 18px 42px;
  margin: 32px 0 0;
  padding: 22px 0 0;
  list-style: none;
  border-top: 1px solid var(--line-soft);
}

.page-about .ab-hero__facts li {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.page-about .ab-hero__facts strong {
  font-family: var(--font-mono);
  font-size: 30px;
  line-height: 1;
  color: var(--gold);
  font-variant-numeric: tabular-nums;
}

.page-about .ab-hero__facts span {
  font-size: var(--fs-7);
  color: var(--muted);
}

.page-about .ab-hero__figure {
  position: relative;
  z-index: 1;
  margin: 40px 0 0;
  padding: 0 var(--gutter);
}

.page-about .ab-hero__figure figcaption,
.page-about .ab-chapter__figure figcaption,
.page-about .ab-flow-media figcaption {
  margin-top: 10px;
  font-size: var(--fs-7);
  color: var(--muted);
}

.page-about .ab-chapter__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--ab-gap);
}

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

.page-about .ab-rail__num {
  display: block;
  font-family: var(--font-mono);
  font-size: var(--fs-6);
  color: var(--blue);
  letter-spacing: .08em;
}

.page-about .ab-rail__line {
  display: block;
  width: 1px;
  height: 72px;
  margin-top: 12px;
  background: linear-gradient(180deg, var(--blue) 0%, rgba(47, 109, 224, 0) 100%);
}

.page-about .ab-flags {
  display: flex;
  gap: 5px;
  margin: 0 0 16px;
}

.page-about .ab-flags i {
  display: block;
  width: 24px;
  height: 3px;
  border-radius: 2px;
}

.page-about .ab-flags i:nth-child(1) { background: var(--blue); }
.page-about .ab-flags i:nth-child(2) { background: var(--paper); }
.page-about .ab-flags i:nth-child(3) { background: var(--red); }
.page-about .ab-flags i:nth-child(4) { background: var(--green); }
.page-about .ab-flags i:nth-child(5) { background: var(--yellow); }

.page-about .ab-body {
  max-width: var(--ab-body-max);
}

.page-about .ab-body--wide {
  max-width: 56rem;
}

.page-about .ab-body h2 {
  margin: 0 0 18px;
  font-family: var(--font-head);
  font-weight: 900;
  font-size: var(--fs-2);
  line-height: 1.24;
  letter-spacing: -.01em;
  color: var(--paper);
}

.page-about .ab-body p {
  margin: 0 0 18px;
  font-size: var(--fs-5);
  line-height: 1.78;
  color: rgba(242, 246, 252, .82);
}

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

.page-about .ab-body a {
  color: var(--blue);
  text-decoration: none;
  border-bottom: 1px solid rgba(47, 109, 224, .45);
}

.page-about .ab-body a:hover {
  color: var(--gold);
  border-bottom-color: var(--gold);
}

/* 团队分工 */
.page-about .ab-roles {
  list-style: none;
  margin: 26px 0 0;
  padding: 0;
  display: grid;
  gap: 14px;
}

.page-about .ab-role {
  position: relative;
  padding: 20px 22px 20px 24px;
  background: var(--panel);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius);
  box-shadow: var(--shadow-1);
}

.page-about .ab-role__count {
  position: absolute;
  top: 16px;
  right: 20px;
  font-family: var(--font-mono);
  font-size: 26px;
  line-height: 1;
  color: rgba(245, 194, 74, .5);
  font-variant-numeric: tabular-nums;
}

.page-about .ab-role h3 {
  margin: 0 0 8px;
  font-size: var(--fs-4);
  font-weight: 800;
  color: var(--paper);
}

.page-about .ab-role p {
  margin: 0;
  font-size: var(--fs-6);
  line-height: 1.7;
  color: var(--muted);
}

.page-about .ab-chapter__figure {
  margin: 28px 0 0;
}

/* 流程带 */
.page-about .ab-flow-wrap {
  margin-top: 30px;
}

.page-about .ab-flow {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-auto-flow: column;
  grid-auto-columns: minmax(228px, 1fr);
  overflow-x: auto;
  overscroll-behavior-x: contain;
  border-top: 1px solid var(--line-soft);
  border-bottom: 1px solid var(--line-soft);
  scroll-snap-type: x proximity;
  -webkit-overflow-scrolling: touch;
}

.page-about .ab-flow > li {
  position: relative;
  scroll-snap-align: start;
  padding: 26px 22px 24px;
  border-right: 1px solid var(--line-soft);
  transition: background-color .2s ease;
}

.page-about .ab-flow > li:last-child {
  border-right: 0;
}

.page-about .ab-flow > li::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--blue);
}

.page-about .ab-flow > li:nth-child(2)::before { background: var(--paper); }
.page-about .ab-flow > li:nth-child(3)::before { background: var(--red); }
.page-about .ab-flow > li:nth-child(4)::before { background: var(--green); }
.page-about .ab-flow > li:nth-child(5)::before { background: var(--yellow); }

.page-about .ab-flow > li:hover,
.page-about .ab-flow > li:focus-within {
  background: var(--panel-hi);
}

.page-about .ab-flow__num {
  display: block;
  margin-bottom: 10px;
  font-family: var(--font-mono);
  font-size: var(--fs-7);
  letter-spacing: .1em;
  color: var(--blue);
  font-variant-numeric: tabular-nums;
}

.page-about .ab-flow h3 {
  margin: 0 0 8px;
  font-size: var(--fs-5);
  font-weight: 800;
  color: var(--paper);
}

.page-about .ab-flow p {
  margin: 0;
  font-size: var(--fs-7);
  line-height: 1.72;
  color: var(--muted);
}

.page-about .ab-flow-media {
  margin-top: 34px;
}

.page-about .ab-flow-media figure {
  margin: 0;
}

/* 数字块 */
.page-about .ab-figures {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
  margin-top: 28px;
}

.page-about .ab-figure {
  padding: 20px 22px;
  background: var(--panel);
  border: 1px solid var(--line-soft);
  border-left: 3px solid var(--gold);
  border-radius: var(--radius);
}

.page-about .ab-figure strong {
  display: block;
  font-family: var(--font-mono);
  font-size: 34px;
  line-height: 1.1;
  color: var(--gold);
  font-variant-numeric: tabular-nums;
}

.page-about .ab-figure span {
  display: block;
  margin-top: 6px;
  font-size: var(--fs-7);
  color: var(--muted);
}

/* 时间轴 */
.page-about .ab-timeline {
  list-style: none;
  margin: 26px 0 0;
  padding: 0 0 0 26px;
  border-left: 1px solid var(--line-soft);
}

.page-about .ab-timeline > li {
  position: relative;
}

.page-about .ab-timeline > li::before {
  content: "";
  position: absolute;
  left: -31px;
  top: 22px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--night);
  border: 2px solid var(--blue);
  box-sizing: border-box;
}

.page-about .ab-tl > summary {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 6px 16px;
  padding: 14px 4px;
  cursor: pointer;
  list-style: none;
  border-bottom: 1px solid var(--line-soft);
  transition: color .2s ease;
}

.page-about .ab-tl > summary::-webkit-details-marker {
  display: none;
}

.page-about .ab-tl > summary::after {
  content: "+";
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 18px;
  line-height: 1;
  color: var(--blue);
  transition: transform .2s ease, color .2s ease;
}

.page-about .ab-tl[open] > summary::after {
  transform: rotate(45deg);
  color: var(--gold);
}

.page-about .ab-tl > summary:hover::after {
  color: var(--gold);
}

.page-about .ab-tl__year {
  font-family: var(--font-mono);
  font-size: var(--fs-4);
  color: var(--gold);
  font-variant-numeric: tabular-nums;
}

.page-about .ab-tl__title {
  font-size: var(--fs-5);
  font-weight: 700;
  color: var(--paper);
}

.page-about .ab-tl__panel {
  padding: 14px 4px 20px;
  max-width: 40rem;
}

.page-about .ab-tl__panel p {
  margin: 0;
  font-size: var(--fs-6);
  line-height: 1.78;
  color: rgba(242, 246, 252, .74);
}

/* 三条做法 */
.page-about .ab-rules {
  list-style: none;
  margin: 26px 0 0;
  padding: 0;
  display: grid;
  gap: 14px;
}

.page-about .ab-rule {
  padding: 22px 24px;
  background: var(--panel);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius);
  box-shadow: var(--shadow-1);
}

.page-about .ab-rule--blue { border-left: 3px solid var(--blue); }
.page-about .ab-rule--green { border-left: 3px solid var(--green); }
.page-about .ab-rule--yellow { border-left: 3px solid var(--yellow); }

.page-about .ab-rule h3 {
  margin: 0 0 10px;
  font-size: var(--fs-4);
  font-weight: 800;
  color: var(--paper);
}

.page-about .ab-rule p {
  margin: 0;
  font-size: var(--fs-6);
  line-height: 1.78;
  color: var(--muted);
}

/* 结尾 */
.page-about .ab-next {
  padding-bottom: 72px;
}

.page-about .ab-next__inner {
  display: grid;
  gap: 22px;
  padding: 32px clamp(20px, 3vw, 36px);
  background: var(--grad-night);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius);
  box-shadow: var(--shadow-2);
}

.page-about .ab-next__text h2 {
  margin: 0 0 10px;
  font-family: var(--font-head);
  font-weight: 900;
  font-size: var(--fs-3);
  color: var(--paper);
}

.page-about .ab-next__text p {
  margin: 0;
  max-width: 40em;
  font-size: var(--fs-6);
  line-height: 1.75;
  color: var(--muted);
}

.page-about .ab-next__links {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

@media (min-width: 720px) {
  .page-about .ab-figures {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .ab-roles {
    gap: 16px;
  }

  .page-about .ab-flow {
    grid-auto-columns: minmax(220px, 1fr);
  }
}

@media (min-width: 900px) {
  .page-about .ab-rail {
    display: block;
  }

  .page-about .ab-chapter__grid {
    grid-template-columns: var(--ab-rail-w) minmax(0, 1fr);
    gap: 44px;
  }

  .page-about .ab-chapter--split .ab-chapter__grid {
    grid-template-columns: var(--ab-rail-w) minmax(0, 1fr) minmax(0, 336px);
    gap: 36px;
    align-items: start;
  }

  .page-about .ab-chapter--split .ab-chapter__figure {
    margin: 42px 0 0;
  }

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

  .page-about .ab-next__inner {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
    gap: 32px;
  }

  .page-about .ab-next__links {
    justify-content: flex-end;
  }

  .page-about .ab-hero__facts {
    gap: 18px 64px;
  }
}

@media (min-width: 1180px) {
  .page-about .ab-hero__head {
    padding-top: 8px;
  }

  .page-about .ab-flow > li {
    padding: 30px 26px 28px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about [data-reveal],
  .page-about .ab-flow > li,
  .page-about .ab-tl > summary::after {
    transition: none;
  }
}
<<<END>>>