.page-about {
  --ab-body-on-light: #23323B;
  --ab-muted-on-light: #4C6570;
  --ab-stack-gap: clamp(22px, 3.6vw, 40px);
  background: var(--c-ink);
  color: var(--c-mist);
  font-family: var(--font-body);
  padding-block: clamp(16px, 2.6vw, 30px) clamp(48px, 8vw, 104px);
  overflow-x: clip;
}

.page-about .breadcrumbs {
  margin-bottom: clamp(14px, 2.4vw, 26px);
}

/* ---------- 页头 ---------- */
.page-about .about-head {
  display: grid;
  gap: clamp(18px, 3.4vw, 40px);
  padding-block: clamp(10px, 1.8vw, 22px) clamp(26px, 4vw, 44px);
  border-bottom: var(--line-thick) solid var(--c-celadon);
}

.page-about .about-head .eyebrow {
  margin: 0 0 12px;
  color: var(--c-steel);
}

.page-about .about-head h1 {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(30px, 5.6vw, 58px);
  line-height: 1.09;
  letter-spacing: -0.02em;
  color: var(--c-mist);
  text-wrap: balance;
}

.page-about .about-mark {
  color: var(--c-amber);
  border-bottom: 4px solid var(--c-amber);
  padding-bottom: 2px;
}

.page-about .about-lede {
  margin: 0;
  font-size: clamp(15px, 1.55vw, 17px);
  line-height: 1.85;
  color: var(--c-paper);
}

.page-about .about-facts {
  list-style: none;
  margin: clamp(18px, 3vw, 28px) 0 0;
  padding: var(--line);
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: var(--line);
  background: var(--c-black);
  border: var(--line) solid var(--c-black);
}

.page-about .fact {
  display: flex;
  flex-direction: column;
  gap: 5px;
  padding: clamp(11px, 1.6vw, 15px);
  background: var(--c-ink-deep);
}

.page-about .fact__num {
  font-family: var(--font-num);
  font-size: clamp(23px, 3vw, 33px);
  line-height: 1;
  color: var(--c-amber);
}

.page-about .fact__label {
  font-size: 12px;
  line-height: 1.45;
  color: var(--c-steel);
}

/* ---------- 章节堆叠 ---------- */
.page-about .chapters {
  display: grid;
  gap: var(--ab-stack-gap);
  padding-block: clamp(26px, 4vw, 48px);
}

.page-about .chapter {
  position: relative;
  padding: clamp(20px, 3.2vw, 44px);
  background: var(--c-mist);
  color: var(--c-ink);
  border: var(--line-thick) solid var(--c-black);
  box-shadow: var(--shadow);
}

.page-about .chapter--deep {
  background: var(--c-ink-deep);
  color: var(--c-mist);
  border-color: var(--c-paper);
  box-shadow: 6px 6px 0 var(--c-celadon);
}

.page-about .chapter__grid {
  display: grid;
  gap: clamp(14px, 2.6vw, 28px);
}

.page-about .chapter__num {
  display: block;
  font-family: var(--font-num);
  font-size: clamp(42px, 6.2vw, 74px);
  line-height: 0.85;
  color: var(--c-amber);
}

.page-about .chapter__kicker {
  display: block;
  margin-top: 10px;
  font-size: 12px;
  letter-spacing: 0.2em;
  color: var(--ab-muted-on-light);
}

.page-about .chapter--deep .chapter__kicker {
  color: var(--c-steel);
}

.page-about .chapter__title {
  margin: 0 0 clamp(12px, 2vw, 20px);
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(22px, 3.2vw, 35px);
  line-height: 1.2;
  letter-spacing: -0.012em;
  color: inherit;
}

.page-about .chapter__main p {
  margin: 0 0 14px;
  font-size: clamp(15px, 1.45vw, 17px);
  line-height: 1.85;
  color: var(--ab-body-on-light);
}

.page-about .chapter--deep .chapter__main p {
  color: var(--c-paper);
}

.page-about .chapter__note {
  margin-top: clamp(14px, 2vw, 20px) !important;
  padding-left: 14px;
  border-left: 4px solid var(--c-celadon);
  font-size: 14px !important;
}

.page-about .chapter__sub {
  margin: clamp(22px, 3.2vw, 34px) 0 clamp(10px, 1.6vw, 16px);
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(16px, 2vw, 20px);
  line-height: 1.35;
  color: var(--c-ink);
}

/* ---------- 配图 ---------- */
.page-about .credit {
  margin: clamp(16px, 2.6vw, 28px) 0 0;
  background: var(--c-ink-deep);
  border: var(--line) solid var(--c-black);
  box-shadow: var(--shadow-sm);
  overflow: hidden;
}

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

.page-about .credit figcaption {
  padding: 9px 13px;
  font-size: 12.5px;
  line-height: 1.6;
  color: var(--c-paper);
  border-top: var(--line) solid var(--c-black);
}

/* ---------- 年份与问答折叠 ---------- */
.page-about .folds {
  margin-top: clamp(14px, 2.4vw, 22px);
  border-bottom: var(--line) solid var(--c-black);
}

.page-about .chapter--deep .folds {
  border-bottom-color: var(--c-steel);
}

.page-about .fold {
  border-top: var(--line) solid var(--c-black);
}

.page-about .chapter--deep .fold {
  border-top-color: var(--c-steel);
}

.page-about .fold__head {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  align-items: center;
  gap: clamp(11px, 2.2vw, 22px);
  padding: clamp(11px, 1.7vw, 17px) 0;
  cursor: pointer;
  list-style: none;
  transition: color var(--dur-fast) var(--ease);
}

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

.page-about .fold__head:hover {
  color: var(--c-amber);
}

.page-about .fold__head:focus-visible {
  outline: 2px solid var(--c-amber);
  outline-offset: 3px;
}

.page-about .fold__lead {
  font-family: var(--font-num);
  font-size: clamp(24px, 3.4vw, 40px);
  line-height: 1;
  color: var(--c-coral);
}

.page-about .fold__title {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(14.5px, 1.6vw, 18px);
  line-height: 1.4;
  color: inherit;
}

.page-about .fold__mark {
  position: relative;
  width: 20px;
  height: 20px;
  flex: none;
  color: currentColor;
}

.page-about .fold__mark::before,
.page-about .fold__mark::after {
  content: "";
  position: absolute;
  left: 50%;
  top: 50%;
  background: currentColor;
  transform: translate(-50%, -50%);
}

.page-about .fold__mark::before {
  width: 16px;
  height: 2px;
}

.page-about .fold__mark::after {
  width: 2px;
  height: 16px;
  transition: transform var(--dur-fast) var(--ease), opacity var(--dur-fast) var(--ease);
}

.page-about .fold[open] .fold__mark::after {
  transform: translate(-50%, -50%) scaleY(0);
  opacity: 0;
}

.page-about .fold__body {
  padding: 0 0 clamp(12px, 2vw, 18px);
}

.page-about .fold__body p {
  margin: 0;
  max-width: 62ch;
  font-size: 14.5px;
  line-height: 1.85;
}

/* ---------- 五步流程 ---------- */
.page-about .steps {
  list-style: none;
  margin: clamp(16px, 2.4vw, 26px) 0 0;
  padding: var(--line);
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--line);
  background: var(--c-black);
  border: var(--line) solid var(--c-black);
}

.page-about .step {
  padding: clamp(13px, 2vw, 18px);
  background: var(--c-ink-deep);
}

.page-about .step__n {
  display: block;
  font-family: var(--font-num);
  font-size: 30px;
  line-height: 1;
  color: var(--c-amber);
}

.page-about .step h3 {
  margin: 8px 0 6px;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 15px;
  color: var(--c-white);
}

.page-about .step p {
  margin: 0;
  font-size: 13px;
  line-height: 1.7;
  color: var(--c-paper);
}

/* ---------- 覆盖示意 ---------- */
.page-about .coverage {
  margin-top: clamp(16px, 2.6vw, 26px);
  padding: clamp(6px, 1.4vw, 14px);
  border: var(--line) solid var(--c-steel);
  background: rgba(11, 31, 42, 0.55);
}

.page-about .coverage svg {
  display: block;
  width: 100%;
  height: auto;
}

.page-about .coverage__node {
  fill: var(--c-steel);
}

.page-about .coverage__node--hub {
  fill: var(--c-amber);
}

.page-about .coverage__ring {
  fill: none;
  stroke: var(--c-amber);
  stroke-width: 2;
  opacity: 0.45;
}

.page-about .coverage__link {
  fill: none;
  stroke: var(--c-celadon);
  stroke-width: 2;
  stroke-dasharray: 5 6;
  opacity: 0.85;
}

.page-about .coverage__label {
  fill: var(--c-mist);
  font-family: var(--font-body);
  font-size: 14px;
  font-weight: 700;
}

/* ---------- 指标与合作类别 ---------- */
.page-about .metrics {
  list-style: none;
  margin: clamp(16px, 2.4vw, 26px) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: clamp(10px, 1.8vw, 16px);
}

.page-about .metric {
  padding: clamp(12px, 1.8vw, 18px);
  background: var(--c-white);
  border: var(--line) solid var(--c-black);
  box-shadow: var(--shadow-sm);
}

.page-about .metric__num {
  display: block;
  font-family: var(--font-num);
  font-size: clamp(25px, 3.2vw, 37px);
  line-height: 1;
  color: var(--c-celadon);
}

.page-about .metric__title {
  display: block;
  margin-top: 7px;
  font-size: 14px;
  font-weight: 700;
  line-height: 1.4;
  color: var(--c-ink);
}

.page-about .metric__note {
  display: block;
  margin-top: 4px;
  font-size: 12.5px;
  line-height: 1.6;
  color: var(--ab-muted-on-light);
}

.page-about .kinds {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
}

.page-about .kind {
  padding: 10px 12px;
  background: var(--c-white);
  border: var(--line) solid var(--c-black);
  border-left: 5px solid var(--c-celadon);
}

.page-about .kind__name {
  display: block;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 15px;
  color: var(--c-ink);
}

.page-about .kind__note {
  display: block;
  margin-top: 4px;
  font-size: 12.5px;
  line-height: 1.6;
  color: var(--ab-muted-on-light);
}

/* ---------- 结尾行动区 ---------- */
.page-about .about-cta {
  margin-top: clamp(28px, 4.6vw, 54px);
  padding: clamp(22px, 3.4vw, 40px);
  background: var(--c-ink-deep);
  border: var(--line-thick) solid var(--c-celadon);
  box-shadow: var(--shadow);
}

.page-about .about-cta .eyebrow {
  margin: 0 0 10px;
  color: var(--c-amber);
}

.page-about .about-cta__title {
  margin: 0 0 14px;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(22px, 3.2vw, 34px);
  line-height: 1.22;
  color: var(--c-mist);
}

.page-about .about-cta__text {
  margin: 0;
  max-width: 68ch;
  font-size: clamp(14.5px, 1.45vw, 16.5px);
  line-height: 1.85;
  color: var(--c-paper);
}

.page-about .about-cta__actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px;
  margin-top: clamp(16px, 2.4vw, 26px);
}

/* ---------- 断点 ---------- */
@media (min-width: 560px) {
  .page-about .steps {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .kinds {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

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

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

  .page-about .kinds {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (min-width: 860px) {
  .page-about .about-head {
    grid-template-columns: minmax(0, 1.12fr) minmax(0, 0.88fr);
    align-items: end;
    gap: clamp(24px, 5vw, 72px);
  }
}

@media (min-width: 900px) {
  .page-about .chapter__grid {
    grid-template-columns: minmax(0, 148px) minmax(0, 1fr);
    gap: clamp(22px, 4vw, 56px);
    align-items: start;
  }

  .page-about .chapter__aside {
    position: sticky;
    top: 104px;
  }

  .page-about .credit--shift {
    margin-inline-end: clamp(0px, 7vw, 110px);
  }
}

@media (min-width: 1000px) {
  .page-about .steps {
    grid-template-columns: repeat(5, minmax(0, 1fr));
  }

  .page-about .chapter:nth-child(odd) {
    margin-inline-end: clamp(0px, 5vw, 76px);
  }

  .page-about .chapter:nth-child(even) {
    margin-inline-start: clamp(0px, 4vw, 56px);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .fold__mark::after,
  .page-about .fold__head {
    transition: none;
  }
}
<<<END>>>