.page-about {
  --about-card-bg: var(--c-ink-2);
  --about-divider: var(--line-1);
  --about-axis: var(--c-slate);
  display: block;
  padding-bottom: clamp(48px, 8vw, 96px);
  color: var(--text-2);
  background: transparent;
}

.page-about .about-sr-title {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}

/* ---------- 面包屑 ---------- */
.page-about .about-crumbs {
  padding-top: clamp(18px, 3vw, 30px);
  margin-bottom: clamp(10px, 1.5vw, 18px);
}

/* ---------- 页头 ---------- */
.page-about .about-head {
  padding-bottom: clamp(30px, 5vw, 52px);
  border-bottom: 1px solid var(--about-divider);
}

.page-about .about-kicker {
  margin: 0 0 16px;
  color: var(--c-accent);
}

.page-about .about-title {
  margin: 0;
  font-size: clamp(30px, 6.2vw, 58px);
  line-height: 1.15;
  font-weight: 800;
  letter-spacing: -0.01em;
  color: var(--text-1);
  max-width: 20ch;
}

.page-about .about-lede {
  margin: clamp(18px, 2.5vw, 26px) 0 0;
  max-width: 62ch;
  font-size: clamp(15px, 1.7vw, 17px);
  line-height: 1.85;
  color: var(--text-2);
}

.page-about .about-facts {
  list-style: none;
  margin: clamp(28px, 4vw, 42px) 0 0;
  padding: clamp(20px, 3vw, 28px) 0 0;
  border-top: 1px solid var(--about-divider);
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: clamp(16px, 2.4vw, 26px);
}

.page-about .about-facts__item {
  display: flex;
  flex-direction: column;
  gap: 6px;
  min-width: 0;
}

.page-about .about-facts__num {
  font-size: clamp(24px, 3.6vw, 34px);
  font-weight: 700;
  line-height: 1;
  color: var(--c-accent);
  letter-spacing: -0.02em;
}

.page-about .about-facts__item:nth-child(2) .about-facts__num,
.page-about .about-facts__item:nth-child(4) .about-facts__num {
  color: var(--c-mist);
}

.page-about .about-facts__label {
  font-size: 13px;
  line-height: 1.5;
  color: var(--text-3);
}

/* ---------- 通用区块标题 ---------- */
.page-about .about-h2 {
  margin: 0;
  font-size: clamp(22px, 3.4vw, 34px);
  line-height: 1.3;
  font-weight: 700;
  color: var(--text-1);
  letter-spacing: -0.005em;
}

.page-about .about-section-head {
  margin-bottom: clamp(22px, 3.4vw, 36px);
}

.page-about .about-section-head .section__lead {
  margin-top: 14px;
  max-width: 64ch;
  color: var(--text-2);
  line-height: 1.8;
  font-size: 15px;
}

/* ---------- 品牌起点与使命 ---------- */
.page-about .about-mission {
  padding: clamp(34px, 5.5vw, 62px) 0 0;
}

.page-about .about-mission__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--gap);
}

.page-about .about-mission__card {
  padding: clamp(20px, 3vw, 30px);
  background: var(--about-card-bg);
  border: 1px solid var(--about-divider);
  border-radius: var(--r-lg);
}

.page-about .about-mission__card .card__meta {
  margin: 0 0 12px;
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--c-slate);
}

.page-about .about-mission__card .card__title {
  margin: 0 0 12px;
  font-size: clamp(18px, 2.3vw, 22px);
  line-height: 1.4;
  font-weight: 700;
  color: var(--text-1);
}

.page-about .about-mission__card .card__body {
  margin: 0;
  font-size: 15px;
  line-height: 1.85;
  color: var(--text-2);
}

.page-about .about-mission__card.card--accent {
  background: linear-gradient(158deg, rgba(255, 107, 53, 0.16), rgba(19, 47, 76, 0.9) 58%);
  border-color: rgba(255, 107, 53, 0.42);
}

.page-about .about-mission__card.card--accent .card__meta {
  color: var(--c-accent);
}

/* ---------- 发展时间轴 ---------- */
.page-about .about-tl-section {
  padding: clamp(44px, 7vw, 82px) 0 0;
}

.page-about .about-tl-figure {
  margin: 0 0 clamp(28px, 4vw, 44px);
}

.page-about .about-tl-figure .figure__caption {
  margin-top: 10px;
  font-size: 13px;
  color: var(--text-3);
}

.page-about .about-tl {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.page-about .about-tl::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 24px;
  bottom: 24px;
  width: 2px;
  background: linear-gradient(
    to bottom,
    var(--c-accent) 0%,
    rgba(255, 107, 53, 0.35) 22%,
    var(--c-slate) 55%,
    var(--about-divider) 100%
  );
}

.page-about .about-tl__item {
  position: relative;
  padding-left: 34px;
}

.page-about .about-tl__item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 18px;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--c-ink);
  border: 2px solid var(--c-slate);
  z-index: 1;
  transition: border-color var(--t-fast), background var(--t-fast);
}

.page-about .about-tl__item[open]::before {
  border-color: var(--c-accent);
  background: var(--c-accent);
  box-shadow: 0 0 0 5px rgba(255, 107, 53, 0.16);
}

.page-about .about-tl__summary {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 10px 16px;
  padding: 14px 18px;
  cursor: pointer;
  list-style: none;
  background: var(--about-card-bg);
  border: 1px solid var(--about-divider);
  border-radius: var(--r-md);
  transition: border-color var(--t-fast), background var(--t-fast);
}

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

.page-about .about-tl__summary:hover {
  border-color: var(--line-2);
}

.page-about .about-tl__item[open] .about-tl__summary {
  border-color: rgba(255, 107, 53, 0.4);
  border-bottom-left-radius: 0;
  border-bottom-right-radius: 0;
}

.page-about .about-tl__year {
  font-size: 17px;
  font-weight: 700;
  color: var(--c-accent);
  letter-spacing: 0.04em;
}

.page-about .about-tl__title {
  flex: 1 1 200px;
  min-width: 0;
  font-size: clamp(15px, 1.8vw, 17px);
  line-height: 1.55;
  font-weight: 600;
  color: var(--text-1);
}

.page-about .about-tl__body {
  padding: 4px 18px 18px;
  background: var(--c-ink-3);
  border: 1px solid rgba(255, 107, 53, 0.4);
  border-top: none;
  border-bottom-left-radius: var(--r-md);
  border-bottom-right-radius: var(--r-md);
}

.page-about .about-tl__body p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.85;
  color: var(--text-2);
  max-width: 66ch;
}

/* ---------- 团队与研发 ---------- */
.page-about .about-team {
  padding: clamp(44px, 7vw, 82px) 0 0;
}

.page-about .about-team__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(22px, 3.4vw, 40px);
}

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

.page-about .about-team__figure .figure__caption {
  margin-top: 10px;
  font-size: 13px;
  color: var(--text-3);
}

.page-about .about-team__text .kicker {
  margin: 0 0 12px;
  color: var(--c-slate);
}

.page-about .about-team__lead {
  margin: 16px 0 0;
  font-size: 15px;
  line-height: 1.85;
  color: var(--text-2);
  max-width: 58ch;
}

.page-about .about-team__stats {
  list-style: none;
  margin: clamp(22px, 3vw, 32px) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
}

.page-about .about-stat {
  padding: 16px 18px;
  background: var(--about-card-bg);
  border: 1px solid var(--about-divider);
  border-radius: var(--r-md);
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 4px;
}

.page-about .about-stat .stat__value {
  font-size: clamp(24px, 3.4vw, 30px);
  font-weight: 700;
  line-height: 1.1;
  color: var(--text-1);
}

.page-about .about-stat .stat__value--accent {
  color: var(--c-amber);
}

.page-about .about-stat .stat__unit {
  font-size: 13px;
  color: var(--text-3);
}

.page-about .about-stat .stat__label {
  flex: 1 1 100%;
  font-size: 13px;
  line-height: 1.5;
  color: var(--text-3);
}

.page-about .about-team__note {
  margin: 20px 0 0;
  padding-left: 16px;
  border-left: 2px solid var(--c-steel);
  font-size: 14px;
  line-height: 1.8;
  color: var(--text-2);
}

/* ---------- 资质认证 ---------- */
.page-about .about-certs {
  padding: clamp(44px, 7vw, 82px) 0 0;
}

.page-about .about-certs__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(20px, 3vw, 32px);
}

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

.page-about .about-certs__figure .figure__caption {
  margin-top: 10px;
  font-size: 13px;
  color: var(--text-3);
}

.page-about .about-certs__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
}

.page-about .about-certs__item {
  padding: 18px 20px;
  background: var(--about-card-bg);
  border: 1px solid var(--about-divider);
  border-radius: var(--r-md);
  transition: border-color var(--t-fast), transform var(--t-fast);
}

.page-about .about-certs__item:hover,
.page-about .about-certs__item:focus-within {
  border-color: var(--c-steel);
  transform: translateY(-2px);
}

.page-about .about-certs__item .chip {
  margin-bottom: 12px;
}

.page-about .about-certs__item .card__title {
  margin: 0 0 8px;
  font-size: 17px;
  line-height: 1.45;
  font-weight: 700;
  color: var(--text-1);
}

.page-about .about-certs__item .card__body {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--text-2);
}

/* ---------- 合作生态 ---------- */
.page-about .about-partners {
  padding: clamp(44px, 7vw, 82px) 0 0;
}

.page-about .about-partners__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--gap);
}

.page-about .about-partners__card {
  padding: clamp(20px, 3vw, 28px);
  background: var(--about-card-bg);
  border: 1px solid var(--about-divider);
  border-radius: var(--r-lg);
  position: relative;
  overflow: hidden;
}

.page-about .about-partners__card::after {
  content: "";
  position: absolute;
  right: -30px;
  bottom: -30px;
  width: 96px;
  height: 96px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(176, 196, 222, 0.14), transparent 70%);
  pointer-events: none;
}

.page-about .about-partners__card:nth-child(1)::after {
  background: radial-gradient(circle, rgba(255, 107, 53, 0.22), transparent 70%);
}

.page-about .about-partners__role {
  margin: 0 0 12px;
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--c-accent);
}

.page-about .about-partners__card:nth-child(2) .about-partners__role,
.page-about .about-partners__card:nth-child(3) .about-partners__role {
  color: var(--c-slate);
}

.page-about .about-partners__card .card__title {
  margin: 0 0 10px;
  font-size: clamp(18px, 2.3vw, 22px);
  line-height: 1.4;
  font-weight: 700;
  color: var(--text-1);
}

.page-about .about-partners__card .card__body {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--text-2);
}

.page-about .about-partners__foot {
  margin: clamp(22px, 3vw, 30px) 0 0;
  padding: 18px 20px;
  border-left: 3px solid var(--c-steel);
  background: rgba(44, 95, 138, 0.12);
  border-radius: 0 var(--r-sm) var(--r-sm) 0;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--text-2);
}

/* ---------- 旧版追溯 ---------- */
.page-about .about-legacy {
  padding: clamp(44px, 7vw, 82px) 0 0;
}

.page-about .about-legacy__inner {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(24px, 3.6vw, 40px);
  padding: clamp(24px, 4vw, 44px);
  background: linear-gradient(160deg, var(--c-ink-3), var(--c-ink-2) 62%);
  border: 1px solid var(--line-2);
  border-radius: var(--r-xl);
}

.page-about .about-legacy__text .kicker {
  margin: 0 0 12px;
  color: var(--c-slate);
}

.page-about .about-legacy__text p {
  margin: 16px 0 0;
  font-size: 15px;
  line-height: 1.85;
  color: var(--text-2);
  max-width: 60ch;
}

.page-about .about-legacy__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: clamp(20px, 3vw, 28px);
}

.page-about .about-legacy__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.page-about .about-legacy__step {
  display: flex;
  align-items: flex-start;
  gap: 14px;
  padding: 14px 16px;
  background: rgba(10, 30, 60, 0.55);
  border: 1px solid var(--about-divider);
  border-radius: var(--r-md);
}

.page-about .about-legacy__idx {
  flex: 0 0 auto;
  font-size: 13px;
  font-weight: 700;
  color: var(--c-accent);
  letter-spacing: 0.06em;
  padding-top: 2px;
}

.page-about .about-legacy__label {
  flex: 1 1 auto;
  min-width: 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--text-2);
}

/* ---------- 下一步 ---------- */
.page-about .about-next {
  padding: clamp(44px, 7vw, 82px) 0 0;
}

.page-about .about-next__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--gap);
  margin-top: clamp(20px, 3vw, 28px);
}

.page-about .about-next__link {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: clamp(18px, 2.6vw, 24px);
  background: var(--about-card-bg);
  border: 1px solid var(--about-divider);
  border-radius: var(--r-lg);
  text-decoration: none;
  transition: border-color var(--t-fast), transform var(--t-fast), background var(--t-fast);
}

.page-about .about-next__link:hover,
.page-about .about-next__link:focus-visible {
  border-color: var(--c-accent);
  transform: translateY(-3px);
  background: var(--c-ink-3);
}

.page-about .about-next__tag {
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--c-slate);
}

.page-about .about-next__title {
  font-size: clamp(17px, 2.2vw, 20px);
  font-weight: 700;
  color: var(--text-1);
}

.page-about .about-next__desc {
  font-size: 14px;
  line-height: 1.75;
  color: var(--text-2);
}

/* ---------- 响应式 ---------- */
@media (min-width: 640px) {
  .page-about .about-facts {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

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

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

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

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

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

@media (min-width: 900px) {
  .page-about .about-facts {
    grid-template-columns: repeat(5, minmax(0, 1fr));
  }

  .page-about .about-team__grid {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    align-items: start;
  }

  .page-about .about-certs__grid {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    align-items: start;
  }

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

  .page-about .about-legacy__inner {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    align-items: start;
  }

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

  .page-about .about-tl__item {
    padding-left: 44px;
  }

  .page-about .about-tl::before {
    left: 9px;
  }

  .page-about .about-tl__item::before {
    width: 20px;
    height: 20px;
    top: 16px;
  }

  .page-about .about-tl__summary {
    padding: 16px 22px;
  }

  .page-about .about-tl__body {
    padding: 6px 22px 22px;
  }
}

@media (min-width: 1080px) {
  .page-about .about-team__stats {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}