.page-about {
  --about-pad: clamp(52px, 7vw, 96px);
  --about-sticky: 132px;
  color: var(--c-text);
  background: var(--c-bg);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding: 30px 0 clamp(44px, 6vw, 72px);
  border-bottom: 1px solid var(--c-line);
  overflow: hidden;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image: linear-gradient(to right, var(--c-line) 1px, transparent 1px);
  background-size: 96px 100%;
  opacity: .28;
  pointer-events: none;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  top: -140px;
  right: -120px;
  width: 420px;
  height: 420px;
  background: radial-gradient(circle, rgba(41, 231, 220, .16), transparent 68%);
  pointer-events: none;
}

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

.page-about .breadcrumb {
  margin-bottom: clamp(28px, 5vw, 52px);
  color: var(--c-mute);
}

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

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

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

.page-about .about-hero__kicker {
  color: var(--c-cyan);
  margin: 0 0 18px;
}

.page-about .about-hero__title {
  margin: 0;
  font-family: var(--font-cond);
  font-weight: 800;
  font-size: clamp(32px, 8.4vw, 84px);
  line-height: 1.02;
  letter-spacing: -.02em;
  max-width: 17em;
}

.page-about .about-hero__lede {
  margin-top: clamp(24px, 4vw, 40px);
  display: grid;
  gap: 14px;
  max-width: 36em;
}

.page-about .about-hero__lede p {
  margin: 0;
  font-size: 17px;
  line-height: 1.6;
  color: var(--c-dim);
}

.page-about .about-hero__lede p:first-child {
  color: var(--c-text);
}

.page-about .about-stats {
  margin: clamp(32px, 5vw, 52px) 0 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--c-line);
  border: 1px solid var(--c-line);
}

.page-about .about-stats__item {
  background: var(--c-panel);
  padding: 18px 16px 20px;
}

.page-about .about-stats dt {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--c-mute);
  margin-bottom: 10px;
}

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

.page-about .about-stats__num {
  font-size: clamp(28px, 5vw, 40px);
  font-weight: 600;
  color: var(--c-text);
  font-variant-numeric: tabular-nums;
}

.page-about .about-stats__unit {
  font-size: 13px;
  color: var(--c-dim);
}

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

.page-about .about-jump {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 12px 18px;
  border: 1px solid var(--c-line);
  border-radius: 2px;
  color: var(--c-text);
  text-decoration: none;
  font-size: 14px;
  transition: border-color var(--dur), color var(--dur), background var(--dur);
}

.page-about .about-jump:hover {
  border-color: var(--c-cyan);
  color: var(--c-cyan);
  background: rgba(41, 231, 220, .06);
}

.page-about .about-jump__arrow {
  font-family: var(--font-mono);
  color: var(--c-orange);
}

/* ---------- 通用区块 ---------- */
.page-about .about-block {
  padding: var(--about-pad) 0;
  border-bottom: 1px solid var(--c-line);
}

.page-about .about-block .shell {
  position: relative;
}

.page-about .about-lede {
  margin: 24px 0 0;
  max-width: 34em;
  font-size: 16px;
  line-height: 1.6;
  color: var(--c-dim);
}

.page-about .about-split {
  margin-top: 32px;
  display: grid;
  gap: 32px;
}

.page-about .about-split__text p {
  margin: 0 0 1.4em;
  font-size: 16px;
  line-height: 1.7;
  color: var(--c-dim);
  max-width: 34em;
}

.page-about .about-split__text p:first-child {
  color: var(--c-text);
}

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

.page-about .about-entries {
  display: grid;
  gap: 14px;
  align-content: start;
}

.page-about .about-entry {
  display: block;
  padding: 20px 18px 22px;
  text-decoration: none;
  color: inherit;
  border-radius: 2px;
}

.page-about .about-entry__idx {
  color: var(--c-orange);
}

.page-about .about-entry__title {
  margin: 10px 0 8px;
  font-family: var(--font-cond);
  font-weight: 800;
  font-size: 22px;
  letter-spacing: -.01em;
}

.page-about .about-entry .card__meta {
  margin: 0;
  font-size: 14px;
  line-height: 1.6;
  color: var(--c-dim);
}

/* ---------- 版本沿革 ---------- */
.page-about .about-block--timeline {
  background: linear-gradient(180deg, rgba(12, 20, 32, .8), var(--c-bg) 320px);
}

.page-about .about-figure {
  margin: 32px 0 0;
  border-radius: 2px;
}

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

.page-about .about-cap {
  margin-top: 12px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--c-mute);
}

.page-about .about-rail {
  margin-top: 36px;
  display: grid;
  gap: 28px;
}

.page-about .about-rail__side .label {
  color: var(--c-mute);
  margin: 0 0 12px;
}

.page-about .ver-axis {
  list-style: none;
  margin: 0;
  padding: 0 0 6px;
  display: flex;
  gap: 8px;
  overflow-x: auto;
  scrollbar-width: thin;
}

.page-about .ver-axis__link {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  padding: 9px 14px;
  white-space: nowrap;
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--c-dim);
  text-decoration: none;
  border: 1px solid var(--c-line);
  border-radius: 2px;
  transition: color var(--dur), border-color var(--dur), background var(--dur);
}

.page-about .ver-axis__link:hover {
  color: var(--c-text);
  border-color: var(--c-cyan-dim);
}

.page-about .ver-axis__link.is-current {
  color: var(--c-cyan);
  border-color: var(--c-cyan);
  background: rgba(41, 231, 220, .08);
}

.page-about .ver-axis__idx {
  font-size: 11px;
  color: var(--c-mute);
}

.page-about .ver-axis__link.is-current .ver-axis__idx {
  color: var(--c-cyan);
}

.page-about .ver-item {
  display: grid;
  gap: 14px;
  padding: 26px 0 30px;
  border-top: 1px solid var(--c-line);
  scroll-margin-top: 150px;
  transition: border-color var(--dur);
}

.page-about .ver-item:last-child {
  border-bottom: 1px solid var(--c-line);
}

.page-about .ver-item:hover {
  border-top-color: var(--c-cyan);
}

.page-about .ver-item__num {
  margin: 0;
  font-size: clamp(38px, 9vw, 66px);
  font-weight: 600;
  line-height: .88;
  letter-spacing: -.03em;
  color: var(--c-text);
  font-variant-numeric: tabular-nums;
  transition: color var(--dur);
}

.page-about .ver-item:hover .ver-item__num {
  color: var(--c-cyan);
}

.page-about .ver-item.is-current .ver-item__num {
  color: var(--c-cyan);
}

.page-about .ver-item__body .tag {
  display: inline-block;
  margin: 0 0 12px;
}

.page-about .ver-item__body h3 {
  margin: 0 0 12px;
  font-family: var(--font-cond);
  font-weight: 800;
  font-size: clamp(20px, 3.6vw, 27px);
  line-height: 1.24;
  letter-spacing: -.01em;
}

.page-about .ver-item__body > p {
  margin: 0 0 14px;
  font-size: 15px;
  line-height: 1.7;
  color: var(--c-dim);
  max-width: 34em;
}

.page-about .ver-item__more {
  border-top: 1px dashed var(--c-line);
  padding-top: 10px;
}

.page-about .ver-item__more summary {
  list-style: none;
  cursor: pointer;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--c-cyan);
  padding: 4px 0;
}

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

.page-about .ver-item__more summary::before {
  content: "+ ";
  color: var(--c-orange);
}

.page-about .ver-item__more[open] summary::before {
  content: "− ";
}

.page-about .ver-item__more ul {
  margin: 12px 0 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 8px;
}

.page-about .ver-item__more li {
  position: relative;
  padding-left: 16px;
  font-size: 14px;
  line-height: 1.6;
  color: var(--c-dim);
}

.page-about .ver-item__more li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 8px;
  width: 6px;
  height: 6px;
  background: var(--c-cyan-dim);
}

/* ---------- 团队 ---------- */
.page-about .team-strip {
  margin-top: 32px;
  display: grid;
  gap: 1px;
  background: var(--c-line);
  border: 1px solid var(--c-line);
}

.page-about .duty {
  background: var(--c-panel);
  padding: 24px 20px 26px;
  transition: background var(--dur), box-shadow var(--dur);
  outline: none;
}

.page-about .duty:nth-child(1) {
  border-top: 2px solid var(--c-cyan);
}

.page-about .duty:nth-child(2) {
  border-top: 2px solid var(--c-orange);
}

.page-about .duty:nth-child(3) {
  border-top: 2px solid var(--c-magenta);
}

.page-about .duty:hover,
.page-about .duty:focus-within {
  background: #111c2b;
}

.page-about .duty__num {
  margin: 0;
  font-size: clamp(34px, 7vw, 48px);
  font-weight: 600;
  line-height: 1;
  color: var(--c-text);
  font-variant-numeric: tabular-nums;
}

.page-about .duty__role {
  margin: 12px 0 8px;
  font-family: var(--font-cond);
  font-weight: 800;
  font-size: 20px;
  letter-spacing: -.01em;
}

.page-about .duty__desc {
  margin: 0;
  font-size: 14px;
  line-height: 1.6;
  color: var(--c-dim);
}

.page-about .duty-items {
  display: grid;
  grid-template-rows: 1fr;
}

.page-about .duty-items > ul {
  overflow: hidden;
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 8px;
}

.page-about .duty-items li {
  position: relative;
  padding-left: 14px;
  font-size: 14px;
  line-height: 1.6;
  color: var(--c-dim);
}

.page-about .duty-items li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 9px;
  width: 5px;
  height: 5px;
  background: var(--c-cyan);
}

.page-about .about-team__fig {
  margin: 32px 0 0;
  max-width: 720px;
  border-radius: 2px;
}

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

/* ---------- 流程 ---------- */
.page-about .flow {
  margin: 32px 0 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 1px;
  background: var(--c-line);
  border: 1px solid var(--c-line);
}

.page-about .flow__step {
  background: var(--c-bg);
  padding: 24px 18px 28px;
  border-top: 2px solid transparent;
  transition: border-color var(--dur), background var(--dur);
}

.page-about .flow__step:hover {
  background: var(--c-panel);
  border-top-color: var(--c-orange);
}

.page-about .flow__idx {
  display: block;
  font-size: 13px;
  letter-spacing: .16em;
  color: var(--c-orange);
  margin-bottom: 14px;
}

.page-about .flow__step h3 {
  margin: 0 0 10px;
  font-family: var(--font-cond);
  font-weight: 800;
  font-size: 19px;
  letter-spacing: -.01em;
}

.page-about .flow__step p {
  margin: 0;
  font-size: 14px;
  line-height: 1.65;
  color: var(--c-dim);
}

/* ---------- 数据来源 ---------- */
.page-about .source-grid {
  margin-top: 32px;
  display: grid;
  gap: 30px;
}

.page-about .about-source__fig {
  margin: 0;
  border-radius: 2px;
}

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

.page-about .source-list {
  margin: 26px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .source-list__item {
  display: grid;
  gap: 6px;
  padding: 16px 0;
  border-top: 1px solid var(--c-line);
}

.page-about .source-list__item:last-child {
  border-bottom: 1px solid var(--c-line);
}

.page-about .source-list__key {
  font-size: 12px;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--c-cyan);
}

.page-about .source-list__item p {
  margin: 0;
  font-size: 14px;
  line-height: 1.65;
  color: var(--c-dim);
}

.page-about .about-source__note {
  margin: 22px 0 0;
  padding: 16px 18px;
  border-left: 2px solid var(--c-cyan);
  background: var(--c-panel);
  font-size: 14px;
  line-height: 1.7;
  color: var(--c-dim);
}

/* ---------- 资质与行动 ---------- */
.page-about .about-block--trust {
  border-bottom: 0;
}

.page-about .trust-grid {
  margin-top: 32px;
  display: grid;
  gap: 1px;
  background: var(--c-line);
  border: 1px solid var(--c-line);
}

.page-about .trust-card {
  background: var(--c-panel);
  padding: 24px 20px 26px;
}

.page-about .trust-card__num {
  margin: 0 0 12px;
  font-size: clamp(26px, 5vw, 34px);
  font-weight: 600;
  color: var(--c-cyan);
  font-variant-numeric: tabular-nums;
}

.page-about .trust-card h3 {
  margin: 0 0 10px;
  font-family: var(--font-cond);
  font-weight: 800;
  font-size: 18px;
  letter-spacing: -.01em;
}

.page-about .trust-card p {
  margin: 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--c-dim);
}

.page-about .about-cta {
  margin-top: 40px;
  padding: 30px 22px 32px;
  background: var(--c-panel);
  border: 1px solid var(--c-line);
  border-left: 4px solid var(--c-orange);
  border-radius: 2px;
  display: grid;
  gap: 24px;
}

.page-about .about-cta__text h3 {
  margin: 0 0 12px;
  font-family: var(--font-cond);
  font-weight: 800;
  font-size: clamp(20px, 3.6vw, 26px);
  line-height: 1.25;
  letter-spacing: -.01em;
}

.page-about .about-cta__text p {
  margin: 0;
  max-width: 34em;
  font-size: 15px;
  line-height: 1.7;
  color: var(--c-dim);
}

.page-about .about-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  align-content: start;
}

/* ---------- 断点 ---------- */
@media (min-width: 640px) {
  .page-about .about-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
  .page-about .about-stats__item {
    padding: 22px 20px 24px;
  }
}

@media (min-width: 860px) {
  .page-about .about-split {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, .95fr);
    gap: 48px;
  }
  .page-about .team-strip,
  .page-about .flow,
  .page-about .trust-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
  .page-about .flow {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
  .page-about .duty-items {
    grid-template-rows: 0fr;
    transition: grid-template-rows .24s ease;
  }
  .page-about .duty-items > ul {
    margin-top: 0;
  }
  .page-about .duty:hover .duty-items,
  .page-about .duty:focus-within .duty-items {
    grid-template-rows: 1fr;
  }
  .page-about .duty:hover .duty-items > ul,
  .page-about .duty:focus-within .duty-items > ul {
    margin-top: 16px;
  }
  .page-about .about-cta {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
    padding: 36px 32px;
  }
  .page-about .about-cta__actions {
    flex-direction: column;
    align-items: stretch;
  }
}

@media (min-width: 1000px) {
  .page-about .source-grid {
    grid-template-columns: minmax(0, 58%) minmax(0, 1fr);
    gap: 44px;
    align-items: start;
  }
  .page-about .about-rail {
    grid-template-columns: var(--rail) minmax(0, 1fr);
    gap: 44px;
  }
  .page-about .about-rail__side {
    position: sticky;
    top: var(--about-sticky);
    align-self: start;
  }
  .page-about .ver-axis {
    flex-direction: column;
    overflow: visible;
    gap: 0;
    border-left: 1px solid var(--c-line);
    padding-bottom: 0;
  }
  .page-about .ver-axis__link {
    border: 0;
    border-left: 2px solid transparent;
    border-radius: 0;
    margin-left: -1px;
    padding: 10px 12px;
  }
  .page-about .ver-axis__link.is-current {
    background: linear-gradient(90deg, rgba(41, 231, 220, .12), transparent 70%);
  }
  .page-about .ver-axis__link:hover {
    border-left-color: var(--c-cyan-dim);
  }
  .page-about .ver-axis__link.is-current:hover {
    border-left-color: var(--c-cyan);
  }
  .page-about .ver-item {
    grid-template-columns: minmax(150px, 200px) minmax(0, 1fr);
    gap: 36px;
    align-items: start;
  }
  .page-about .ver-item:nth-child(even) {
    margin-left: 40px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-jump,
  .page-about .about-entry,
  .page-about .ver-axis__link,
  .page-about .ver-item,
  .page-about .ver-item__num,
  .page-about .duty,
  .page-about .duty-items,
  .page-about .flow__step {
    transition: none;
  }
}