.page-about {
  --ab-fg: var(--ivory);
  --ab-fg-dim: var(--muted);
  --ab-line: var(--hair);
  --ab-line-strong: var(--hair-strong);
  --ab-accent: var(--lime);
  --ab-accent-warm: var(--orange);
  background: var(--ink);
  color: var(--ivory);
  overflow-x: hidden;
}

.page-about .ab-band {
  padding-block: clamp(42px, 6.5vw, 88px);
}

.page-about .ab-band--ink {
  background: var(--ink);
}

.page-about .ab-band--night {
  background: var(--night);
}

.page-about .ab-band--ivory {
  background: var(--ivory);
  color: var(--charcoal);
  --ab-fg: var(--charcoal);
  --ab-fg-dim: #47555a;
  --ab-line: rgba(6, 42, 36, 0.14);
  --ab-line-strong: rgba(6, 42, 36, 0.3);
  --ab-accent: var(--stand);
  --ab-accent-warm: var(--wine);
}

/* ---------- 首屏 ---------- */
.page-about .ab-hero {
  position: relative;
  padding-block: clamp(18px, 3vw, 30px) clamp(46px, 7vw, 90px);
  background:
    radial-gradient(120% 92% at 14% 0%, var(--stand) 0%, var(--ink) 58%, var(--ink-deep) 100%);
}

.page-about .ab-hero::after {
  content: "";
  position: absolute;
  right: -80px;
  bottom: -80px;
  width: 280px;
  height: 280px;
  border: 1px solid var(--hair-strong);
  transform: rotate(24deg);
  pointer-events: none;
}

.page-about .ab-crumbs {
  margin-bottom: clamp(20px, 3vw, 34px);
  position: relative;
  z-index: 1;
}

.page-about .ab-hero__grid {
  display: grid;
  gap: clamp(26px, 5vw, 54px);
  position: relative;
  z-index: 1;
}

.page-about .ab-eyebrow {
  color: var(--silver);
  margin: 0 0 16px;
}

.page-about .ab-hero__title {
  margin: 0 0 20px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(38px, 8.4vw, 78px);
  line-height: 1.02;
  letter-spacing: 0.01em;
  color: var(--ivory);
}

.page-about .ab-hero__lede {
  margin: 0 0 clamp(24px, 4vw, 36px);
  max-width: 34em;
  font-size: clamp(15.5px, 2vw, 17.5px);
  line-height: 1.85;
  color: var(--muted);
}

.page-about .ab-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 0;
  background: var(--hair);
  border-top: 1px solid var(--hair);
  border-bottom: 1px solid var(--hair);
}

.page-about .ab-stat {
  background: rgba(10, 26, 47, 0.55);
  padding: 14px 14px 16px;
}

.page-about .ab-stat dt {
  font-size: 11.5px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--muted-soft);
  margin-bottom: 6px;
}

.page-about .ab-stat dd {
  margin: 0;
  font-family: var(--font-mono);
  font-size: clamp(22px, 3.4vw, 30px);
  line-height: 1;
  color: var(--lime);
}

.page-about .ab-stat dd .num {
  font-size: inherit;
}

.page-about .ab-hero__media {
  position: relative;
  margin: 0;
  aspect-ratio: 4 / 3;
  overflow: hidden;
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 44px), calc(100% - 44px) 100%, 0 100%);
  box-shadow: 0 24px 60px rgba(0, 0, 0, 0.45);
}

.page-about .ab-hero__img {
  display: block;
  width: 100%;
  height: 100%;
  max-width: 100%;
  object-fit: cover;
}

.page-about .ab-hero__caption {
  position: absolute;
  left: 0;
  bottom: 0;
  padding: 10px 16px;
  background: rgba(4, 29, 25, 0.82);
  border-top: 1px solid var(--hair-strong);
  font-size: 12.5px;
  letter-spacing: 0.04em;
  color: var(--silver);
}

/* ---------- 目录条带 ---------- */
.page-about .ab-index {
  background: var(--night);
  border-block: 1px solid var(--hair);
}

.page-about .ab-index__list {
  display: flex;
  gap: 0;
  margin: 0;
  padding: 0;
  list-style: none;
  overflow-x: auto;
  scrollbar-width: none;
  -webkit-overflow-scrolling: touch;
}

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

.page-about .ab-index__item {
  flex: 0 0 auto;
}

.page-about .ab-index__link {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  padding: 15px 16px;
  font-size: 13.5px;
  text-decoration: none;
  color: var(--muted);
  white-space: nowrap;
  border-bottom: 2px solid transparent;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .ab-index__link:hover,
.page-about .ab-index__link.is-active,
.page-about .ab-index__link[aria-current="true"] {
  color: var(--lime);
  border-bottom-color: var(--lime);
}

.page-about .ab-index__no {
  font-size: 11px;
  color: var(--silver);
  opacity: 0.7;
}

/* ---------- 章节骨架 ---------- */
.page-about .ab-sec__grid {
  display: grid;
  gap: 18px;
}

.page-about .ab-sec__side {
  display: flex;
  align-items: baseline;
  gap: 12px;
}

.page-about .ab-side__label {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--ab-fg-dim);
}

.page-about .ab-no {
  display: block;
  font-size: clamp(40px, 7vw, 64px);
  line-height: 0.9;
  color: var(--ab-line-strong);
}

@supports (-webkit-text-stroke: 1px currentColor) {
  .page-about .ab-no {
    color: transparent;
    -webkit-text-stroke: 1.4px var(--ab-line-strong);
  }
}

.page-about .ab-h2 {
  margin: 0 0 16px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(27px, 4.6vw, 44px);
  line-height: 1.14;
  letter-spacing: 0.005em;
  color: var(--ab-fg);
}

.page-about .ab-lede {
  margin: 0 0 clamp(22px, 3.5vw, 32px);
  max-width: 40em;
  font-size: 15.5px;
  line-height: 1.85;
  color: var(--ab-fg-dim);
}

.page-about .ab-cols {
  display: grid;
  gap: clamp(20px, 3.5vw, 34px);
}

.page-about .ab-prose p {
  margin: 0 0 1em;
  font-size: 16px;
  line-height: 1.9;
  color: var(--ab-fg);
}

.page-about .ab-prose p:last-child {
  margin-bottom: 0;
}

.page-about .ab-note {
  align-self: start;
  padding: 20px 20px 20px 18px;
  border-left: 3px solid var(--ab-accent);
  background: rgba(14, 59, 53, 0.1);
}

.page-about .ab-note--contact {
  background: rgba(6, 42, 36, 0.35);
}

.page-about .ab-band--night .ab-note {
  background: rgba(14, 59, 53, 0.42);
}

.page-about .ab-note__title {
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--ab-accent);
}

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

.page-about .ab-note__row {
  display: grid;
  gap: 3px;
  padding: 9px 0;
  border-top: 1px solid var(--ab-line);
}

.page-about .ab-note__row:first-child {
  border-top: 0;
  padding-top: 0;
}

.page-about .ab-note__row dt {
  font-size: 11.5px;
  letter-spacing: 0.1em;
  color: var(--ab-fg-dim);
}

.page-about .ab-note__row dd {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.6;
  color: var(--ab-fg);
}

.page-about .ab-note__mono {
  font-family: var(--font-mono);
  font-size: 13.5px;
  word-break: break-all;
}

.page-about .ab-note__link {
  display: inline-block;
  margin-top: 16px;
  font-size: 13.5px;
  color: var(--ab-accent-warm);
  text-decoration: none;
  border-bottom: 1px solid currentColor;
  padding-bottom: 2px;
}

.page-about .ab-note__link:hover {
  color: var(--ab-fg);
}

/* ---------- 准则折叠卡 ---------- */
.page-about .ab-rules {
  border-bottom: 1px solid var(--ab-line);
}

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

.page-about .ab-rule__sum {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  align-items: center;
  gap: 14px;
  padding: 20px 0;
  cursor: pointer;
  list-style: none;
}

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

.page-about .ab-rule__no {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--ab-accent);
  letter-spacing: 0.08em;
  padding: 4px 8px;
  border: 1px solid var(--ab-line-strong);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 7px), calc(100% - 7px) 100%, 0 100%);
}

.page-about .ab-rule__name {
  font-size: clamp(16.5px, 2.4vw, 20px);
  font-weight: 700;
  line-height: 1.5;
  color: var(--ab-fg);
  transition: color var(--dur) var(--ease);
}

.page-about .ab-rule__sum:hover .ab-rule__name {
  color: var(--ab-accent);
}

.page-about .ab-rule__cue {
  position: relative;
  width: 26px;
  height: 26px;
  border: 1px solid var(--ab-line-strong);
  border-radius: 50%;
  flex: none;
}

.page-about .ab-rule__cue::before,
.page-about .ab-rule__cue::after {
  content: "";
  position: absolute;
  left: 7px;
  right: 7px;
  top: 50%;
  height: 1.5px;
  background: var(--ab-accent);
  transform: translateY(-50%);
}

.page-about .ab-rule__cue::after {
  transform: translateY(-50%) rotate(90deg);
  transition: transform var(--dur) var(--ease);
}

.page-about .ab-rule[open] .ab-rule__cue::after {
  transform: translateY(-50%) rotate(0deg);
}

.page-about .ab-rule__body {
  padding: 0 0 22px;
  max-width: 44em;
}

.page-about .ab-rule__body p {
  margin: 0;
  font-size: 15.5px;
  line-height: 1.9;
  color: var(--ab-fg-dim);
}

/* ---------- 校订节奏 ---------- */
.page-about .ab-track {
  display: none;
  width: 100%;
  height: 24px;
  margin-bottom: 10px;
  color: var(--hair-strong);
}

.page-about .ab-steps {
  display: grid;
  gap: 14px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .ab-step {
  padding: 22px 22px 24px;
  background: var(--stand);
  border-top: 2px solid var(--lime);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 20px), calc(100% - 20px) 100%, 0 100%);
}

.page-about .ab-step__time {
  display: block;
  margin-bottom: 10px;
  font-size: 12.5px;
  letter-spacing: 0.16em;
  color: var(--lime);
}

.page-about .ab-step__title {
  margin: 0 0 10px;
  font-size: 16px;
  font-weight: 700;
  line-height: 1.5;
  color: var(--ivory);
}

.page-about .ab-step p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--muted);
}

.page-about .ab-foot-note {
  margin: 26px 0 0;
  padding-top: 18px;
  border-top: 1px solid var(--ab-line);
  font-size: 14px;
  line-height: 1.85;
  color: var(--ab-fg-dim);
}

.page-about .ab-inline-link {
  color: var(--ab-accent-warm);
  text-decoration: none;
  border-bottom: 1px solid currentColor;
}

.page-about .ab-inline-link:hover {
  color: var(--ab-fg);
}

/* ---------- 团队 ---------- */
.page-about .ab-crew {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
  margin: 0 0 clamp(24px, 4vw, 38px);
  padding: 0;
  list-style: none;
}

.page-about .ab-crew__item {
  padding: 16px 15px 18px;
  border: 1px solid var(--ab-line);
  background: rgba(6, 42, 36, 0.03);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 12px), calc(100% - 12px) 100%, 0 100%);
  transition: border-color var(--dur) var(--ease), background var(--dur) var(--ease);
}

.page-about .ab-crew__item:hover {
  border-color: var(--ab-accent);
  background: rgba(6, 42, 36, 0.07);
}

.page-about .ab-crew__num {
  display: block;
  font-size: clamp(26px, 4.6vw, 36px);
  line-height: 1;
  color: var(--ab-accent);
  margin-bottom: 8px;
}

.page-about .ab-crew__role {
  margin: 0 0 6px;
  font-size: 14.5px;
  font-weight: 700;
  color: var(--ab-fg);
}

.page-about .ab-crew__item p {
  margin: 0;
  font-size: 12.8px;
  line-height: 1.7;
  color: var(--ab-fg-dim);
}

.page-about .ab-team__split {
  display: grid;
  gap: clamp(20px, 3.5vw, 32px);
}

.page-about .ab-team__media {
  margin: 0;
  aspect-ratio: 14 / 9;
  overflow: hidden;
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 26px), calc(100% - 26px) 100%, 0 100%);
}

.page-about .ab-team__media img {
  display: block;
  width: 100%;
  height: 100%;
  max-width: 100%;
  object-fit: cover;
}

.page-about .ab-team__h3 {
  margin: 0 0 12px;
  font-size: clamp(17px, 2.6vw, 21px);
  font-weight: 700;
  line-height: 1.4;
  color: var(--ab-fg);
}

.page-about .ab-team__text p {
  margin: 0 0 1em;
  font-size: 15px;
  line-height: 1.9;
  color: var(--ab-fg-dim);
}

.page-about .ab-team__cta {
  margin: 18px 0 0;
}

/* ---------- 版本演进 ---------- */
.page-about .ab-years {
  display: grid;
  gap: 0;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .ab-year {
  position: relative;
  padding: 20px 0 24px;
  border-top: 1px solid var(--ab-line-strong);
  transition: border-color var(--dur) var(--ease);
}

.page-about .ab-year::before {
  content: "";
  position: absolute;
  top: -5px;
  left: 0;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--silver);
  transition: background var(--dur) var(--ease), transform var(--dur) var(--ease);
}

.page-about .ab-year:hover {
  border-top-color: var(--lime);
}

.page-about .ab-year:hover::before {
  background: var(--lime);
  transform: scale(1.35);
}

.page-about .ab-year__tag {
  display: block;
  margin-bottom: 10px;
  font-size: clamp(22px, 3.6vw, 30px);
  color: var(--silver);
  letter-spacing: 0.04em;
  transition: color var(--dur) var(--ease);
}

.page-about .ab-year:hover .ab-year__tag {
  color: var(--lime);
}

.page-about .ab-year__title {
  margin: 0 0 8px;
  font-size: 15.5px;
  font-weight: 700;
  line-height: 1.5;
  color: var(--ivory);
}

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

/* ---------- 天津 ---------- */
.page-about .ab-region__media {
  position: relative;
  margin: clamp(24px, 4vw, 38px) 0 0;
  aspect-ratio: 16 / 9;
  overflow: hidden;
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 34px), calc(100% - 34px) 100%, 0 100%);
}

.page-about .ab-region__media img {
  display: block;
  width: 100%;
  height: 100%;
  max-width: 100%;
  object-fit: cover;
}

.page-about .ab-region__caption {
  position: absolute;
  left: 0;
  bottom: 0;
  padding: 9px 15px;
  background: rgba(4, 29, 25, 0.82);
  border-top: 1px solid var(--hair-strong);
  font-size: 12.5px;
  color: var(--silver);
}

/* ---------- 收尾 ---------- */
.page-about .ab-close {
  background: var(--ink-deep);
  border-top: 3px solid var(--lime);
  padding-block: clamp(34px, 5vw, 56px);
}

.page-about .ab-close__inner {
  display: grid;
  gap: 18px;
}

.page-about .ab-close__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(24px, 4vw, 34px);
  line-height: 1.2;
  color: var(--ivory);
}

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

.page-about .ab-close__links .btn {
  flex: 0 1 auto;
}

/* ---------- 响应式 ---------- */
@media (min-width: 700px) {
  .page-about .ab-crew {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

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

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

@media (min-width: 860px) {
  .page-about .ab-hero__grid {
    grid-template-columns: minmax(0, 1.02fr) minmax(0, 0.98fr);
    align-items: end;
  }

  .page-about .ab-cols {
    grid-template-columns: minmax(0, 1fr) minmax(240px, 300px);
  }

  .page-about .ab-cols--reverse {
    grid-template-columns: minmax(0, 1fr) minmax(250px, 320px);
  }

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

  .page-about .ab-track {
    display: block;
  }

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

@media (min-width: 1000px) {
  .page-about .ab-sec__grid {
    grid-template-columns: 104px minmax(0, 1fr);
    gap: clamp(26px, 4vw, 56px);
  }

  .page-about .ab-sec__side {
    flex-direction: column;
    align-items: flex-start;
    gap: 10px;
    position: sticky;
    top: 28px;
    align-self: start;
  }

  .page-about .ab-side__label {
    writing-mode: vertical-rl;
    letter-spacing: 0.32em;
  }

  .page-about .ab-crew {
    grid-template-columns: repeat(5, minmax(0, 1fr));
  }

  .page-about .ab-years {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 0 20px;
  }

  .page-about .ab-year {
    padding-top: 22px;
    padding-bottom: 8px;
  }

  .page-about .ab-index__list {
    justify-content: center;
  }

  .page-about .ab-index__link {
    padding: 16px 22px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-rule__cue::after,
  .page-about .ab-year::before,
  .page-about .ab-year__tag,
  .page-about .ab-crew__item {
    transition: none;
  }
}