.page-about {
  --ab-pad: clamp(46px, 7vw, 96px);
  --ab-gap: clamp(18px, 3vw, 34px);
  position: relative;
  padding-bottom: clamp(40px, 6vw, 84px);
  background:
    radial-gradient(120% 90% at 6% -14%, rgba(53, 232, 208, 0.10), transparent 58%),
    radial-gradient(90% 70% at 104% 2%, rgba(255, 122, 47, 0.07), transparent 52%);
}

.page-about .ab-unit {
  font-size: 0.5em;
  margin-left: 4px;
  letter-spacing: 0;
}

/* ---------- 首屏 ---------- */
.page-about .ab-hero {
  padding-top: clamp(18px, 3vw, 36px);
}

.page-about .ab-hero__grid {
  display: grid;
  gap: clamp(26px, 4vw, 48px);
}

.page-about .ab-hero__title {
  margin: 14px 0 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(36px, 8.4vw, 78px);
  line-height: 1.04;
  letter-spacing: -0.02em;
  color: var(--text-primary);
}

.page-about .ab-hero__accent {
  color: var(--accent-cyan);
}

.page-about .ab-hero__lead {
  margin: 20px 0 0;
  max-width: 52ch;
  font-size: clamp(15px, 0.5vw + 14px, 17px);
  line-height: 1.8;
  color: var(--text-secondary);
}

.page-about .ab-hero__facts {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 24px;
  margin: 26px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .ab-hero__facts li {
  display: flex;
  align-items: baseline;
  gap: 8px;
  font-size: 13px;
  color: var(--text-muted);
}

.page-about .ab-hero__facts .mono {
  font-size: 20px;
  font-weight: 700;
  color: var(--accent-cyan);
}

.page-about .ab-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 30px;
}

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

.page-about .ab-hero__media .media-frame__inner {
  aspect-ratio: 3 / 4;
  overflow: hidden;
  border-radius: var(--r-xl);
  border: 1px solid var(--line-moss);
  background: var(--bg-deep-moss);
}

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

/* ---------- 目录 ---------- */
.page-about .ab-toc {
  margin-top: clamp(30px, 5vw, 58px);
  border-top: 1px solid var(--line-moss);
  border-bottom: 1px solid var(--line-moss);
  background: rgba(14, 27, 23, 0.7);
}

.page-about .ab-toc__list {
  display: flex;
  gap: 10px;
  margin: 0;
  padding: 16px 0;
  list-style: none;
  overflow-x: auto;
  scrollbar-width: none;
}

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

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

.page-about .ab-toc__list a {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 9px 16px;
  border: 1px solid var(--line-moss);
  border-radius: var(--r-pill);
  background: var(--surface-panel);
  color: var(--text-secondary);
  font-size: 13px;
  text-decoration: none;
  white-space: nowrap;
  transition: border-color 180ms ease, color 180ms ease, background-color 180ms ease;
}

.page-about .ab-toc__list a .mono {
  color: var(--accent-cyan);
  font-size: 12px;
}

.page-about .ab-toc__list a:hover,
.page-about .ab-toc__list a:focus-visible {
  border-color: var(--accent-cyan);
  color: var(--text-primary);
  background: var(--surface-raised);
}

/* ---------- 通用板块骨架 ---------- */
.page-about .ab-section {
  padding: var(--ab-pad) 0;
}

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

.page-about .ab-head {
  display: grid;
  gap: 10px;
  max-width: 800px;
}

.page-about .ab-head__num {
  font-size: 12px;
  letter-spacing: 0.22em;
  color: var(--accent-cyan);
  opacity: 0.85;
}

.page-about .ab-head__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(25px, 4.2vw, 46px);
  line-height: 1.16;
  letter-spacing: -0.01em;
  color: var(--text-primary);
}

.page-about .ab-head__note {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--text-secondary);
}

/* ---------- 缘起 ---------- */
.page-about .ab-origin {
  display: grid;
  gap: clamp(22px, 3.5vw, 44px);
  margin-top: clamp(26px, 4vw, 44px);
}

.page-about .ab-origin__prose p {
  margin: 0 0 16px;
  font-size: 15px;
  line-height: 1.85;
  color: var(--text-secondary);
}

.page-about .ab-origin__prose p:first-child {
  color: var(--text-primary);
}

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

.page-about .ab-origin__aside {
  padding: clamp(18px, 2.4vw, 26px);
  border: 1px solid var(--line-moss);
  border-radius: var(--r-lg);
  background: var(--surface-panel);
}

.page-about .ab-origin__aside-title {
  margin: 0 0 14px;
  font-size: 12px;
  letter-spacing: 0.2em;
  color: var(--text-muted);
}

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

.page-about .ab-leagues__item {
  display: grid;
  grid-template-columns: 6px 1fr auto;
  align-items: center;
  gap: 12px;
}

.page-about .ab-leagues__bar {
  display: block;
  width: 6px;
  height: 26px;
  border-radius: var(--r-pill);
  opacity: 0.85;
}

.page-about .ab-leagues__bar--1 { background: var(--accent-cyan); }
.page-about .ab-leagues__bar--2 { background: var(--accent-gold); }
.page-about .ab-leagues__bar--3 { background: var(--accent-orange); }
.page-about .ab-leagues__bar--4 { background: var(--text-secondary); }
.page-about .ab-leagues__bar--5 { background: var(--signal-red); }

.page-about .ab-leagues__name {
  font-size: 14px;
  color: var(--text-primary);
}

.page-about .ab-leagues__meta {
  font-size: 12px;
  color: var(--text-muted);
}

/* ---------- 数据来源 ---------- */
.page-about .ab-sources {
  display: grid;
  gap: clamp(22px, 3.5vw, 40px);
  margin-top: clamp(26px, 4vw, 44px);
}

.page-about .ab-sources__list {
  display: grid;
  gap: 14px;
}

.page-about .ab-source {
  padding: clamp(18px, 2.4vw, 26px);
  border: 1px solid var(--line-moss);
  border-radius: var(--r-lg);
  background: var(--surface-panel);
}

.page-about .ab-source--rule {
  background: linear-gradient(120deg, rgba(255, 122, 47, 0.10), transparent 70%), var(--surface-panel);
  border-color: rgba(255, 122, 47, 0.34);
}

.page-about .ab-source h3 {
  margin: 12px 0 8px;
  font-size: 17px;
  line-height: 1.4;
  color: var(--text-primary);
}

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

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

.page-about .ab-sources__media .media-frame__inner {
  aspect-ratio: 12 / 7;
  overflow: hidden;
  border-radius: var(--r-lg);
  border: 1px solid var(--line-moss);
  background: var(--bg-deep-moss);
}

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

.page-about .ab-rhythm {
  display: grid;
  gap: 1px;
  margin-top: clamp(24px, 3.5vw, 40px);
  border: 1px solid var(--line-moss);
  border-radius: var(--r-lg);
  overflow: hidden;
  background: var(--line-moss);
}

.page-about .ab-rhythm .stat {
  display: grid;
  gap: 6px;
  padding: 20px 22px;
  background: var(--bg-deep-moss);
}

.page-about .ab-rhythm .stat__value {
  font-size: clamp(24px, 3vw, 32px);
  font-weight: 700;
  color: var(--accent-cyan);
  line-height: 1.1;
}

.page-about .ab-rhythm .stat__value--orange { color: var(--accent-orange); }
.page-about .ab-rhythm .stat__value--gold { color: var(--accent-gold); }

.page-about .ab-rhythm .stat__label {
  font-size: 13px;
  line-height: 1.6;
  color: var(--text-muted);
}

/* ---------- 记录边界 ---------- */
.page-about .ab-scope__grid {
  display: grid;
  gap: clamp(16px, 3vw, 28px);
  margin-top: clamp(26px, 4vw, 44px);
}

.page-about .ab-scope__col {
  padding: clamp(18px, 2.4vw, 28px);
  border: 1px solid var(--line-moss);
  border-radius: var(--r-lg);
  background: var(--surface-panel);
}

.page-about .ab-scope__col--keep { border-top: 3px solid var(--accent-cyan); }
.page-about .ab-scope__col--skip { border-top: 3px solid var(--signal-red); }

.page-about .ab-scope__col-title {
  display: flex;
  align-items: center;
  gap: 10px;
  margin: 0 0 14px;
  font-size: 15px;
  letter-spacing: 0.04em;
  color: var(--text-primary);
}

.page-about .ab-scope__dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--accent-cyan);
}

.page-about .ab-scope__col--skip .ab-scope__dot {
  background: var(--signal-red);
}

.page-about .ab-scope__item {
  border-top: 1px solid var(--line-moss);
  padding: 12px 0;
}

.page-about .ab-scope__item:first-of-type {
  border-top: 0;
  padding-top: 0;
}

.page-about .ab-scope__item summary {
  display: flex;
  align-items: baseline;
  gap: 10px;
  cursor: pointer;
  list-style: none;
  font-size: 14.5px;
  font-weight: 600;
  line-height: 1.6;
  color: var(--text-primary);
}

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

.page-about .ab-scope__item summary::after {
  content: "+";
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 15px;
  color: var(--accent-cyan);
  transition: transform 200ms ease;
}

.page-about .ab-scope__item[open] summary::after {
  content: "−";
  transform: rotate(180deg);
}

.page-about .ab-scope__item p {
  margin: 8px 0 0;
  font-size: 13.5px;
  line-height: 1.8;
  color: var(--text-secondary);
}

.page-about .ab-quote {
  margin: clamp(24px, 3.5vw, 40px) 0 0;
  padding: clamp(22px, 3vw, 34px);
  border: 1px solid var(--line-moss);
  border-radius: var(--r-lg);
  background:
    repeating-linear-gradient(90deg, rgba(53, 232, 208, 0.055) 0 1px, transparent 1px 34px),
    repeating-linear-gradient(0deg, rgba(53, 232, 208, 0.055) 0 1px, transparent 1px 34px),
    var(--bg-deep-moss);
}

.page-about .ab-quote p {
  margin: 0;
  font-size: clamp(15px, 0.6vw + 14px, 18px);
  line-height: 1.8;
  color: var(--text-primary);
}

.page-about .ab-quote__src {
  margin-top: 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--text-muted);
}

/* ---------- 时间线 ---------- */
.page-about .ab-tl {
  display: grid;
  grid-auto-flow: column;
  grid-auto-columns: minmax(232px, 76%);
  gap: 14px;
  margin-top: clamp(26px, 4vw, 44px);
  padding-bottom: 8px;
  overflow-x: auto;
  scroll-snap-type: x mandatory;
  scrollbar-width: thin;
}

.page-about .ab-tl__node {
  position: relative;
  scroll-snap-align: start;
  min-width: 0;
  padding: 18px 20px 22px;
  border: 1px solid var(--line-moss);
  border-radius: var(--r-md);
  background: var(--surface-panel);
}

.page-about .ab-tl__year {
  display: block;
  font-size: 20px;
  font-weight: 700;
  color: var(--accent-cyan);
  letter-spacing: -0.01em;
}

.page-about .ab-tl__title {
  margin: 10px 0 8px;
  font-size: 16px;
  line-height: 1.4;
  color: var(--text-primary);
}

.page-about .ab-tl__node p {
  margin: 0;
  font-size: 13.5px;
  line-height: 1.8;
  color: var(--text-secondary);
}

/* ---------- 团队 ---------- */
.page-about .ab-team {
  display: grid;
  gap: 12px;
  margin-top: clamp(26px, 4vw, 44px);
}

.page-about .ab-team__cell {
  padding: clamp(18px, 2.2vw, 26px);
  border: 1px solid var(--line-moss);
  border-left: 3px solid var(--accent-cyan);
  border-radius: var(--r-md);
  background: var(--surface-panel);
}

.page-about .ab-team__num {
  display: block;
  font-size: 28px;
  font-weight: 700;
  line-height: 1;
  color: var(--accent-gold);
}

.page-about .ab-team__name {
  margin: 12px 0 8px;
  font-size: 16px;
  color: var(--text-primary);
}

.page-about .ab-team__cell p {
  margin: 0;
  font-size: 13.5px;
  line-height: 1.8;
  color: var(--text-secondary);
}

.page-about .ab-team__media {
  margin: clamp(24px, 3.5vw, 40px) 0 0;
}

.page-about .ab-team__media .media-frame__inner {
  aspect-ratio: 7 / 4;
  overflow: hidden;
  border-radius: var(--r-lg);
  border: 1px solid var(--line-moss);
  background: var(--bg-deep-moss);
}

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

/* ---------- 纠错 ---------- */
.page-about .ab-fix {
  display: grid;
  gap: clamp(22px, 3.5vw, 40px);
  margin-top: clamp(26px, 4vw, 44px);
}

.page-about .ab-fix__steps {
  display: grid;
  gap: 1px;
  margin: 0;
  padding: 0;
  list-style: none;
  border: 1px solid var(--line-moss);
  border-radius: var(--r-lg);
  overflow: hidden;
  background: var(--line-moss);
}

.page-about .ab-fix__step {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 16px;
  padding: 20px 22px;
  background: var(--surface-panel);
}

.page-about .ab-fix__idx {
  font-size: 13px;
  font-weight: 700;
  color: var(--accent-cyan);
  padding-top: 3px;
}

.page-about .ab-fix__step h3 {
  margin: 0 0 6px;
  font-size: 15.5px;
  color: var(--text-primary);
}

.page-about .ab-fix__step p {
  margin: 0;
  font-size: 13.5px;
  line-height: 1.8;
  color: var(--text-secondary);
}

.page-about .ab-fix__contact {
  padding: clamp(20px, 2.6vw, 28px);
  border: 1px solid var(--line-moss);
  border-radius: var(--r-lg);
  background: var(--bg-deep-moss);
}

.page-about .ab-fix__contact-title {
  margin: 0 0 16px;
  font-size: 12px;
  letter-spacing: 0.2em;
  color: var(--text-muted);
}

.page-about .ab-fix__list {
  margin: 0;
  display: grid;
  gap: 12px;
}

.page-about .ab-fix__row {
  display: grid;
  gap: 4px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--line-moss);
}

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

.page-about .ab-fix__row dt {
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--text-muted);
}

.page-about .ab-fix__row dd {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.6;
  color: var(--text-primary);
  word-break: break-word;
}

.page-about .ab-fix__row dd a {
  color: var(--accent-cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(53, 232, 208, 0.4);
}

.page-about .ab-fix__contact-note {
  margin: 18px 0 0;
  font-size: 12.5px;
  line-height: 1.8;
  color: var(--text-muted);
}

.page-about .ab-more {
  margin-top: clamp(26px, 4vw, 44px);
  padding-top: clamp(20px, 3vw, 30px);
  border-top: 1px solid var(--line-moss);
}

.page-about .ab-more__title {
  margin: 0 0 14px;
  font-size: 12px;
  letter-spacing: 0.2em;
  color: var(--text-muted);
}

.page-about .ab-more__list {
  display: grid;
  gap: 8px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .ab-more__list a {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding: 14px 18px;
  border: 1px solid var(--line-moss);
  border-radius: var(--r-md);
  background: var(--surface-panel);
  color: var(--text-primary);
  font-size: 14.5px;
  text-decoration: none;
  transition: border-color 180ms ease, background-color 180ms ease, color 180ms ease;
}

.page-about .ab-more__list a .mono {
  font-size: 12px;
  color: var(--accent-cyan);
}

.page-about .ab-more__list a:hover,
.page-about .ab-more__list a:focus-visible {
  border-color: var(--accent-cyan);
  background: var(--surface-raised);
}

/* ---------- 响应式 ---------- */
@media (min-width: 620px) {
  .page-about .ab-rhythm {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .ab-team {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .ab-more__list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .ab-tl {
    grid-auto-columns: minmax(260px, 46%);
  }
}

@media (min-width: 900px) {
  .page-about .ab-hero__grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
    align-items: end;
  }

  .page-about .ab-origin {
    grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
    align-items: start;
  }

  .page-about .ab-sources {
    grid-template-columns: minmax(0, 6fr) minmax(0, 5fr);
    align-items: start;
  }

  .page-about .ab-scope__grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .ab-fix {
    grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
    align-items: start;
  }
}

@media (min-width: 1000px) {
  .page-about .ab-rhythm {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .ab-tl {
    grid-auto-flow: row;
    grid-template-columns: repeat(6, minmax(0, 1fr));
    gap: 22px;
    padding-top: 48px;
    overflow: visible;
    scroll-snap-type: none;
  }

  .page-about .ab-tl::before {
    content: "";
    position: absolute;
    top: 16px;
    left: 0;
    right: 0;
    height: 1px;
    background: linear-gradient(90deg, var(--accent-cyan), var(--line-moss) 45%, var(--line-moss));
  }

  .page-about .ab-tl {
    position: relative;
  }

  .page-about .ab-tl__node {
    padding: 0;
    border: 0;
    background: transparent;
  }

  .page-about .ab-tl__node::before {
    content: "";
    position: absolute;
    top: -38px;
    left: 0;
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: var(--accent-cyan);
    box-shadow: 0 0 0 4px rgba(53, 232, 208, 0.14);
  }

  .page-about .ab-tl__node::after {
    content: "";
    position: absolute;
    top: -30px;
    left: 4px;
    width: 1px;
    height: 24px;
    background: var(--line-moss);
  }

  .page-about .ab-tl__year {
    font-size: 18px;
  }
}

@media (min-width: 1160px) {
  .page-about .ab-team {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-toc__list a,
  .page-about .ab-scope__item summary::after,
  .page-about .ab-more__list a {
    transition: none;
  }

  .page-about .ab-scope__item[open] summary::after {
    transform: none;
  }
}