.page-about {
  --ab-rail: 44px;
  --ab-rule: rgba(201, 191, 166, 0.3);
  --ab-hair: rgba(201, 191, 166, 0.16);
  background-color: var(--ink);
  color: var(--text-soft);
  overflow-x: clip;
}

/* ---------- 首屏 ---------- */
.page-about .ab-hero {
  position: relative;
  padding: clamp(36px, 6vw, 68px) 0 clamp(44px, 7vw, 84px);
  background:
    radial-gradient(120% 90% at 88% 0%, rgba(226, 87, 30, 0.16), transparent 58%),
    linear-gradient(180deg, var(--brick-dark) 0%, var(--ink) 100%);
  border-bottom: 1px solid var(--ab-hair);
}

.page-about .ab-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(var(--ab-hair) 1px, transparent 1px),
    linear-gradient(90deg, var(--ab-hair) 1px, transparent 1px);
  background-size: 84px 84px;
  -webkit-mask-image: linear-gradient(180deg, rgba(0, 0, 0, 0.55), transparent 88%);
  mask-image: linear-gradient(180deg, rgba(0, 0, 0, 0.55), transparent 88%);
  pointer-events: none;
}

.page-about .ab-hero-grid {
  position: relative;
  z-index: 1;
  display: grid;
  gap: 32px;
  align-items: start;
}

.page-about .ab-hero-copy h1 {
  margin: 10px 0 18px;
  color: var(--white);
}

.page-about .ab-lede {
  max-width: 46ch;
  margin: 0 0 26px;
  font-size: var(--fs-400);
  line-height: 1.75;
  color: var(--text-soft);
}

.page-about .ab-hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.page-about .ab-board {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  border: 1px solid var(--line);
  background: rgba(20, 23, 26, 0.62);
}

.page-about .ab-board-cell {
  padding: 18px 14px;
  border-right: 1px solid var(--line-faint);
  border-bottom: 1px solid var(--line-faint);
}

.page-about .ab-board-cell:nth-child(2n) {
  border-right: 0;
}

.page-about .ab-board-cell:nth-child(n + 3) {
  border-bottom: 0;
}

.page-about .ab-board-num {
  display: block;
  font-family: var(--font-mono);
  font-size: 30px;
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--teal);
}

.page-about .ab-board-label {
  display: block;
  margin-top: 8px;
  font-size: var(--fs-200);
  line-height: 1.5;
  color: var(--text-soft);
}

/* ---------- 通用章节头 ---------- */
.page-about .ab-sec-head {
  max-width: 62ch;
  margin-bottom: 30px;
}

.page-about .ab-sec-head h2 {
  margin: 10px 0 14px;
  font-family: var(--font-display);
  font-size: var(--fs-700);
  line-height: 1.15;
  letter-spacing: -0.01em;
  color: var(--white);
}

.page-about .ab-sec-head p {
  margin: 0;
  max-width: 52ch;
  font-size: var(--fs-400);
  line-height: 1.75;
}

.page-about .ab-seasons,
.page-about .ab-ways-section,
.page-about .ab-archive {
  border-top: 1px solid var(--ab-rule);
}

/* ---------- 时间线 ---------- */
.page-about .ab-figure {
  margin: 0 0 32px;
}

.page-about .ab-filter {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
  margin: 0 0 34px;
}

.page-about .ab-filter .filter-btn {
  border-radius: 0;
  border: 1px solid var(--line);
  background: transparent;
  color: var(--text-soft);
  font-family: var(--font-body);
  font-size: var(--fs-300);
  padding: 8px 16px;
  cursor: pointer;
  transition: border-color 0.2s ease, color 0.2s ease, background-color 0.2s ease;
}

.page-about .ab-filter .filter-btn:hover {
  border-color: var(--line-strong);
  color: var(--white);
}

.page-about .ab-filter .filter-btn[aria-pressed="true"] {
  background: var(--orange);
  border-color: var(--orange);
  color: var(--white);
}

.page-about .ab-filter .filter-count {
  font-family: var(--font-mono);
  font-size: var(--fs-200);
  color: var(--seam);
  letter-spacing: 0.04em;
}

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

.page-about .ab-era {
  display: grid;
  grid-template-columns: var(--ab-rail) minmax(0, 1fr);
  gap: 14px;
  padding-bottom: 46px;
}

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

.page-about .ab-era-rail {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
  padding-top: 6px;
}

.page-about .ab-era-rail::before {
  content: "";
  position: absolute;
  top: 6px;
  bottom: -46px;
  left: 50%;
  width: 1px;
  background: var(--ab-hair);
  transform: translateX(-50%);
}

.page-about .ab-era:last-child .ab-era-rail::before {
  bottom: auto;
  height: 32px;
}

.page-about .ab-era-node {
  position: relative;
  z-index: 1;
  width: 13px;
  height: 13px;
  background: var(--brick-dark);
  border: 1px solid var(--line-strong);
  transition: background-color 0.35s ease, border-color 0.35s ease, box-shadow 0.35s ease;
}

.page-about .ab-era.is-visible .ab-era-node {
  background: var(--orange);
  border-color: var(--orange);
  box-shadow: 0 0 0 4px rgba(226, 87, 30, 0.16);
}

.page-about .ab-era-idx {
  font-family: var(--font-mono);
  font-size: var(--fs-200);
  letter-spacing: 0.06em;
  color: var(--seam);
}

.page-about .ab-era-body {
  min-width: 0;
}

.page-about .ab-era-season {
  margin: 0 0 6px;
  font-family: var(--font-mono);
  font-size: var(--fs-200);
  letter-spacing: 0.1em;
  color: var(--orange);
}

.page-about .ab-era-body h3 {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-size: var(--fs-500);
  line-height: 1.3;
  letter-spacing: -0.01em;
  color: var(--white);
}

.page-about .ab-era-body p {
  margin: 0 0 14px;
  max-width: 46ch;
  font-size: var(--fs-400);
  line-height: 1.75;
}

.page-about .ab-facts {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 10px;
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .ab-facts li {
  padding: 4px 10px;
  border: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: var(--fs-200);
  letter-spacing: 0.02em;
  color: var(--teal);
}

/* ---------- 团队 ---------- */
.page-about .ab-team {
  background: var(--brick-dark);
  border-top: 1px solid var(--ab-hair);
  border-bottom: 1px solid var(--ab-hair);
}

.page-about .ab-team-grid {
  display: grid;
  gap: 34px;
  align-items: start;
}

.page-about .ab-team-copy h2 {
  margin: 10px 0 16px;
  font-family: var(--font-display);
  font-size: var(--fs-700);
  line-height: 1.15;
  letter-spacing: -0.01em;
  color: var(--white);
}

.page-about .ab-team-copy p {
  margin: 0 0 14px;
  max-width: 48ch;
  font-size: var(--fs-400);
  line-height: 1.75;
}

.page-about .ab-roster {
  margin: 24px 0 0;
  padding: 0;
  border-top: 1px solid var(--line);
}

.page-about .ab-roster-row {
  display: grid;
  grid-template-columns: 72px minmax(0, 1fr);
  gap: 4px 16px;
  align-items: baseline;
  padding: 14px 0;
  border-bottom: 1px solid var(--line-faint);
}

.page-about .ab-roster-num {
  font-family: var(--font-mono);
  font-size: var(--fs-500);
  letter-spacing: -0.02em;
  color: var(--teal);
}

.page-about .ab-roster-row dd {
  margin: 0;
  font-size: var(--fs-300);
  line-height: 1.6;
  color: var(--text-soft);
}

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

/* ---------- 合作生态（浅色分区） ---------- */
.page-about .ab-eco {
  --text-soft: rgba(20, 23, 26, 0.78);
  --text-dim: #3a4046;
  --seam: #3a4046;
  --line: rgba(20, 23, 26, 0.2);
  --line-faint: rgba(20, 23, 26, 0.1);
  --line-strong: rgba(20, 23, 26, 0.36);
  --ab-rule: rgba(20, 23, 26, 0.22);
  --ab-hair: rgba(20, 23, 26, 0.12);
  background: var(--white);
  color: var(--ink);
}

.page-about .ab-eco .ab-sec-head h2 {
  color: var(--ink);
}

.page-about .ab-eco .eyebrow {
  color: var(--orange-deep);
}

.page-about .ab-eco .eyebrow::before {
  background: var(--orange-deep);
}

.page-about .ab-eco-grid {
  display: grid;
  gap: 1px;
  background: var(--line-faint);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.page-about .ab-eco-cell {
  padding: 24px 20px;
  background: var(--white);
}

.page-about .ab-eco-num {
  display: block;
  font-family: var(--font-mono);
  font-size: 36px;
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--teal-deep);
}

.page-about .ab-eco-cell h3 {
  margin: 12px 0 8px;
  font-family: var(--font-display);
  font-size: var(--fs-500);
  line-height: 1.3;
  color: var(--ink);
}

.page-about .ab-eco-cell p {
  margin: 0;
  font-size: var(--fs-300);
  line-height: 1.75;
  color: var(--text-soft);
}

.page-about .ab-atlas-wrap {
  display: grid;
  gap: 28px;
  margin-top: 34px;
  align-items: start;
}

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

.page-about .ab-atlas-title {
  margin: 0 0 16px;
  font-size: var(--fs-300);
  line-height: 1.7;
  color: var(--text-soft);
}

.page-about .ab-atlas-num {
  font-family: var(--font-mono);
  font-size: var(--fs-500);
  color: var(--orange-deep);
}

.page-about .ab-atlas-grid {
  display: grid;
  grid-template-columns: repeat(8, 1fr);
  gap: 6px;
  max-width: 288px;
  margin-bottom: 16px;
}

.page-about .ab-cell {
  display: block;
  aspect-ratio: 1 / 1;
  border: 1px solid var(--line);
  background: transparent;
}

.page-about .ab-cell.on {
  background: var(--orange);
  border-color: var(--orange);
}

.page-about .ab-atlas-legend {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px 16px;
  margin: 0;
  font-family: var(--font-mono);
  font-size: var(--fs-200);
  color: var(--text-dim);
}

.page-about .ab-legend-box {
  display: inline-block;
  width: 11px;
  height: 11px;
  margin-right: 6px;
  border: 1px solid var(--line-strong);
  vertical-align: -1px;
}

.page-about .ab-legend-box.on {
  background: var(--orange);
  border-color: var(--orange);
}

/* ---------- 加入方式 ---------- */
.page-about .ab-ways {
  display: grid;
  gap: 1px;
  background: var(--ab-hair);
  border: 1px solid var(--line);
}

.page-about .ab-way {
  padding: 26px 20px;
  background: var(--ink);
}

.page-about .ab-way-idx {
  display: block;
  font-family: var(--font-mono);
  font-size: var(--fs-200);
  letter-spacing: 0.1em;
  color: var(--orange);
}

.page-about .ab-way h3 {
  margin: 12px 0 10px;
  font-family: var(--font-display);
  font-size: var(--fs-500);
  line-height: 1.3;
  color: var(--white);
}

.page-about .ab-way p {
  margin: 0 0 16px;
  font-size: var(--fs-400);
  line-height: 1.75;
}

.page-about .ab-way-list {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--line-faint);
}

.page-about .ab-way-list li {
  padding: 9px 0 9px 16px;
  position: relative;
  font-family: var(--font-mono);
  font-size: var(--fs-200);
  color: var(--teal);
  border-bottom: 1px solid var(--line-faint);
}

.page-about .ab-way-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 16px;
  width: 7px;
  height: 1px;
  background: var(--orange);
}

.page-about .ab-ways-note {
  margin: 22px 0 0;
  font-size: var(--fs-300);
  line-height: 1.75;
  color: var(--text-soft);
}

.page-about .ab-ways-note a {
  color: var(--flare);
  text-decoration: underline;
  text-underline-offset: 3px;
}

/* ---------- 数据来路 ---------- */
.page-about .ab-source {
  background: var(--brick-dark);
  border-top: 1px solid var(--ab-hair);
}

.page-about .ab-source-grid {
  display: grid;
  gap: 30px;
  align-items: start;
}

.page-about .ab-source-copy h2 {
  margin: 10px 0 16px;
  font-family: var(--font-display);
  font-size: var(--fs-700);
  line-height: 1.15;
  letter-spacing: -0.01em;
  color: var(--white);
}

.page-about .ab-source-copy p {
  margin: 0 0 14px;
  max-width: 48ch;
  font-size: var(--fs-400);
  line-height: 1.75;
}

.page-about .ab-source-copy a {
  color: var(--flare);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.page-about .ab-source-card {
  border: 1px solid var(--line);
  background: rgba(20, 23, 26, 0.55);
  padding: 22px 20px;
}

.page-about .ab-source-card-title {
  margin: 0 0 14px;
  font-family: var(--font-display);
  font-size: var(--fs-500);
  color: var(--white);
}

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

.page-about .ab-timing li {
  display: grid;
  gap: 4px;
  padding: 12px 0;
  border-top: 1px solid var(--line-faint);
}

.page-about .ab-timing-k {
  font-family: var(--font-mono);
  font-size: var(--fs-200);
  letter-spacing: 0.06em;
  color: var(--orange);
}

.page-about .ab-timing-v {
  font-size: var(--fs-300);
  line-height: 1.65;
  color: var(--text-soft);
}

/* ---------- 赛季归档 ---------- */
.page-about .ab-arch-grid {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: 12px;
}

.page-about .ab-arch-cell {
  grid-column: span 6;
  display: grid;
  gap: 10px;
  padding: 16px 14px;
  border: 1px solid var(--line-faint);
  background: linear-gradient(160deg, rgba(58, 64, 70, 0.42), rgba(20, 23, 26, 0.2));
  transition: border-color 0.25s ease, transform 0.25s ease;
}

.page-about .ab-arch-cell:hover {
  border-color: var(--line-strong);
  transform: translateY(-2px);
}

.page-about .ab-arch-year {
  font-family: var(--font-mono);
  font-size: var(--fs-500);
  letter-spacing: -0.02em;
  color: var(--white);
}

.page-about .ab-arch-dots {
  display: flex;
  gap: 4px;
}

.page-about .ab-arch-dots i {
  display: block;
  width: 6px;
  height: 14px;
  background: var(--brick-mid);
  border: 1px solid var(--line-faint);
}

.page-about .ab-arch-dots i.on {
  background: var(--teal);
  border-color: var(--teal);
}

.page-about .ab-arch-note {
  font-size: var(--fs-200);
  line-height: 1.55;
  color: var(--text-soft);
}

.page-about .ab-arch-foot {
  margin: 26px 0 0;
  max-width: 62ch;
  font-size: var(--fs-300);
  line-height: 1.8;
  color: var(--text-soft);
  border-top: 1px solid var(--ab-hair);
  padding-top: 18px;
}

/* ---------- 收尾 ---------- */
.page-about .ab-cta {
  border-top: 1px solid var(--ab-rule);
  background:
    radial-gradient(90% 120% at 12% 50%, rgba(226, 87, 30, 0.18), transparent 62%),
    var(--brick-dark);
  padding: clamp(40px, 6vw, 72px) 0;
}

.page-about .ab-cta-inner {
  display: grid;
  gap: 22px;
  align-items: center;
}

.page-about .ab-cta-copy h2 {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-size: var(--fs-600);
  line-height: 1.25;
  letter-spacing: -0.01em;
  color: var(--white);
}

.page-about .ab-cta-copy p {
  margin: 0;
  max-width: 48ch;
  font-size: var(--fs-400);
  line-height: 1.75;
}

.page-about .ab-cta-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.page-about .ab-cta .btn {
  border-radius: 0;
}

/* ---------- 响应式 ---------- */
@media (min-width: 700px) {
  .page-about {
    --ab-rail: 64px;
  }

  .page-about .ab-roster-row {
    grid-template-columns: 130px minmax(0, 1fr);
    gap: 4px 24px;
    align-items: center;
  }

  .page-about .ab-timing li {
    grid-template-columns: 150px minmax(0, 1fr);
    gap: 4px 20px;
    align-items: baseline;
  }

  .page-about .ab-arch-cell {
    grid-column: span 4;
  }
}

@media (min-width: 900px) {
  .page-about .ab-hero-grid {
    grid-template-columns: minmax(0, 1.1fr) minmax(0, 0.9fr);
    gap: 56px;
    align-items: center;
  }

  .page-about .ab-board-cell {
    padding: 22px 20px;
  }

  .page-about .ab-board-num {
    font-size: 38px;
  }

  .page-about .ab-team-grid {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
    gap: 48px;
    align-items: center;
  }

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

  .page-about .ab-atlas-wrap {
    grid-template-columns: minmax(0, 0.95fr) minmax(0, 1.05fr);
    gap: 44px;
    align-items: center;
  }

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

  .page-about .ab-way {
    padding: 30px 24px;
  }

  .page-about .ab-source-grid {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr);
    gap: 48px;
    align-items: start;
  }

  .page-about .ab-cta-inner {
    grid-template-columns: minmax(0, 1fr) auto;
    gap: 32px;
  }

  .page-about .ab-era {
    gap: 28px;
  }

  .page-about .ab-era-body h3 {
    font-size: var(--fs-600);
  }
}

@media (min-width: 1200px) {
  .page-about .ab-arch-cell {
    grid-column: span 3;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-era-node,
  .page-about .ab-arch-cell,
  .page-about .ab-filter .filter-btn {
    transition: none;
  }

  .page-about .ab-arch-cell:hover {
    transform: none;
  }
}

/* 渐进增强：仅在脚本就绪后隐藏待显现内容 */
.js-motion .page-about .reveal {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity 0.55s ease, transform 0.55s ease;
}

.js-motion .page-about .reveal.is-visible {
  opacity: 1;
  transform: none;
}

@media (prefers-reduced-motion: reduce) {
  .js-motion .page-about .reveal {
    opacity: 1;
    transform: none;
    transition: none;
  }
}