.page-about {
  --about-gap: clamp(1.5rem, 4vw, 3.25rem);
  background: var(--c-ink);
  color: var(--text-on-light);
  overflow-x: clip;
}

.page-about .section {
  padding-block: clamp(3rem, 8vw, 5.5rem);
}

.page-about .about-h2 {
  margin: .5rem 0 0;
  font-size: clamp(1.5rem, 3.6vw, 2.125rem);
  line-height: 1.26;
  letter-spacing: -.01em;
}

.page-about .about-lede {
  margin: 1.125rem 0 0;
  max-width: 38rem;
  font-size: 1rem;
  line-height: 1.85;
}

/* ---------- 面包屑 ---------- */

.page-about .about-crumb {
  background: var(--c-ink);
  padding: 1.125rem 0 .5rem;
  font-size: .8125rem;
}

/* ---------- 首屏 ---------- */

.page-about .about-hero {
  position: relative;
  background: var(--c-ink);
  border-bottom: 1px solid var(--line-on-dark);
  padding-bottom: clamp(1.75rem, 5vw, 3rem);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    repeating-linear-gradient(90deg, var(--line-on-dark) 0 1px, transparent 1px 96px),
    repeating-linear-gradient(0deg, var(--line-on-dark) 0 1px, transparent 1px 96px);
  pointer-events: none;
}

.page-about .about-hero__inner {
  position: relative;
  z-index: 1;
  padding-top: clamp(1.25rem, 3vw, 2rem);
  padding-bottom: clamp(1.75rem, 4vw, 2.75rem);
}

.page-about .about-hero__title {
  margin: .5rem 0 0;
  max-width: 52rem;
  font-size: clamp(1.9rem, 5.4vw, 3.15rem);
  line-height: 1.16;
  letter-spacing: -.02em;
  font-weight: 900;
  color: var(--text-on-dark);
}

.page-about .about-hero__lede {
  margin: 1.25rem 0 0;
  max-width: 42rem;
  font-size: clamp(.9375rem, 1.5vw, 1.0625rem);
  line-height: 1.9;
  color: var(--text-on-dark-soft);
}

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

.page-about .about-facts__list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 0;
  padding: 0;
  list-style: none;
  background: var(--line-on-dark);
  border-top: 1px solid var(--line-on-dark);
  border-bottom: 1px solid var(--line-on-dark);
}

.page-about .about-fact {
  background: var(--c-ink);
  padding: 1.125rem .875rem 1.125rem 1rem;
}

.page-about .about-fact__num {
  display: block;
  font-size: clamp(1.375rem, 3.4vw, 1.875rem);
  line-height: 1.1;
  letter-spacing: .02em;
  color: var(--c-brass-lit);
}

.page-about .about-fact__num small {
  font-size: .55em;
  margin-left: .12em;
  letter-spacing: .04em;
}

.page-about .about-fact__label {
  display: block;
  margin-top: .45rem;
  font-size: .8125rem;
  line-height: 1.6;
  color: var(--text-on-dark-soft);
}

@media (min-width: 720px) {
  .page-about .about-facts__list {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
  .page-about .about-fact {
    padding: 1.375rem 1.125rem 1.375rem 1.25rem;
  }
}

/* ---------- 通用图版 ---------- */

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

.page-about .about-figure img {
  display: block;
  width: 100%;
  height: auto;
  border: 1px solid var(--line);
  filter: saturate(.72) contrast(1.03);
}

.page-about .about-figure__cap {
  margin-top: .7rem;
  font-family: var(--font-mono);
  font-size: .75rem;
  line-height: 1.7;
  letter-spacing: .03em;
  color: var(--c-stone);
}

/* ---------- 品牌缘起 ---------- */

.page-about .about-origin {
  background: var(--c-paper-warm);
  color: var(--text-on-light);
}

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

.page-about .about-origin__body p {
  margin: 1rem 0 0;
  max-width: 34rem;
  line-height: 1.9;
  color: var(--text-on-light-soft);
}

.page-about .about-origin__fig img {
  aspect-ratio: 4 / 3;
  object-fit: cover;
  clip-path: polygon(0 0, calc(100% - var(--cut)) 0, 100% var(--cut), 100% 100%, 0 100%);
}

@media (min-width: 920px) {
  .page-about .about-origin__grid {
    grid-template-columns: minmax(0, 1.1fr) minmax(0, .9fr);
    align-items: start;
  }
  .page-about .about-origin__fig {
    margin-top: 1.5rem;
  }
}

/* ---------- 发展脉络 ---------- */

.page-about .about-timeline {
  background: var(--c-ink-2);
  color: var(--text-on-dark);
}

.page-about .about-timeline .about-lede {
  color: var(--text-on-dark-soft);
}

.page-about .about-timeline__band {
  margin: clamp(1.75rem, 4vw, 2.5rem) 0 0;
  line-height: 0;
}

.page-about .about-timeline__band img {
  display: block;
  width: 100%;
  height: clamp(72px, 13vw, 160px);
  object-fit: cover;
  opacity: .5;
  filter: saturate(.45) brightness(.85);
}

.page-about .about-timeline__tabs {
  margin-top: clamp(1.75rem, 4vw, 2.5rem);
}

.page-about .about-timeline__panels {
  margin-top: 1.75rem;
}

.page-about .about-timeline__list {
  display: grid;
  gap: 1.5rem;
  margin: 0;
  padding: 0 0 0 1.25rem;
  list-style: none;
  border-left: 1px solid var(--c-brass);
}

.page-about .about-node {
  position: relative;
  display: grid;
  gap: .3rem;
}

.page-about .about-node::before {
  content: "";
  position: absolute;
  left: calc(-1.25rem - 3.5px);
  top: .5rem;
  width: 7px;
  height: 7px;
  background: var(--c-ink-2);
  border: 1px solid var(--c-brass);
  border-radius: 50%;
}

.page-about .about-node__stamp {
  display: block;
  font-size: .75rem;
  letter-spacing: .1em;
  color: var(--c-brass-lit);
}

.page-about .about-node__text {
  margin: 0;
  max-width: 38rem;
  font-size: .9375rem;
  line-height: 1.85;
  color: var(--text-on-dark-soft);
}

/* ---------- 组织与分工 ---------- */

.page-about .about-team {
  background: var(--c-paper);
  color: var(--text-on-light);
}

.page-about .about-team .about-lede {
  color: var(--text-on-light-soft);
}

.page-about .about-team__tabs {
  margin-top: clamp(1.75rem, 4vw, 2.5rem);
}

.page-about .about-team__panels {
  display: grid;
  gap: 1rem;
  margin-top: 1.5rem;
}

.page-about .about-team__panel {
  background: var(--c-paper-warm);
  border: 1px solid var(--line);
  border-left: 3px solid var(--c-brass);
  padding: clamp(1.25rem, 3vw, 1.75rem);
}

.page-about .about-team__count {
  display: block;
  font-size: clamp(1.625rem, 4.4vw, 2.375rem);
  line-height: 1;
  color: var(--c-brass);
  letter-spacing: .01em;
}

.page-about .about-team__panel h3 {
  margin: .55rem 0 0;
  font-size: 1.0625rem;
  letter-spacing: .01em;
}

.page-about .about-team__panel p {
  margin: .65rem 0 0;
  max-width: 42rem;
  font-size: .9375rem;
  line-height: 1.85;
  color: var(--text-on-light-soft);
}

.page-about .about-team__panel .about-team__duty {
  margin-top: .95rem;
  padding-top: .85rem;
  border-top: 1px dashed var(--line-strong);
  font-size: .875rem;
}

/* ---------- 服务能力 ---------- */

.page-about .about-reach {
  background: var(--c-ink);
  color: var(--text-on-dark);
}

.page-about .about-reach .about-lede {
  color: var(--text-on-dark-soft);
}

.page-about .about-reach__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  margin-top: clamp(1.75rem, 4vw, 2.5rem);
  background: var(--line-on-dark);
  border: 1px solid var(--line-on-dark);
}

.page-about .about-reach__cell {
  background: var(--c-ink);
  padding: clamp(1.125rem, 2.6vw, 1.65rem);
}

.page-about .about-reach__cell h3 {
  margin: 0;
  font-family: var(--font-mono);
  font-size: .75rem;
  font-weight: 500;
  letter-spacing: .12em;
  color: var(--c-brass);
}

.page-about .about-reach__num {
  display: block;
  margin-top: .4rem;
  font-size: clamp(1.5rem, 3.6vw, 2rem);
  line-height: 1.1;
  color: var(--text-on-dark);
}

.page-about .about-reach__cell p {
  margin: .7rem 0 0;
  font-size: .9375rem;
  line-height: 1.8;
  color: var(--text-on-dark-soft);
}

.page-about .about-reach__band {
  margin: clamp(1.75rem, 4vw, 2.5rem) 0 0;
}

.page-about .about-reach__band img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 16 / 7;
  object-fit: cover;
  filter: saturate(.5) brightness(.9);
  border-top: 1px solid var(--line-on-dark);
  border-bottom: 1px solid var(--line-on-dark);
}

.page-about .about-reach__band-cap {
  max-width: var(--wrap);
  margin: .65rem auto 0;
  padding-inline: var(--gutter);
  font-family: var(--font-mono);
  font-size: .75rem;
  letter-spacing: .03em;
  color: var(--c-feather);
}

@media (min-width: 860px) {
  .page-about .about-reach__grid {
    grid-template-columns: 1.35fr 1fr 1fr 1.55fr;
  }
}

/* ---------- 合作与内容来源 ---------- */

.page-about .about-partners {
  background: var(--c-paper-warm);
  color: var(--text-on-light);
}

.page-about .about-partners .about-lede {
  color: var(--text-on-light-soft);
}

.page-about .about-partners__grid {
  display: grid;
  gap: var(--about-gap);
  margin-top: clamp(1.75rem, 4vw, 2.5rem);
}

.page-about .about-partner-card {
  border-top: 2px solid var(--c-brass);
  padding-top: 1.125rem;
}

.page-about .about-partner-card h3 {
  margin: 0;
  font-size: 1.0625rem;
  line-height: 1.5;
}

.page-about .about-partner-card p {
  margin: .7rem 0 0;
  font-size: .9375rem;
  line-height: 1.85;
  color: var(--text-on-light-soft);
}

.page-about .about-sectors {
  display: flex;
  flex-wrap: wrap;
  gap: .5rem;
  margin: 1.75rem 0 0;
  padding: 0;
  list-style: none;
}

@media (min-width: 880px) {
  .page-about .about-partners__grid {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  }
}

/* ---------- 资质与备案 ---------- */

.page-about .about-credentials {
  background: var(--c-paper);
  color: var(--text-on-light);
}

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

.page-about .about-credentials__intro p {
  margin: 1rem 0 0;
  max-width: 30rem;
  line-height: 1.9;
  color: var(--text-on-light-soft);
}

.page-about .about-credentials__list {
  display: grid;
  gap: .75rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-cred {
  background: var(--c-paper-warm);
  border: 1px solid var(--line);
  border-left: 3px solid var(--c-brass);
}

.page-about .about-cred > summary {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
  padding: 1rem clamp(1rem, 2.5vw, 1.3rem);
  cursor: pointer;
  font-size: .9375rem;
  font-weight: 600;
  line-height: 1.6;
  list-style: none;
}

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

.page-about .about-cred > summary::after {
  content: "+";
  flex: none;
  font-family: var(--font-mono);
  font-size: 1.125rem;
  line-height: 1;
  color: var(--c-brass);
}

.page-about .about-cred[open] > summary::after {
  content: "–";
}

.page-about .about-cred > p {
  margin: 0;
  padding: 0 clamp(1rem, 2.5vw, 1.3rem) 1.15rem;
  max-width: 44rem;
  font-size: .875rem;
  line-height: 1.85;
  color: var(--text-on-light-soft);
}

@media (min-width: 900px) {
  .page-about .about-credentials__grid {
    grid-template-columns: minmax(0, .85fr) minmax(0, 1.15fr);
    align-items: start;
    gap: clamp(2rem, 5vw, 4rem);
  }
}

/* ---------- 下一步 ---------- */

.page-about .about-next {
  background: var(--c-ink-2);
  color: var(--text-on-dark);
}

.page-about .about-next .about-lede {
  color: var(--text-on-dark-soft);
}

.page-about .about-next__grid {
  display: grid;
  gap: 1rem;
  margin-top: clamp(1.75rem, 4vw, 2.5rem);
}

.page-about .about-next__card {
  display: flex;
  flex-direction: column;
  gap: .75rem;
  padding: clamp(1.25rem, 3vw, 1.75rem);
  background: var(--c-ink-3);
  border: 1px solid var(--line-on-dark);
  border-top: 2px solid var(--c-brass);
}

.page-about .about-next__card h3 {
  margin: 0;
  font-size: 1.0625rem;
  line-height: 1.5;
  color: var(--text-on-dark);
}

.page-about .about-next__card p {
  margin: 0;
  font-size: .9375rem;
  line-height: 1.85;
  color: var(--text-on-dark-soft);
}

.page-about .about-next__card .btn {
  align-self: flex-start;
  margin-top: auto;
}

.page-about .about-next__note {
  margin: clamp(1.5rem, 4vw, 2.25rem) 0 0;
  padding-top: 1.125rem;
  border-top: 1px solid var(--line-on-dark);
  max-width: 44rem;
  font-size: .875rem;
  line-height: 1.85;
  color: var(--text-on-dark-soft);
}

.page-about .about-next__note a {
  color: var(--c-brass-lit);
  text-decoration: underline;
  text-underline-offset: 3px;
}

@media (min-width: 880px) {
  .page-about .about-next__grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}