.page-about {
  --about-gap: clamp(18px, 3vw, 32px);
  background:
    radial-gradient(920px 540px at 10% -8%, rgba(242, 169, 59, .10), transparent 66%),
    radial-gradient(720px 420px at 92% 6%, rgba(56, 242, 196, .06), transparent 70%),
    var(--ink);
  color: var(--fog);
  font-family: var(--font-body);
  padding-bottom: clamp(40px, 7vw, 96px);
  overflow-x: hidden;
}

.page-about .crumbs {
  margin-top: clamp(16px, 3vw, 28px);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  display: grid;
  gap: clamp(24px, 4vw, 40px);
  padding-block: clamp(18px, 3vw, 30px) clamp(34px, 6vw, 68px);
}

.page-about .hero-rail {
  list-style: none;
  margin: 0;
  padding: 0 0 0 16px;
  display: flex;
  flex-wrap: wrap;
  gap: 16px 28px;
  border-left: 2px solid rgba(242, 169, 59, .55);
}

.page-about .rail-stat {
  display: flex;
  flex-direction: column;
  gap: 4px;
  min-width: 82px;
}

.page-about .rail-num {
  font-family: var(--font-mono);
  font-size: clamp(19px, 2.4vw, 24px);
  line-height: 1.1;
  color: var(--amber-soft);
  font-variant-numeric: tabular-nums;
}

.page-about .rail-label {
  font-size: 11px;
  letter-spacing: .12em;
  color: var(--slate);
}

.page-about .hero-copy {
  min-width: 0;
}

.page-about .hero-kicker {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .18em;
  color: var(--jade);
}

.page-about .hero-kicker::before {
  content: "";
  width: 26px;
  height: 1px;
  background: var(--jade);
}

.page-about h1 {
  margin: 14px 0 0;
  font-family: var(--font-display);
  font-size: clamp(40px, 7.4vw, 82px);
  line-height: .96;
  letter-spacing: -.02em;
  font-weight: 700;
  color: var(--fog);
}

.page-about h1 em {
  font-style: normal;
  color: var(--amber);
}

.page-about .hero-lede {
  margin: 18px 0 0;
  max-width: 54ch;
  font-size: clamp(15px, 1.6vw, 17px);
  line-height: 1.85;
  color: var(--fog-dim);
}

.page-about .hero-figure {
  position: relative;
  margin: 0;
  min-width: 0;
}

.page-about .hero-figure .media-frame::after {
  content: "";
  position: absolute;
  inset: auto 0 0 0;
  height: 52%;
  background: linear-gradient(to top, rgba(7, 17, 31, .92), transparent);
  pointer-events: none;
}

@media (min-width: 960px) {
  .page-about .about-hero {
    grid-template-columns: 132px minmax(0, 1.05fr) minmax(0, .95fr);
    align-items: start;
  }

  .page-about .hero-rail {
    flex-direction: column;
    gap: 26px;
  }
}

/* ---------- 通用分节 ---------- */
.page-about .sec {
  border-top: 1px solid var(--line);
  padding-block: clamp(34px, 6vw, 74px);
}

.page-about .sec-inner {
  display: grid;
  gap: clamp(20px, 3.5vw, 40px);
}

.page-about .sec-aside {
  display: flex;
  flex-direction: column;
  gap: 12px;
  min-width: 0;
}

.page-about .aside-index {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--amber);
}

.page-about .aside-note {
  margin: 0;
  padding-left: 14px;
  border-left: 1px solid var(--line);
  font-size: 13px;
  line-height: 1.75;
  color: var(--slate);
}

.page-about .aside-figure {
  margin: 6px 0 0;
}

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

.page-about .sec-title {
  margin: 0 0 16px;
  font-family: var(--font-display);
  font-size: clamp(26px, 3.6vw, 42px);
  line-height: 1.08;
  letter-spacing: -.01em;
  font-weight: 700;
  color: var(--fog);
}

.page-about .prose p {
  margin: 0 0 14px;
  max-width: 66ch;
  font-size: 15.5px;
  line-height: 1.85;
  color: var(--fog-dim);
}

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

.page-about .prose strong {
  color: var(--fog);
  font-weight: 600;
}

@media (min-width: 900px) {
  .page-about .sec-inner {
    grid-template-columns: 210px minmax(0, 1fr);
    gap: clamp(28px, 5vw, 64px);
  }
}

/* ---------- 数字条 ---------- */
.page-about .stat-row {
  list-style: none;
  margin: 26px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius-m);
  overflow: hidden;
}

.page-about .stat-cell {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 16px 14px;
  background: var(--ink-2);
  transition: background var(--dur) var(--ease);
}

.page-about .stat-cell:hover {
  background: var(--steel);
}

.page-about .stat-num {
  font-family: var(--font-mono);
  font-size: clamp(22px, 3vw, 30px);
  line-height: 1;
  color: var(--amber-soft);
  font-variant-numeric: tabular-nums;
}

.page-about .stat-cap {
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--slate);
}

@media (min-width: 760px) {
  .page-about .stat-row {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

/* ---------- 三步流程 ---------- */
.page-about .flow {
  display: grid;
  gap: 1px;
  margin-top: 24px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius-m);
  overflow: hidden;
}

.page-about .flow-step {
  position: relative;
  padding: 22px 20px 24px;
  background: var(--steel);
  transition: background var(--dur) var(--ease);
}

.page-about .flow-step::before {
  content: "";
  position: absolute;
  inset: 0 0 auto 0;
  height: 2px;
  background: var(--amber);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--dur) var(--ease);
}

.page-about .flow-step:hover,
.page-about .flow-step:focus-within {
  background: var(--ink-2);
}

.page-about .flow-step:hover::before,
.page-about .flow-step:focus-within::before {
  transform: scaleX(1);
}

.page-about .flow-step:focus-visible {
  outline: 2px solid var(--jade);
  outline-offset: -2px;
}

.page-about .flow-num {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .16em;
  color: var(--jade);
}

.page-about .flow-step h3 {
  margin: 10px 0 8px;
  font-family: var(--font-display);
  font-size: 20px;
  line-height: 1.2;
  color: var(--fog);
}

.page-about .flow-step p {
  margin: 0;
  font-size: 14px;
  line-height: 1.78;
  color: var(--fog-dim);
}

@media (min-width: 820px) {
  .page-about .flow {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

/* ---------- 时间线 ---------- */
.page-about .tl {
  margin: 24px 0 0;
  padding: 0 0 0 22px;
  list-style: none;
  border-left: 1px solid var(--line);
  display: grid;
  gap: 2px;
}

.page-about .tl-item {
  position: relative;
}

.page-about .tl-item::before {
  content: "";
  position: absolute;
  left: -27px;
  top: 21px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--ink);
  border: 1px solid var(--amber);
  box-shadow: 0 0 0 4px rgba(242, 169, 59, .08);
}

.page-about .tl-item[open]::before {
  background: var(--jade);
  border-color: var(--jade);
  box-shadow: 0 0 0 4px rgba(56, 242, 196, .12);
}

.page-about .tl summary {
  list-style: none;
  cursor: pointer;
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  align-items: baseline;
  gap: 12px;
  padding: 12px 0;
}

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

.page-about .tl summary:focus-visible {
  outline: 2px solid var(--jade);
  outline-offset: 4px;
  border-radius: var(--radius-s);
}

.page-about .tl-year {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .08em;
  color: var(--jade);
  font-variant-numeric: tabular-nums;
}

.page-about .tl-title {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(17px, 2vw, 21px);
  line-height: 1.25;
  font-weight: 600;
  color: var(--fog);
}

.page-about .tl-mark {
  font-family: var(--font-mono);
  font-size: 16px;
  line-height: 1;
  color: var(--amber);
  transition: transform var(--dur) var(--ease), color var(--dur) var(--ease);
}

.page-about .tl-item[open] .tl-mark {
  transform: rotate(45deg);
  color: var(--jade);
}

.page-about .tl-body {
  padding: 0 0 16px;
}

.page-about .tl-body p {
  margin: 0;
  max-width: 62ch;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--fog-dim);
}

/* ---------- 中段图文 ---------- */
.page-about .mid-band {
  display: grid;
  gap: 18px;
  padding-block: clamp(32px, 5vw, 62px);
  border-top: 1px solid var(--line);
}

.page-about .mid-band .media {
  margin: 0;
  min-width: 0;
}

.page-about .band-text h3 {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-size: clamp(21px, 2.6vw, 28px);
  line-height: 1.2;
  color: var(--amber-soft);
}

.page-about .band-text p {
  margin: 0;
  max-width: 56ch;
  font-size: 15px;
  line-height: 1.82;
  color: var(--fog-dim);
}

@media (min-width: 900px) {
  .page-about .mid-band {
    grid-template-columns: minmax(0, .95fr) minmax(0, 1.05fr);
    align-items: center;
    gap: clamp(24px, 4vw, 52px);
  }
}

/* ---------- 覆盖分类 ---------- */
.page-about .cover-list {
  list-style: none;
  margin: 24px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(148px, 1fr));
  gap: 10px;
}

.page-about .cover-item {
  display: flex;
  flex-direction: column;
  gap: 5px;
  padding: 14px 16px;
  border: 1px solid var(--line);
  border-radius: var(--radius-s);
  background: rgba(18, 40, 61, .55);
  transition: border-color var(--dur) var(--ease), background var(--dur) var(--ease);
}

.page-about .cover-item:hover {
  border-color: rgba(242, 169, 59, .45);
  background: rgba(18, 40, 61, .85);
}

.page-about .cover-item strong {
  font-size: 15px;
  font-weight: 600;
  color: var(--fog);
}

.page-about .cover-item span {
  font-family: var(--font-mono);
  font-size: 12px;
  line-height: 1.6;
  color: var(--slate);
}

/* ---------- 收束入口 ---------- */
.page-about .about-cta {
  display: grid;
  gap: 20px;
  margin-top: clamp(36px, 6vw, 74px);
  padding: clamp(24px, 4vw, 44px);
  border: 1px solid var(--line);
  border-radius: var(--radius-l);
  background: linear-gradient(135deg, rgba(18, 40, 61, .95), rgba(12, 27, 42, .92) 55%, rgba(7, 17, 31, .96));
}

.page-about .about-cta h2 {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-size: clamp(22px, 3vw, 32px);
  line-height: 1.15;
  color: var(--fog);
}

.page-about .about-cta p {
  margin: 0;
  max-width: 54ch;
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--fog-dim);
}

.page-about .cta-links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.page-about .cta-links .btn {
  min-width: 132px;
  justify-content: center;
  text-align: center;
}

@media (min-width: 820px) {
  .page-about .about-cta {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
  }

  .page-about .cta-links {
    justify-content: flex-end;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .flow-step,
  .page-about .flow-step::before,
  .page-about .tl-mark,
  .page-about .cover-item,
  .page-about .stat-cell {
    transition: none;
  }
}