.page-about {
  --ab-line: rgba(30, 42, 58, 0.13);
  --ab-line-strong: rgba(30, 42, 58, 0.26);
  position: relative;
  overflow-x: clip;
  background: var(--tb-paper);
}

.page-about::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  z-index: 0;
  background-image:
    radial-gradient(circle at 18% 22%, rgba(176, 141, 87, 0.07) 0 1px, transparent 1px),
    radial-gradient(circle at 72% 64%, rgba(30, 42, 58, 0.05) 0 1px, transparent 1px);
  background-size: 23px 23px, 31px 31px;
}

.page-about > * {
  position: relative;
  z-index: 1;
}

/* ---------- 面包屑 ---------- */
.page-about .ab-crumb {
  padding-top: 1.25rem;
  padding-bottom: 0.25rem;
}

/* ---------- 首屏 ---------- */
.page-about .ab-hero {
  position: relative;
  padding: 1.75rem 0 3rem;
}

.page-about .ab-hero::after {
  content: "卷";
  position: absolute;
  right: -1.5rem;
  top: -2.5rem;
  font-family: var(--tb-font-head);
  font-size: clamp(8rem, 26vw, 18rem);
  line-height: 1;
  color: rgba(30, 42, 58, 0.045);
  pointer-events: none;
  user-select: none;
}

.page-about .ab-hero__grid {
  display: grid;
  gap: 1.75rem;
}

.page-about .ab-hero__main h1 {
  margin: 0.7rem 0 0;
  font-family: var(--tb-font-head);
  font-weight: 700;
  font-size: clamp(2.15rem, 7vw, 4.35rem);
  line-height: 1.06;
  letter-spacing: -0.015em;
  color: var(--tb-ink);
}

.page-about .ab-hero__lede {
  margin: 1.35rem 0 0;
  max-width: 46rem;
  font-size: 1.045rem;
  line-height: 1.85;
  color: var(--tb-graphite);
}

.page-about .ab-hero__aside {
  padding: 1.1rem 1.15rem 1.2rem;
  border-left: 3px solid var(--tb-gold);
  background: rgba(214, 204, 184, 0.42);
}

.page-about .ab-hero__aside-k {
  margin: 0;
  font-size: 0.75rem;
  letter-spacing: 0.16em;
  color: var(--tb-copper);
}

.page-about .ab-hero__aside-v {
  margin: 0.4rem 0 0;
  font-family: var(--tb-font-mono);
  font-size: 1.45rem;
  color: var(--tb-ink);
  letter-spacing: 0.02em;
}

.page-about .ab-hero__aside-t {
  margin: 0.7rem 0 0;
  font-size: 0.875rem;
  line-height: 1.75;
  color: var(--tb-graphite);
}

@media (min-width: 900px) {
  .page-about .ab-hero__grid {
    grid-template-columns: minmax(0, 1.62fr) minmax(0, 0.88fr);
    gap: 3rem;
    align-items: end;
  }
  .page-about .ab-hero__aside {
    margin-bottom: 0.35rem;
  }
}

/* ---------- 关键数字条 ---------- */
.page-about .ab-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  margin: 2.75rem 0 0;
  border-top: 1px solid var(--ab-line-strong);
  border-left: 1px solid var(--ab-line);
}

.page-about .ab-stats > div {
  padding: 1rem 1rem 1.2rem;
  border-right: 1px solid var(--ab-line);
  border-bottom: 1px solid var(--ab-line);
}

.page-about .ab-stats dt {
  font-size: 0.75rem;
  letter-spacing: 0.12em;
  color: var(--tb-graphite);
}

.page-about .ab-stats dd {
  margin: 0.4rem 0 0;
  font-family: var(--tb-font-mono);
  font-size: 1.4rem;
  color: var(--tb-copper);
  letter-spacing: 0.01em;
}

.page-about .ab-stats p {
  margin: 0.45rem 0 0;
  font-size: 0.8125rem;
  line-height: 1.6;
  color: var(--tb-graphite);
}

@media (min-width: 780px) {
  .page-about .ab-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
  .page-about .ab-stats dd {
    font-size: 1.6rem;
  }
}

/* ---------- 章节头 ---------- */
.page-about .ab-head {
  display: grid;
  gap: 1.1rem;
  padding-bottom: 1.4rem;
  border-bottom: 1px solid var(--ab-line-strong);
}

.page-about .ab-head h2 {
  margin: 0.5rem 0 0;
  font-family: var(--tb-font-head);
  font-weight: 700;
  font-size: clamp(1.65rem, 4vw, 2.5rem);
  line-height: 1.2;
  color: var(--tb-ink);
}

.page-about .ab-head__lede {
  margin: 0;
  font-size: 0.95rem;
  line-height: 1.85;
  color: var(--tb-graphite);
}

@media (min-width: 900px) {
  .page-about .ab-head {
    grid-template-columns: minmax(0, 1.1fr) minmax(0, 0.9fr);
    gap: 3rem;
    align-items: end;
  }
  .page-about .ab-head--tight {
    grid-template-columns: minmax(0, 1fr);
  }
}

/* ---------- 时间轴 ---------- */
.page-about .ab-timeline {
  padding: 3.25rem 0 3.5rem;
}

.page-about .ab-timeline__fig {
  margin: 2.25rem 0 0;
}

.page-about .ab-axis {
  list-style: none;
  margin: 1.75rem 0 0;
  padding: 0;
}

.page-about .ab-axis__item {
  display: grid;
  gap: 0.35rem 1.5rem;
  padding: 1.4rem 0 1.5rem;
  border-top: 1px dashed rgba(30, 42, 58, 0.22);
  transition: background-color 0.26s ease, box-shadow 0.26s ease;
}

.page-about .ab-axis__year {
  font-family: var(--tb-font-mono);
  font-size: 1.35rem;
  letter-spacing: 0.05em;
  color: var(--tb-gold);
}

.page-about .ab-axis__panel h3 {
  margin: 0;
  font-family: var(--tb-font-head);
  font-size: 1.3rem;
  font-weight: 700;
  line-height: 1.35;
  color: var(--tb-ink);
}

.page-about .ab-axis__panel p {
  margin: 0.62rem 0 0;
  max-width: 44rem;
  font-size: 0.95rem;
  line-height: 1.85;
  color: var(--tb-graphite);
}

@media (hover: hover) {
  .page-about .ab-axis__item:hover {
    background: rgba(58, 157, 138, 0.07);
    box-shadow: inset 3px 0 0 var(--tb-copper);
  }
}

.page-about .ab-axis__item:focus-within {
  background: rgba(58, 157, 138, 0.09);
  box-shadow: inset 3px 0 0 var(--tb-copper);
}

@media (min-width: 820px) {
  .page-about .ab-axis__item {
    grid-template-columns: 8.5rem minmax(0, 1fr);
    gap: 0 2.75rem;
    padding: 1.9rem 0 2rem;
  }
  .page-about .ab-axis__year {
    font-size: 1.85rem;
    text-align: right;
    padding-top: 0.15rem;
  }
}

/* ---------- 四类内容拼贴 ---------- */
.page-about .ab-duties {
  padding: 3rem 0 3.5rem;
  background: linear-gradient(180deg, rgba(214, 204, 184, 0.55), rgba(214, 204, 184, 0.12));
  border-top: 1px solid var(--ab-line);
  border-bottom: 1px solid var(--ab-line);
}

.page-about .ab-duties__grid {
  display: grid;
  gap: 1rem;
  margin-top: 2.25rem;
}

.page-about .ab-duty {
  position: relative;
  padding: 1.3rem 1.2rem 1.4rem 1.5rem;
  background: var(--tb-paper);
  border: 1px solid var(--ab-line);
  overflow: hidden;
}

.page-about .ab-duty::before {
  content: "";
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  width: 4px;
  background: linear-gradient(180deg, var(--tb-copper), rgba(47, 107, 94, 0));
}

.page-about .ab-duty--b::before {
  background: linear-gradient(180deg, var(--tb-gold), rgba(176, 141, 87, 0));
}

.page-about .ab-duty--c::before {
  background: linear-gradient(180deg, var(--tb-violet), rgba(74, 63, 107, 0));
}

.page-about .ab-duty--d::before {
  background: linear-gradient(180deg, var(--tb-cinnabar), rgba(193, 71, 59, 0));
}

.page-about .ab-duty__code {
  margin: 0;
  font-family: var(--tb-font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.16em;
  color: var(--tb-sand);
}

.page-about .ab-duty h3 {
  margin: 0.5rem 0 0;
  font-family: var(--tb-font-head);
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--tb-ink);
}

.page-about .ab-duty > p {
  margin: 0.65rem 0 0;
  font-size: 0.925rem;
  line-height: 1.8;
  color: var(--tb-graphite);
}

.page-about .ab-duty__facts {
  list-style: none;
  margin: 1rem 0 0;
  padding: 0.75rem 0 0;
  border-top: 1px dashed rgba(30, 42, 58, 0.2);
}

.page-about .ab-duty__facts li {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem 0.75rem;
  justify-content: space-between;
  padding: 0.28rem 0;
  font-size: 0.85rem;
}

.page-about .ab-duty__k {
  color: var(--tb-graphite);
}

.page-about .ab-duty__v {
  font-family: var(--tb-font-mono);
  color: var(--tb-copper);
}

@media (min-width: 880px) {
  .page-about .ab-duties__grid {
    grid-template-columns: repeat(12, minmax(0, 1fr));
  }
  .page-about .ab-duty--a { grid-column: span 8; }
  .page-about .ab-duty--b { grid-column: span 4; }
  .page-about .ab-duty--c { grid-column: span 5; }
  .page-about .ab-duty--d { grid-column: span 7; }
}

/* ---------- 团队印鉴 ---------- */
.page-about .ab-team {
  padding: 3.25rem 0 3.5rem;
}

.page-about .ab-team__inner {
  display: grid;
  gap: 2rem;
}

.page-about .ab-team__copy h2 {
  margin: 0.5rem 0 0;
  font-family: var(--tb-font-head);
  font-weight: 700;
  font-size: clamp(1.65rem, 4vw, 2.5rem);
  line-height: 1.2;
  color: var(--tb-ink);
}

.page-about .ab-team__copy > p {
  margin: 1rem 0 0;
  font-size: 0.95rem;
  line-height: 1.85;
  color: var(--tb-graphite);
}

.page-about .ab-seals {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0.85rem;
  list-style: none;
  margin: 1.75rem 0 0;
  padding: 0;
}

.page-about .ab-seal {
  position: relative;
  padding: 1.1rem 1.05rem 1.15rem;
  background: rgba(232, 225, 211, 0.7);
  border: 1px solid rgba(193, 71, 59, 0.3);
  transition: transform 0.24s ease, border-color 0.24s ease, box-shadow 0.24s ease;
}

.page-about .ab-seal__mark {
  display: inline-block;
  width: 2rem;
  height: 2rem;
  line-height: 2rem;
  text-align: center;
  font-family: var(--tb-font-head);
  font-size: 1rem;
  color: var(--tb-cinnabar);
  border: 1px solid rgba(193, 71, 59, 0.55);
  border-radius: 3px;
  background: rgba(193, 71, 59, 0.06);
}

.page-about .ab-seal h3 {
  margin: 0.7rem 0 0;
  font-family: var(--tb-font-head);
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--tb-ink);
}

.page-about .ab-seal p {
  margin: 0.5rem 0 0;
  font-size: 0.86rem;
  line-height: 1.75;
  color: var(--tb-graphite);
}

.page-about .ab-seal__link {
  display: inline-block;
  margin-top: 0.85rem;
  font-size: 0.82rem;
  letter-spacing: 0.04em;
  color: var(--tb-copper);
  text-decoration: none;
  border-bottom: 1px solid rgba(47, 107, 94, 0.4);
  transition: color 0.2s ease, border-color 0.2s ease;
}

.page-about .ab-seal__link:hover {
  color: var(--tb-copper-lit);
  border-bottom-color: var(--tb-copper-lit);
}

.page-about .ab-seal__link:focus-visible {
  outline: 2px solid var(--tb-copper-lit);
  outline-offset: 3px;
}

@media (hover: hover) {
  .page-about .ab-seal:hover {
    transform: translateY(-3px);
    border-color: var(--tb-cinnabar);
    box-shadow: 0 10px 22px rgba(30, 42, 58, 0.11);
  }
}

.page-about .ab-seal:focus-within {
  transform: translateY(-3px);
  border-color: var(--tb-cinnabar);
  box-shadow: 0 10px 22px rgba(30, 42, 58, 0.11);
}

.page-about .ab-team__fig {
  margin: 0;
}

@media (min-width: 620px) {
  .page-about .ab-seals {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 960px) {
  .page-about .ab-team__inner {
    grid-template-columns: minmax(0, 1.25fr) minmax(0, 0.75fr);
    gap: 3rem;
    align-items: start;
  }
  .page-about .ab-team__fig {
    position: sticky;
    top: calc(var(--tb-mast-h) + 1.5rem);
  }
}

/* ---------- 授权编号 ---------- */
.page-about .ab-code {
  padding: 3rem 0 3.5rem;
  background: rgba(30, 42, 58, 0.945);
  color: var(--tb-paper);
}

.page-about .ab-code__inner {
  display: grid;
  gap: 2rem;
}

.page-about .ab-code .tb-eyebrow {
  color: var(--tb-gold);
}

.page-about .ab-code .ab-head {
  border-bottom-color: rgba(232, 225, 211, 0.24);
  padding-bottom: 1.1rem;
}

.page-about .ab-code .ab-head h2 {
  color: var(--tb-paper);
}

.page-about .ab-code__fig {
  margin: 0;
}

.page-about .ab-code__fig .tb-media__caption {
  color: rgba(232, 225, 211, 0.72);
}

.page-about .ab-code__svg {
  display: block;
  width: 100%;
  max-width: 760px;
  height: auto;
  margin: 1.5rem 0 0;
}

.page-about .ab-code__seg rect {
  fill: rgba(232, 225, 211, 0.06);
  stroke: var(--tb-gold);
  stroke-width: 1.2;
}

.page-about .ab-code__val {
  font-family: var(--tb-font-mono);
  font-size: 21px;
  fill: var(--tb-paper);
  text-anchor: middle;
}

.page-about .ab-code__lab {
  font-family: var(--tb-font-body);
  font-size: 12px;
  fill: rgba(232, 225, 211, 0.68);
  text-anchor: middle;
  letter-spacing: 0.06em;
}

.page-about .ab-code__link {
  stroke: var(--tb-gold);
  stroke-width: 1.4;
  stroke-dasharray: 4 4;
  opacity: 0.65;
}

.page-about .ab-code__sample {
  margin: 1.35rem 0 0;
  font-size: 0.9rem;
  color: rgba(232, 225, 211, 0.82);
}

.page-about .ab-code__sample .tb-num {
  font-family: var(--tb-font-mono);
  color: var(--tb-copper-lit);
  letter-spacing: 0.04em;
}

.page-about .ab-code__notes {
  display: grid;
  gap: 1rem;
  margin: 1.6rem 0 0;
}

.page-about .ab-code__notes > div {
  padding-top: 0.85rem;
  border-top: 1px solid rgba(232, 225, 211, 0.2);
}

.page-about .ab-code__notes dt {
  font-family: var(--tb-font-head);
  font-size: 1rem;
  color: var(--tb-gold);
}

.page-about .ab-code__notes dd {
  margin: 0.42rem 0 0;
  font-size: 0.875rem;
  line-height: 1.75;
  color: rgba(232, 225, 211, 0.8);
}

@media (min-width: 900px) {
  .page-about .ab-code__inner {
    grid-template-columns: minmax(0, 0.72fr) minmax(0, 1.28fr);
    gap: 3rem;
    align-items: start;
  }
  .page-about .ab-code__notes {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 1.4rem;
  }
}

/* ---------- 历史版本 ---------- */
.page-about .ab-version {
  padding: 3.25rem 0 3.5rem;
}

.page-about .ab-version__inner {
  display: grid;
  gap: 2rem;
}

.page-about .ab-version__copy h2 {
  margin: 0.5rem 0 0;
  font-family: var(--tb-font-head);
  font-weight: 700;
  font-size: clamp(1.6rem, 3.8vw, 2.35rem);
  line-height: 1.22;
  color: var(--tb-ink);
}

.page-about .ab-version__copy > p {
  margin: 1rem 0 0;
  max-width: 46rem;
  font-size: 0.95rem;
  line-height: 1.85;
  color: var(--tb-graphite);
}

.page-about .ab-version__list {
  list-style: none;
  margin: 1.6rem 0 0;
  padding: 0;
  counter-reset: none;
}

.page-about .ab-version__list li {
  display: grid;
  grid-template-columns: 2.2rem minmax(0, 1fr);
  gap: 0.9rem;
  padding: 0.9rem 0;
  border-top: 1px dashed rgba(30, 42, 58, 0.2);
}

.page-about .ab-version__idx {
  font-family: var(--tb-font-mono);
  font-size: 0.85rem;
  color: var(--tb-gold);
  letter-spacing: 0.08em;
}

.page-about .ab-version__list p {
  margin: 0;
  font-size: 0.9rem;
  line-height: 1.8;
  color: var(--tb-graphite);
}

.page-about .ab-version__aside {
  padding: 1.2rem 1.15rem 1.3rem;
  background: rgba(214, 204, 184, 0.45);
  border-top: 3px solid var(--tb-copper);
}

.page-about .ab-version__aside .tb-note {
  margin: 0 0 1.15rem;
  font-size: 0.875rem;
  line-height: 1.8;
  color: var(--tb-graphite);
}

@media (min-width: 900px) {
  .page-about .ab-version__inner {
    grid-template-columns: minmax(0, 1.45fr) minmax(0, 0.55fr);
    gap: 3.25rem;
    align-items: start;
  }
}

/* ---------- 后续入口 ---------- */
.page-about .ab-next {
  padding: 2.75rem 0 3.75rem;
  border-top: 1px solid var(--ab-line-strong);
}

.page-about .ab-next__list {
  display: grid;
  gap: 0.85rem;
  list-style: none;
  margin: 1.5rem 0 0;
  padding: 0;
}

.page-about .ab-next__list a {
  display: block;
  padding: 1rem 1.1rem;
  text-decoration: none;
  color: var(--tb-ink);
  background: var(--tb-paper-deep);
  border-left: 3px solid transparent;
  transition: border-color 0.24s ease, background-color 0.24s ease, transform 0.24s ease;
}

.page-about .ab-next__n {
  display: block;
  font-family: var(--tb-font-head);
  font-size: 1.1rem;
  font-weight: 700;
}

.page-about .ab-next__d {
  display: block;
  margin-top: 0.35rem;
  font-size: 0.85rem;
  line-height: 1.7;
  color: var(--tb-graphite);
}

.page-about .ab-next__list a:hover {
  border-left-color: var(--tb-copper);
  background: rgba(58, 157, 138, 0.12);
  transform: translateX(3px);
}

.page-about .ab-next__list a:focus-visible {
  outline: 2px solid var(--tb-copper-lit);
  outline-offset: 2px;
  border-left-color: var(--tb-copper);
}

@media (min-width: 760px) {
  .page-about .ab-next__list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 1rem;
  }
}

@media (min-width: 1080px) {
  .page-about .ab-next__list {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

/* ---------- 减少动效 ---------- */
@media (prefers-reduced-motion: reduce) {
  .page-about .ab-axis__item,
  .page-about .ab-seal,
  .page-about .ab-next__list a {
    transition: none;
  }
  .page-about .ab-seal:hover,
  .page-about .ab-seal:focus-within,
  .page-about .ab-next__list a:hover {
    transform: none;
  }
}
<<<END>>>