.page-about {
  --ab-gap: clamp(0.75rem, 2vw, 1.25rem);
  background: var(--rb-cream);
  color: var(--rb-ink);
}

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

/* ---------- 首屏 ---------- */
.page-about .ab-hero {
  padding-top: calc(var(--rb-header-h) + clamp(1.5rem, 5vw, 3.5rem));
  padding-bottom: clamp(2rem, 5vw, 3.5rem);
  overflow: hidden;
}

.page-about .ab-hero__inner {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(1.5rem, 3.5vw, 2.5rem);
  align-items: start;
}

.page-about .ab-crumbs__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.45rem;
  font-size: 11px;
  letter-spacing: 0.18em;
  color: var(--rb-graphite);
}

.page-about .ab-crumbs__list li + li::before {
  content: "/";
  margin-right: 0.45rem;
  color: var(--rb-line-strong);
}

.page-about .ab-crumbs a {
  color: var(--rb-graphite);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 0.18s ease, border-color 0.18s ease;
}

.page-about .ab-crumbs a:hover,
.page-about .ab-crumbs a:focus-visible {
  color: var(--rb-red);
  border-bottom-color: var(--rb-red);
}

.page-about .ab-hero__title {
  margin: 0.6rem 0 1.15rem;
  font-family: var(--rb-font-sans);
  font-weight: 300;
  font-size: clamp(2.2rem, 7vw, 5.2rem);
  line-height: 1.04;
  letter-spacing: -0.02em;
  text-wrap: balance;
}

.page-about .ab-hero__accent {
  color: var(--rb-red);
}

.page-about .ab-hero__lede {
  max-width: 34em;
  margin: 0 0 1.6rem;
  font-size: clamp(1rem, 2vw, 1.125rem);
  line-height: 1.8;
  color: var(--rb-ink);
}

.page-about .ab-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.7rem;
}

.page-about .ab-hero__panel {
  background: var(--rb-navy);
  color: var(--rb-paper);
  border-radius: var(--rb-r-lg);
  padding: clamp(0.9rem, 2.2vw, 1.5rem);
  overflow: hidden;
}

.page-about .ab-hero__svg {
  display: block;
  width: 100%;
  height: auto;
  border-radius: var(--rb-r-sm);
}

.page-about .ab-hero__panel-cap {
  margin: 0.85rem 0 0;
  font-family: var(--rb-font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--rb-cyan);
}

/* ---------- 关键数字带 ---------- */
.page-about .ab-stats {
  margin: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--rb-line);
  border: 1px solid var(--rb-line);
  border-radius: var(--rb-r-md);
  overflow: hidden;
}

.page-about .ab-stats__item {
  background: var(--rb-paper);
  padding: clamp(0.9rem, 2.4vw, 1.4rem);
}

.page-about .ab-stats__label {
  margin: 0 0 0.5rem;
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--rb-graphite);
}

.page-about .ab-stats__value {
  margin: 0;
  font-family: var(--rb-font-num);
  font-weight: 600;
  font-size: clamp(1.9rem, 5vw, 2.9rem);
  line-height: 1;
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.01em;
}

.page-about .ab-stats__unit {
  margin-left: 0.25rem;
  font-family: var(--rb-font-sans);
  font-size: 0.9rem;
  font-weight: 400;
  color: var(--rb-graphite);
}

@media (min-width: 720px) {
  .page-about .ab-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (min-width: 960px) {
  .page-about .ab-hero__inner {
    grid-template-columns: minmax(0, 1.08fr) minmax(0, 0.92fr);
  }
  .page-about .ab-crumbs,
  .page-about .ab-stats {
    grid-column: 1 / -1;
  }
}

/* ---------- 主体两栏 ---------- */
.page-about .ab-body {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(1.5rem, 4vw, 2.5rem);
  padding-bottom: clamp(2.5rem, 6vw, 4.5rem);
}

.page-about .ab-toc {
  display: none;
}

@media (min-width: 1000px) {
  .page-about .ab-body {
    grid-template-columns: 186px minmax(0, 1fr);
    gap: clamp(2rem, 4vw, 4rem);
  }
  .page-about .ab-toc {
    display: block;
    position: sticky;
    top: calc(var(--rb-header-h) + 1.5rem);
    align-self: start;
    padding-top: 0.4rem;
  }
}

.page-about .ab-toc__title {
  margin: 0 0 0.9rem;
  font-size: 11px;
  letter-spacing: 0.2em;
  color: var(--rb-orange);
}

.page-about .ab-toc__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0.55rem;
  counter-reset: abtoc;
}

.page-about .ab-toc__list li {
  counter-increment: abtoc;
}

.page-about .ab-toc__list a {
  display: block;
  font-size: 0.875rem;
  line-height: 1.4;
  color: var(--rb-graphite);
  text-decoration: none;
  padding-left: 0.9rem;
  border-left: 2px solid var(--rb-line);
  transition: color 0.18s ease, border-color 0.18s ease;
}

.page-about .ab-toc__list a::before {
  content: counter(abtoc, decimal-leading-zero) " ";
  font-family: var(--rb-font-mono);
  font-size: 0.6875rem;
  color: var(--rb-orange);
  margin-right: 0.15rem;
}

.page-about .ab-toc__list a:hover,
.page-about .ab-toc__list a:focus-visible,
.page-about .ab-toc__list a[aria-current="true"] {
  color: var(--rb-ink);
  border-left-color: var(--rb-red);
}

/* ---------- 通用分区 ---------- */
.page-about .ab-section {
  padding-bottom: clamp(2.25rem, 5.5vw, 4rem);
  border-bottom: 1px solid var(--rb-line);
  scroll-margin-top: calc(var(--rb-header-h) + 1rem);
}

.page-about .ab-section + .ab-section {
  padding-top: clamp(2.25rem, 5.5vw, 4rem);
}

.page-about .ab-section:last-child {
  border-bottom: 0;
  padding-bottom: 0;
}

.page-about .ab-section .rb-section__head {
  margin-bottom: clamp(1.25rem, 3vw, 1.9rem);
}

.page-about .ab-section h2 {
  margin: 0.4rem 0 0;
  font-family: var(--rb-font-sans);
  font-weight: 300;
  font-size: clamp(1.6rem, 3.6vw, 2.5rem);
  line-height: 1.14;
  letter-spacing: -0.015em;
  text-wrap: balance;
}

.page-about .ab-section h3 {
  margin: 0 0 0.45rem;
  font-size: 1rem;
  font-weight: 700;
  letter-spacing: 0.01em;
}

.page-about .ab-section__lede {
  max-width: 40em;
  margin: 0.8rem 0 0;
  font-size: 1rem;
  line-height: 1.75;
  color: var(--rb-graphite);
}

.page-about .ab-prose {
  max-width: 62ch;
  display: grid;
  gap: 1rem;
}

.page-about .ab-prose p {
  margin: 0;
  line-height: 1.8;
  color: var(--rb-ink);
}

.page-about .ab-prose + .rb-note {
  margin-top: clamp(1.25rem, 3vw, 1.9rem);
}

/* ---------- 团队 ---------- */
.page-about .ab-team__figure {
  margin: 0 0 clamp(1.5rem, 3.5vw, 2.25rem);
}

.page-about .ab-roles {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--rb-line);
  border: 1px solid var(--rb-line);
  border-radius: var(--rb-r-md);
  overflow: hidden;
}

.page-about .ab-role {
  background: var(--rb-paper);
  padding: clamp(1rem, 2.2vw, 1.35rem);
  display: grid;
  gap: 0.4rem;
  align-content: start;
}

.page-about .ab-role__name {
  margin: 0;
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--rb-graphite);
}

.page-about .ab-role__num {
  margin: 0;
  font-family: var(--rb-font-num);
  font-weight: 600;
  font-size: clamp(2.1rem, 5vw, 2.9rem);
  line-height: 1;
  font-variant-numeric: tabular-nums;
}

.page-about .ab-role__desc {
  margin: 0;
  font-size: 0.875rem;
  line-height: 1.65;
  color: var(--rb-graphite);
}

.page-about .ab-role__bar {
  display: block;
  height: 4px;
  border-radius: var(--rb-r-pill);
  margin-top: 0.35rem;
  background: var(--rb-red);
}

.page-about .ab-role:nth-child(1) .ab-role__bar { width: 100%; background: var(--rb-red); }
.page-about .ab-role:nth-child(2) .ab-role__bar { width: 64%; background: var(--rb-orange); }
.page-about .ab-role:nth-child(3) .ab-role__bar { width: 55%; background: var(--rb-navy); }
.page-about .ab-role:nth-child(4) .ab-role__bar { width: 45%; background: var(--rb-navy); }
.page-about .ab-role:nth-child(5) .ab-role__bar { width: 27%; background: var(--rb-graphite); }

@media (min-width: 640px) {
  .page-about .ab-roles {
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  }
}

/* ---------- 流程 ---------- */
.page-about .ab-flow {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--ab-gap);
}

.page-about .ab-flow__step {
  position: relative;
  background: var(--rb-paper);
  border: 1px solid var(--rb-line);
  border-radius: var(--rb-r-lg);
  padding: clamp(1.15rem, 2.6vw, 1.65rem);
  transition: transform 0.2s ease, box-shadow 0.2s ease, border-color 0.2s ease;
}

.page-about .ab-flow__step:hover {
  transform: translateY(-3px);
  border-color: var(--rb-cyan);
  box-shadow: 0 10px 26px rgba(27, 22, 17, 0.09);
}

.page-about .ab-flow__no {
  display: block;
  margin-bottom: 0.5rem;
  font-family: var(--rb-font-num);
  font-weight: 600;
  font-size: 2.4rem;
  line-height: 1;
  color: var(--rb-orange);
}

.page-about .ab-flow__step p {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.7;
  color: var(--rb-graphite);
}

@media (min-width: 800px) {
  .page-about .ab-flow {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

/* ---------- 青训 ---------- */
.page-about .ab-youth {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(1.25rem, 3vw, 2rem);
}

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

.page-about .ab-youth__body p {
  margin: 0 0 1rem;
  line-height: 1.8;
}

.page-about .ab-youth__list {
  list-style: none;
  margin: 0 0 1rem;
  padding: 0;
  display: grid;
  gap: 0.75rem;
}

.page-about .ab-youth__list li {
  padding-left: 1rem;
  border-left: 3px solid var(--rb-navy);
  font-size: 0.9375rem;
  line-height: 1.7;
  color: var(--rb-graphite);
}

.page-about .ab-youth__list li:nth-child(2) {
  border-left-color: var(--rb-red);
}

.page-about .ab-youth__list li:nth-child(3) {
  border-left-color: var(--rb-orange);
}

.page-about .ab-youth__list strong {
  color: var(--rb-ink);
}

@media (min-width: 860px) {
  .page-about .ab-youth {
    grid-template-columns: minmax(0, 0.82fr) minmax(0, 1.18fr);
    align-items: start;
  }
}

/* ---------- 联赛与专题 ---------- */
.page-about .ab-leagues {
  list-style: none;
  margin: 0 0 clamp(1.4rem, 3vw, 1.9rem);
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.page-about .ab-leagues li {
  border: 1px solid var(--rb-line-strong);
  border-radius: var(--rb-r-pill);
  padding: 0.38rem 1rem;
  font-size: 0.875rem;
  letter-spacing: 0.02em;
  color: var(--rb-ink);
  background: var(--rb-paper);
}

.page-about .ab-topics {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--ab-gap);
}

.page-about .ab-topic {
  background: var(--rb-paper);
  border-radius: var(--rb-r-md);
  border-left: 5px solid var(--rb-red);
  padding: clamp(1.1rem, 2.4vw, 1.5rem);
}

.page-about .ab-topic:nth-child(2) { border-left-color: var(--rb-navy); }
.page-about .ab-topic:nth-child(3) { border-left-color: var(--rb-orange); }
.page-about .ab-topic:nth-child(4) { border-left-color: var(--rb-maroon); }

.page-about .ab-topic__fig {
  margin: 0.45rem 0 0.5rem;
  font-family: var(--rb-font-num);
  font-weight: 600;
  font-size: clamp(1.5rem, 3.6vw, 2rem);
  line-height: 1.05;
  font-variant-numeric: tabular-nums;
}

.page-about .ab-topic__desc {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.7;
  color: var(--rb-graphite);
}

@media (min-width: 720px) {
  .page-about .ab-topics {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 1040px) {
  .page-about .ab-topics {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

/* ---------- 版本时间线 ---------- */
.page-about .ab-timeline {
  list-style: none;
  margin: 0 0 clamp(1.5rem, 3.5vw, 2.25rem);
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1rem;
}

.page-about .ab-timeline__item {
  position: relative;
  padding-top: 1.15rem;
  border-top: 2px solid var(--rb-line-strong);
}

.page-about .ab-timeline__item::before {
  content: "";
  position: absolute;
  top: -6px;
  left: 0;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--rb-red);
}

.page-about .ab-timeline__ver {
  display: inline-block;
  margin-bottom: 0.55rem;
  padding: 0.22rem 0.7rem;
  border-radius: var(--rb-r-pill);
  background: var(--rb-ink);
  color: var(--rb-cream);
  font-family: var(--rb-font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.08em;
}

.page-about .ab-timeline__item p {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.7;
  color: var(--rb-graphite);
}

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

@media (min-width: 760px) {
  .page-about .ab-timeline {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 1.25rem;
  }
}

/* ---------- 合作与认可 ---------- */
.page-about .ab-partners {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--ab-gap);
}

.page-about .ab-partners__num {
  margin: 0 0 0.35rem;
  font-family: var(--rb-font-num);
  font-weight: 600;
  font-size: clamp(2.8rem, 7vw, 4.5rem);
  line-height: 1;
  font-variant-numeric: tabular-nums;
  color: var(--rb-red);
}

.page-about .ab-partners__title {
  margin: 0 0 0.4rem;
  font-size: 1.0625rem;
  font-weight: 700;
}

.page-about .ab-partners__desc {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.7;
  color: var(--rb-graphite);
}

.page-about .ab-partners__badge {
  display: inline-block;
  margin: 0 0 0.7rem;
  padding: 0.3rem 0.85rem;
  border-radius: var(--rb-r-pill);
  border: 1px solid var(--rb-cyan);
  color: var(--rb-cyan);
  font-size: 11px;
  letter-spacing: 0.16em;
}

.page-about .ab-partners .rb-card--navy {
  color: var(--rb-paper);
}

.page-about .ab-partners .ab-partners__desc--inv {
  color: rgba(255, 252, 246, 0.82);
  font-size: 1.0625rem;
  max-width: 42em;
}

@media (min-width: 720px) {
  .page-about .ab-partners {
    grid-template-columns: repeat(12, minmax(0, 1fr));
  }
  .page-about .ab-partners > .rb-span-6 {
    grid-column: span 6;
  }
  .page-about .ab-partners > .rb-span-12 {
    grid-column: span 12;
  }
}

/* ---------- 页尾行动区 ---------- */
.page-about .ab-cta {
  padding-bottom: clamp(3rem, 7vw, 5.5rem);
}

.page-about .ab-cta__box {
  background: var(--rb-navy);
  color: var(--rb-paper);
  border-radius: var(--rb-r-lg);
  padding: clamp(1.75rem, 4.5vw, 3.25rem);
  display: grid;
  gap: 0.9rem;
}

.page-about .ab-cta__index {
  margin: 0;
  color: var(--rb-cyan);
}

.page-about .ab-cta__box h2 {
  margin: 0;
  font-family: var(--rb-font-sans);
  font-weight: 300;
  font-size: clamp(1.6rem, 4.2vw, 2.75rem);
  line-height: 1.12;
  letter-spacing: -0.015em;
  text-wrap: balance;
}

.page-about .ab-cta__lede {
  max-width: 40em;
  margin: 0;
  font-size: 1rem;
  line-height: 1.8;
  color: rgba(255, 252, 246, 0.85);
}

.page-about .ab-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.7rem;
  margin-top: 0.4rem;
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-flow__step {
    transition: none;
  }
  .page-about .ab-flow__step:hover {
    transform: none;
  }
}