.page-about {
  background: var(--paper);
  color: var(--ink);
  overflow-x: hidden;
}

/* ============ 面包屑 ============ */
.page-about .breadcrumb {
  padding-block: 28px 4px;
  font-size: 13px;
  color: var(--graphite);
  letter-spacing: .02em;
}
.page-about .breadcrumb a {
  color: var(--graphite);
  text-decoration: none;
  border-bottom: 1.5px solid transparent;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}
.page-about .breadcrumb a:hover {
  color: var(--ink);
  border-bottom-color: var(--gold);
}
.page-about .breadcrumb-sep {
  margin-inline: 8px;
  color: var(--archive);
}

/* ============ 首屏 ============ */
.page-about .about-hero {
  padding-block: 32px 56px;
}
.page-about .about-hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 32px;
  align-items: center;
}
.page-about .about-hero-copy .lede {
  margin-top: 20px;
  max-width: 46ch;
}
.page-about .about-hero-frame {
  aspect-ratio: 8 / 3;
}
.page-about .about-hero-frame img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.page-about .about-hero-meta {
  margin: 48px 0 0;
  padding: 24px 0 0;
  border-top: var(--bw-strong) solid var(--ink);
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 22px 24px;
}
.page-about .about-hero-meta dt {
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--graphite);
  text-transform: uppercase;
}
.page-about .about-hero-meta dd {
  margin: 8px 0 0;
  font-size: 28px;
  font-weight: 300;
  line-height: 1.05;
  color: var(--ink);
  letter-spacing: -0.01em;
}

/* ============ 通用 section 强化 ============ */
.page-about .about-scope,
.page-about .about-timeline,
.page-about .about-revision,
.page-about .about-quality,
.page-about .about-network,
.page-about .about-team {
  border-top: var(--bw) solid var(--ink);
}
.page-about .section-index {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--gold);
}

/* ============ 业务范围 ============ */
.page-about .scope-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 32px;
  margin-top: 36px;
}
.page-about .scope-story p {
  margin: 0 0 16px;
  font-size: 16px;
  line-height: 1.85;
  color: var(--graphite);
}
.page-about .scope-link {
  color: var(--ink);
  text-decoration: none;
  border-bottom: 2px solid var(--gold);
  padding-bottom: 1px;
  transition: background var(--dur) var(--ease);
}
.page-about .scope-link:hover {
  background: var(--gold-lite);
}

.page-about .series-list {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: var(--bw-strong) solid var(--ink);
}
.page-about .series-list li {
  display: grid;
  grid-template-columns: 64px minmax(0, 1fr);
  grid-template-rows: auto auto;
  column-gap: 18px;
  padding: 18px 14px;
  border-bottom: var(--bw) solid var(--ink);
  align-items: baseline;
  transition: background var(--dur) var(--ease), transform var(--dur) var(--ease);
}
.page-about .series-list li:hover {
  background: var(--grid);
  transform: translateX(4px);
}
.page-about .series-code {
  grid-row: 1 / span 2;
  align-self: center;
  font-size: 30px;
  font-weight: 400;
  color: var(--ink);
  border-right: var(--bw) solid var(--archive);
  padding-right: 14px;
  text-align: center;
  line-height: 1;
}
.page-about .series-name {
  font-size: 17px;
  font-weight: 500;
  color: var(--ink);
}
.page-about .series-use {
  margin-top: 4px;
  font-size: 13px;
  line-height: 1.65;
  color: var(--graphite);
}

/* ============ 时间轴 ============ */
.page-about .timeline {
  list-style: none;
  margin: 44px 0 0;
  padding: 0;
}
.page-about .tl-node {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 10px;
  padding: 24px 8px 24px 38px;
  border-bottom: var(--bw) solid var(--archive);
  transition: background var(--dur) var(--ease);
}
.page-about .tl-node::before {
  content: "";
  position: absolute;
  left: 12px;
  top: 0;
  bottom: 0;
  width: 2px;
  background: var(--ink);
}
.page-about .tl-node::after {
  content: "";
  position: absolute;
  left: 5px;
  top: 30px;
  width: 16px;
  height: 16px;
  background: var(--paper);
  border: var(--bw-strong) solid var(--ink);
  transition: background var(--dur) var(--ease), transform var(--dur) var(--ease);
}
.page-about .tl-node:hover {
  background: var(--grid);
}
.page-about .tl-node:hover::after {
  background: var(--gold);
  transform: translateX(3px);
}
.page-about .tl-year {
  font-size: 22px;
  font-weight: 400;
  color: var(--gold);
  letter-spacing: .02em;
  line-height: 1;
}
.page-about .tl-content h3 {
  margin: 0;
  font-size: 19px;
  font-weight: 500;
  color: var(--ink);
  font-family: var(--font-head);
}
.page-about .tl-content p {
  margin: 8px 0 0;
  font-size: 15px;
  line-height: 1.75;
  color: var(--graphite);
  max-width: 62ch;
}
.page-about .tl-note {
  max-height: 0;
  overflow: hidden;
  opacity: 0;
  margin: 0 !important;
  font-size: 13px !important;
  color: var(--gold) !important;
  transition: max-height var(--dur) var(--ease), opacity var(--dur) var(--ease), margin var(--dur) var(--ease);
}
.page-about .tl-node:hover .tl-note,
.page-about .tl-node:focus-within .tl-note {
  max-height: 80px;
  opacity: 1;
  margin-top: 10px !important;
}
.page-about .tl-arch {
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--archive);
}
.page-about .tl-node--current {
  background: linear-gradient(90deg, rgba(227, 199, 126, .28), rgba(247, 244, 237, 0) 68%);
}
.page-about .tl-node--current::after {
  background: var(--ink);
}
.page-about .tl-node--current .tl-year {
  color: var(--ink);
}
.page-about .tl-node--current .tl-arch {
  color: var(--gold);
}

/* ============ 修订对照 ============ */
.page-about .revision-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 32px;
  margin-top: 36px;
}
.page-about .about-revision-frame {
  aspect-ratio: 4 / 3;
}
.page-about .about-revision-frame img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}
.page-about .revision-lead {
  margin: 0 0 20px;
  font-size: 15px;
  line-height: 1.8;
  color: var(--graphite);
}
.page-about .revision-detail {
  display: grid;
  gap: 12px;
  align-content: start;
}
.page-about .rev-item {
  border: var(--bw-strong) solid var(--ink);
  background: var(--paper);
  transition: box-shadow var(--dur) var(--ease), transform var(--dur) var(--ease);
}
.page-about .rev-item:hover {
  box-shadow: var(--shadow-sm);
  transform: translate(-2px, -2px);
}
.page-about .rev-item[open] {
  border-left-width: 6px;
  border-left-color: var(--revise);
}
.page-about .rev-summary {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 16px 18px;
  cursor: pointer;
  list-style: none;
  font-size: 16px;
}
.page-about .rev-summary::-webkit-details-marker {
  display: none;
}
.page-about .rev-idx {
  flex: 0 0 34px;
  text-align: center;
  border-right: var(--bw) solid var(--archive);
  padding-right: 10px;
  color: var(--revise);
  font-weight: 600;
}
.page-about .rev-title {
  flex: 1 1 auto;
  font-weight: 500;
  color: var(--ink);
}
.page-about .rev-hint {
  flex: 0 0 auto;
  font-size: 12px;
  color: var(--slate);
}
.page-about .rev-summary::after {
  content: "+";
  flex: 0 0 18px;
  text-align: center;
  font-family: var(--font-mono);
  font-size: 18px;
  line-height: 1;
  color: var(--gold);
}
.page-about .rev-item[open] .rev-summary::after {
  content: "−";
}
.page-about .rev-body {
  padding: 0 18px 18px 18px;
  border-top: var(--bw) dashed var(--archive);
  margin-top: 0;
}
.page-about .rev-body p {
  margin: 14px 0 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--graphite);
}

/* ============ 质量与出厂 ============ */
.page-about .quality-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 24px;
  margin-top: 36px;
}
.page-about .q-list {
  list-style: none;
  margin: 0;
  padding: 0;
}
.page-about .q-list li {
  display: flex;
  align-items: baseline;
  gap: 16px;
  padding: 14px 0;
  border-bottom: var(--bw) solid var(--archive);
}
.page-about .q-list--cert li:first-child {
  border-top: var(--bw-strong) solid var(--ink);
}
.page-about .q-list--cert .q-key {
  flex: 0 0 116px;
  font-size: 13px;
  color: var(--celadon);
  letter-spacing: .04em;
}
.page-about .q-list--process {
  margin-top: 8px;
}
.page-about .q-list--process .q-num {
  flex: 0 0 92px;
  font-size: 30px;
  font-weight: 300;
  line-height: 1;
  color: var(--ink);
}
.page-about .q-val {
  font-size: 14px;
  line-height: 1.7;
  color: var(--graphite);
}
.page-about .about-quality-frame {
  aspect-ratio: 14 / 9;
}
.page-about .about-quality-frame img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

/* ============ 服务与交付 ============ */
.page-about .network-stats {
  list-style: none;
  margin: 36px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0;
  border-top: var(--bw-strong) solid var(--ink);
  border-left: var(--bw) solid var(--ink);
}
.page-about .network-stats li {
  padding: 22px 18px;
  border-right: var(--bw) solid var(--ink);
  border-bottom: var(--bw) solid var(--ink);
  background: var(--paper);
  transition: background var(--dur) var(--ease);
}
.page-about .network-stats li:hover {
  background: var(--celadon-lite);
}
.page-about .stat-num {
  display: block;
  font-size: 34px;
  font-weight: 300;
  line-height: 1;
  color: var(--ink);
}
.page-about .stat-label {
  display: block;
  margin-top: 10px;
  font-size: 12.5px;
  line-height: 1.6;
  color: var(--graphite);
}

.page-about .delivery-steps {
  list-style: none;
  margin: 32px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0;
}
.page-about .delivery-step {
  position: relative;
  padding: 24px 0 24px 0;
  border-bottom: var(--bw) solid var(--archive);
}
.page-about .delivery-step:first-child {
  border-top: var(--bw) solid var(--archive);
}
.page-about .step-idx {
  font-size: 12px;
  letter-spacing: .16em;
  color: var(--slate);
}
.page-about .delivery-step h3 {
  margin: 8px 0 0;
  font-family: var(--font-head);
  font-size: 20px;
  font-weight: 500;
  color: var(--ink);
}
.page-about .delivery-step p {
  margin: 8px 0 0;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--graphite);
  max-width: 34ch;
}

/* ============ 团队 ============ */
.page-about .team-roster {
  list-style: none;
  margin: 36px 0 0;
  padding: 0;
  border-top: var(--bw-strong) solid var(--ink);
}
.page-about .team-row {
  display: grid;
  grid-template-columns: 40px minmax(0, 1fr) auto;
  grid-template-areas:
    "num name count"
    "duty duty duty";
  gap: 10px 14px;
  align-items: baseline;
  padding: 24px 4px;
  border-bottom: var(--bw) solid var(--ink);
  transition: background var(--dur) var(--ease), padding-left var(--dur) var(--ease);
}
.page-about .team-row:hover {
  background: var(--grid);
  padding-left: 12px;
}
.page-about .team-num {
  grid-area: num;
  font-size: 13px;
  color: var(--gold);
  letter-spacing: .1em;
}
.page-about .team-name {
  grid-area: name;
  font-family: var(--font-head);
  font-size: 20px;
  font-weight: 500;
  color: var(--ink);
}
.page-about .team-count {
  grid-area: count;
  font-size: 14px;
  color: var(--ink);
}
.page-about .team-duty {
  grid-area: duty;
  margin: 4px 0 0;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--graphite);
  max-width: 68ch;
}

/* ============ 底部引导 ============ */
.page-about .about-cta {
  padding-bottom: 88px;
}
.page-about .about-cta-band {
  border: var(--bw-strong) solid var(--ink);
  border-left-width: 8px;
  border-left-color: var(--gold);
  background: var(--paper);
  box-shadow: var(--shadow);
  padding: clamp(26px, 4vw, 46px);
  display: grid;
  gap: 26px;
  align-items: center;
}
.page-about .about-cta-copy h2 {
  margin: 0;
  font-family: var(--font-head);
  font-size: clamp(22px, 3vw, 30px);
  font-weight: 400;
  line-height: 1.3;
  color: var(--ink);
}
.page-about .about-cta-copy p {
  margin: 12px 0 0;
  font-size: 15px;
  line-height: 1.75;
  color: var(--graphite);
  max-width: 52ch;
}
.page-about .about-cta-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
}

/* ============ 响应式 ============ */
@media (min-width: 640px) {
  .page-about .about-hero-meta {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
  .page-about .network-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
  .page-about .delivery-steps {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 0 28px;
  }
  .page-about .delivery-step:first-child {
    border-top: var(--bw) solid var(--archive);
  }
}

@media (min-width: 900px) {
  .page-about .about-hero-grid {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    gap: clamp(36px, 4vw, 68px);
  }
  .page-about .scope-grid {
    grid-template-columns: minmax(0, 4fr) minmax(0, 8fr);
    gap: clamp(32px, 5vw, 72px);
  }
  .page-about .revision-grid {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    gap: clamp(28px, 4vw, 56px);
  }
  .page-about .quality-grid {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    gap: clamp(28px, 4vw, 56px);
    align-items: start;
  }
  .page-about .about-cta-band {
    grid-template-columns: minmax(0, 1fr) auto;
    gap: 40px;
  }
  .page-about .about-cta-actions {
    flex-wrap: nowrap;
  }
}

@media (min-width: 1100px) {
  .page-about .tl-node {
    grid-template-columns: 116px minmax(0, 1fr) 70px;
    align-items: start;
    column-gap: 28px;
    padding: 26px 8px 26px 40px;
  }
  .page-about .tl-year {
    text-align: right;
    padding-right: 16px;
    border-right: var(--bw) solid var(--archive);
  }
  .page-about .tl-arch {
    text-align: right;
  }
  .page-about .tl-node::after {
    top: 32px;
  }
}

@media (max-width: 520px) {
  .page-about .rev-hint {
    display: none;
  }
  .page-about .series-code {
    font-size: 24px;
    padding-right: 10px;
  }
  .page-about .about-hero-meta dd {
    font-size: 24px;
  }
  .page-about .stat-num {
    font-size: 28px;
  }
}
<<<END>>>