.page-about {
  background: var(--paper);
}

/* ── 面包屑 ───────────────────────────── */
.page-about .ab-crumbs {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: clamp(16px, 4vw, 28px) 0 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--brown);
}

.page-about .ab-crumbs a {
  color: var(--cobalt);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color 0.25s var(--ease);
}

.page-about .ab-crumbs a:hover {
  border-bottom-color: var(--cobalt);
}

.page-about .ab-crumbs__sep {
  color: var(--fog);
}

/* ── 首屏 ─────────────────────────────── */
.page-about .ab-hero {
  position: relative;
  overflow: hidden;
  padding: clamp(20px, 4vw, 38px) 0 clamp(44px, 8vw, 88px);
}

.page-about .ab-hero__wedge {
  position: absolute;
  top: -16%;
  right: -14%;
  width: min(520px, 74vw);
  height: min(520px, 74vw);
  background: linear-gradient(162deg, var(--kiwi) 0%, #6f9c26 100%);
  clip-path: polygon(100% 0, 100% 100%, 0 64%, 24% 0);
  pointer-events: none;
  z-index: 0;
}

.page-about .ab-hero__grid {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(28px, 5vw, 48px);
  align-items: end;
}

.page-about .ab-hero__lead .eyebrow {
  margin: 0 0 14px;
}

.page-about .ab-hero h1 {
  margin: 0 0 20px;
  font-size: clamp(38px, 9.5vw, 74px);
  line-height: 1.02;
  letter-spacing: -0.02em;
  font-weight: 900;
  color: var(--ink);
  max-width: 13ch;
}

.page-about .ab-hero .lede {
  margin: 0 0 26px;
  max-width: 36em;
  color: var(--ink-2);
}

/* 首屏数据条 */
.page-about .ab-facts {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--brown);
  border: 1px solid var(--brown);
  border-radius: var(--r-m);
  overflow: hidden;
}

.page-about .ab-fact {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: clamp(14px, 3vw, 20px);
  background: var(--paper-2);
}

.page-about .ab-fact__num {
  font-family: var(--font-mono);
  font-size: clamp(24px, 6vw, 34px);
  line-height: 1;
  font-weight: 600;
  color: var(--ink);
  font-variant-numeric: tabular-nums;
}

.page-about .ab-fact__unit {
  font-size: 13px;
  font-weight: 600;
  color: var(--cobalt);
}

.page-about .ab-fact__label {
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--brown);
}

/* ── 通用区块标题 ─────────────────────── */
.page-about .ab-head {
  max-width: 46em;
  margin: 0 0 clamp(28px, 5vw, 48px);
}

.page-about .ab-head h2 {
  margin: 0 0 16px;
  font-size: clamp(26px, 5.4vw, 40px);
  line-height: 1.18;
  letter-spacing: -0.01em;
  color: var(--ink);
}

.page-about .ab-head .prose {
  margin: 0;
}

/* ── 赛季时间轴 ───────────────────────── */
.page-about .ab-evolution {
  padding: clamp(36px, 7vw, 76px) 0 clamp(20px, 4vw, 34px);
}

.page-about .ab-timeline {
  position: relative;
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .ab-timeline::before {
  content: "";
  position: absolute;
  left: 22px;
  top: 8px;
  bottom: 8px;
  width: 2px;
  border-radius: 2px;
  background: linear-gradient(180deg, var(--kiwi) 0%, var(--fog) 72%, transparent 100%);
}

.page-about .ab-node {
  position: relative;
  display: grid;
  grid-template-columns: 44px minmax(0, 1fr);
  gap: clamp(12px, 3vw, 26px);
  padding-bottom: clamp(34px, 6vw, 60px);
}

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

.page-about .ab-node__rail {
  position: relative;
  z-index: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  padding-top: 2px;
}

.page-about .ab-node__idx {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--brown);
  background: var(--paper);
  padding: 2px 4px;
  border-radius: var(--r-s);
}

.page-about .ab-node__mark {
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--paper);
  border: 2px solid var(--brown);
  box-shadow: 0 0 0 4px var(--paper);
}

.page-about .ab-node--s2 .ab-node__mark {
  border-color: var(--cobalt);
}

.page-about .ab-node--s3 .ab-node__mark {
  border-color: var(--kiwi);
}

.page-about .ab-node--s4 .ab-node__mark {
  border-color: var(--cyan-ink);
  background: var(--cyan);
}

.page-about .ab-node__body {
  padding-top: 2px;
}

.page-about .ab-node__eyebrow {
  display: inline-block;
  margin: 0 0 14px;
  padding: 5px 12px;
  border-radius: var(--r-pill);
  background: var(--brown);
  color: var(--paper-2);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
}

.page-about .ab-node--s2 .ab-node__eyebrow {
  background: var(--cobalt);
}

.page-about .ab-node--s3 .ab-node__eyebrow {
  background: var(--kiwi);
  color: var(--ink);
}

.page-about .ab-node--s4 .ab-node__eyebrow {
  background: var(--ink-2);
  color: var(--cyan);
}

.page-about .ab-node h3 {
  margin: 0 0 12px;
  font-size: clamp(20px, 4.4vw, 28px);
  line-height: 1.3;
  letter-spacing: -0.01em;
  color: var(--ink);
}

.page-about .ab-node__text {
  margin: 0 0 18px;
  max-width: 36em;
  font-size: 15.5px;
  line-height: 1.85;
  color: var(--ink-2);
}

/* ── 图片 ─────────────────────────────── */
.page-about .ab-figure {
  margin: 0 0 18px;
}

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

.page-about .ab-media__img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  aspect-ratio: 3 / 2;
  object-fit: cover;
  border-radius: var(--r-m);
  background: var(--fog);
}

.page-about .ab-media__cap {
  margin: 9px 0 0;
  font-size: 12.5px;
  line-height: 1.7;
  color: var(--brown);
}

/* ── 团队面板 ─────────────────────────── */
.page-about .ab-team {
  padding: clamp(30px, 6vw, 64px) 0;
}

.page-about .ab-team__panel {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(30px, 5vw, 52px);
  padding: clamp(26px, 5vw, 56px);
  border-radius: var(--r-organic);
  background: var(--ink-2);
  color: var(--paper-2);
}

.page-about .ab-team__intro .eyebrow {
  color: var(--cyan);
  margin: 0 0 14px;
}

.page-about .ab-team__intro h2 {
  margin: 0 0 16px;
  font-size: clamp(24px, 5vw, 36px);
  line-height: 1.2;
  color: var(--paper-2);
}

.page-about .ab-team__intro .prose {
  color: #d5d9d4;
}

.page-about .ab-team__chart {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: clamp(20px, 4vw, 30px);
}

.page-about .ab-donut {
  position: relative;
  display: grid;
  place-items: center;
  width: min(236px, 60vw);
  aspect-ratio: 1 / 1;
  border-radius: 50%;
  background: conic-gradient(
    from -90deg,
    var(--kiwi) 0 52.4%,
    var(--cobalt) 52.4% 81%,
    var(--cyan) 81% 100%
  );
  transition: transform 0.45s var(--ease);
}

.page-about .ab-donut::after {
  content: "";
  position: absolute;
  inset: 24%;
  border-radius: 50%;
  background: var(--ink-2);
}

.page-about .ab-donut:hover {
  transform: scale(1.035);
}

.page-about .ab-donut__core {
  position: relative;
  z-index: 1;
  font-family: var(--font-mono);
  font-size: clamp(30px, 7vw, 44px);
  line-height: 1;
  color: var(--paper-2);
  font-variant-numeric: tabular-nums;
}

.page-about .ab-legend {
  list-style: none;
  margin: 0;
  padding: 0;
  width: 100%;
  display: grid;
  gap: 12px;
}

.page-about .ab-legend__row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px 10px;
  padding-bottom: 10px;
  border-bottom: 1px solid rgba(255, 253, 247, 0.14);
}

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

.page-about .ab-legend__dot {
  flex: none;
  width: 10px;
  height: 10px;
  border-radius: 50%;
}

.page-about .ab-legend__dot--a { background: var(--kiwi); }
.page-about .ab-legend__dot--b { background: var(--cobalt); }
.page-about .ab-legend__dot--c { background: var(--cyan); }

.page-about .ab-legend__name {
  font-size: 15px;
  font-weight: 700;
  color: var(--paper-2);
}

.page-about .ab-legend__val {
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 14px;
  color: var(--cyan);
  font-variant-numeric: tabular-nums;
}

.page-about .ab-legend__note {
  flex-basis: 100%;
  font-size: 12.5px;
  line-height: 1.7;
  color: #a8b0ad;
}

/* ── 资料库阶梯 ───────────────────────── */
.page-about .ab-library {
  padding: clamp(40px, 8vw, 86px) 0;
}

.page-about .ab-stair {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: clamp(14px, 3vw, 22px);
}

.page-about .ab-stair__item {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: clamp(16px, 3vw, 22px);
  background: var(--paper-2);
  border: 1px solid var(--fog);
  border-top: 4px solid var(--kiwi);
  border-radius: var(--r-s) var(--r-s) var(--r-m) var(--r-m);
}

.page-about .ab-stair__item:nth-child(2) { border-top-color: var(--cobalt); }
.page-about .ab-stair__item:nth-child(3) { border-top-color: var(--brown); }
.page-about .ab-stair__item:nth-child(4) { border-top-color: var(--flag-y); }

.page-about .ab-stair__num {
  font-family: var(--font-mono);
  font-size: clamp(26px, 6vw, 38px);
  line-height: 1;
  color: var(--ink);
  font-variant-numeric: tabular-nums;
}

.page-about .ab-stair__unit {
  font-size: 13px;
  font-weight: 700;
  color: var(--brown);
}

.page-about .ab-stair__text {
  margin: 6px 0 0;
  font-size: 13.5px;
  line-height: 1.7;
  color: var(--ink-2);
}

.page-about .ab-library__note {
  margin: clamp(26px, 5vw, 44px) 0 0;
  max-width: 40em;
  padding-left: 16px;
  border-left: 3px solid var(--kiwi);
  font-size: 14px;
  line-height: 1.85;
  color: var(--brown);
}

/* ── 视觉母题 ─────────────────────────── */
.page-about .ab-visual {
  padding: clamp(34px, 7vw, 72px) 0;
}

.page-about .ab-visual__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(26px, 5vw, 52px);
  align-items: center;
}

.page-about .ab-visual__text .eyebrow {
  margin: 0 0 14px;
}

.page-about .ab-visual h2 {
  margin: 0 0 16px;
  font-size: clamp(24px, 5vw, 36px);
  line-height: 1.2;
  color: var(--ink);
}

.page-about .ab-rules {
  list-style: none;
  margin: 24px 0 0;
  padding: 0;
  display: grid;
  gap: 12px;
}

.page-about .ab-rules li {
  display: grid;
  grid-template-columns: 14px minmax(0, 1fr);
  gap: 12px;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--ink-2);
}

.page-about .ab-rules li::before {
  content: "";
  width: 10px;
  height: 10px;
  margin-top: 9px;
  border-radius: 2px;
  background: var(--kiwi);
  transform: rotate(45deg);
}

/* ── 协作生态 ─────────────────────────── */
.page-about .ab-collab {
  padding: clamp(30px, 6vw, 62px) 0;
}

.page-about .ab-collab__band {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: clamp(20px, 4vw, 32px);
}

.page-about .ab-collab h2 {
  margin: 0 0 16px;
  max-width: 22em;
  font-size: clamp(24px, 5vw, 36px);
  line-height: 1.2;
  color: var(--ink);
}

/* ── 下一步 ───────────────────────────── */
.page-about .ab-next {
  padding: clamp(34px, 7vw, 72px) 0;
}

.page-about .ab-next h2 {
  margin: 12px 0 0;
  font-size: clamp(24px, 5vw, 36px);
  line-height: 1.2;
  color: var(--ink);
}

.page-about .ab-next__list {
  list-style: none;
  margin: clamp(24px, 4vw, 38px) 0 0;
  padding: 0;
  display: grid;
  gap: clamp(20px, 4vw, 30px);
}

.page-about .ab-next__list li {
  padding-top: 16px;
  border-top: 2px solid var(--ink);
}

.page-about .ab-next__num {
  display: block;
  margin-bottom: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--brown);
}

.page-about .ab-next__list h3 {
  margin: 0 0 8px;
  font-size: 18px;
  line-height: 1.4;
  color: var(--ink);
}

.page-about .ab-next__list p {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--ink-2);
}

/* ── 结尾 ─────────────────────────────── */
.page-about .ab-cta {
  padding: 0 0 clamp(40px, 8vw, 88px);
}

.page-about .ab-cta__inner {
  display: grid;
  gap: 22px;
  padding: clamp(28px, 5vw, 52px);
  border-radius: var(--r-organic);
  background: var(--kiwi);
}

.page-about .ab-cta__inner h2 {
  margin: 0 0 10px;
  font-size: clamp(22px, 4.4vw, 32px);
  line-height: 1.24;
  color: var(--ink);
}

.page-about .ab-cta__inner p {
  margin: 0;
  max-width: 34em;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--ink-2);
}

/* ── 桌面端 ───────────────────────────── */
@media (min-width: 880px) {
  .page-about .ab-hero__grid {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr);
  }

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

  .page-about .ab-team__panel {
    grid-template-columns: minmax(0, 1.08fr) minmax(0, 0.92fr);
    align-items: center;
  }

  .page-about .ab-stair {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    align-items: start;
  }

  .page-about .ab-stair__item:nth-child(2) { margin-top: 28px; }
  .page-about .ab-stair__item:nth-child(3) { margin-top: 56px; }
  .page-about .ab-stair__item:nth-child(4) { margin-top: 84px; }

  .page-about .ab-library {
    padding-bottom: clamp(60px, 9vw, 110px);
  }

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

  .page-about .ab-cta__inner {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
  }
}

@media (min-width: 1024px) {
  .page-about .ab-node {
    grid-template-columns: 64px minmax(0, 1fr);
    gap: 34px;
  }

  .page-about .ab-timeline::before {
    left: 32px;
  }

  .page-about .ab-node:nth-child(even) .ab-node__body {
    margin-left: clamp(24px, 4vw, 56px);
  }

  .page-about .ab-hero h1 {
    max-width: 12ch;
  }
}