.page-about {
  --ab-rule-color: rgba(127, 169, 140, 0.28);
  --ab-rule-faint: rgba(127, 169, 140, 0.16);
  --ab-blue-color: rgba(76, 127, 176, 0.45);
  --ab-measure: 66ch;
  position: relative;
  display: block;
  overflow-x: clip;
  color: var(--cream);
  background:
    radial-gradient(120% 72% at 86% -8%, rgba(30, 107, 76, 0.26), transparent 62%),
    radial-gradient(90% 60% at 4% 104%, rgba(232, 180, 76, 0.07), transparent 60%),
    var(--night);
}

.page-about .section {
  position: relative;
  padding-top: clamp(48px, 7vw, 92px);
  padding-bottom: clamp(48px, 7vw, 92px);
  border-top: 1px solid var(--ab-rule-faint);
}

.page-about .ab-sechead__note {
  color: var(--stone);
  font-size: 12px;
  letter-spacing: 0.12em;
  white-space: nowrap;
}

.page-about .ab-intro {
  max-width: var(--ab-measure);
  margin: 0 0 clamp(28px, 4vw, 44px);
  color: rgba(242, 239, 230, 0.84);
  font-size: 16px;
  line-height: 1.6;
}

.page-about .ab-caption,
.page-about .ab-note {
  color: var(--stone);
  font-size: 12.5px;
  letter-spacing: 0.04em;
}

.page-about .ab-note {
  margin-top: clamp(24px, 3vw, 36px);
  padding-left: 14px;
  border-left: 1px solid var(--ab-blue-color);
}

/* ---------- 首屏 ---------- */
.page-about .ab-hero {
  position: relative;
  padding: clamp(28px, 5vw, 60px) 0 0;
  overflow: hidden;
}

.page-about .ab-hero__bg {
  position: absolute;
  top: 0;
  right: 0;
  width: min(62%, 900px);
  height: 100%;
  z-index: 0;
  opacity: 0.24;
  pointer-events: none;
  -webkit-mask-image: linear-gradient(90deg, transparent 0%, #000 46%, #000 100%);
  mask-image: linear-gradient(90deg, transparent 0%, #000 46%, #000 100%);
}

.page-about .ab-hero__bg img {
  display: block;
  width: 100%;
  height: 100%;
  max-width: 100%;
  object-fit: cover;
  filter: saturate(0.7) contrast(1.05);
}

.page-about .ab-hero__inner {
  position: relative;
  z-index: 1;
}

.page-about .ab-hero .breadcrumb {
  margin-bottom: clamp(28px, 4vw, 48px);
}

.page-about .ab-hero__title {
  margin: 12px 0 0;
  max-width: 22ch;
  font-size: clamp(32px, 6vw, 62px);
  font-weight: 700;
  line-height: 1.14;
  letter-spacing: -0.02em;
  color: var(--cream);
}

.page-about .ab-hero__lead {
  max-width: 58ch;
  margin: 20px 0 0;
  font-size: 16px;
  line-height: 1.62;
  color: rgba(242, 239, 230, 0.8);
}

.page-about .ab-hero__lead + .ab-hero__lead {
  margin-top: 14px;
  color: rgba(242, 239, 230, 0.66);
}

.page-about .ab-ledger {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(158px, 1fr));
  gap: 1px;
  margin: clamp(36px, 5vw, 64px) 0 0;
  padding: 0;
  list-style: none;
  background: var(--ab-rule-color);
  border-top: 1px solid var(--ab-rule-color);
  border-bottom: 1px solid var(--ab-rule-color);
}

.page-about .ab-ledger__item {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 20px 18px 24px;
  background: var(--night);
}

.page-about .ab-ledger__num {
  font-size: clamp(26px, 3.4vw, 40px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.03em;
  color: var(--lamp);
}

.page-about .ab-ledger__label {
  font-size: 12px;
  line-height: 1.5;
  letter-spacing: 0.06em;
  color: var(--stone);
}

/* ---------- 锚点条 ---------- */
.page-about .ab-anchors {
  border-top: 1px solid var(--ab-rule-color);
  border-bottom: 1px solid var(--ab-rule-color);
  background: var(--board);
}

.page-about .ab-anchors__list {
  display: flex;
  gap: clamp(16px, 3vw, 40px);
  margin: 0;
  padding: 13px 0;
  list-style: none;
  overflow-x: auto;
  scrollbar-width: none;
}

.page-about .ab-anchors__list::-webkit-scrollbar {
  display: none;
}

.page-about .ab-anchors__list a {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  white-space: nowrap;
  font-size: 13.5px;
  color: rgba(242, 239, 230, 0.72);
  text-decoration: none;
  transition: color var(--dur-fast) var(--ease);
}

.page-about .ab-anchors__list a .mono {
  font-size: 11px;
  color: var(--blue);
}

.page-about .ab-anchors__list a:hover,
.page-about .ab-anchors__list a:focus-visible {
  color: var(--lamp);
}

/* ---------- 三层结构 ---------- */
.page-about .ab-layers__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(28px, 4vw, 48px);
}

.page-about .ab-layers__figure .media-frame {
  border: 1px solid var(--ab-rule-color);
}

.page-about .ab-layers__figure .ab-caption {
  margin: 12px 0 0;
}

.page-about .ab-stairs {
  display: block;
  width: 100%;
  height: auto;
  margin-bottom: 14px;
}

.page-about .ab-stairs__bar {
  fill: var(--board);
  stroke: rgba(127, 169, 140, 0.4);
  stroke-width: 1;
}

.page-about .ab-stairs__bar--1 {
  fill: rgba(30, 107, 76, 0.32);
  stroke: rgba(127, 169, 140, 0.5);
}

.page-about .ab-stairs__bar--3 {
  fill: rgba(232, 180, 76, 0.1);
  stroke: rgba(232, 180, 76, 0.46);
}

.page-about .ab-stairs__link {
  stroke: var(--ab-blue-color);
  stroke-width: 1;
  stroke-dasharray: 4 4;
}

.page-about .ab-stairs__legend {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 22px;
  margin: 0 0 26px;
  padding: 0;
  list-style: none;
  font-size: 12px;
  color: var(--stone);
}

.page-about .ab-stairs__legend li {
  display: inline-flex;
  align-items: center;
  gap: 8px;
}

.page-about .ab-chip {
  display: inline-block;
  width: 22px;
  height: 8px;
  border-radius: 1px;
}

.page-about .ab-chip--l1 {
  background: rgba(30, 107, 76, 0.75);
}

.page-about .ab-chip--l2 {
  background: var(--board);
  border: 1px solid rgba(127, 169, 140, 0.5);
}

.page-about .ab-chip--l3 {
  background: rgba(232, 180, 76, 0.45);
}

.page-about .ab-layer {
  border-top: 1px solid var(--ab-rule-color);
}

.page-about .ab-layer:last-child {
  border-bottom: 1px solid var(--ab-rule-color);
}

.page-about .ab-layer summary {
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding: 16px 0;
  cursor: pointer;
  list-style: none;
}

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

.page-about .ab-layer summary::after {
  content: "+";
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 15px;
  line-height: 1;
  color: var(--moss);
  transition: color var(--dur-fast) var(--ease);
}

.page-about .ab-layer[open] summary::after {
  content: "–";
  color: var(--lamp);
}

.page-about .ab-layer summary:hover::after,
.page-about .ab-layer summary:focus-visible::after {
  color: var(--lamp);
}

.page-about .ab-layer__no {
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--blue);
}

.page-about .ab-layer__name {
  font-size: 17px;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--cream);
}

.page-about .ab-layer__hint {
  font-size: 11.5px;
  letter-spacing: 0.08em;
  color: var(--stone);
}

.page-about .ab-layer__fields {
  display: grid;
  grid-template-columns: 1fr;
  gap: 8px 28px;
  margin: 0 0 20px;
  padding: 0 0 0 2px;
  list-style: none;
  font-size: 13px;
  color: rgba(242, 239, 230, 0.76);
}

.page-about .ab-layer__fields li {
  position: relative;
  padding-left: 16px;
}

.page-about .ab-layer__fields li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.62em;
  width: 7px;
  height: 1px;
  background: var(--moss);
}

/* ---------- 四维度 ---------- */
.page-about .ab-dims__list {
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .ab-dim {
  display: grid;
  grid-template-columns: 1fr;
  gap: 10px;
  padding: 24px 0;
  border-top: 1px solid var(--ab-rule-color);
}

.page-about .ab-dim:last-child {
  border-bottom: 1px solid var(--ab-rule-color);
}

.page-about .ab-dim__name {
  font-size: 15px;
  letter-spacing: 0.02em;
  color: var(--lamp);
}

.page-about .ab-dim__text {
  margin: 0;
  max-width: var(--ab-measure);
  font-size: 15.5px;
  line-height: 1.62;
  color: rgba(242, 239, 230, 0.84);
}

.page-about .ab-dim__meta {
  margin: 10px 0 0;
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--stone);
}

/* ---------- 赛事归类 ---------- */
.page-about .ab-comp__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0;
}

.page-about .ab-comp__item {
  padding: 24px 0 26px;
  border-top: 1px solid var(--ab-rule-color);
}

.page-about .ab-comp__grid .ab-comp__item:last-child {
  border-bottom: 1px solid var(--ab-rule-color);
}

.page-about .ab-comp__tag {
  margin: 0 0 10px;
  font-size: 11.5px;
  letter-spacing: 0.14em;
  color: var(--clay);
}

.page-about .ab-comp__name {
  margin: 0 0 10px;
  font-size: 22px;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--cream);
}

.page-about .ab-comp__text {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.6;
  color: rgba(242, 239, 230, 0.76);
}

/* ---------- 归档流程 ---------- */
.page-about .ab-flow__track {
  position: relative;
  display: grid;
  grid-template-columns: 1fr;
  gap: 0;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .ab-flow__step {
  position: relative;
  padding: 20px 0 24px 20px;
  border-top: 1px solid var(--ab-rule-color);
  border-left: 1px solid var(--ab-blue-color);
}

.page-about .ab-flow__track .ab-flow__step:last-child {
  border-bottom: 1px solid var(--ab-rule-color);
}

.page-about .ab-flow__no {
  margin: 0 0 8px;
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--blue);
}

.page-about .ab-flow__name {
  margin: 0 0 8px;
  font-size: 17px;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--cream);
}

.page-about .ab-flow__text {
  margin: 0 0 12px;
  font-size: 14.5px;
  line-height: 1.6;
  color: rgba(242, 239, 230, 0.76);
}

.page-about .ab-flow__tip {
  margin: 0;
  font-size: 11.5px;
  line-height: 1.6;
  letter-spacing: 0.02em;
  color: var(--stone);
  opacity: 0.72;
  transition: opacity var(--dur) var(--ease), color var(--dur) var(--ease);
}

.page-about .ab-flow__step:hover .ab-flow__tip {
  opacity: 1;
  color: var(--lamp);
}

/* ---------- 演进阶段 ---------- */
.page-about .ab-evo__list {
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .ab-evo__item {
  display: grid;
  grid-template-columns: 1fr;
  gap: 10px;
  padding: 26px 0 30px;
  border-top: 1px solid var(--ab-rule-color);
}

.page-about .ab-evo__list .ab-evo__item:last-child {
  border-bottom: 1px solid var(--ab-rule-color);
}

.page-about .ab-evo__no {
  display: block;
  font-size: clamp(46px, 11vw, 84px);
  font-weight: 700;
  line-height: 0.82;
  letter-spacing: -0.05em;
  color: rgba(127, 169, 140, 0.34);
}

@supports (-webkit-text-stroke: 1px #000) {
  .page-about .ab-evo__no {
    color: transparent;
    -webkit-text-stroke: 1px rgba(127, 169, 140, 0.55);
  }
}

.page-about .ab-evo__tag {
  margin: 0 0 6px;
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--clay);
}

.page-about .ab-evo__title {
  margin: 0 0 8px;
  font-size: 19px;
  font-weight: 700;
  letter-spacing: -0.015em;
  color: var(--cream);
}

.page-about .ab-evo__text {
  margin: 0;
  max-width: var(--ab-measure);
  font-size: 15px;
  line-height: 1.62;
  color: rgba(242, 239, 230, 0.76);
}

/* ---------- 值班分工 ---------- */
.page-about .ab-duty__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(28px, 4vw, 52px);
}

.page-about .ab-duty__figure {
  padding: 26px 0 0;
  border-top: 1px solid var(--ab-rule-color);
}

.page-about .ab-duty__num {
  margin: 0;
  font-size: clamp(64px, 15vw, 128px);
  font-weight: 700;
  line-height: 0.84;
  letter-spacing: -0.05em;
  color: var(--lamp);
}

.page-about .ab-duty__cap {
  margin: 14px 0 0;
  font-size: 12.5px;
  line-height: 1.7;
  letter-spacing: 0.04em;
  color: var(--stone);
}

.page-about .ab-duty__facts {
  display: grid;
  gap: 0;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .ab-duty__fact {
  padding: 20px 0;
  border-top: 1px solid var(--ab-rule-color);
}

.page-about .ab-duty__facts .ab-duty__fact:last-child {
  border-bottom: 1px solid var(--ab-rule-color);
}

.page-about .ab-duty__name {
  margin: 0 0 8px;
  font-size: 17px;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--cream);
}

.page-about .ab-duty__fact p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.62;
  color: rgba(242, 239, 230, 0.76);
}

.page-about .ab-cumulative {
  display: grid;
  grid-template-columns: 1fr;
  gap: 10px;
  margin-top: clamp(32px, 4vw, 52px);
  padding: 22px 0 24px;
  border-top: 1px solid var(--ab-blue-color);
  border-bottom: 1px solid var(--ab-blue-color);
}

.page-about .ab-cumulative__label {
  margin: 0;
  font-size: 11.5px;
  letter-spacing: 0.16em;
  color: var(--blue);
}

.page-about .ab-cumulative__text {
  margin: 0;
  max-width: var(--ab-measure);
  font-size: 15.5px;
  line-height: 1.62;
  color: rgba(242, 239, 230, 0.86);
}

/* ---------- 继续查阅 ---------- */
.page-about .ab-next__list {
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .ab-next__link {
  display: grid;
  grid-template-columns: 1fr;
  gap: 8px;
  padding: 22px 0 24px;
  border-top: 1px solid var(--ab-rule-color);
  color: inherit;
  text-decoration: none;
  transition: background var(--dur) var(--ease);
}

.page-about .ab-next__list li:last-child .ab-next__link {
  border-bottom: 1px solid var(--ab-rule-color);
}

.page-about .ab-next__name {
  position: relative;
  font-size: 20px;
  font-weight: 700;
  letter-spacing: -0.015em;
  color: var(--cream);
  transition: color var(--dur-fast) var(--ease);
}

.page-about .ab-next__name::after {
  content: "→";
  display: inline-block;
  margin-left: 10px;
  font-size: 15px;
  color: var(--moss);
  transform: translateX(-4px);
  opacity: 0;
  transition: transform var(--dur) var(--ease), opacity var(--dur) var(--ease);
}

.page-about .ab-next__desc {
  font-size: 14.5px;
  line-height: 1.62;
  color: rgba(242, 239, 230, 0.72);
}

.page-about .ab-next__link:hover .ab-next__name,
.page-about .ab-next__link:focus-visible .ab-next__name {
  color: var(--lamp);
}

.page-about .ab-next__link:hover .ab-next__name::after,
.page-about .ab-next__link:focus-visible .ab-next__name::after {
  transform: translateX(0);
  opacity: 1;
}

.page-about .ab-next__link:focus-visible {
  outline: 1px solid var(--lamp);
  outline-offset: 4px;
}

/* ---------- 响应式 ---------- */
@media (min-width: 600px) {
  .page-about .ab-layer__fields {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .ab-comp__grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    column-gap: 32px;
  }

  .page-about .ab-comp__grid .ab-comp__item:nth-last-child(2) {
    border-bottom: 1px solid var(--ab-rule-color);
  }

  .page-about .ab-comp__grid .ab-comp__item:last-child {
    border-bottom: 1px solid var(--ab-rule-color);
  }
}

@media (min-width: 760px) {
  .page-about .ab-layers__grid {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    align-items: start;
  }

  .page-about .ab-dim {
    grid-template-columns: 170px minmax(0, 1fr);
    gap: 6px 32px;
    padding: 26px 0;
  }

  .page-about .ab-evo__item {
    grid-template-columns: 150px minmax(0, 1fr);
    gap: 12px 36px;
  }

  .page-about .ab-duty__grid {
    grid-template-columns: minmax(0, 4fr) minmax(0, 8fr);
    align-items: start;
  }

  .page-about .ab-cumulative {
    grid-template-columns: 170px minmax(0, 1fr);
    gap: 6px 32px;
    align-items: baseline;
  }

  .page-about .ab-next__link {
    grid-template-columns: 200px minmax(0, 1fr);
    gap: 6px 32px;
    align-items: baseline;
  }
}

@media (min-width: 900px) {
  .page-about .ab-comp__grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    column-gap: 28px;
  }

  .page-about .ab-comp__grid .ab-comp__item {
    border-bottom: 1px solid var(--ab-rule-color);
    padding-right: 4px;
  }

  .page-about .ab-flow__track {
    grid-template-columns: repeat(5, minmax(0, 1fr));
    column-gap: 26px;
  }

  .page-about .ab-flow__track::before {
    content: "";
    position: absolute;
    left: 0;
    right: 0;
    top: 5px;
    height: 1px;
    background: var(--ab-blue-color);
  }

  .page-about .ab-flow__step {
    padding: 30px 0 0;
    border-top: none;
    border-left: none;
  }

  .page-about .ab-flow__track .ab-flow__step:last-child {
    border-bottom: none;
  }

  .page-about .ab-flow__step::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    width: 11px;
    height: 11px;
    border-radius: 50%;
    background: var(--night);
    border: 1px solid var(--blue);
  }
}

@media (min-width: 1080px) {
  .page-about .ab-hero__lead {
    font-size: 17px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-next__name::after,
  .page-about .ab-anchors__list a,
  .page-about .ab-flow__tip,
  .page-about .ab-next__name {
    transition: none;
  }

  .page-about .ab-next__name::after {
    transform: none;
    opacity: 1;
  }
}