.page-about {
  --about-rail-w: 228px;
  --about-gap: clamp(60px, 9vw, 128px);
  --about-line: 2px;
}

/* ---------- 面包屑与首屏 ---------- */
.page-about .about-top {
  padding-top: calc(var(--header-h) + 22px);
}

.page-about .about-top .breadcrumb {
  margin: 0;
}

.page-about .about-hero {
  padding-top: clamp(26px, 4vw, 46px);
  padding-bottom: clamp(40px, 6vw, 72px);
}

.page-about .about-hero-grid {
  display: grid;
  gap: clamp(32px, 5vw, 58px);
}

.page-about .about-hero-text > .field-label {
  margin: 0;
  color: var(--cyan);
}

.page-about .about-hero h1 {
  margin: 14px 0 20px;
  color: var(--silver);
}

.page-about .about-hero h1 strong {
  color: var(--white);
  background: linear-gradient(transparent 63%, rgba(255, 106, 31, .3) 63%);
}

.page-about .about-hero .lede {
  margin: 0;
  max-width: 60ch;
}

.page-about .spec-list {
  margin: clamp(26px, 3.4vw, 40px) 0 0;
  padding: 0;
  border-top: var(--about-line) solid var(--edge);
}

.page-about .spec-row {
  display: grid;
  gap: 4px 20px;
  padding: 13px 0;
  border-bottom: 1px solid var(--edge);
}

.page-about .spec-row dt {
  margin: 0;
  color: var(--cyan);
}

.page-about .spec-row dd {
  margin: 0;
  font-size: 15px;
  line-height: 1.65;
  color: var(--silver);
}

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

.page-about .about-hero-figure .figure-frame {
  aspect-ratio: 3 / 4;
  border: var(--about-line) solid var(--edge);
  background: var(--ink-2);
  box-shadow: var(--shadow-hard);
  overflow: hidden;
}

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

.page-about .figure-cap {
  margin-top: 12px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .1em;
  color: var(--graphite);
}

/* ---------- 主从骨架 ---------- */
.page-about .about-shell {
  display: flex;
  flex-direction: column;
  gap: clamp(44px, 7vw, 76px);
  padding-bottom: clamp(64px, 9vw, 128px);
}

.page-about .about-rail {
  order: -1;
  border: var(--about-line) solid var(--edge);
  background: var(--ink-2);
  padding: 16px 18px 18px;
}

.page-about .about-rail .section-index-title {
  margin: 0 0 12px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--graphite);
}

.page-about .about-rail nav {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.page-about .about-rail .index-link {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  padding: 7px 10px;
  border: 1px solid var(--edge);
  font-size: 13px;
  color: var(--silver);
  text-decoration: none;
  transition: border-color var(--dur) var(--ease), color var(--dur) var(--ease), background-color var(--dur) var(--ease);
}

.page-about .about-rail .index-link .num {
  font-size: 11px;
  color: var(--graphite);
  transition: color var(--dur) var(--ease);
}

.page-about .about-rail .index-link:hover {
  border-color: var(--cyan);
  color: var(--white);
}

.page-about .about-rail .index-link.is-current {
  border-color: var(--orange);
  background: rgba(255, 106, 31, .08);
  color: var(--white);
}

.page-about .about-rail .index-link.is-current .num {
  color: var(--orange);
}

.page-about .about-top-link {
  display: inline-flex;
  margin-top: 16px;
  padding-bottom: 2px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .12em;
  color: var(--orange);
  text-decoration: none;
  border-bottom: 1px solid var(--orange);
}

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

.page-about .about-sec {
  padding: 0;
}

.page-about .about-sec + .about-sec {
  margin-top: var(--about-gap);
}

/* ---------- 章节头 ---------- */
.page-about .about-sec-head {
  display: grid;
  gap: 10px;
  margin-bottom: clamp(26px, 3.6vw, 44px);
  padding-bottom: 18px;
  border-bottom: var(--about-line) solid var(--edge);
}

.page-about .about-sec-kicker {
  display: flex;
  align-items: center;
  gap: 12px;
  margin: 0;
}

.page-about .about-sec-kicker .field-label {
  margin: 0;
  color: var(--cyan);
}

.page-about .about-sec-head .h-lg {
  margin: 0;
}

.page-about .about-sec-head .meta-note {
  margin: 0;
  max-width: 66ch;
}

.page-about .about-sec-head .btn-line {
  color: var(--orange);
}

/* ---------- 沿革时间轴 ---------- */
.page-about .stage-list {
  list-style: none;
  margin: 0;
  padding: 0 0 0 clamp(20px, 3vw, 36px);
  border-left: var(--about-line) solid var(--edge);
}

.page-about .stage {
  position: relative;
}

.page-about .stage::before {
  content: "";
  position: absolute;
  left: calc(-1 * clamp(20px, 3vw, 36px) - 7px);
  top: 26px;
  width: 12px;
  height: 12px;
  background: var(--ink);
  border: var(--about-line) solid var(--edge);
  transition: background-color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .stage[data-live]::before {
  background: var(--orange);
  border-color: var(--orange);
}

.page-about .stage-details {
  border-bottom: 1px solid var(--edge);
}

.page-about .stage-summary {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 6px 14px;
  padding: 17px 0;
  cursor: pointer;
  list-style: none;
}

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

.page-about .stage-summary:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 3px;
}

.page-about .stage-no {
  font-size: 15px;
  color: var(--cyan);
}

.page-about .stage[data-live] .stage-no {
  color: var(--orange);
}

.page-about .stage-name {
  font-family: var(--font-display);
  font-size: clamp(1.15rem, 2.4vw, 1.5rem);
  font-weight: 700;
  letter-spacing: .01em;
  color: var(--white);
}

.page-about .stage-cap {
  flex: 1 1 200px;
  font-size: 13.5px;
  line-height: 1.6;
  color: var(--graphite);
}

.page-about .stage-mark {
  position: relative;
  flex: 0 0 auto;
  align-self: center;
  width: 14px;
  height: 14px;
  margin-left: auto;
}

.page-about .stage-mark::before,
.page-about .stage-mark::after {
  content: "";
  position: absolute;
  background: var(--cyan);
}

.page-about .stage-mark::before {
  left: 0;
  top: 6px;
  width: 14px;
  height: 2px;
}

.page-about .stage-mark::after {
  left: 6px;
  top: 0;
  width: 2px;
  height: 14px;
  transition: transform var(--dur) var(--ease);
}

.page-about .stage-details[open] .stage-mark::after {
  transform: scaleY(0);
}

.page-about .stage-body {
  max-width: 66ch;
  padding: 0 0 20px;
}

.page-about .stage-body p {
  margin: 0 0 10px;
  font-size: 15px;
  line-height: 1.72;
  color: var(--silver);
}

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

/* ---------- 业务线错落卡 ---------- */
.page-about .line-grid {
  display: grid;
  gap: clamp(20px, 2.6vw, 32px);
}

.page-about .line-card {
  border: var(--about-line) solid var(--edge);
  background: var(--ink-2);
  padding: clamp(20px, 2.6vw, 30px);
  transition: border-color var(--dur) var(--ease), box-shadow var(--dur) var(--ease);
}

.page-about .line-card--alt {
  background: var(--ink);
}

.page-about .line-head {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding-bottom: 14px;
  border-bottom: var(--about-line) solid var(--edge);
}

.page-about .line-no {
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--orange);
}

.page-about .line-head .h-md {
  flex: 1 1 auto;
  margin: 0;
}

.page-about .line-cols {
  display: grid;
  gap: 20px;
  margin-top: 18px;
}

.page-about .line-col .field-label {
  margin: 0;
  color: var(--cyan);
}

.page-about .line-col--no .field-label {
  color: var(--graphite);
}

.page-about .line-col ul {
  display: grid;
  gap: 8px;
  margin: 10px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .line-col li {
  position: relative;
  padding-left: 17px;
  font-size: 14.5px;
  line-height: 1.65;
  color: var(--silver);
}

.page-about .line-col li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .66em;
  width: 9px;
  height: 2px;
  background: var(--cyan);
}

.page-about .line-col--no li::before {
  background: var(--graphite);
}

/* ---------- 同步机制 ---------- */
.page-about .sync-figure {
  margin: 0 0 clamp(28px, 3.6vw, 44px);
}

.page-about .sync-figure .figure-frame {
  aspect-ratio: 16 / 7;
  border: var(--about-line) solid var(--edge);
  background:
    linear-gradient(var(--edge) 1px, transparent 1px) 0 0 / 100% 32px,
    linear-gradient(90deg, var(--edge) 1px, transparent 1px) 0 0 / 32px 100%,
    var(--ink-2);
  overflow: hidden;
}

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

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

.page-about .flow-step {
  padding: 18px 0;
  border-top: var(--about-line) solid var(--edge);
}

.page-about .flow-no {
  display: block;
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--cyan);
}

.page-about .flow-title {
  margin: 8px 0 8px;
  font-family: var(--font-display);
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--white);
}

.page-about .flow-text {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.68;
  color: var(--silver);
}

.page-about .sync-conflict {
  margin-top: clamp(24px, 3vw, 36px);
  padding: 18px 20px;
  border-left: 6px solid var(--amber);
  background: rgba(217, 138, 31, .07);
}

.page-about .sync-conflict .field-label {
  margin: 0 0 8px;
  color: var(--amber);
}

.page-about .sync-conflict p:last-child {
  margin: 0;
  max-width: 68ch;
  font-size: 14.5px;
  line-height: 1.7;
  color: var(--silver);
}

/* ---------- 资质归档表 ---------- */
.page-about .ledger-wrap {
  border: var(--about-line) solid var(--edge);
  background: var(--ink-2);
  overflow-x: auto;
}

.page-about .ledger {
  width: 100%;
  min-width: 620px;
  border-collapse: collapse;
  font-size: 14.5px;
}

.page-about .ledger th,
.page-about .ledger td {
  padding: 14px 16px;
  text-align: left;
  vertical-align: top;
  border-bottom: 1px solid var(--edge);
  border-right: 1px solid var(--edge);
  line-height: 1.6;
}

.page-about .ledger thead th {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--graphite);
  background: var(--ink);
}

.page-about .ledger tbody th {
  font-weight: 700;
  color: var(--white);
  white-space: nowrap;
}

.page-about .ledger td {
  color: var(--silver);
}

.page-about .ledger tbody tr:last-child th,
.page-about .ledger tbody tr:last-child td {
  border-bottom: 0;
}

.page-about .ledger tbody tr {
  transition: background-color var(--dur) var(--ease), box-shadow var(--dur) var(--ease);
}

.page-about .ledger tbody tr:hover {
  background: rgba(34, 217, 206, .07);
  box-shadow: inset 4px 0 0 var(--orange);
}

.page-about .note-foot {
  max-width: 70ch;
  margin: clamp(18px, 2.4vw, 26px) 0 0;
  font-size: 13px;
  line-height: 1.7;
  color: var(--graphite);
}

/* ---------- 协作分工 ---------- */
.page-about .team-grid {
  display: grid;
  gap: clamp(24px, 3.4vw, 40px);
}

.page-about .team-roles {
  display: grid;
  gap: 0;
  border-top: var(--about-line) solid var(--edge);
}

.page-about .role {
  padding: 18px 0;
  border-bottom: 1px solid var(--edge);
}

.page-about .role-no {
  display: block;
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--orange);
}

.page-about .role .h-md {
  margin: 6px 0 8px;
}

.page-about .role p {
  margin: 0;
  max-width: 60ch;
  font-size: 14.5px;
  line-height: 1.7;
  color: var(--silver);
}

.page-about .team-figure {
  margin: 0;
  align-self: start;
}

.page-about .team-figure .figure-frame {
  aspect-ratio: 1 / 1;
  border: var(--about-line) solid var(--edge);
  background: var(--ink-2);
  box-shadow: var(--shadow-hard);
  overflow: hidden;
}

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

/* ---------- 责任边界 ---------- */
.page-about .about-limits {
  padding: clamp(24px, 3.4vw, 40px) 0 0;
  border-top: var(--about-line) solid var(--edge);
}

.page-about .about-limits .field-label {
  margin: 0 0 10px;
  color: var(--orange);
}

.page-about .about-limits .h-lg {
  margin: 0 0 20px;
}

.page-about .limits-note {
  max-width: 64ch;
}

.page-about .limits-note p {
  margin: 0 0 14px;
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--silver);
}

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

.page-about .limits-links {
  color: var(--graphite);
}

.page-about .limits-links .btn-line {
  margin: 0 4px;
  color: var(--cyan);
}

/* ---------- 响应式 ---------- */
@media (min-width: 620px) {
  .page-about .spec-row {
    grid-template-columns: 132px minmax(0, 1fr);
    align-items: baseline;
  }

  .page-about .line-cols {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    column-gap: 26px;
  }

  .page-about .about-rail nav {
    gap: 8px 10px;
  }
}

@media (min-width: 900px) {
  .page-about .about-hero-grid {
    grid-template-columns: minmax(0, 1.04fr) minmax(0, 0.66fr);
    align-items: start;
  }

  .page-about .line-grid {
    grid-template-columns: repeat(12, minmax(0, 1fr));
  }

  .page-about .line-card:nth-child(1) {
    grid-column: 1 / span 7;
  }

  .page-about .line-card:nth-child(2) {
    grid-column: 5 / span 8;
  }

  .page-about .line-card:nth-child(3) {
    grid-column: 2 / span 8;
  }

  .page-about .flow {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    border-top: var(--about-line) solid var(--edge);
  }

  .page-about .flow-step {
    padding: 20px 22px 24px 0;
    border-top: 0;
    border-bottom: 0;
  }

  .page-about .flow-step + .flow-step {
    padding-left: 22px;
    border-left: 1px solid var(--edge);
  }

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

@media (min-width: 1024px) {
  .page-about .about-shell {
    display: grid;
    grid-template-columns: minmax(0, 1fr) var(--about-rail-w);
    column-gap: clamp(36px, 4vw, 68px);
    align-items: start;
  }

  .page-about .about-body {
    grid-area: 1 / 1;
  }

  .page-about .about-rail {
    order: 0;
    grid-area: 1 / 2;
    position: sticky;
    top: calc(var(--header-h) + 26px);
  }

  .page-about .about-rail nav {
    flex-direction: column;
    gap: 0;
  }

  .page-about .about-rail .index-link {
    width: 100%;
    padding: 10px 2px;
    border: 0;
    border-bottom: 1px solid var(--edge);
  }

  .page-about .about-rail .index-link:last-child {
    border-bottom: 0;
  }

  .page-about .about-rail .index-link.is-current {
    background: transparent;
    box-shadow: inset 3px 0 0 var(--orange);
    padding-left: 10px;
  }

  .page-about .about-top-link {
    margin-top: 18px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .stage-mark::after,
  .page-about .line-card,
  .page-about .ledger tbody tr,
  .page-about .about-rail .index-link {
    transition: none;
  }
}