.page-about {
  --about-rail: 680px;
  --about-line: var(--yx-line);
}

/* ---------- 面包屑上下文 ---------- */
.page-about .yx-crumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--yx-sp-1);
  margin: 0 auto;
  padding: var(--yx-sp-4) 0 0;
  max-width: min(var(--yx-shell), 100% - 48px);
  font-size: 13px;
  line-height: 21px;
  color: var(--yx-muted);
}

.page-about .yx-crumbs__item {
  color: var(--yx-muted);
  text-decoration: none;
}

.page-about .yx-crumbs__item:hover,
.page-about .yx-crumbs__item:focus-visible {
  color: var(--yx-cyan);
}

.page-about .yx-crumbs__sep {
  color: var(--yx-line);
}

.page-about .yx-crumbs__current {
  color: var(--yx-text);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  padding-block: var(--yx-sp-5) var(--yx-sp-5);
}

.page-about .about-hero__inner {
  display: grid;
  gap: var(--yx-sp-5);
  align-items: end;
}

.page-about .about-hero__lead {
  max-width: 46em;
}

.page-about .about-hero__text {
  color: var(--yx-text-soft);
}

.page-about .about-hero__facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 0;
  background: var(--about-line);
  border: 1px solid var(--about-line);
}

.page-about .about-fact {
  padding: var(--yx-sp-3) var(--yx-sp-3);
  background: var(--yx-ink);
}

.page-about .about-fact__k {
  margin: 0 0 var(--yx-sp-1);
  font-size: 13px;
  line-height: 21px;
  color: var(--yx-muted);
}

.page-about .about-fact__v {
  margin: 0;
  font-size: 20px;
  line-height: 30px;
  color: var(--yx-text);
}

.page-about .about-fact__v .yx-mono {
  color: var(--yx-cyan);
}

/* ---------- 服务范围 ---------- */
.page-about .about-scope {
  border-top: 1px solid var(--about-line);
}

.page-about .about-scope__inner {
  display: grid;
  gap: var(--yx-sp-4);
}

.page-about .about-scope__head {
  margin-bottom: 0;
}

.page-about .about-scope__col {
  max-width: var(--about-rail);
  color: var(--yx-text-soft);
}

.page-about .about-scope__col p {
  margin: 0 0 var(--yx-sp-3);
}

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

.page-about .about-scope__col .yx-mono {
  color: var(--yx-cyan);
}

.page-about .about-scope__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--about-line);
  border: 1px solid var(--about-line);
}

.page-about .about-scope__item {
  position: relative;
  padding: var(--yx-sp-3);
  background: var(--yx-ink);
}

.page-about .about-scope__idx {
  display: block;
  margin-bottom: var(--yx-sp-2);
  font-size: 13px;
  color: var(--yx-orange);
  letter-spacing: .08em;
}

.page-about .about-scope__title {
  margin: 0 0 var(--yx-sp-1);
  font-size: 18px;
  line-height: 28px;
  font-weight: 700;
  color: var(--yx-text);
}

.page-about .about-scope__desc {
  margin: 0;
  font-size: 14px;
  line-height: 24px;
  color: var(--yx-muted);
}

/* ---------- 时间轴 ---------- */
.page-about .about-timeline {
  border-top: 1px solid var(--about-line);
}

.page-about .about-timeline__inner {
  display: grid;
  gap: var(--yx-sp-4);
}

.page-about .about-timeline__figure {
  margin: 0;
}

.page-about .about-track {
  position: relative;
  list-style: none;
  margin: 0;
  padding: 0 0 0 32px;
}

.page-about .about-track::before {
  content: "";
  position: absolute;
  left: 9px;
  top: 10px;
  bottom: 10px;
  width: 1px;
  background: var(--about-line);
}

.page-about .about-track__item {
  position: relative;
  border-bottom: 1px solid var(--about-line);
}

.page-about .about-track__item:last-child {
  border-bottom: 0;
}

.page-about .about-track__item::before {
  content: "";
  position: absolute;
  left: -28px;
  top: 26px;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--yx-orange);
  box-shadow: 0 0 0 4px var(--yx-ink);
  z-index: 1;
}

.page-about .about-node {
  display: block;
}

.page-about .about-node__head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: var(--yx-sp-2);
  padding: var(--yx-sp-3) 0;
  cursor: pointer;
  list-style: none;
}

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

.page-about .about-node__head::marker {
  content: "";
}

.page-about .about-node__year {
  font-size: 14px;
  letter-spacing: .06em;
  color: var(--yx-cyan);
}

.page-about .about-node__label {
  font-size: 20px;
  line-height: 30px;
  font-weight: 700;
  color: var(--yx-text);
}

.page-about .about-node__hint {
  margin-left: auto;
  font-size: 12px;
  line-height: 20px;
  color: var(--yx-muted);
  padding: 2px 10px;
  border: 1px solid var(--about-line);
}

.page-about .about-node[open] .about-node__hint {
  color: var(--yx-ink);
  background: var(--yx-cyan);
  border-color: var(--yx-cyan);
}

.page-about .about-node[open] .about-node__hint::before {
  content: "收起";
  font-size: 12px;
}

.page-about .about-node[open] .about-node__hint {
  font-size: 0;
}

.page-about .about-node[open] .about-node__hint::before {
  font-size: 12px;
}

.page-about .about-node__body {
  max-width: var(--about-rail);
  padding: 0 0 var(--yx-sp-4);
}

.page-about .about-node__body p {
  margin: 0;
  font-size: 15px;
  line-height: 27px;
  color: var(--yx-text-soft);
}

/* ---------- 团队 ---------- */
.page-about .about-team {
  border-top: 1px solid var(--about-line);
}

.page-about .about-team__inner {
  display: grid;
  gap: var(--yx-sp-4);
}

.page-about .about-team__figure {
  margin: 0;
}

.page-about .about-team__lead {
  max-width: var(--about-rail);
  margin: 0;
  color: var(--yx-text-soft);
}

.page-about .about-team__grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--about-line);
  border: 1px solid var(--about-line);
}

.page-about .about-team__stat {
  padding: var(--yx-sp-4) var(--yx-sp-3);
  background: var(--yx-ink);
}

.page-about .about-team__stat--key {
  background: var(--yx-panel);
}

.page-about .about-team__num {
  margin: 0;
  font-size: 44px;
  line-height: 1.05;
  font-weight: 700;
  color: var(--yx-text);
  letter-spacing: -.02em;
}

.page-about .about-team__stat--key .about-team__num {
  color: var(--yx-orange);
}

.page-about .about-team__unit {
  margin: var(--yx-sp-1) 0 var(--yx-sp-2);
  font-size: 13px;
  line-height: 21px;
  color: var(--yx-cyan);
}

.page-about .about-team__desc {
  margin: 0;
  font-size: 13px;
  line-height: 21px;
  color: var(--yx-muted);
}

.page-about .about-team__rhythm {
  display: grid;
  gap: 1px;
  background: var(--about-line);
  border: 1px solid var(--about-line);
}

.page-about .about-rhythm {
  padding: var(--yx-sp-3);
  background: var(--yx-ink);
  border-left: 2px solid var(--yx-cyan);
}

.page-about .about-rhythm__k {
  margin: 0 0 var(--yx-sp-1);
  font-family: var(--yx-font-serif);
  font-size: 17px;
  line-height: 26px;
  color: var(--yx-text);
}

.page-about .about-rhythm__v {
  margin: 0;
  font-size: 14px;
  line-height: 24px;
  color: var(--yx-muted);
}

/* ---------- 四象限分类 ---------- */
.page-about .about-tags {
  border-top: 1px solid var(--about-line);
}

.page-about .about-tags__inner {
  display: grid;
  gap: var(--yx-sp-4);
}

.page-about .about-tags__figure {
  margin: 0;
}

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

.page-about .about-quad__cell {
  position: relative;
  padding: var(--yx-sp-4) var(--yx-sp-3);
  background: var(--yx-panel);
  transition: background-color 160ms var(--yx-ease);
}

.page-about .about-quad__cell:hover {
  background: #16304A;
}

.page-about .about-quad__cell::after {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  width: 2px;
  height: 0;
  background: var(--yx-orange);
  transition: height 200ms var(--yx-ease);
}

.page-about .about-quad__cell:hover::after {
  height: 100%;
}

.page-about .about-quad__idx {
  display: block;
  margin-bottom: var(--yx-sp-2);
  font-size: 13px;
  letter-spacing: .1em;
  color: var(--yx-cyan);
}

.page-about .about-quad__title {
  margin: 0 0 var(--yx-sp-2);
  font-size: 19px;
  line-height: 28px;
  font-weight: 700;
  color: var(--yx-text);
}

.page-about .about-quad__desc {
  margin: 0 0 var(--yx-sp-3);
  font-size: 14px;
  line-height: 24px;
  color: var(--yx-text-soft);
}

.page-about .about-quad__meta {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: var(--yx-sp-1);
  margin: 0;
  padding-top: var(--yx-sp-2);
  border-top: 1px solid var(--about-line);
  font-size: 13px;
  line-height: 21px;
  color: var(--yx-muted);
}

.page-about .about-quad__count {
  font-size: 18px;
  font-weight: 700;
  color: var(--yx-orange);
}

.page-about .about-quad__cell:hover .about-quad__count {
  color: var(--yx-cyan);
}

/* ---------- 回访收益 ---------- */
.page-about .about-return {
  border-top: 1px solid var(--about-line);
}

.page-about .about-return__inner {
  display: grid;
  gap: var(--yx-sp-4);
}

.page-about .about-return__col {
  max-width: var(--about-rail);
  color: var(--yx-text-soft);
}

.page-about .about-return__col p {
  margin: 0;
}

.page-about .about-return__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0;
  max-width: 860px;
}

.page-about .about-return__item {
  position: relative;
  padding: var(--yx-sp-3) 0 var(--yx-sp-3) var(--yx-sp-4);
  border-top: 1px solid var(--about-line);
}

.page-about .about-return__item::before {
  content: "";
  position: absolute;
  left: 0;
  top: calc(var(--yx-sp-3) + 4px);
  width: 2px;
  height: 40px;
  background: var(--yx-cyan);
}

.page-about .about-return__title {
  margin: 0 0 var(--yx-sp-1);
  font-size: 17px;
  line-height: 26px;
  font-weight: 700;
  color: var(--yx-text);
}

.page-about .about-return__item p {
  margin: 0;
  font-size: 14px;
  line-height: 25px;
  color: var(--yx-muted);
}

/* ---------- 合作与审查 ---------- */
.page-about .about-review {
  border-top: 1px solid var(--about-line);
}

.page-about .about-review__inner {
  display: grid;
  gap: var(--yx-sp-4);
}

.page-about .about-review__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--yx-sp-3);
}

.page-about .about-review__item {
  padding: var(--yx-sp-4);
  border: 1px solid var(--about-line);
  background: var(--yx-panel);
}

.page-about .about-review__item--wide {
  background:
    linear-gradient(140deg, rgba(196, 208, 224, .16), rgba(185, 166, 255, .14)),
    var(--yx-panel);
  border-color: rgba(196, 208, 224, .35);
}

.page-about .about-review__num {
  margin: 0;
  font-size: 40px;
  line-height: 1.05;
  font-weight: 700;
  letter-spacing: -.02em;
  color: var(--yx-text);
}

.page-about .about-review__item--wide .about-review__num {
  color: var(--yx-silver);
}

.page-about .about-review__unit {
  margin: var(--yx-sp-1) 0 var(--yx-sp-3);
  font-size: 14px;
  line-height: 22px;
  color: var(--yx-cyan);
}

.page-about .about-review__desc {
  margin: 0;
  font-size: 14px;
  line-height: 24px;
  color: var(--yx-text-soft);
}

/* ---------- 去向 ---------- */
.page-about .about-next {
  border-top: 1px solid var(--about-line);
}

.page-about .about-next__inner {
  display: grid;
  gap: var(--yx-sp-4);
}

.page-about .about-next__title {
  margin: 0 0 var(--yx-sp-2);
}

.page-about .about-next__text {
  margin: 0;
  max-width: var(--about-rail);
  color: var(--yx-muted);
}

.page-about .about-next__actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--yx-sp-2);
}

/* ---------- 返回顶部 ---------- */
.page-about .yx-top {
  position: fixed;
  right: 20px;
  bottom: 24px;
  z-index: 20;
  opacity: 0;
  pointer-events: none;
  transition: opacity 200ms var(--yx-ease);
}

.page-about .yx-top.is-in {
  opacity: 1;
  pointer-events: auto;
}

/* ---------- 响应式 ---------- */
@media (min-width: 640px) {
  .page-about .about-diagram {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

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

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

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

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

  .page-about .about-review__item--wide {
    grid-column: 1 / -1;
  }
}

@media (min-width: 960px) {
  .page-about .about-hero__inner {
    grid-template-columns: minmax(0, 1fr) minmax(280px, 340px);
    gap: var(--yx-sp-6);
  }

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

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

  .page-about .about-review__grid {
    grid-template-columns: 1.4fr 1fr 1fr;
  }

  .page-about .about-review__item--wide {
    grid-column: auto;
  }

  .page-about .about-next__inner {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: end;
    gap: var(--yx-sp-5);
  }

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

@media (prefers-reduced-motion: reduce) {
  .page-about .about-quad__cell,
  .page-about .about-quad__cell::after,
  .page-about .yx-top {
    transition: none;
  }
}