.page-about {
  --about-bd: 2px solid var(--line);
  --about-gap: clamp(48px, 6vw, 96px);
  background: var(--ink);
  color: var(--text);
  overflow-x: clip;
  padding-bottom: clamp(24px, 4vw, 48px);
}

/* 面包屑 */
.page-about .crumbs {
  padding-top: clamp(14px, 2vw, 22px);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .06em;
}
.page-about .crumbs__link {
  color: var(--mute);
  text-decoration: none;
  transition: color .2s var(--ease);
}
.page-about .crumbs__link:hover,
.page-about .crumbs__link:focus-visible {
  color: var(--pulse);
}
.page-about .crumbs__sep {
  color: var(--line);
}
.page-about .crumbs__item[aria-current] {
  color: var(--soft);
}

/* 首屏 */
.page-about .about-hero {
  padding: clamp(18px, 3vw, 32px) 0 clamp(30px, 4.5vw, 56px);
}
.page-about .about-hero__grid {
  display: grid;
  gap: clamp(26px, 3.5vw, 46px);
  align-items: end;
}
.page-about .about-hero__eyebrow {
  margin: 0 0 12px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .16em;
  color: var(--pulse);
}
.page-about .about-hero__title {
  margin: 0 0 18px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(34px, 6vw, 62px);
  line-height: 1.03;
  letter-spacing: -.01em;
  color: var(--paper);
  max-width: 15em;
}
.page-about .about-hero__lede {
  margin: 0 0 24px;
  font-family: var(--font-body);
  font-size: clamp(15px, 1.6vw, 17px);
  line-height: 1.78;
  color: var(--text);
  max-width: 30em;
}
.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}
.page-about .about-hero__tiles {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 12px;
}
.page-about .about-hero__tile {
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding: 14px 16px;
  border: var(--about-bd);
  background: var(--pitch);
  box-shadow: var(--hard-sm);
}
.page-about .about-hero__num {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(24px, 3vw, 30px);
  line-height: 1;
  color: var(--amber);
  flex: none;
}
.page-about .about-hero__cap {
  font-size: 13px;
  line-height: 1.55;
  color: var(--text);
}

/* 章节骨架 */
.page-about .about-block {
  padding: clamp(28px, 4vw, 52px) 0;
}
.page-about .about-block__inner {
  border-left: var(--about-bd);
  padding-left: clamp(16px, 2.6vw, 34px);
}
.page-about .about-head {
  margin-bottom: clamp(22px, 3vw, 36px);
}
.page-about .about-head__num {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .16em;
  color: var(--mute);
}
.page-about .about-head__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(24px, 3.4vw, 38px);
  line-height: 1.16;
  letter-spacing: -.005em;
  color: var(--paper);
  max-width: 18em;
}
.page-about .about-head__note {
  margin: 12px 0 0;
  max-width: 34em;
  font-size: 15px;
  line-height: 1.78;
  color: var(--text);
}

/* 起源章节 */
.page-about .about-split {
  display: grid;
  gap: clamp(24px, 3vw, 40px);
}
.page-about .about-copy p {
  margin: 0 0 1.1em;
  font-size: 16px;
  line-height: 1.82;
  max-width: 34em;
}
.page-about .about-copy p:last-child {
  margin-bottom: 0;
}
.page-about .about-copy--drop > p:first-of-type::first-letter {
  float: left;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 3.1em;
  line-height: .88;
  padding: 5px 10px 0 0;
  color: var(--pulse);
}
.page-about .about-quote {
  margin: 24px 0 0;
  padding: 4px 0 4px 18px;
  border-left: 4px solid var(--pulse);
  font-size: clamp(16px, 2vw, 19px);
  line-height: 1.72;
  color: var(--soft);
  max-width: 28em;
}
.page-about .about-aside {
  border: var(--about-bd);
  background: var(--pitch);
  box-shadow: var(--hard);
  padding: clamp(18px, 2.4vw, 26px);
}
.page-about .about-aside__title {
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--pulse);
}
.page-about .about-aside__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 12px;
}
.page-about .about-aside__item {
  display: grid;
  grid-template-columns: 26px minmax(0, 1fr);
  gap: 10px;
  font-size: 14px;
  line-height: 1.7;
  padding-bottom: 12px;
  border-bottom: 1px dashed var(--line);
}
.page-about .about-aside__item:last-child {
  border-bottom: 0;
  padding-bottom: 0;
}
.page-about .about-aside__idx {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--amber);
  padding-top: 3px;
}

/* 团队技能树 */
.page-about .about-tree {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 26px;
}
.page-about .about-tree__node {
  position: relative;
  padding: 18px 18px 20px;
  border: var(--about-bd);
  background: var(--pitch);
  box-shadow: var(--hard-sm);
  outline: none;
  transition: border-color .22s var(--ease), transform .22s var(--ease);
}
.page-about .about-tree__node::after {
  content: "";
  position: absolute;
  inset: 0 auto 0 0;
  width: 0;
  background: var(--pulse);
  transition: width .22s var(--ease);
}
.page-about .about-tree__node:hover,
.page-about .about-tree__node:focus-visible {
  border-color: var(--pulse);
  transform: translate(-2px, -2px);
}
.page-about .about-tree__node:hover::after,
.page-about .about-tree__node:focus-visible::after {
  width: 5px;
}
.page-about .about-tree__node:focus-visible {
  outline: 3px solid var(--pulse);
  outline-offset: 4px;
}
.page-about .about-tree__node:not(:last-child)::before {
  content: "";
  position: absolute;
  left: 26px;
  bottom: -26px;
  width: 2px;
  height: 26px;
  background: var(--pulse);
  opacity: .5;
}
.page-about .about-tree__group {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 10px;
  margin-bottom: 8px;
}
.page-about .about-tree__name {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.15rem;
  letter-spacing: .02em;
  color: var(--paper);
}
.page-about .about-tree__count {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 1.5rem;
  line-height: 1;
  color: var(--amber);
}
.page-about .about-tree__role {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .12em;
  color: var(--mute);
}
.page-about .about-tree__desc {
  margin: 0;
  font-size: 14px;
  line-height: 1.78;
  color: var(--text);
}

/* 图片容器 */
.page-about .about-figure {
  margin: clamp(26px, 3vw, 40px) 0 0;
}
.page-about .about-figure img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  border: var(--about-bd);
  box-shadow: var(--hard);
  background: var(--pitch);
}
.page-about .about-figure figcaption {
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 12.5px;
  line-height: 1.6;
  letter-spacing: .03em;
  color: var(--mute);
}

/* 流程 */
.page-about .about-flow {
  list-style: none;
  margin: 0;
  padding: 0;
}
.page-about .about-flow__step {
  display: grid;
  grid-template-columns: 40px minmax(0, 1fr);
  gap: 14px;
  padding: 20px 0;
  border-top: 1px dashed var(--line);
}
.page-about .about-flow__step:last-child {
  border-bottom: 1px dashed var(--line);
}
.page-about .about-flow__idx {
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
  color: var(--pulse);
  padding-top: 4px;
}
.page-about .about-flow__name {
  margin: 0 0 6px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.15rem;
  letter-spacing: .02em;
  color: var(--paper);
}
.page-about .about-flow__desc {
  margin: 0;
  font-size: 15px;
  line-height: 1.78;
  max-width: 40em;
  color: var(--text);
}

/* 时间线 */
.page-about .about-tl {
  list-style: none;
  margin: 0;
  padding: 0;
  position: relative;
}
.page-about .about-tl::before {
  content: "";
  position: absolute;
  left: 15px;
  top: 8px;
  bottom: 8px;
  width: 2px;
  background: linear-gradient(180deg, var(--pulse), var(--line));
}
.page-about .about-tl__item {
  position: relative;
  display: grid;
  gap: 8px;
  padding: 0 0 30px 40px;
  outline: none;
}
.page-about .about-tl__item:last-child {
  padding-bottom: 0;
}
.page-about .about-tl__item::before {
  content: "";
  position: absolute;
  left: 11px;
  top: 8px;
  width: 10px;
  height: 10px;
  background: var(--amber);
  box-shadow: 0 0 0 3px var(--ink);
  transition: transform .22s var(--ease);
}
.page-about .about-tl__item:hover::before,
.page-about .about-tl__item:focus-visible::before {
  transform: scale(1.35);
}
.page-about .about-tl__item:focus-visible {
  outline: 3px solid var(--pulse);
  outline-offset: 6px;
}
.page-about .about-tl__year {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 1.35rem;
  line-height: 1;
  letter-spacing: .02em;
  color: var(--amber);
}
.page-about .about-tl__name {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.2rem;
  letter-spacing: .02em;
  color: var(--paper);
  transition: color .2s var(--ease);
}
.page-about .about-tl__item:hover .about-tl__name,
.page-about .about-tl__item:focus-visible .about-tl__name {
  color: var(--pulse);
}
.page-about .about-tl__desc {
  margin: 0;
  font-size: 15px;
  line-height: 1.78;
  max-width: 34em;
  color: var(--text);
}

/* 结果数字 */
.page-about .about-metrics {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 24px;
}
.page-about .about-metrics__item {
  display: grid;
  gap: 8px;
  padding-top: 14px;
  border-top: 4px solid var(--amber);
}
.page-about .about-metrics__num {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(30px, 4vw, 44px);
  line-height: 1;
  color: var(--paper);
}
.page-about .about-metrics__label {
  font-size: 13.5px;
  line-height: 1.65;
  color: var(--text);
}

/* 合作生态 */
.page-about .about-partners {
  display: grid;
  gap: 18px;
}
.page-about .about-partners__item {
  border: var(--about-bd);
  background: var(--pitch);
  box-shadow: var(--hard-sm);
  padding: clamp(18px, 2.4vw, 26px);
}
.page-about .about-partners__num {
  display: block;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(26px, 3.4vw, 36px);
  line-height: 1;
  color: var(--pulse);
  margin-bottom: 10px;
}
.page-about .about-partners__name {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.1rem;
  letter-spacing: .02em;
  color: var(--paper);
}
.page-about .about-partners__desc {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--text);
}
.page-about .about-partners__note {
  margin: 20px 0 0;
  padding-left: 16px;
  border-left: 4px solid var(--pulse);
  font-size: 14.5px;
  line-height: 1.78;
  max-width: 40em;
  color: var(--soft);
}

/* 下一步 */
.page-about .about-next {
  padding: clamp(30px, 4vw, 52px) 0 clamp(16px, 2vw, 24px);
}
.page-about .about-next__title {
  margin: 0 0 18px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(20px, 2.6vw, 26px);
  letter-spacing: .02em;
  color: var(--paper);
}
.page-about .about-next__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 12px;
}
.page-about .about-next__item {
  display: grid;
  gap: 4px;
  padding: 14px 16px;
  border: var(--about-bd);
  background: var(--pitch);
  box-shadow: var(--hard-sm);
  transition: border-color .2s var(--ease);
}
.page-about .about-next__item:hover,
.page-about .about-next__item:focus-within {
  border-color: var(--pulse);
}
.page-about .about-next__link {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.05rem;
  letter-spacing: .02em;
  color: var(--soft);
  text-decoration: none;
}
.page-about .about-next__link:hover,
.page-about .about-next__link:focus-visible {
  color: var(--pulse);
  outline: none;
  text-decoration: underline;
  text-underline-offset: 4px;
}
.page-about .about-next__desc {
  font-size: 13.5px;
  line-height: 1.6;
  color: var(--mute);
}

/* 响应式 */
@media (min-width: 720px) {
  .page-about .about-hero__tile:nth-child(2) {
    margin-left: 18px;
  }
  .page-about .about-hero__tile:nth-child(3) {
    margin-left: 36px;
  }
  .page-about .about-next__list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 14px;
  }
}

@media (min-width: 860px) {
  .page-about .about-tree {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 48px;
    align-items: start;
  }
  .page-about .about-tree__node:not(:last-child)::before {
    left: auto;
    bottom: auto;
    top: 32px;
    right: -48px;
    width: 48px;
    height: 2px;
  }
  .page-about .about-tl::before {
    left: 105px;
  }
  .page-about .about-tl__item {
    grid-template-columns: 88px minmax(0, 1fr);
    column-gap: 32px;
    padding-left: 0;
    padding-bottom: 34px;
    align-items: start;
  }
  .page-about .about-tl__item::before {
    left: 100px;
    top: 6px;
  }
  .page-about .about-tl__year {
    text-align: right;
  }
}

@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
  }
  .page-about .about-split {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    align-items: start;
  }
  .page-about .about-flow-wrap {
    display: grid;
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: clamp(24px, 3vw, 44px);
    align-items: start;
  }
  .page-about .about-figure--side {
    margin-top: 0;
  }
  .page-about .about-metrics {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 28px;
  }
  .page-about .about-metrics__item:nth-child(2) {
    margin-top: 26px;
  }
  .page-about .about-metrics__item:nth-child(3) {
    margin-top: 52px;
  }
  .page-about .about-partners {
    grid-template-columns: minmax(0, 6fr) minmax(0, 5fr);
    gap: 24px;
  }
}

@media (min-width: 1024px) {
  .page-about .about-next__list {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-tree__node,
  .page-about .about-tree__node::after,
  .page-about .about-tl__item::before,
  .page-about .about-tl__name,
  .page-about .about-next__item {
    transition: none;
  }
  .page-about .about-tree__node:hover,
  .page-about .about-tree__node:focus-visible {
    transform: none;
  }
  .page-about .about-tl__item:hover::before,
  .page-about .about-tl__item:focus-visible::before {
    transform: none;
  }
}