.page-about {
  --ab-hair: var(--line);
  --ab-hair-strong: var(--line-strong);
  --ab-light: rgba(243, 236, 221, 0.16);
  --ab-light-soft: rgba(243, 236, 221, 0.72);
  --ab-gold-tint: rgba(181, 138, 42, 0.1);
}

/* 首屏 */
.page-about .about-hero {
  position: relative;
  padding: clamp(22px, 4vw, 44px) 0 clamp(36px, 6vw, 76px);
  border-bottom: 1px solid var(--ab-hair-strong);
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: -2px;
  height: 2px;
  background: linear-gradient(90deg, var(--ochre) 0 16%, var(--gold) 16% 24%, transparent 24%);
}

.page-about .about-hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(28px, 4vw, 56px);
  align-items: start;
}

.page-about .about-hero h1 {
  margin: 14px 0 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(34px, 5.6vw, 66px);
  line-height: 1.14;
  letter-spacing: -0.01em;
}

.page-about .about-deck {
  margin: clamp(18px, 2.5vw, 26px) 0 0;
  max-width: 54ch;
  font-size: clamp(15px, 1.2vw, 17px);
  line-height: 1.85;
  color: var(--ink);
}

.page-about .hero-tags {
  margin: 26px 0 0;
  padding: 0;
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.page-about .about-hero-side {
  border-top: 1px solid var(--ab-hair-strong);
  padding-top: 18px;
}

.page-about .side-label {
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.22em;
  color: var(--ochre);
}

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

.page-about .side-timeline li {
  display: grid;
  grid-template-columns: 58px minmax(0, 1fr);
  gap: 12px;
  padding: 11px 0;
  border-top: 1px dashed var(--ab-hair);
  transition: background-color 0.3s var(--ease);
}

.page-about .side-timeline li:last-child {
  border-bottom: 1px dashed var(--ab-hair);
}

.page-about .side-timeline li:hover {
  background: var(--ab-gold-tint);
}

.page-about .side-year {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--lake);
}

.page-about .side-text {
  font-size: 13.5px;
  line-height: 1.65;
  color: var(--mist);
}

.page-about .about-hero-side .note {
  margin-top: 18px;
}

/* 通用块 */
.page-about .ab-block {
  padding: clamp(44px, 7vw, 88px) 0;
}

.page-about .ab-block + .ab-block {
  border-top: 1px solid var(--ab-hair);
}

.page-about .section-title {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(24px, 3.2vw, 34px);
  line-height: 1.28;
  margin: 10px 0 0;
}

.page-about .section-note {
  margin: 14px 0 0;
  max-width: 56ch;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--mist);
}

.page-about .prose p {
  margin: 0 0 1.15em;
  font-size: 15.5px;
  line-height: 1.85;
}

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

.page-about .ab-sub {
  margin: clamp(28px, 4vw, 40px) 0 12px;
  font-family: var(--font-display);
  font-size: clamp(19px, 2.2vw, 24px);
  font-weight: 700;
  line-height: 1.4;
}

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

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

.page-about .figure figcaption {
  margin-top: 10px;
  padding-top: 8px;
  border-top: 1px solid var(--ab-hair);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--mist);
}

.page-about .note {
  font-size: 13px;
  line-height: 1.75;
  color: var(--mist);
  border-left: 2px solid var(--gold);
  padding-left: 12px;
}

/* 缘起 */
.page-about .origin-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(28px, 4vw, 56px);
  align-items: start;
}

.page-about .origin-main .section-head {
  margin-bottom: 20px;
}

.page-about .origin-side .figure figcaption {
  border-top-color: var(--ab-hair-strong);
}

/* 团队 */
.page-about .about-team {
  background: var(--forest);
  color: var(--paper);
  border-top: 0;
}

.page-about .about-team .eyebrow {
  color: var(--gold);
}

.page-about .about-team .section-title,
.page-about .about-team .team-title {
  color: var(--paper);
}

.page-about .about-team .section-note {
  color: var(--ab-light-soft);
}

.page-about .team-head {
  margin-bottom: clamp(24px, 3.5vw, 40px);
}

.page-about .team-figure {
  margin-bottom: clamp(24px, 3.5vw, 40px);
}

.page-about .team-figure figcaption {
  border-top-color: var(--ab-light);
  color: rgba(243, 236, 221, 0.62);
}

.page-about .team-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--ab-light);
  border: 1px solid var(--ab-light);
}

.page-about .team-cell {
  position: relative;
  background: var(--forest);
  padding: 24px 20px 28px;
}

.page-about .team-cell::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 36px;
  height: 2px;
  background: var(--gold);
}

.page-about .team-num {
  margin: 0 0 12px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--gold);
}

.page-about .team-title {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-size: 18px;
  font-weight: 700;
}

.page-about .team-text {
  margin: 0;
  font-size: 13.5px;
  line-height: 1.8;
  color: rgba(243, 236, 221, 0.74);
}

/* 方法 */
.page-about .method-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(28px, 4vw, 56px);
  align-items: start;
}

.page-about .rail-nav {
  margin-top: 22px;
  border-top: 1px solid var(--ab-hair-strong);
}

.page-about .rail-nav a {
  display: flex;
  align-items: baseline;
  gap: 10px;
  padding: 9px 0;
  border-bottom: 1px solid var(--ab-hair);
  color: var(--ink);
  text-decoration: none;
  font-size: 13.5px;
  transition: color 0.25s var(--ease), padding-left 0.25s var(--ease);
}

.page-about .rail-nav a:hover,
.page-about .rail-nav a:focus-visible {
  color: var(--lake);
  padding-left: 4px;
}

.page-about .rail-idx {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--ochre);
}

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

.page-about .method-steps li {
  display: grid;
  grid-template-columns: 44px minmax(0, 1fr);
  gap: 16px;
  padding: 20px 0;
  border-top: 1px solid var(--ab-hair-strong);
}

.page-about .method-steps li:last-child {
  border-bottom: 1px solid var(--ab-hair-strong);
}

.page-about .step-num {
  font-family: var(--font-mono);
  font-size: 20px;
  line-height: 1.2;
  color: var(--lake-deep);
}

.page-about .step-title {
  margin: 0 0 6px;
  font-family: var(--font-display);
  font-size: 18px;
  font-weight: 700;
}

.page-about .step-text {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--mist);
}

.page-about .chrono-list {
  margin-top: 30px;
  border-bottom: 1px solid var(--ab-hair-strong);
}

.page-about .chrono-node {
  border-top: 1px solid var(--ab-hair-strong);
}

.page-about .chrono-node summary {
  display: grid;
  grid-template-columns: 62px minmax(0, 1fr) 18px;
  gap: 12px;
  align-items: center;
  padding: 15px 6px;
  cursor: pointer;
  list-style: none;
  font-family: var(--font-display);
  font-size: 16.5px;
  font-weight: 700;
  transition: background-color 0.25s var(--ease);
}

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

.page-about .chrono-node summary:hover,
.page-about .chrono-node summary:focus-visible {
  background: var(--ab-gold-tint);
}

.page-about .chrono-year {
  font-family: var(--font-mono);
  font-size: 12.5px;
  font-weight: 400;
  color: var(--ochre);
}

.page-about .chrono-mark {
  position: relative;
  width: 12px;
  height: 12px;
  justify-self: end;
}

.page-about .chrono-mark::before,
.page-about .chrono-mark::after {
  content: "";
  position: absolute;
  background: var(--lake);
  transition: transform 0.3s var(--ease);
}

.page-about .chrono-mark::before {
  top: 5px;
  left: 0;
  width: 12px;
  height: 1px;
}

.page-about .chrono-mark::after {
  top: 0;
  left: 5px;
  width: 1px;
  height: 12px;
}

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

.page-about .chrono-body {
  margin: 0;
  padding: 0 6px 18px 80px;
  font-size: 14px;
  line-height: 1.85;
  color: var(--mist);
}

/* 生态 */
.page-about .about-network {
  background: var(--lake-deep);
  color: var(--paper);
  border-top: 0;
}

.page-about .about-network .eyebrow {
  color: var(--gold);
}

.page-about .about-network .section-title,
.page-about .about-network .prose p {
  color: var(--paper);
}

.page-about .network-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(28px, 4vw, 52px);
  align-items: start;
}

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

.page-about .net-stats {
  margin: clamp(24px, 3vw, 34px) 0 0;
  padding: 0;
  list-style: none;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--ab-light);
  border: 1px solid var(--ab-light);
}

.page-about .net-stats li {
  background: var(--lake-deep);
  padding: 16px 16px 18px;
}

.page-about .net-num {
  display: block;
  font-family: var(--font-mono);
  font-size: 25px;
  line-height: 1.1;
  color: var(--gold);
}

.page-about .net-label {
  display: block;
  margin-top: 6px;
  font-size: 12.5px;
  letter-spacing: 0.04em;
  color: rgba(243, 236, 221, 0.7);
}

.page-about .network-figure figcaption {
  border-top-color: var(--ab-light);
  color: rgba(243, 236, 221, 0.62);
}

/* 纠错 */
.page-about .about-quality {
  background: var(--paper-2);
  border-top: 0;
}

.page-about .quality-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(26px, 4vw, 52px);
  align-items: start;
}

.page-about .quality-lead .prose {
  margin-top: 18px;
}

.page-about .quality-lead .note {
  margin-top: 18px;
  max-width: 42ch;
}

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

.page-about .quality-list li {
  display: grid;
  grid-template-columns: 34px minmax(0, 1fr);
  gap: 14px;
  padding: 18px 0;
  border-top: 1px solid var(--ab-hair-strong);
}

.page-about .quality-list li:last-child {
  border-bottom: 1px solid var(--ab-hair-strong);
}

.page-about .q-num {
  padding-top: 3px;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--ochre);
}

.page-about .q-title {
  margin: 0 0 6px;
  font-family: var(--font-display);
  font-size: 17px;
  font-weight: 700;
}

.page-about .q-text {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--mist);
}

/* 下一步 */
.page-about .about-next {
  background: var(--ink);
  color: var(--paper);
  border-top: 0;
}

.page-about .about-next .eyebrow {
  color: var(--gold);
}

.page-about .about-next .section-title {
  color: var(--paper);
}

.page-about .about-next .section-note {
  color: rgba(243, 236, 221, 0.7);
}

.page-about .path-grid {
  margin-top: clamp(26px, 3.5vw, 40px);
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--ab-light);
  border: 1px solid var(--ab-light);
}

.page-about .path-card {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 24px 22px 22px;
  background: var(--ink);
  color: var(--paper);
  text-decoration: none;
  transition: background-color 0.3s var(--ease);
}

.page-about .path-card:hover,
.page-about .path-card:focus-visible {
  background: var(--forest);
}

.page-about .path-tag {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  color: var(--gold);
}

.page-about .path-title {
  font-family: var(--font-display);
  font-size: 19px;
  font-weight: 700;
  line-height: 1.4;
}

.page-about .path-text {
  font-size: 13.5px;
  line-height: 1.8;
  color: rgba(243, 236, 221, 0.7);
}

.page-about .path-arrow {
  margin-top: 4px;
  font-family: var(--font-mono);
  font-size: 15px;
  color: var(--lake);
  transition: transform 0.3s var(--ease);
}

.page-about .path-card:hover .path-arrow {
  transform: translateX(4px);
}

.page-about .next-foot {
  margin-top: clamp(24px, 3vw, 34px);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 14px 22px;
}

.page-about .next-note {
  margin: 0;
  font-size: 13px;
  color: rgba(243, 236, 221, 0.66);
}

/* 断点 */
@media (min-width: 700px) {
  .page-about .team-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

@media (min-width: 900px) {
  .page-about .about-hero-grid {
    grid-template-columns: minmax(0, 1.55fr) minmax(0, 1fr);
  }

  .page-about .about-hero-side {
    border-top: 0;
    border-left: 1px solid var(--ab-hair-strong);
    padding-top: 0;
    padding-left: clamp(18px, 2.2vw, 30px);
  }

  .page-about .origin-grid {
    grid-template-columns: minmax(0, 1.45fr) minmax(0, 1fr);
  }

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

  .page-about .method-grid {
    grid-template-columns: minmax(0, 240px) minmax(0, 1fr);
  }

  .page-about .method-rail {
    position: sticky;
    top: 118px;
  }

  .page-about .network-grid {
    grid-template-columns: minmax(0, 1fr) minmax(0, 0.9fr);
  }

  .page-about .quality-grid {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1.15fr);
  }

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

@media (max-width: 420px) {
  .page-about .chrono-node summary {
    grid-template-columns: 54px minmax(0, 1fr) 16px;
    gap: 8px;
    font-size: 15px;
  }

  .page-about .chrono-body {
    padding-left: 62px;
  }

  .page-about .net-num {
    font-size: 21px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .side-timeline li,
  .page-about .rail-nav a,
  .page-about .chrono-node summary,
  .page-about .path-card,
  .page-about .path-arrow,
  .page-about .chrono-mark::before,
  .page-about .chrono-mark::after {
    transition: none;
  }

  .page-about .path-card:hover .path-arrow {
    transform: none;
  }
}
<<<END>>>