.page-about {
  --about-rail: 96px;
  --about-pad: 32px;
  background: var(--z9-ink);
  color: var(--z9-paper);
  font-family: var(--z9-font-body);
  padding: 0 var(--z9-gutter) 96px;
  max-width: var(--z9-wrap);
  margin: 0 auto;
  box-sizing: border-box;
}

.page-about *,
.page-about *::before,
.page-about *::after {
  box-sizing: border-box;
}

/* ── 面包屑 ───────────────────────────── */
.page-about .about-crumb {
  padding-top: 28px;
  margin-bottom: 36px;
}

/* ── 首屏 ─────────────────────────────── */
.page-about .about-hero {
  padding-bottom: 64px;
  border-bottom: 1px solid var(--z9-line);
}

.page-about .about-hero__eyebrow {
  margin: 0 0 20px;
}

.page-about .about-hero__title {
  margin: 0 0 26px;
  max-width: 14em;
}

.page-about .about-hero__lede {
  margin: 0 0 44px;
  max-width: 34em;
}

.page-about .about-hero__facts {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 20px 28px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-hero__fact {
  margin: 0;
  padding-left: 16px;
  border-left: 1px solid var(--z9-line);
}

.page-about .about-hero__fact dt {
  margin: 0 0 6px;
  font-family: var(--z9-font-mono);
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--z9-mist);
}

.page-about .about-hero__fact dd {
  margin: 0;
  display: flex;
  align-items: baseline;
  gap: 6px;
}

.page-about .about-hero__num {
  font-family: var(--z9-font-mono);
  font-size: 30px;
  font-weight: 600;
  line-height: 1;
  color: var(--z9-cyan);
  font-variant-numeric: tabular-nums;
}

.page-about .about-hero__unit {
  font-size: 14px;
  color: var(--z9-mist);
}

/* ── 区块骨架 ─────────────────────────── */
.page-about .about-block {
  display: grid;
  grid-template-columns: 1fr;
  gap: 20px;
  padding: 64px 0 0;
  margin-top: 64px;
  border-top: 1px solid var(--z9-line);
}

.page-about .about-block__rail {
  display: none;
}

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

.page-about .about-block__body > .z9-h2 {
  margin: 0 0 22px;
  max-width: 18em;
}

.page-about .about-block__tail {
  margin-top: 32px;
}

.page-about .about-inline-link {
  color: var(--z9-cyan);
  text-decoration: none;
  border-bottom: 1px solid var(--z9-line);
  transition: border-color 200ms var(--z9-ease);
}

.page-about .about-inline-link:hover,
.page-about .about-inline-link:focus-visible {
  border-bottom-color: var(--z9-cyan);
}

/* ── 数据产品清单 ─────────────────────── */
.page-about .about-products {
  list-style: none;
  margin: 40px 0 0;
  padding: 0;
  border-top: 1px solid var(--z9-line);
}

.page-about .about-products li {
  display: grid;
  grid-template-columns: 46px minmax(0, 1fr);
  gap: 6px 14px;
  padding: 20px 0;
  border-bottom: 1px solid var(--z9-line);
}

.page-about .about-products__no {
  grid-column: 1;
  grid-row: 1 / span 2;
  font-family: var(--z9-font-mono);
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--z9-brick);
}

.page-about .about-products__name {
  grid-column: 2;
  grid-row: 1;
  font-size: 17px;
  font-weight: 700;
  color: var(--z9-paper);
}

.page-about .about-products__desc {
  grid-column: 2;
  grid-row: 2;
  font-size: 15px;
  line-height: 1.75;
  color: var(--z9-mist);
}

/* ── 团队四组 ─────────────────────────── */
.page-about .about-roles {
  display: grid;
  grid-template-columns: 1fr;
  margin-top: 40px;
  border-top: 1px solid var(--z9-line);
}

.page-about .about-role {
  padding: 28px 0;
  border-bottom: 1px solid var(--z9-line);
}

.page-about .about-role__idx {
  margin: 0 0 10px;
  font-family: var(--z9-font-mono);
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--z9-orange);
}

.page-about .about-role__title {
  margin: 0 0 10px;
}

.page-about .about-role__text {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--z9-mist);
}

/* ── 图片 ─────────────────────────────── */
.page-about .about-figure {
  margin: 44px 0 0;
}

.page-about .about-figure img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  border: 1px solid var(--z9-line);
  background: var(--z9-brown);
}

.page-about .about-figure--team img {
  aspect-ratio: 4 / 3;
}

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

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

/* ── 履历库 ───────────────────────────── */
.page-about .about-library {
  margin-top: 40px;
}

.page-about .about-library__filters {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 28px;
}

.page-about .about-library__list {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--z9-line);
}

.page-about .about-library__item {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 22px 0;
  border-bottom: 1px solid var(--z9-line);
}

.page-about .about-library__key {
  margin: 0;
  font-family: var(--z9-font-mono);
  font-size: 13px;
  letter-spacing: .12em;
  color: var(--z9-orange);
}

.page-about .about-library__val {
  margin: 0;
  max-width: 42em;
  font-size: 15.5px;
  line-height: 1.8;
  color: var(--z9-paper);
}

.page-about [data-filtered="off"] {
  display: none;
}

/* ── 四步流程 ─────────────────────────── */
.page-about .about-steps {
  list-style: none;
  margin: 40px 0 0;
  padding: 0;
}

.page-about .about-steps__item {
  display: grid;
  grid-template-columns: 46px minmax(0, 1fr);
  gap: 6px 18px;
  padding: 26px 0;
  border-top: 1px solid var(--z9-line);
}

.page-about .about-steps__item:last-child {
  border-bottom: 1px solid var(--z9-line);
}

.page-about .about-steps__no {
  grid-column: 1;
  grid-row: 1 / span 2;
  font-family: var(--z9-font-mono);
  font-size: 26px;
  font-weight: 600;
  line-height: 1;
  color: var(--z9-cyan);
  font-variant-numeric: tabular-nums;
}

.page-about .about-steps__title {
  grid-column: 2;
  grid-row: 1;
  margin: 0;
}

.page-about .about-steps__text {
  grid-column: 2;
  grid-row: 2;
  margin: 6px 0 0;
  max-width: 40em;
  font-size: 15.5px;
  line-height: 1.8;
  color: var(--z9-mist);
}

/* ── 发展时间线 ───────────────────────── */
.page-about .about-timeline {
  list-style: none;
  margin: 48px 0 0;
  padding: 0 0 0 26px;
  border-left: 1px solid var(--z9-line);
}

.page-about .about-timeline__item {
  position: relative;
  padding-bottom: 38px;
}

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

.page-about .about-timeline__item::before {
  content: "";
  position: absolute;
  left: -32px;
  top: 9px;
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: var(--z9-mist);
  box-shadow: 0 0 0 4px var(--z9-ink);
}

.page-about .about-timeline__item:nth-child(1)::before {
  background: var(--z9-mist);
}

.page-about .about-timeline__item:nth-child(2)::before {
  background: var(--z9-heat-1);
}

.page-about .about-timeline__item:nth-child(3)::before {
  background: var(--z9-heat-2);
}

.page-about .about-timeline__item:nth-child(4)::before {
  background: var(--z9-cyan);
}

.page-about .about-timeline__item:nth-child(5)::before {
  background: var(--z9-cyan);
  box-shadow: 0 0 0 4px var(--z9-ink), 0 0 12px rgba(59, 240, 200, .5);
}

.page-about .about-timeline__title {
  margin: 0 0 8px;
}

.page-about .about-timeline__title a {
  color: var(--z9-paper);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color 200ms var(--z9-ease), color 200ms var(--z9-ease);
}

.page-about .about-timeline__title a:hover,
.page-about .about-timeline__title a:focus-visible {
  color: var(--z9-cyan);
  border-bottom-color: var(--z9-cyan);
}

.page-about .about-timeline__text {
  margin: 0;
  max-width: 42em;
  font-size: 15.5px;
  line-height: 1.8;
  color: var(--z9-mist);
}

/* ── 合作与服务 ───────────────────────── */
.page-about .about-partners {
  list-style: none;
  margin: 40px 0 0;
  padding: 1px;
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  background: var(--z9-line);
  border: 1px solid var(--z9-line);
}

.page-about .about-partners__item {
  background: var(--z9-ink);
  padding: 26px 22px;
}

.page-about .about-partners__title {
  margin: 0 0 10px;
  color: var(--z9-paper);
}

.page-about .about-partners__text {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--z9-mist);
}

/* ── 结尾引导 ─────────────────────────── */
.page-about .about-cta {
  margin-top: 80px;
  padding: 40px 24px;
  border: 1px solid var(--z9-line);
  background:
    linear-gradient(158deg, rgba(59, 240, 200, .07) 0%, rgba(255, 106, 43, .05) 46%, rgba(10, 28, 23, 0) 78%),
    var(--z9-ink);
}

.page-about .about-cta__title {
  margin: 0 0 16px;
  max-width: 20em;
}

.page-about .about-cta__text {
  margin: 0;
  max-width: 40em;
}

.page-about .about-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin: 28px 0 0;
}

/* ── 平板 ─────────────────────────────── */
@media (min-width: 720px) {
  .page-about {
    --about-pad: 44px;
  }

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

  .page-about .about-role {
    padding: 32px 26px;
  }

  .page-about .about-role:nth-child(odd) {
    padding-left: 0;
  }

  .page-about .about-role:nth-child(even) {
    border-left: 1px solid var(--z9-line);
  }

  .page-about .about-role:nth-last-child(-n+2) {
    border-bottom: 1px solid var(--z9-line);
  }

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

  .page-about .about-products li {
    grid-template-columns: 56px 190px minmax(0, 1fr);
    align-items: baseline;
  }

  .page-about .about-products__no {
    grid-row: 1;
  }

  .page-about .about-products__name {
    grid-column: 2;
  }

  .page-about .about-products__desc {
    grid-column: 3;
    grid-row: 1;
  }

  .page-about .about-steps__item {
    grid-template-columns: 68px minmax(0, 1fr) 52%;
    align-items: start;
  }

  .page-about .about-steps__no {
    grid-row: 1;
    font-size: 30px;
  }

  .page-about .about-steps__title {
    grid-column: 2;
  }

  .page-about .about-steps__text {
    grid-column: 3;
    grid-row: 1;
    margin-top: 0;
  }

  .page-about .about-library__item {
    display: grid;
    grid-template-columns: 170px minmax(0, 1fr);
    gap: 4px 24px;
    align-items: baseline;
  }

  .page-about .about-library__val {
    max-width: none;
  }
}

/* ── 桌面 ─────────────────────────────── */
@media (min-width: 900px) {
  .page-about {
    padding-bottom: 120px;
  }

  .page-about .about-block {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: 44px;
    padding-top: 88px;
    margin-top: 88px;
    align-items: start;
  }

  .page-about .about-block__rail {
    display: block;
    position: sticky;
    top: calc(var(--z9-notice-h) + 40px);
    writing-mode: vertical-rl;
    text-orientation: mixed;
    padding-left: 14px;
    border-left: 1px solid var(--z9-line);
    font-family: var(--z9-font-mono);
    font-size: 12px;
    letter-spacing: .2em;
    color: var(--z9-mist);
    height: max-content;
  }

  .page-about .about-block__rail span + span {
    display: inline-block;
    margin-top: 12px;
    color: var(--z9-orange);
  }

  .page-about .about-hero__title {
    max-width: 12em;
  }

  .page-about .about-cta {
    padding: 56px var(--about-pad);
  }
}

/* ── 宽屏 ─────────────────────────────── */
@media (min-width: 1080px) {
  .page-about .about-roles {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .about-role {
    padding: 36px 22px;
    border-left: 1px solid var(--z9-line);
  }

  .page-about .about-role:nth-child(odd) {
    padding-left: 22px;
  }

  .page-about .about-role:nth-child(4n+1) {
    padding-left: 0;
    border-left: 0;
  }

  .page-about .about-role:nth-last-child(-n+2) {
    border-bottom: 1px solid var(--z9-line);
  }
}

/* ── 减少动效 ─────────────────────────── */
@media (prefers-reduced-motion: reduce) {
  .page-about * {
    transition: none !important;
    animation: none !important;
  }
}