.page-about {
  --ab-gap: clamp(56px, 8vw, 120px);
  --ab-hair: rgba(33, 230, 193, 0.28);
  display: block;
}

/* ---------- 首屏 ---------- */
.page-about .ab-hero {
  position: relative;
  overflow: hidden;
  padding: clamp(26px, 5vw, 56px) 0 clamp(52px, 8vw, 104px);
  background:
    radial-gradient(120% 90% at 78% -10%, rgba(33, 230, 193, 0.16), transparent 60%),
    radial-gradient(90% 70% at 8% 0%, rgba(255, 122, 51, 0.10), transparent 55%),
    linear-gradient(180deg, var(--ink-800), var(--ink-900) 72%);
}

.page-about .ab-hero-tag {
  margin: clamp(28px, 5vw, 56px) 0 0;
  color: var(--cyan);
}

.page-about .ab-title {
  margin: 18px 0 0;
  font-family: var(--font-sans);
  font-weight: 200;
  font-size: clamp(46px, 8.4vw, 128px);
  line-height: 0.94;
  letter-spacing: -0.02em;
  color: var(--mist);
}

.page-about .ab-lede {
  max-width: 60ch;
  margin: clamp(20px, 3vw, 32px) 0 0;
  color: var(--steel);
  font-size: 17px;
  line-height: 1.8;
}

.page-about .ab-figures {
  list-style: none;
  margin: clamp(34px, 5vw, 56px) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 20px 22px;
}

.page-about .ab-figures li {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding-top: 14px;
  border-top: 1px solid var(--line-soft);
}

.page-about .ab-figures .data-figure {
  font-size: clamp(28px, 4vw, 44px);
  line-height: 1;
  color: var(--cyan);
}

.page-about .ab-unit {
  font-size: 0.45em;
  margin-left: 2px;
  color: var(--cyan-soft);
}

.page-about .ab-fig-label {
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--steel);
}

/* ---------- 通用区块 ---------- */
.page-about .ab-sec {
  padding: var(--ab-gap) 0;
}

.page-about .ab-sec-alt {
  background: linear-gradient(180deg, var(--ink-800), var(--ink-900));
  border-top: 1px solid var(--line-soft);
  border-bottom: 1px solid var(--line-soft);
}

.page-about .ab-sec-head {
  max-width: 760px;
  margin-bottom: clamp(30px, 5vw, 58px);
}

.page-about .ab-sec-head h2 {
  margin: 12px 0 0;
  font-size: clamp(28px, 3.4vw, 46px);
  line-height: 1.15;
  font-weight: 600;
  color: var(--mist);
}

.page-about .ab-sec-head .lede {
  margin: 16px 0 0;
  color: var(--steel);
  font-size: 17px;
  line-height: 1.8;
}

/* ---------- 三条入口 ---------- */
.page-about .ab-lanes {
  display: grid;
  grid-template-columns: 1fr;
  gap: 20px;
}

.page-about .ab-lane {
  padding: clamp(22px, 3vw, 34px);
  border-radius: var(--r-lg);
  border: 1px solid var(--line-soft);
  background: linear-gradient(150deg, rgba(22, 53, 95, 0.5), rgba(8, 18, 43, 0.35));
}

.page-about .ab-lane:first-child {
  border-color: var(--ab-hair);
  box-shadow: inset 0 1px 0 rgba(33, 230, 193, 0.25);
}

.page-about .ab-lane .index-label {
  color: var(--cyan);
}

.page-about .ab-lane h3 {
  margin: 12px 0 10px;
  font-size: clamp(20px, 2.2vw, 26px);
  font-weight: 600;
  line-height: 1.25;
  color: var(--mist);
}

.page-about .ab-lane p {
  margin: 0;
  color: var(--steel);
  font-size: 16px;
  line-height: 1.8;
}

.page-about .ab-fold {
  margin-top: 18px;
  border-top: 1px solid var(--line-soft);
  padding-top: 14px;
}

.page-about .ab-fold > summary {
  list-style: none;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 14px;
  letter-spacing: 0.08em;
  color: var(--orange);
}

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

.page-about .ab-fold > summary::after {
  content: "+";
  font-family: var(--font-mono);
  font-size: 15px;
  line-height: 1;
}

.page-about .ab-fold[open] > summary::after {
  content: "−";
}

.page-about .ab-fold p {
  margin: 12px 0 0;
  color: var(--steel);
  font-size: 15px;
  line-height: 1.78;
}

/* ---------- 时间轴 ---------- */
.page-about .ab-tl-figure {
  margin: 0 0 clamp(34px, 5vw, 62px);
}

.page-about .ab-tl-figure figcaption,
.page-about .ab-data-figure figcaption,
.page-about .ab-team-figure figcaption {
  margin-top: 12px;
  color: var(--steel);
}

.page-about .ab-tl-figure img,
.page-about .ab-data-figure img,
.page-about .ab-team-figure img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
}

.page-about .ab-timeline {
  position: relative;
  list-style: none;
  margin: 0;
  padding: 0 0 0 40px;
}

.page-about .ab-timeline::before {
  content: "";
  position: absolute;
  left: 13px;
  top: 8px;
  bottom: 8px;
  width: 2px;
  border-radius: var(--pill);
  background: linear-gradient(180deg, transparent, var(--cyan) 10%, var(--cyan) 90%, transparent);
  opacity: 0.45;
}

.page-about .ab-tl-item {
  position: relative;
  margin-bottom: 20px;
}

.page-about .ab-tl-item:last-child {
  margin-bottom: 0;
}

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

.page-about .ab-node::before {
  content: "";
  position: absolute;
  left: -33px;
  top: 22px;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--ink-900);
  border: 2px solid var(--cyan);
  box-shadow: 0 0 0 4px rgba(33, 230, 193, 0.10), 0 0 14px rgba(33, 230, 193, 0.45);
  transition: transform 0.3s var(--ease), box-shadow 0.3s var(--ease), background 0.3s var(--ease);
}

.page-about .ab-node[open]::before {
  transform: scale(1.25);
  background: var(--cyan);
  box-shadow: 0 0 0 6px rgba(33, 230, 193, 0.14), 0 0 22px rgba(33, 230, 193, 0.7);
}

.page-about .ab-node > summary {
  list-style: none;
  cursor: pointer;
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 8px 14px;
  padding: 16px 20px;
  border-radius: var(--r-md);
  border: 1px solid var(--line-soft);
  background: linear-gradient(150deg, rgba(22, 53, 95, 0.5), rgba(8, 18, 43, 0.35));
  transition: border-color 0.3s var(--ease), box-shadow 0.3s var(--ease), background 0.3s var(--ease);
}

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

.page-about .ab-node > summary::marker {
  content: "";
}

.page-about .ab-node > summary:hover,
.page-about .ab-node > summary:focus-visible {
  border-color: var(--ab-hair);
  box-shadow: 0 0 0 1px rgba(33, 230, 193, 0.16);
}

.page-about .ab-node[open] > summary {
  border-color: var(--ab-hair);
  background: linear-gradient(150deg, rgba(22, 53, 95, 0.78), rgba(8, 18, 43, 0.5));
}

.page-about .ab-year {
  color: var(--orange);
}

.page-about .ab-node-title {
  margin: 0;
  font-size: clamp(17px, 1.8vw, 21px);
  font-weight: 600;
  line-height: 1.3;
  color: var(--mist);
}

.page-about .ab-node-body {
  padding: 16px 20px 6px;
}

.page-about .ab-node-body p {
  margin: 0;
  color: var(--steel);
  font-size: 16px;
  line-height: 1.8;
}

/* ---------- 数据 ---------- */
.page-about .ab-data-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(28px, 4vw, 54px);
}

.page-about .ab-data-copy h2 {
  margin: 12px 0 0;
  font-size: clamp(28px, 3.4vw, 46px);
  line-height: 1.15;
  font-weight: 600;
  color: var(--mist);
}

.page-about .ab-data-copy .lede {
  margin: 16px 0 0;
  color: var(--steel);
  font-size: 17px;
  line-height: 1.8;
}

.page-about .ab-data-copy > p:last-child {
  margin: 22px 0 0;
  color: var(--steel);
  font-size: 16px;
  line-height: 1.8;
}

.page-about .ab-data-list {
  list-style: none;
  margin: 26px 0 0;
  padding: 0;
  display: grid;
  gap: 14px;
}

.page-about .ab-data-list li {
  display: flex;
  align-items: baseline;
  gap: 16px;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--line-soft);
}

.page-about .ab-data-list .data-figure {
  flex: 0 0 auto;
  min-width: 74px;
  font-size: clamp(26px, 3vw, 38px);
  line-height: 1;
  color: var(--cyan);
}

.page-about .ab-data-list span:last-child {
  color: var(--steel);
  font-size: 16px;
  line-height: 1.7;
}

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

/* ---------- 团队 ---------- */
.page-about .ab-team-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(28px, 4vw, 48px);
}

.page-about .ab-team-roles {
  display: grid;
  gap: 16px;
}

.page-about .ab-role {
  padding: 20px 22px;
  border-radius: var(--r-md);
  background: rgba(22, 53, 95, 0.34);
  border-left: 2px solid var(--ab-hair);
}

.page-about .ab-role h3 {
  margin: 0 0 8px;
  font-size: 18px;
  font-weight: 600;
  color: var(--mist);
}

.page-about .ab-role p {
  margin: 0;
  color: var(--steel);
  font-size: 15.5px;
  line-height: 1.78;
}

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

/* ---------- 赛事观察 ---------- */
.page-about .ab-articles {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--line-soft);
}

.page-about .ab-articles li {
  display: grid;
  grid-template-columns: 1fr;
  gap: 8px;
  padding: 22px 0;
  border-bottom: 1px solid var(--line-soft);
}

.page-about .ab-article-idx {
  font-size: 20px;
  letter-spacing: 0.08em;
  color: var(--orange);
}

.page-about .ab-articles h3 {
  margin: 0 0 6px;
  font-size: clamp(18px, 2vw, 22px);
  font-weight: 600;
  color: var(--mist);
}

.page-about .ab-articles p {
  margin: 0;
  color: var(--steel);
  font-size: 16px;
  line-height: 1.8;
}

.page-about .ab-inline-cta {
  margin: clamp(26px, 4vw, 40px) 0 0;
}

/* ---------- 合作 ---------- */
.page-about .ab-partners {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 18px;
}

.page-about .ab-partners li {
  padding: 26px 24px;
  border-radius: var(--r-lg);
  border: 1px solid var(--line-soft);
  background: linear-gradient(160deg, rgba(14, 30, 66, 0.85), rgba(8, 18, 43, 0.45));
}

.page-about .ab-partners h3 {
  margin: 0 0 10px;
  font-size: 19px;
  font-weight: 600;
  color: var(--mist);
}

.page-about .ab-partners p {
  margin: 0;
  color: var(--steel);
  font-size: 15.5px;
  line-height: 1.78;
}

.page-about .ab-partner-note {
  margin: clamp(28px, 4vw, 44px) 0 0;
  color: var(--steel);
  font-size: 16px;
  line-height: 1.8;
}

.page-about .ab-partner-note a {
  color: var(--cyan);
}

/* ---------- 三条原则 ---------- */
.page-about .ab-pledge-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 22px;
}

.page-about .ab-pledge-list li {
  padding-left: 22px;
  border-left: 2px solid var(--ab-hair);
}

.page-about .ab-pledge-list .index-label {
  color: var(--orange);
  margin: 0;
}

.page-about .ab-pledge-list h3 {
  margin: 8px 0 8px;
  font-size: 19px;
  font-weight: 600;
  line-height: 1.35;
  color: var(--mist);
}

.page-about .ab-pledge-list p {
  margin: 0;
  color: var(--steel);
  font-size: 16px;
  line-height: 1.8;
}

.page-about .ab-cta {
  margin-top: clamp(38px, 5vw, 62px);
  padding: clamp(28px, 4vw, 44px);
  border-radius: var(--r-lg);
  border: 1px solid var(--line-soft);
  background:
    radial-gradient(90% 140% at 100% 0%, rgba(255, 122, 51, 0.20), transparent 62%),
    linear-gradient(120deg, rgba(33, 230, 193, 0.12), rgba(8, 18, 43, 0.4) 70%);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 18px 26px;
}

.page-about .ab-cta p {
  margin: 0;
  font-size: clamp(18px, 2vw, 22px);
  color: var(--mist);
}

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

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

  .page-about .ab-articles li {
    grid-template-columns: 110px minmax(0, 1fr);
    gap: 6px 20px;
    align-items: baseline;
  }
}

@media (min-width: 820px) {
  .page-about .ab-partners {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 22px;
  }

  .page-about .ab-partners li:nth-child(2) {
    margin-top: -18px;
  }

  .page-about .ab-partners li:nth-child(3) {
    margin-top: 18px;
  }

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

@media (min-width: 880px) {
  .page-about .ab-timeline {
    padding: 0;
  }

  .page-about .ab-timeline::before {
    left: 50%;
    margin-left: -1px;
  }

  .page-about .ab-tl-item {
    width: calc(50% - 46px);
  }

  .page-about .ab-tl-item:nth-child(odd) {
    margin-right: auto;
  }

  .page-about .ab-tl-item:nth-child(even) {
    margin-left: auto;
  }

  .page-about .ab-tl-item:nth-child(odd) .ab-node::before {
    left: auto;
    right: -39px;
  }

  .page-about .ab-tl-item:nth-child(even) .ab-node::before {
    left: -53px;
    right: auto;
  }
}

@media (min-width: 900px) {
  .page-about .ab-lanes {
    grid-template-columns: repeat(12, 1fr);
  }

  .page-about .ab-lane:nth-child(1) {
    grid-column: span 7;
  }

  .page-about .ab-lane:nth-child(2) {
    grid-column: span 5;
  }

  .page-about .ab-lane:nth-child(3) {
    grid-column: span 12;
    display: grid;
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    gap: 10px 34px;
    align-items: start;
  }

  .page-about .ab-lane:nth-child(3) .index-label {
    grid-column: 1;
  }

  .page-about .ab-lane:nth-child(3) h3 {
    grid-column: 1;
    margin-top: 8px;
  }

  .page-about .ab-lane:nth-child(3) > p {
    grid-column: 2;
    grid-row: 1 / span 3;
  }

  .page-about .ab-lane:nth-child(3) .ab-fold {
    grid-column: 1;
    grid-row: 4;
  }

  .page-about .ab-data-grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    align-items: start;
  }

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

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-node::before,
  .page-about .ab-node > summary {
    transition: none;
  }

  .page-about .ab-node[open]::before {
    transform: none;
  }
}