.page-about {
  --about-gap: 24px;
  --about-block: 72px;
  padding-bottom: 8px;
}

.page-about .crumbs {
  margin: 22px 0 26px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .04em;
  color: var(--slate);
}

.page-about .crumbs a {
  color: var(--navy-600);
  text-decoration: none;
}

.page-about .crumbs a:hover {
  color: var(--signal);
}

.page-about .crumbs__sep {
  margin: 0 8px;
  color: var(--line);
}

.page-about section {
  margin-bottom: var(--about-block);
}

.page-about .section-head {
  margin-bottom: 28px;
}

.page-about .section-head__title {
  font-family: var(--font-serif);
  font-size: clamp(21px, 3.4vw, 30px);
  line-height: 1.3;
  letter-spacing: -.01em;
  color: var(--navy-900);
}

.page-about .section-head__meta {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--cyan-dark);
}

/* ---------- 首屏 ---------- */

.page-about .about-hero {
  margin-bottom: 64px;
}

.page-about .about-hero__frame {
  position: relative;
  border: 1px solid var(--line);
  border-left: 4px solid var(--navy-800);
  background: var(--paper);
  padding: 42px 22px 30px;
}

.page-about .about-hero__frame::before,
.page-about .about-hero__frame::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  height: 9px;
  background-image: repeating-linear-gradient(90deg, var(--line) 0 1px, transparent 1px 18px);
  pointer-events: none;
}

.page-about .about-hero__frame::before {
  top: 0;
}

.page-about .about-hero__frame::after {
  bottom: 0;
}

.page-about .about-hero__kicker {
  margin: 0 0 16px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .2em;
  color: var(--cyan-dark);
}

.page-about .about-hero h1 {
  margin: 0 0 20px;
  font-family: var(--font-serif);
  font-size: clamp(26px, 6.4vw, 48px);
  line-height: 1.18;
  letter-spacing: -.01em;
  color: var(--navy-900);
  max-width: 22ch;
}

.page-about .about-hero__lead {
  margin: 0 0 32px;
  font-size: 15px;
  line-height: 1.85;
  color: var(--mute);
  max-width: 60ch;
}

.page-about .about-hero__stats {
  list-style: none;
  margin: 0;
  padding: 24px 0 0;
  border-top: 1px solid var(--line);
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 20px 16px;
}

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

.page-about .about-hero__num {
  font-family: var(--font-mono);
  font-size: 34px;
  font-weight: 700;
  line-height: 1;
  color: var(--navy-800);
  font-variant-numeric: tabular-nums;
}

.page-about .about-hero__lbl {
  font-size: 13px;
  line-height: 1.5;
  color: var(--slate);
}

/* ---------- 起步 ---------- */

.page-about .about-start__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 28px;
}

.page-about .about-start__copy p {
  margin: 0 0 18px;
  font-size: 15px;
  line-height: 1.85;
  color: var(--mute);
}

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

.page-about .about-start__panel {
  background: var(--sand);
  border: 1px solid var(--line);
  padding: 22px 20px;
}

.page-about .about-start__panel-k {
  margin: 0 0 16px;
  font-family: var(--font-serif);
  font-size: 16px;
  color: var(--navy-900);
}

.page-about .about-start__list {
  list-style: none;
  margin: 0 0 18px;
  padding: 0;
}

.page-about .about-start__list li {
  display: flex;
  gap: 10px;
  align-items: flex-start;
  padding: 9px 0;
  border-bottom: 1px dashed var(--line);
  font-size: 13px;
  line-height: 1.7;
  color: var(--mute);
}

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

.page-about .about-start__list .tag {
  flex: 0 0 auto;
  margin-top: 2px;
}

.page-about .about-start__note {
  margin: 0;
  padding-top: 14px;
  border-top: 1px solid rgba(26, 29, 33, .12);
  font-family: var(--font-mono);
  font-size: 12px;
  line-height: 1.8;
  color: var(--navy-600);
}

/* ---------- 时间轴 ---------- */

.page-about .about-tl__layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: 34px;
}

.page-about .about-tl__list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .about-tl__item {
  position: relative;
  padding: 0 0 34px 32px;
}

.page-about .about-tl__item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 7px;
  width: 11px;
  height: 11px;
  border: 1px solid var(--cyan);
  background: var(--paper);
  transform: rotate(45deg);
  transition: background-color 200ms var(--ease), border-color 200ms var(--ease);
}

.page-about .about-tl__item::after {
  content: "";
  position: absolute;
  left: 5px;
  top: 24px;
  bottom: 0;
  width: 1px;
  background: var(--line);
}

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

.page-about .about-tl__item:last-child::after {
  display: none;
}

.page-about .about-tl__item:hover::before,
.page-about .about-tl__item:focus-within::before {
  background: var(--signal);
  border-color: var(--signal);
}

.page-about .about-tl__item:hover::after,
.page-about .about-tl__item:focus-within::after {
  background: var(--cyan);
}

.page-about .about-tl__idx {
  display: block;
  font-family: var(--font-mono);
  font-size: 28px;
  font-weight: 700;
  line-height: 1;
  color: var(--cyan-dark);
  opacity: .38;
  letter-spacing: -.02em;
  margin-bottom: 6px;
  transition: opacity 200ms var(--ease), color 200ms var(--ease);
}

.page-about .about-tl__item:hover .about-tl__idx,
.page-about .about-tl__item:focus-within .about-tl__idx {
  opacity: 1;
  color: var(--signal);
}

.page-about .about-tl__k {
  margin: 0 0 6px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .12em;
  color: var(--slate);
}

.page-about .about-tl__title {
  margin: 0 0 8px;
  font-family: var(--font-serif);
  font-size: 18px;
  line-height: 1.4;
  color: var(--navy-900);
}

.page-about .about-tl__body p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.85;
  color: var(--mute);
}

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

.page-about .about-tl__figure .media__frame {
  aspect-ratio: 5 / 6;
  overflow: hidden;
  background: var(--sand);
  border: 1px solid var(--line);
}

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

.page-about .about-tl__cap {
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  line-height: 1.7;
  color: var(--slate);
}

/* ---------- 团队 ---------- */

.page-about .about-team__lead {
  margin: 0 0 26px;
  font-size: 15px;
  line-height: 1.85;
  color: var(--mute);
  max-width: 58ch;
}

.page-about .about-team__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
  margin-bottom: 32px;
}

.page-about .about-team__card {
  background: var(--sand);
  border: 1px solid var(--line);
  padding: 18px 18px 4px;
}

.page-about .about-team__sum {
  display: flex;
  align-items: baseline;
  gap: 12px;
  cursor: pointer;
  list-style: none;
  padding-bottom: 14px;
}

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

.page-about .about-team__sum::after {
  content: "+";
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 18px;
  line-height: 1;
  color: var(--navy-600);
}

.page-about .about-team__card[open] .about-team__sum::after {
  content: "–";
  color: var(--signal);
}

.page-about .about-team__num {
  font-family: var(--font-mono);
  font-size: 38px;
  font-weight: 700;
  line-height: 1;
  color: var(--signal);
  font-variant-numeric: tabular-nums;
}

.page-about .about-team__role {
  font-family: var(--font-serif);
  font-size: 17px;
  color: var(--navy-900);
}

.page-about .about-team__card .acc__body {
  padding: 0 0 18px;
  border-top: 1px solid rgba(26, 29, 33, .12);
  padding-top: 14px;
}

.page-about .about-team__card .acc__body p {
  margin: 0;
  font-size: 14px;
  line-height: 1.85;
  color: var(--mute);
}

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

.page-about .about-team__figure .media__frame {
  aspect-ratio: 16 / 9;
  overflow: hidden;
  background: var(--navy-900);
  border: 1px solid var(--line);
}

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

.page-about .about-team__cap {
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  line-height: 1.7;
  color: var(--slate);
}

/* ---------- 资质 ---------- */

.page-about .about-cert__layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: 28px;
  margin-bottom: 30px;
}

.page-about .about-cert__copy p {
  margin: 0 0 16px;
  font-size: 15px;
  line-height: 1.85;
  color: var(--mute);
}

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

.page-about .about-cert__groups {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.page-about .about-cert__group {
  border: 1px solid var(--line);
  border-top: 3px solid var(--navy-600);
  background: var(--white);
  padding: 16px 14px;
}

.page-about .about-cert__group h3 {
  margin: 0 0 8px;
  font-family: var(--font-mono);
  font-size: 14px;
  letter-spacing: .06em;
  color: var(--navy-900);
}

.page-about .about-cert__group p {
  margin: 0;
  font-size: 12.5px;
  line-height: 1.7;
  color: var(--slate);
}

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

.page-about .about-cert__figure .media__frame {
  aspect-ratio: 10 / 7;
  overflow: hidden;
  background: var(--navy-900);
  border: 1px solid var(--line);
}

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

.page-about .about-cert__cap {
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  line-height: 1.7;
  color: var(--slate);
}

/* ---------- 区域 ---------- */

.page-about .about-region__lead {
  margin: 0 0 22px;
  font-size: 15px;
  line-height: 1.85;
  color: var(--mute);
  max-width: 62ch;
}

.page-about .about-region__filters {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
  margin-bottom: 22px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--line);
}

.page-about .about-region__count {
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .08em;
  color: var(--slate);
}

.page-about .about-region__panels {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
}

.page-about .about-region__card {
  background: var(--paper);
  border: 1px solid var(--line);
  border-left: 3px solid var(--cyan);
  padding: 22px 20px;
}

.page-about .about-region__card .card__meta {
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .12em;
  color: var(--cyan-dark);
  margin: 0 0 10px;
}

.page-about .about-region__card .card__title {
  font-family: var(--font-serif);
  font-size: 19px;
  line-height: 1.4;
  color: var(--navy-900);
  margin: 0 0 12px;
}

.page-about .about-region__card .card__text {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.85;
  color: var(--mute);
}

/* ---------- 行业参与 ---------- */

.page-about .about-field__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
  margin-bottom: 28px;
}

.page-about .about-field__item {
  position: relative;
  border: 1px solid var(--line);
  background: var(--white);
  padding: 24px 20px 22px;
}

.page-about .about-field__item::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 52px;
  height: 3px;
  background: var(--signal);
}

.page-about .about-field__num {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 44px;
  font-weight: 700;
  line-height: 1;
  color: var(--navy-800);
  font-variant-numeric: tabular-nums;
}

.page-about .about-field__item h3 {
  margin: 0 0 10px;
  font-family: var(--font-serif);
  font-size: 16px;
  line-height: 1.5;
  color: var(--navy-900);
}

.page-about .about-field__item p {
  margin: 0;
  font-size: 14px;
  line-height: 1.85;
  color: var(--mute);
}

.page-about .about-field__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

/* ---------- 收尾 ---------- */

.page-about .about-cta {
  margin-bottom: 0;
  background: var(--navy-900);
  border-top: 4px solid var(--signal);
  padding: 36px 22px 38px;
}

.page-about .about-cta__k {
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .2em;
  color: var(--cyan);
}

.page-about .about-cta h2 {
  margin: 0 0 14px;
  font-family: var(--font-serif);
  font-size: clamp(20px, 3.6vw, 28px);
  line-height: 1.35;
  color: var(--paper);
  max-width: 26ch;
}

.page-about .about-cta p {
  margin: 0 0 26px;
  font-size: 14.5px;
  line-height: 1.85;
  color: rgba(251, 247, 239, .78);
  max-width: 64ch;
}

.page-about .about-cta__links {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.page-about .about-cta__links .btn--outline {
  border-color: rgba(251, 247, 239, .5);
  color: var(--paper);
}

.page-about .about-cta__links .btn--outline:hover {
  border-color: var(--cyan);
  color: var(--cyan);
}

/* ---------- 响应式 ---------- */

@media (min-width: 640px) {
  .page-about .about-hero__frame {
    padding: 52px 36px 38px;
  }

  .page-about .about-hero__stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 24px;
  }

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

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

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

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

  .page-about .about-cta {
    padding: 46px 40px 50px;
  }
}

@media (min-width: 900px) {
  .page-about {
    --about-block: 92px;
  }

  .page-about .about-start__grid {
    grid-template-columns: minmax(0, 1.55fr) minmax(0, 1fr);
    gap: 44px;
  }

  .page-about .about-tl__layout {
    grid-template-columns: minmax(0, 1fr) 320px;
    gap: 48px;
    align-items: start;
  }

  .page-about .about-tl__figure {
    position: sticky;
    top: 72px;
  }

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

  .page-about .about-tl__idx {
    font-size: 34px;
    margin-left: -14px;
  }

  .page-about .about-cert__layout {
    grid-template-columns: minmax(0, 1.35fr) minmax(0, 1fr);
    gap: 46px;
    align-items: start;
  }

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

@media (min-width: 1200px) {
  .page-about .about-hero__frame {
    padding: 62px 56px 46px;
  }

  .page-about .about-hero h1 {
    max-width: 24ch;
  }

  .page-about .about-tl__layout {
    grid-template-columns: minmax(0, 1fr) 360px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-tl__item::before,
  .page-about .about-tl__item::after,
  .page-about .about-tl__idx {
    transition: none;
  }
}