.page-about {
  --about-rule: 1px solid var(--c-line);
  --about-panel-a: rgba(19, 26, 63, .96);
  --about-panel-b: rgba(27, 42, 107, .42);
  --about-panel-c: rgba(19, 26, 63, .58);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding: calc(var(--header-h) + 56px) 0 56px;
  background:
    radial-gradient(1100px 520px at 78% -12%, rgba(53, 230, 224, .16), transparent 62%),
    radial-gradient(760px 420px at 4% 14%, rgba(255, 63, 164, .12), transparent 66%),
    var(--c-bg);
  border-bottom: var(--about-rule);
}

.page-about .about-hero-band {
  position: absolute;
  top: 10%;
  right: -12%;
  width: 64%;
  height: 220px;
  transform: rotate(-12deg);
  background: linear-gradient(90deg, transparent, rgba(53, 230, 224, .14), rgba(255, 63, 164, .09), transparent);
  filter: blur(30px);
  pointer-events: none;
}

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

.page-about .about-hero-title {
  margin: 0 0 24px;
  color: var(--c-white);
  font-weight: 250;
  font-size: clamp(2.2rem, 7.4vw, 5rem);
  line-height: 1.08;
  letter-spacing: -.01em;
  text-shadow: 0 0 1px rgba(53, 230, 224, .85), 0 0 30px rgba(53, 230, 224, .22);
}

.page-about .about-hero-em {
  color: var(--c-cyan);
  text-shadow: 0 0 1px rgba(53, 230, 224, .9), 0 0 34px rgba(53, 230, 224, .35);
}

.page-about .about-hero-lead {
  max-width: 44ch;
  margin: 0 0 32px;
  color: var(--c-text);
  font-size: clamp(1rem, 2.4vw, 1.12rem);
  line-height: 1.8;
}

.page-about .about-hero-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 12px 32px;
  margin: 0 0 40px;
  padding: 20px 0 0;
  list-style: none;
  border-top: var(--about-rule);
  color: var(--c-muted);
  font-size: .82rem;
  letter-spacing: .04em;
}

.page-about .about-hero-meta .mono {
  margin-right: 8px;
  color: var(--c-cyan);
  font-size: 1rem;
  letter-spacing: .06em;
}

.page-about .about-crumbs {
  font-size: .78rem;
}

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

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

/* ---------- 时间线 ---------- */
.page-about .about-timeline-intro {
  display: grid;
  gap: 32px;
}

.page-about .about-timeline-copy .h2 {
  max-width: 20ch;
}

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

.page-about .about-track {
  position: relative;
  margin: 56px 0 0;
  padding: 0 0 0 28px;
  list-style: none;
  border-left: var(--about-rule);
}

.page-about .about-track-item {
  position: relative;
  border-bottom: var(--about-rule);
}

.page-about .about-track-item::before {
  content: "";
  position: absolute;
  left: calc(-28px - 5px);
  top: 30px;
  width: 9px;
  height: 9px;
  background: var(--c-bg);
  border: 1px solid var(--c-line);
  transform: rotate(45deg);
  transition: background .25s var(--ease), border-color .25s var(--ease), box-shadow .25s var(--ease);
}

.page-about .about-track-item.is-active::before {
  background: var(--c-cyan);
  border-color: var(--c-cyan);
  box-shadow: 0 0 14px rgba(53, 230, 224, .75);
}

.page-about .about-track-head {
  display: grid;
  grid-template-columns: 8.5ch minmax(0, 1fr) auto;
  align-items: baseline;
  gap: 10px 14px;
  width: 100%;
  padding: 24px 0;
  background: none;
  border: 0;
  text-align: left;
  cursor: pointer;
  color: inherit;
  font: inherit;
}

.page-about .about-track-head .step-index {
  color: var(--c-cyan);
  font-size: .78rem;
  letter-spacing: .12em;
}

.page-about .about-track-head .step-title {
  color: var(--c-white);
  font-size: clamp(1rem, 3vw, 1.32rem);
  font-weight: 400;
  line-height: 1.45;
  transition: color .2s var(--ease);
}

.page-about .about-track-head:hover .step-title,
.page-about .about-track-head[aria-expanded="true"] .step-title {
  color: var(--c-cyan);
}

.page-about .about-track-head .step-hint {
  color: var(--c-muted);
  font-size: .72rem;
  letter-spacing: .18em;
  text-transform: uppercase;
}

.page-about .about-track-body {
  max-width: 62ch;
  padding: 0 0 26px;
  color: var(--c-text);
  font-size: .95rem;
  line-height: 1.78;
}

.page-about .about-track-body p {
  margin: 0;
}

/* ---------- 三条主张 ---------- */
.page-about .about-values-head {
  max-width: 46ch;
}

.page-about .about-values-deck {
  display: grid;
  gap: var(--gap);
  margin-top: 40px;
}

.page-about .about-value-card {
  display: flex;
  flex-direction: column;
  gap: 14px;
  padding: 28px 24px 30px;
  border: 1px solid var(--c-line);
  background: linear-gradient(180deg, var(--about-panel-a), rgba(10, 15, 44, .9));
  transition: border-color .25s var(--ease), transform .25s var(--ease);
}

.page-about .about-value-card--b {
  background: linear-gradient(180deg, var(--about-panel-b), rgba(10, 15, 44, .9));
}

.page-about .about-value-card--c {
  background: linear-gradient(180deg, var(--about-panel-c), rgba(10, 15, 44, .9));
}

.page-about .about-value-card:hover {
  border-color: var(--c-cyan);
  transform: translateY(-4px);
}

.page-about .about-value-card .panel-index {
  color: var(--c-muted);
  font-size: .74rem;
  letter-spacing: .16em;
}

.page-about .about-value-card .panel-title {
  margin: 0;
  color: var(--c-white);
  font-size: clamp(1.15rem, 3.4vw, 1.42rem);
  font-weight: 400;
  line-height: 1.35;
}

.page-about .about-value-card .panel-body {
  margin: 0;
  color: var(--c-text);
  font-size: .94rem;
  line-height: 1.75;
}

.page-about .about-value-scene {
  margin: auto 0 0;
  padding-top: 16px;
  border-top: var(--about-rule);
  color: var(--c-muted);
  font-size: .85rem;
  line-height: 1.7;
}

/* ---------- 分类即秩序 ---------- */
.page-about .about-order {
  border-top: var(--about-rule);
}

.page-about .about-order-grid {
  display: grid;
  gap: 40px;
}

.page-about .about-order-text .prose {
  max-width: 54ch;
  margin: 0 0 18px;
  color: var(--c-text);
  font-size: .96rem;
  line-height: 1.78;
}

.page-about .about-order-facts {
  display: grid;
  gap: 12px;
  margin: 28px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-order-facts li {
  display: grid;
  grid-template-columns: 3.2ch minmax(0, 1fr);
  gap: 12px;
  padding: 12px 0;
  border-top: var(--about-rule);
  color: var(--c-text);
  font-size: .9rem;
  line-height: 1.7;
}

.page-about .about-order-facts .mono {
  color: var(--c-gold);
  font-size: .8rem;
  letter-spacing: .1em;
}

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

/* ---------- 团队 ---------- */
.page-about .about-team {
  background: linear-gradient(180deg, rgba(19, 26, 63, .55), transparent 70%);
}

.page-about .about-team-head {
  max-width: 42ch;
}

.page-about .about-team-list {
  margin: 40px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-team-row {
  position: relative;
  display: grid;
  grid-template-columns: 56px minmax(0, 1fr);
  gap: 16px;
  padding: 24px 0;
  border-top: var(--about-rule);
}

.page-about .about-team-row:last-child {
  border-bottom: var(--about-rule);
}

.page-about .about-team-count {
  color: var(--c-gold);
  font-size: 1.7rem;
  font-weight: 300;
  line-height: 1;
  letter-spacing: .04em;
}

.page-about .about-team-role {
  margin: 0 0 8px;
  color: var(--c-white);
  font-size: 1.02rem;
  font-weight: 400;
  letter-spacing: .02em;
}

.page-about .about-team-desc {
  margin: 0;
  max-width: 58ch;
  color: var(--c-text);
  font-size: .92rem;
  line-height: 1.75;
}

/* ---------- 合作生态 ---------- */
.page-about .about-partners-grid {
  display: grid;
  gap: 32px;
}

.page-about .about-partners-figure {
  margin: 0;
  border: 1px solid var(--c-line);
}

.page-about .about-partners-text .prose {
  max-width: 52ch;
  margin: 0 0 8px;
  color: var(--c-text);
  font-size: .96rem;
  line-height: 1.78;
}

.page-about .about-partner-points {
  display: grid;
  gap: 14px;
  margin: 26px 0 30px;
  padding: 0;
  list-style: none;
}

.page-about .about-partner-points li {
  position: relative;
  padding-left: 24px;
  color: var(--c-text);
  font-size: .92rem;
  line-height: 1.74;
}

.page-about .about-partner-points li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .72em;
  width: 13px;
  height: 1px;
  background: var(--c-cyan);
}

/* ---------- 回应 ---------- */
.page-about .about-response {
  border-top: var(--about-rule);
  background:
    radial-gradient(720px 320px at 82% 0%, rgba(53, 230, 224, .1), transparent 68%),
    var(--c-bg);
}

.page-about .about-response-inner .lead {
  max-width: 52ch;
}

.page-about .about-response-list {
  display: grid;
  gap: 1px;
  margin: 34px 0 0;
  padding: 1px;
  list-style: none;
  background: var(--c-line);
  border: 1px solid var(--c-line);
}

.page-about .about-response-item {
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 24px 22px;
  background: var(--c-bg);
}

.page-about .about-response-num {
  color: var(--c-cyan);
  font-size: clamp(1.15rem, 4vw, 1.5rem);
  font-weight: 300;
  letter-spacing: .04em;
}

.page-about .about-response-label {
  color: var(--c-muted);
  font-size: .84rem;
  line-height: 1.65;
}

.page-about .about-response-note {
  max-width: 62ch;
  margin: 32px 0 0;
  color: var(--c-text);
  font-size: .94rem;
  line-height: 1.78;
}

.page-about .about-response-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 30px;
}

/* ---------- 响应式 ---------- */
@media (min-width: 760px) {
  .page-about .about-hero {
    padding: calc(var(--header-h) + 72px) 0 72px;
  }

  .page-about .about-timeline-intro {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: 56px;
    align-items: center;
  }

  .page-about .about-values-deck {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    align-items: start;
  }

  .page-about .about-value-card--a {
    min-height: 330px;
  }

  .page-about .about-value-card--b {
    min-height: 268px;
  }

  .page-about .about-value-card--c {
    min-height: 300px;
  }

  .page-about .about-order-grid {
    grid-template-columns: minmax(0, 6fr) minmax(0, 5fr);
    gap: 64px;
    align-items: center;
  }

  .page-about .about-order-figure {
    order: -1;
  }

  .page-about .about-partners-grid {
    grid-template-columns: minmax(0, 6fr) minmax(0, 5fr);
    gap: 56px;
    align-items: center;
  }

  .page-about .about-team-row {
    grid-template-columns: 120px minmax(0, 1fr);
    gap: 40px;
    padding: 30px 0;
  }

  .page-about .about-team-count {
    font-size: 2.1rem;
  }

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

@media (min-width: 1100px) {
  .page-about .about-hero-title {
    font-size: clamp(3.4rem, 5.4vw, 5.4rem);
  }

  .page-about .about-values-deck {
    gap: 28px;
  }
}

@media (max-width: 520px) {
  .page-about .about-track {
    padding-left: 20px;
  }

  .page-about .about-track-item::before {
    left: calc(-20px - 5px);
  }

  .page-about .about-track-head {
    grid-template-columns: 7ch minmax(0, 1fr);
    grid-template-areas:
      "index hint"
      "title title";
    gap: 6px 12px;
  }

  .page-about .about-track-head .step-index { grid-area: index; }
  .page-about .about-track-head .step-title { grid-area: title; }
  .page-about .about-track-head .step-hint {
    grid-area: hint;
    justify-self: end;
  }

  .page-about .about-team-row {
    grid-template-columns: 44px minmax(0, 1fr);
    gap: 12px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-value-card,
  .page-about .about-track-item::before,
  .page-about .about-track-head .step-title {
    transition: none;
  }

  .page-about .about-value-card:hover {
    transform: none;
  }
}