.page-about {
  --about-rail: 2.6rem;
  --about-node: .9rem;
  padding-bottom: clamp(2rem, 6vw, 4.5rem);
}

.page-about .about-crumbs {
  padding-top: clamp(1rem, 2.5vw, 1.5rem);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  display: grid;
  gap: var(--gap);
  padding-block: clamp(1.25rem, 3.5vw, 2.75rem) clamp(1.5rem, 4vw, 3rem);
}

.page-about .about-hero__lead {
  display: flex;
  flex-direction: column;
  gap: 1.1rem;
  min-width: 0;
}

.page-about .about-hero h1 {
  font-family: var(--font-head);
  font-size: clamp(1.85rem, 5.2vw, 3.05rem);
  line-height: 1.12;
  letter-spacing: -0.02em;
  margin: 0;
  color: var(--c-text);
  text-wrap: balance;
}

.page-about .about-hero__intro {
  font-size: clamp(1rem, 1.6vw, 1.075rem);
  line-height: 1.85;
  color: var(--c-muted);
  margin: 0;
  max-width: 62ch;
}

.page-about .about-hero__facts {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: .75rem 1rem;
  border-top: 2px solid var(--c-line);
  border-bottom: 2px solid var(--c-line);
  padding-block: .9rem;
}

.page-about .about-hero__facts li {
  display: flex;
  flex-direction: column;
  gap: .2rem;
  font-size: .875rem;
  color: var(--c-muted);
  line-height: 1.5;
  min-width: 0;
}

.page-about .about-hero__facts .num {
  font-family: var(--font-mono);
  font-size: 1.35rem;
  letter-spacing: 0.04em;
  color: var(--c-gold);
  line-height: 1.1;
}

.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: .75rem;
}

.page-about .about-hero__figure {
  margin: 0;
  background: var(--grad-dusk);
}

.page-about .about-hero__figure {
  aspect-ratio: 3 / 2;
}

.page-about .about-hero__figure figcaption {
  position: absolute;
  inset: auto 0 0 0;
  padding: .75rem 1rem;
  font-size: .8rem;
  line-height: 1.5;
  color: var(--c-muted);
  background: linear-gradient(180deg, rgba(10, 14, 40, 0) 0%, rgba(10, 14, 40, .88) 65%);
}

.page-about .media {
  position: relative;
  overflow: hidden;
  border: 2px solid var(--c-line);
}

.page-about .media img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: 100%;
  object-fit: cover;
}

/* ---------- 章节索引 ---------- */
.page-about .about-index {
  display: flex;
  flex-wrap: wrap;
  gap: .55rem 1.1rem;
  border-top: 2px solid var(--c-line);
  border-bottom: 2px solid var(--c-line);
  padding-block: .8rem;
}

.page-about .about-index a {
  font-family: var(--font-mono);
  font-size: .8rem;
  letter-spacing: .04em;
  color: var(--c-muted);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 140ms var(--ease), border-color 140ms var(--ease);
}

.page-about .about-index a:hover,
.page-about .about-index a:focus-visible {
  color: var(--c-gold);
  border-bottom-color: var(--c-gold);
}

/* ---------- 起点 ---------- */
.page-about .about-story {
  display: grid;
  gap: var(--gap);
}

.page-about .about-quote {
  margin: 0;
  padding: .35rem 0 .35rem 1.15rem;
  border-left: 3px solid var(--c-gold-lt);
  align-self: start;
}

.page-about .about-quote p {
  margin: 0;
  font-family: var(--font-head);
  font-size: clamp(1.05rem, 2.2vw, 1.3rem);
  line-height: 1.7;
  letter-spacing: -0.01em;
  color: var(--c-gold-lt);
}

/* ---------- 四个大类 ---------- */
.page-about .about-cats {
  list-style: none;
  margin: 0 0 var(--gap);
  padding: 0;
  display: grid;
  gap: 1rem;
  grid-template-columns: repeat(auto-fit, minmax(13rem, 1fr));
}

.page-about .about-cat {
  position: relative;
  background: var(--c-mid);
  border: 2px solid var(--c-line);
  box-shadow: var(--shadow-hard);
  padding: 1.1rem 1rem 1.2rem;
  transition: transform 140ms var(--ease), border-color 140ms var(--ease), box-shadow 140ms var(--ease);
}

.page-about .about-cat:hover,
.page-about .about-cat:focus-within {
  transform: translateY(-2px);
  border-color: var(--c-gold);
  box-shadow: var(--shadow-hard-lg);
}

.page-about .about-cat__no {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: .8rem;
  letter-spacing: .08em;
  color: var(--c-deep);
  background: var(--grad-gold);
  padding: .1rem .45rem;
  margin-bottom: .7rem;
}

.page-about .about-cat__name {
  margin: 0 0 .5rem;
  font-family: var(--font-head);
  font-size: 1.1rem;
  letter-spacing: -0.01em;
  color: var(--c-text);
}

.page-about .about-cat__desc {
  margin: 0;
  font-size: .9rem;
  line-height: 1.75;
  color: var(--c-muted);
}

.page-about .about-structure {
  display: grid;
  gap: var(--gap);
  margin-top: clamp(1.25rem, 3vw, 2rem);
}

.page-about .about-structure__figure {
  margin: 0;
  aspect-ratio: 4 / 3;
  background: var(--grad-dusk);
}

.page-about .about-structure__body h3 {
  margin-top: 0;
  font-family: var(--font-head);
  font-size: 1.2rem;
  letter-spacing: -0.01em;
  color: var(--c-gold-lt);
}

/* ---------- 时间轴 ---------- */
.page-about .about-timeline {
  position: relative;
  list-style: none;
  margin: 0;
  padding: 0 0 0 var(--about-rail);
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 1.5rem;
  top: .5rem;
  bottom: .5rem;
  width: 2px;
  background: linear-gradient(180deg, var(--c-gold) 0%, var(--c-line) 45%, var(--c-line) 100%);
}

.page-about .about-stage {
  position: relative;
  padding-bottom: 1.9rem;
}

.page-about .about-stage:last-child {
  padding-bottom: 0;
}

.page-about .about-stage::before {
  content: "";
  position: absolute;
  left: -1.55rem;
  top: .35rem;
  width: var(--about-node);
  height: var(--about-node);
  background: var(--c-gold);
  border: 2px solid var(--c-deep);
  box-shadow: 0 0 0 3px rgba(216, 166, 74, .16);
}

.page-about .about-stage:nth-child(2)::before {
  background: var(--c-purple);
  box-shadow: 0 0 0 3px rgba(110, 75, 142, .22);
}

.page-about .about-stage:nth-child(3)::before {
  background: var(--c-red);
  box-shadow: 0 0 0 3px rgba(194, 64, 47, .2);
}

.page-about .about-stage__range {
  margin: 0 0 .35rem;
  font-family: var(--font-mono);
  font-size: .8rem;
  letter-spacing: .06em;
  color: var(--c-muted);
  text-transform: uppercase;
}

.page-about .about-stage__title {
  margin: 0 0 .5rem;
  font-family: var(--font-head);
  font-size: clamp(1.1rem, 2.4vw, 1.3rem);
  letter-spacing: -0.01em;
  color: var(--c-text);
}

.page-about .about-stage__body {
  margin: 0;
  font-size: .95rem;
  line-height: 1.85;
  color: var(--c-muted);
  max-width: 66ch;
}

.page-about .stage__detail {
  margin-top: .85rem;
  border-top: 1px dashed var(--c-line);
  padding-top: .6rem;
}

.page-about .stage__detail summary {
  cursor: pointer;
  font-size: .875rem;
  letter-spacing: .02em;
  color: var(--c-gold);
  list-style: none;
  display: inline-flex;
  align-items: center;
  gap: .4rem;
}

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

.page-about .stage__detail summary::before {
  content: "+";
  font-family: var(--font-mono);
  color: var(--c-gold);
}

.page-about .stage__detail[open] summary::before {
  content: "−";
}

.page-about .stage__detail ul {
  margin: .7rem 0 0;
  padding-left: 1.1rem;
  display: grid;
  gap: .35rem;
  font-size: .9rem;
  line-height: 1.75;
  color: var(--c-muted);
}

/* ---------- 团队 ---------- */
.page-about .about-team__lead {
  margin: 0 0 1.1rem;
  font-size: .975rem;
  line-height: 1.85;
  color: var(--c-muted);
  max-width: 66ch;
}

.page-about .about-team {
  display: grid;
  gap: 1rem;
}

.page-about .about-team__item {
  background: var(--c-mid);
  border: 2px solid var(--c-line);
  border-top: 3px solid var(--c-gold);
  padding: 1.05rem 1rem 1.15rem;
}

.page-about .about-team__item:nth-child(2) {
  border-top-color: var(--c-purple);
}

.page-about .about-team__item:nth-child(3) {
  border-top-color: var(--c-red);
}

.page-about .about-team__num {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 2.1rem;
  line-height: 1;
  letter-spacing: .02em;
  color: var(--c-gold);
}

.page-about .about-team__role {
  margin: .45rem 0 .5rem;
  font-family: var(--font-head);
  font-size: 1.05rem;
  letter-spacing: -0.01em;
  color: var(--c-text);
}

.page-about .about-team__desc {
  margin: 0;
  font-size: .875rem;
  line-height: 1.75;
  color: var(--c-muted);
}

/* ---------- 本地协作 ---------- */
.page-about .about-partners {
  display: grid;
  gap: var(--gap);
}

.page-about .about-partners__aside {
  align-self: start;
}

.page-about .about-partners__aside .tag {
  display: inline-block;
  margin-bottom: .7rem;
}

.page-about .about-partners__aside ul {
  margin: 0 0 .9rem;
  padding-left: 1.1rem;
  display: grid;
  gap: .5rem;
  font-size: .9rem;
  line-height: 1.75;
  color: var(--c-muted);
}

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

.page-about .about-partners__link {
  margin: 1.2rem 0 0;
  font-size: .925rem;
  line-height: 1.8;
  color: var(--c-muted);
}

/* ---------- 覆盖与联系 ---------- */
.page-about .about-cover {
  display: grid;
  gap: var(--gap);
}

.page-about .about-cover__figure {
  margin: 0;
  aspect-ratio: 1 / 1;
  background: var(--grad-dusk);
}

.page-about .about-cover__body {
  display: grid;
  gap: var(--gap);
  min-width: 0;
}

.page-about .about-contact {
  border-left: 3px solid var(--c-red);
}

.page-about .about-contact__title {
  margin: 0 0 .9rem;
  font-family: var(--font-head);
  font-size: 1.1rem;
  letter-spacing: -0.01em;
  color: var(--c-text);
}

.page-about .about-contact__list {
  margin: 0 0 .9rem;
  display: grid;
  gap: .7rem;
}

.page-about .about-contact__list > div {
  display: grid;
  gap: .15rem;
}

.page-about .about-contact__key {
  font-size: .75rem;
  letter-spacing: .08em;
  text-transform: uppercase;
  color: var(--c-muted);
}

.page-about .about-contact__val {
  margin: 0;
  font-size: .95rem;
  line-height: 1.6;
  color: var(--c-text);
  word-break: break-word;
}

.page-about .about-contact__val a {
  color: var(--c-gold-lt);
  text-decoration: none;
  border-bottom: 1px solid var(--c-line);
}

.page-about .about-contact__val a:hover,
.page-about .about-contact__val a:focus-visible {
  border-bottom-color: var(--c-gold);
}

.page-about .about-contact__note {
  margin: 0;
  font-size: .85rem;
  line-height: 1.7;
  color: var(--c-muted);
}

.page-about .about-next {
  border-top: 2px solid var(--c-line);
  padding-top: 1rem;
}

.page-about .about-next__title {
  margin: 0 0 .6rem;
  font-size: .78rem;
  letter-spacing: .1em;
  color: var(--c-gold);
}

.page-about .about-next__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: .55rem;
}

/* ---------- 响应式 ---------- */
@media (min-width: 48rem) {
  .page-about .about-team {
    grid-template-columns: 9fr 7fr 12fr;
    align-items: stretch;
  }

  .page-about .about-story {
    grid-template-columns: minmax(0, 1.5fr) minmax(0, 1fr);
    align-items: start;
  }
}

@media (min-width: 62rem) {
  .page-about .about-hero {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, .95fr);
    align-items: start;
  }

  .page-about .about-structure {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1.05fr);
    align-items: start;
  }

  .page-about .about-partners {
    grid-template-columns: minmax(0, 1.45fr) minmax(0, 1fr);
    align-items: start;
  }

  .page-about .about-cover {
    grid-template-columns: minmax(0, .78fr) minmax(0, 1.22fr);
    align-items: start;
  }

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

@media (prefers-reduced-motion: reduce) {
  .page-about .about-cat,
  .page-about .about-index a {
    transition: none;
  }

  .page-about .about-cat:hover,
  .page-about .about-cat:focus-within {
    transform: none;
  }
}