.page-about {
  --about-cut: polygon(0 0, calc(100% - 14px) 0, 100% 14px, 100% 100%, 14px 100%, 0 calc(100% - 14px));
  --about-rule: 1px solid var(--edge);
  --about-rule-soft: 1px solid rgba(31, 92, 134, 0.45);
  --about-gap: clamp(1.25rem, 3vw, 2.5rem);
  display: block;
  color: var(--ice);
  background: var(--deep);
}

/* ---------- 面包屑与首屏 ---------- */

.page-about .crumbs {
  padding-top: clamp(0.9rem, 2.4vw, 1.5rem);
}

.page-about .about-hero {
  position: relative;
  padding: clamp(1.4rem, 3.6vw, 2.75rem) 0 clamp(1.8rem, 4vw, 3rem);
  border-bottom: var(--about-rule);
  overflow: hidden;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  right: -12%;
  bottom: -46%;
  width: min(360px, 62vw);
  height: min(360px, 62vw);
  background: radial-gradient(circle, rgba(53, 224, 194, 0.12), rgba(53, 224, 194, 0) 68%);
  pointer-events: none;
}

.page-about .about-hero__grid {
  display: grid;
  gap: var(--about-gap);
}

.page-about .about-hero__annot {
  color: var(--gold);
  letter-spacing: 0.2em;
  margin: 0 0 0.7rem;
}

.page-about .about-hero__title {
  margin: 0 0 0.9rem;
  font-family: var(--font-cn);
  font-weight: 900;
  letter-spacing: -0.02em;
  line-height: 1.08;
  color: var(--ice);
}

.page-about .about-hero__text {
  margin: 0 0 0.7rem;
  max-width: 46ch;
  color: var(--mist);
}

.page-about .about-hero__sub {
  margin: 0;
  max-width: 48ch;
  color: var(--mist);
}

.page-about .about-facts {
  display: grid;
  gap: 0;
  margin: 0;
  border-top: var(--about-rule);
}

.page-about .about-fact {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.62rem 0;
  border-bottom: var(--about-rule-soft);
}

.page-about .about-fact dt {
  color: var(--mist);
  font-size: 0.8125rem;
  letter-spacing: 0.08em;
}

.page-about .about-fact__num {
  margin: 0;
  color: var(--gold);
  font-size: clamp(1.2rem, 2.4vw, 1.55rem);
  font-weight: 700;
  line-height: 1.1;
}

/* ---------- 主体两栏 ---------- */

.page-about .about-body {
  display: grid;
  gap: clamp(1.4rem, 3vw, 3rem);
  padding: clamp(1.6rem, 4vw, 3rem) 0 clamp(2.5rem, 6vw, 4.5rem);
}

.page-about .about-index {
  min-width: 0;
}

.page-about .about-index__title {
  margin: 0 0 0.5rem;
  padding-bottom: 0.55rem;
  color: var(--gold);
  letter-spacing: 0.2em;
  border-bottom: var(--about-rule);
}

.page-about .about-index__list {
  display: flex;
  gap: 0.25rem;
  margin: 0;
  padding: 0 0 0.4rem;
  list-style: none;
  overflow-x: auto;
  scrollbar-width: thin;
}

.page-about .about-index__list a {
  display: block;
  padding: 0.45rem 0.65rem;
  color: var(--mist);
  font-size: 0.875rem;
  line-height: 1.3;
  white-space: nowrap;
  text-decoration: none;
  border-left: 2px solid transparent;
  transition: color 0.18s ease, background-color 0.18s ease, border-color 0.18s ease;
}

.page-about .about-index__list a:hover,
.page-about .about-index__list a:focus-visible {
  color: var(--ice);
  background: rgba(18, 58, 90, 0.55);
  border-left-color: var(--edge);
}

.page-about .about-index__list a[data-active] {
  color: var(--gold);
  background: rgba(226, 179, 60, 0.1);
  border-left-color: var(--gold);
}

.page-about .about-main {
  min-width: 0;
}

/* ---------- 章节壳 ---------- */

.page-about .about-sec {
  padding-top: clamp(1.6rem, 3.4vw, 2.6rem);
  border-top: var(--about-rule);
}

.page-about .about-sec:first-child {
  padding-top: 0;
  border-top: 0;
}

.page-about .about-sec + .about-sec {
  margin-top: clamp(1.6rem, 3.4vw, 2.6rem);
}

.page-about .sec__idx {
  color: var(--gold);
  letter-spacing: 0.18em;
}

.page-about .sec__title {
  margin: 0.35rem 0 0;
  font-family: var(--font-cn);
  font-weight: 900;
  letter-spacing: -0.015em;
  line-height: 1.16;
  color: var(--ice);
  text-wrap: balance;
}

.page-about .sec__lead {
  margin: 0.6rem 0 0;
  max-width: 60ch;
  color: var(--mist);
}

/* ---------- 三条业务线 ---------- */

.page-about .about-lines {
  display: grid;
  margin-top: clamp(1.1rem, 3vw, 1.9rem);
  border-top: var(--about-rule);
}

.page-about .about-line {
  display: grid;
  gap: 0.35rem;
  padding: 1.05rem 0.5rem 1.05rem 0;
  border-bottom: var(--about-rule-soft);
  transition: background-color 0.2s ease, transform 0.2s ease;
}

.page-about .about-line:hover {
  background: rgba(18, 58, 90, 0.35);
  transform: translateX(4px);
}

.page-about .about-line__idx {
  color: var(--gold);
  font-size: 0.8125rem;
  letter-spacing: 0.12em;
}

.page-about .about-line__name {
  margin: 0;
  color: var(--ice);
}

.page-about .about-line__desc {
  margin: 0;
  color: var(--mist);
}

/* ---------- 项目线覆盖 ---------- */

.page-about .about-scope {
  display: grid;
  gap: clamp(1.1rem, 3vw, 2rem);
  margin-top: clamp(1.1rem, 3vw, 1.9rem);
}

.page-about .about-scope__list {
  display: grid;
  margin: 0;
  padding: 0;
  list-style: none;
  border-top: var(--about-rule);
}

.page-about .about-scope__item {
  display: grid;
  grid-template-columns: 4.2rem minmax(0, 1fr);
  gap: 0.75rem;
  padding: 0.8rem 0;
  border-bottom: var(--about-rule-soft);
  color: var(--mist);
  font-size: 0.9375rem;
  line-height: 1.5;
}

.page-about .about-scope__key {
  color: var(--gold);
  font-weight: 700;
  font-size: 0.875rem;
  letter-spacing: 0.06em;
}

.page-about .about-scope__note {
  margin: 1.1rem 0 0;
  padding-left: 0.9rem;
  border-left: 2px solid var(--gold);
  color: var(--mist);
}

/* ---------- 图片通用 ---------- */

.page-about .media {
  margin: 0;
  aspect-ratio: auto;
  overflow: hidden;
  background: var(--night);
}

.page-about .media img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: cover;
  clip-path: var(--about-cut);
}

.page-about .media__cap {
  padding: 0.5rem 0.7rem;
  color: var(--mist);
  font-size: 0.75rem;
  line-height: 1.45;
  background: var(--night);
}

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

.page-about .about-team__fig {
  margin-top: clamp(1.1rem, 3vw, 1.9rem);
}

.page-about .about-team__fig img {
  aspect-ratio: 14 / 9;
}

/* ---------- 发展历程 ---------- */

.page-about .about-history__fig {
  margin: clamp(1.1rem, 3vw, 1.9rem) 0 0;
}

.page-about .about-history__fig img {
  aspect-ratio: 2 / 1;
}

.page-about .about-timeline {
  display: grid;
  margin: clamp(1.4rem, 3.2vw, 2.2rem) 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-timeline__item {
  position: relative;
  padding: 0 0 1.5rem 1.7rem;
  border-left: 1px solid var(--edge);
}

.page-about .about-timeline__item::before {
  content: "";
  position: absolute;
  left: -4.5px;
  top: 0.55rem;
  width: 8px;
  height: 8px;
  background: var(--deep);
  border: 1px solid var(--gold);
  transform: rotate(45deg);
}

.page-about .about-timeline__year {
  display: block;
  margin-bottom: 0.2rem;
  color: var(--gold);
  font-size: 1.1rem;
  font-weight: 700;
  letter-spacing: 0.04em;
}

.page-about .about-timeline__body h3 {
  margin: 0 0 0.25rem;
  color: var(--ice);
}

.page-about .about-timeline__body p {
  margin: 0;
  max-width: 62ch;
  color: var(--mist);
}

.page-about .about-history__note {
  margin: 0.4rem 0 0;
  color: var(--mist);
  font-size: 0.9375rem;
}

/* ---------- 团队 ---------- */

.page-about .about-team {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  margin-top: clamp(1.1rem, 3vw, 1.9rem);
  background: var(--edge);
  border: 1px solid var(--edge);
}

.page-about .about-team__cell {
  padding: 1.05rem 1rem;
  background: var(--night);
  transition: background-color 0.2s ease;
}

.page-about .about-team__cell:hover {
  background: var(--steel);
}

.page-about .about-team__n {
  display: block;
  color: var(--gold);
  font-size: clamp(1.45rem, 3vw, 1.95rem);
  font-weight: 700;
  line-height: 1;
}

.page-about .about-team__l {
  margin: 0.4rem 0 0;
  color: var(--mist);
  font-size: 0.875rem;
}

.page-about .about-team__note {
  margin: 1.1rem 0 0;
  padding-left: 0.9rem;
  border-left: 2px solid var(--gold);
  color: var(--mist);
}

/* ---------- 数据来源 ---------- */

.page-about .about-sources {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  margin-top: clamp(1.1rem, 3vw, 1.9rem);
  background: var(--edge);
  border: 1px solid var(--edge);
}

.page-about .about-source {
  padding: 1.2rem 1.05rem;
  background: var(--steel);
}

.page-about .about-source__kicker {
  margin: 0;
  color: var(--gold);
  letter-spacing: 0.18em;
}

.page-about .about-source h3 {
  margin: 0.35rem 0 0.45rem;
  color: var(--ice);
}

.page-about .about-source p {
  margin: 0;
  color: var(--mist);
  font-size: 0.9375rem;
}

.page-about .about-sources__note {
  margin: 1.1rem 0 0;
  padding: 0.9rem 1rem;
  color: var(--mist);
  font-size: 0.9375rem;
  background: rgba(4, 18, 31, 0.6);
  border: var(--about-rule);
}

/* ---------- 共建与收录 ---------- */

.page-about .about-credits {
  display: grid;
  gap: clamp(0.9rem, 2.4vw, 1.5rem);
  margin: clamp(1.1rem, 3vw, 1.9rem) 0 0;
}

.page-about .about-credit {
  padding-top: 0.85rem;
  border-top: var(--about-rule);
}

.page-about .about-credit dt {
  display: flex;
  align-items: baseline;
  gap: 0.4rem;
  color: var(--mist);
  font-size: 0.8125rem;
  letter-spacing: 0.08em;
}

.page-about .about-credit__num {
  color: var(--gold);
  font-size: 1.5rem;
  font-weight: 700;
  letter-spacing: 0.02em;
}

.page-about .about-credit dd {
  margin: 0.35rem 0 0;
  color: var(--mist);
  font-size: 0.9375rem;
  line-height: 1.55;
}

.page-about .about-credits__note {
  margin: 1.1rem 0 0;
  color: var(--mist);
  font-size: 0.9375rem;
}

/* ---------- 接下来 ---------- */

.page-about .about-next__list {
  margin: clamp(1.1rem, 3vw, 1.9rem) 0 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 0.85rem;
}

.page-about .about-next__list li {
  position: relative;
  padding-left: 1.5rem;
  color: var(--mist);
  line-height: 1.55;
}

.page-about .about-next__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.62em;
  width: 0.7rem;
  height: 1px;
  background: var(--gold);
}

.page-about .about-next__panel {
  margin-top: clamp(1.2rem, 3vw, 2rem);
  padding: clamp(1.1rem, 3vw, 1.75rem);
  background: linear-gradient(135deg, var(--night), var(--deep));
  border: var(--about-rule);
  clip-path: var(--about-cut);
}

.page-about .about-next__text {
  margin: 0;
  color: var(--mist);
}

.page-about .about-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.55rem;
  margin-top: 0.9rem;
}

/* ---------- 响应式 ---------- */

@media (min-width: 620px) {
  .page-about .about-team {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

@media (min-width: 760px) {
  .page-about .about-line {
    grid-template-columns: 3.2rem minmax(7rem, 11rem) minmax(0, 1fr);
    align-items: baseline;
    gap: 0.4rem 1.25rem;
  }

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

  .page-about .about-timeline__item {
    display: grid;
    grid-template-columns: 5.5rem minmax(0, 1fr) 4.5rem;
    gap: 1.25rem;
    padding-left: 1.5rem;
  }

  .page-about .about-timeline__year {
    margin-bottom: 0;
    text-align: right;
  }
}

@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: 7fr 5fr;
    align-items: end;
  }

  .page-about .about-scope {
    grid-template-columns: 5fr 7fr;
    align-items: start;
  }
}

@media (min-width: 1000px) {
  .page-about .about-team {
    grid-template-columns: repeat(5, minmax(0, 1fr));
  }

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

@media (min-width: 1024px) {
  .page-about .about-body {
    grid-template-columns: minmax(158px, 200px) minmax(0, 1fr);
    align-items: start;
  }

  .page-about .about-index {
    position: sticky;
    top: calc(var(--bar-h) + 1.5rem);
  }

  .page-about .about-index__list {
    flex-direction: column;
    gap: 0.1rem;
    padding: 0;
    overflow: visible;
  }

  .page-about .about-index__list a {
    white-space: normal;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-line,
  .page-about .about-index__list a,
  .page-about .about-team__cell {
    transition: none;
    transform: none;
  }
}