.page-about {
  --ab-cut: rgba(11, 43, 34, .08);
  background: var(--paper-50);
  color: var(--espresso-950);
  font-family: var(--font-body);
  font-size: 17px;
  line-height: 1.75;
  font-weight: 450;
  overflow-x: hidden;
}

.page-about p {
  margin: 0 0 var(--sp-4);
}

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

.page-about .num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-feature-settings: "tnum" 1;
}

/* ---------- 首屏 ---------- */

.page-about .ab-hero {
  position: relative;
  overflow: hidden;
  padding: var(--sp-5) 0 96px;
  border-bottom: var(--rule-light);
}

.page-about .ab-hero__slash {
  position: absolute;
  inset: auto 0 0 0;
  height: 76px;
  background: var(--ink-900);
  clip-path: polygon(0 100%, 100% 0, 100% 100%);
  z-index: 0;
}

.page-about .ab-hero__inner {
  position: relative;
  z-index: 1;
}

.page-about .ab-hero__tag {
  display: block;
  margin: var(--sp-5) 0 var(--sp-3);
  color: var(--lead-500);
}

.page-about .ab-hero__title {
  margin: 0 0 var(--sp-5);
  font-family: var(--font-display);
  font-size: clamp(34px, 9vw, 68px);
  line-height: 1.05;
  letter-spacing: -0.015em;
  font-weight: 700;
  color: var(--espresso-950);
  max-width: 18ch;
}

.page-about .ab-hero__lede {
  max-width: 60ch;
  font-size: 17px;
  line-height: 1.8;
  color: var(--espresso-950);
}

.page-about .ab-hero__stats {
  list-style: none;
  margin: var(--sp-6) 0 0;
  padding: var(--sp-4) var(--sp-4);
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: var(--sp-4) var(--sp-5);
  border: var(--rule-light);
  background: rgba(246, 241, 228, .92);
  box-shadow: var(--shadow-deep);
}

.page-about .ab-hero__stat {
  display: flex;
  flex-direction: column;
  gap: 2px;
  min-width: 0;
}

.page-about .ab-hero__stat-num {
  font-family: var(--font-display);
  font-size: clamp(24px, 5.4vw, 40px);
  line-height: 1;
  font-weight: 700;
  color: var(--ink-900);
}

.page-about .ab-hero__stat-label {
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--lead-500);
}

/* ---------- 章节骨架 ---------- */

.page-about .ab-chapter {
  position: relative;
  padding: clamp(48px, 8vw, 96px) 0;
}

.page-about .ab-chapter--paper {
  background: var(--paper-50);
}

.page-about .ab-chapter--dark {
  background: var(--ink-900);
  color: var(--mint-100);
}

.page-about .ab-chapter--dark::before {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  top: -26px;
  height: 27px;
  background: var(--ink-900);
  clip-path: polygon(0 100%, 100% 0, 100% 100%);
  pointer-events: none;
}

.page-about .ab-chapter__head {
  margin-bottom: var(--sp-6);
}

.page-about .ab-chapter__index {
  margin: 0 0 var(--sp-3);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--orange-500);
}

.page-about .ab-chapter--dark .ab-chapter__index {
  color: var(--amber-300);
}

.page-about .ab-chapter__title {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(26px, 5.6vw, 48px);
  line-height: 1.1;
  letter-spacing: -0.01em;
  font-weight: 700;
  max-width: 22ch;
}

.page-about .ab-chapter--dark .ab-chapter__title {
  color: var(--paper-50);
}

.page-about .ab-chapter__body {
  display: grid;
  gap: var(--sp-6);
}

.page-about .ab-lede {
  max-width: 62ch;
  font-size: 17px;
  color: var(--lead-500);
}

.page-about .ab-lede--on-dark {
  color: var(--mint-100);
}

/* ---------- 01 数字卡 ---------- */

.page-about .ab-figures {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: var(--sp-4);
  border-left: var(--rule-light);
  padding-left: var(--sp-5);
}

.page-about .ab-figure {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding-bottom: var(--sp-4);
  border-bottom: var(--rule-light);
}

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

.page-about .ab-figure__num {
  font-family: var(--font-display);
  font-size: clamp(38px, 9vw, 62px);
  line-height: 1;
  font-weight: 700;
  color: var(--orange-500);
}

.page-about .ab-figure__label {
  font-size: 14px;
  color: var(--lead-500);
}

/* ---------- 02 联赛轨道 ---------- */

.page-about .ab-rail {
  list-style: none;
  margin: 0 0 var(--sp-6);
  padding: var(--sp-3) 0;
  display: flex;
  gap: var(--sp-2);
  overflow-x: auto;
  border-top: var(--rule-dark);
  border-bottom: var(--rule-dark);
  scrollbar-width: thin;
}

.page-about .ab-rail__chip {
  flex: 0 0 auto;
  display: flex;
  align-items: baseline;
  gap: var(--sp-2);
  padding: 6px 12px;
  border: var(--rule-dark);
  background: var(--ink-700);
}

.page-about .ab-rail__name {
  font-size: 14px;
  color: var(--paper-50);
}

.page-about .ab-rail__code {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .14em;
  color: var(--amber-300);
}

.page-about .ab-sidenote {
  align-self: start;
  padding: var(--sp-5);
  border: var(--rule-dark);
  background: rgba(30, 107, 82, .22);
}

.page-about .ab-sidenote__num {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(44px, 11vw, 76px);
  line-height: 1;
  font-weight: 700;
  color: var(--volt-400);
}

.page-about .ab-sidenote__text {
  margin: var(--sp-3) 0 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--mint-100);
}

/* ---------- 03 团队 ---------- */

.page-about .ab-team-figure {
  margin: 0 0 var(--sp-6);
}

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

.page-about .ab-filter {
  display: flex;
  flex-wrap: wrap;
  gap: var(--sp-2);
  margin: var(--sp-5) 0 var(--sp-5);
}

.page-about .ab-pill {
  appearance: none;
  border: var(--rule-light);
  background: transparent;
  color: var(--espresso-950);
  font-family: var(--font-body);
  font-size: 14px;
  padding: 8px 14px;
  cursor: pointer;
  transition: background-color 160ms var(--ease-out), color 160ms var(--ease-out);
}

.page-about .ab-pill:hover {
  background: var(--mint-100);
}

.page-about .ab-pill[aria-pressed="true"] {
  background: var(--ink-900);
  border-color: var(--ink-900);
  color: var(--volt-400);
}

.page-about .ab-lines {
  display: grid;
  gap: var(--sp-5);
}

.page-about .ab-line {
  padding: var(--sp-5) 0 0;
  border-top: 3px solid var(--ink-900);
}

.page-about .ab-line__num {
  margin: 0 0 var(--sp-2);
  font-size: 12px;
  letter-spacing: .16em;
  color: var(--orange-500);
}

.page-about .ab-line__title {
  margin: 0 0 var(--sp-3);
  font-family: var(--font-display);
  font-size: 22px;
  line-height: 1.2;
  font-weight: 700;
}

.page-about .ab-line p:last-child {
  font-size: 16px;
  color: var(--lead-500);
}

/* ---------- 04 赛季日历 ---------- */

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

.page-about .ab-timeline {
  display: block;
  width: 100%;
  height: auto;
  margin-bottom: var(--sp-4);
}

.page-about .ab-nodes {
  list-style: none;
  margin: var(--sp-5) 0 0;
  padding: 0;
  border-top: var(--rule-dark);
}

.page-about .ab-node {
  border-bottom: var(--rule-dark);
}

.page-about .ab-node__summary {
  display: flex;
  align-items: center;
  gap: var(--sp-3);
  padding: var(--sp-4) var(--sp-2);
  cursor: pointer;
  list-style: none;
  transition: background-color 160ms var(--ease-out);
}

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

.page-about .ab-node__summary:hover {
  background: rgba(30, 107, 82, .18);
}

.page-about .ab-node__dot {
  flex: 0 0 auto;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--orange-500);
}

.page-about .ab-node[open] .ab-node__dot {
  background: var(--volt-400);
}

.page-about .ab-node__label {
  flex: 1 1 auto;
  font-family: var(--font-display);
  font-size: 17px;
  font-weight: 700;
  color: var(--paper-50);
}

.page-about .ab-node__meta {
  flex: 0 0 auto;
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--slate-400);
}

.page-about .ab-node__body {
  padding: 0 var(--sp-4) var(--sp-5) 26px;
}

.page-about .ab-node__body p {
  margin: 0;
  font-size: 15px;
  line-height: 1.75;
  color: var(--mint-100);
  max-width: 58ch;
}

/* ---------- 05 合作与共建 ---------- */

.page-about .ab-support {
  list-style: none;
  margin: var(--sp-5) 0 0;
  padding: 0;
  display: grid;
  gap: var(--sp-4);
}

.page-about .ab-support li {
  padding-top: var(--sp-3);
  border-top: var(--rule-light);
}

.page-about .ab-support .index-tag {
  display: inline-block;
  margin-bottom: 6px;
  color: var(--ink-500);
}

.page-about .ab-support p {
  margin: 0;
  font-size: 15px;
  color: var(--lead-500);
}

.page-about .ab-sidecard {
  align-self: start;
  position: relative;
  padding: var(--sp-6) var(--sp-5);
  background: var(--mint-100);
  border: 1px solid var(--espresso-950);
}

.page-about .ab-sidecard::after {
  content: "";
  position: absolute;
  inset: 8px -8px -8px 8px;
  border: 1px solid rgba(35, 24, 15, .35);
  z-index: -1;
}

.page-about .ab-sidecard__num {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(52px, 13vw, 88px);
  line-height: .9;
  font-weight: 700;
  color: var(--ink-900);
}

.page-about .ab-sidecard__text {
  margin: var(--sp-3) 0 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--ink-700);
}

.page-about .ab-coop-figure {
  margin: var(--sp-6) 0 0;
}

/* ---------- 06 客户端 ---------- */

.page-about .ab-chapter--cta {
  background: var(--ink-900);
  color: var(--mint-100);
}

.page-about .ab-chapter--cta::before {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  top: -26px;
  height: 27px;
  background: var(--ink-900);
  clip-path: polygon(0 100%, 100% 0, 100% 100%);
  pointer-events: none;
}

.page-about .ab-cta {
  display: grid;
  gap: var(--sp-6);
}

.page-about .ab-cta__text p {
  max-width: 58ch;
  color: var(--mint-100);
}

.page-about .ab-cta__list {
  list-style: none;
  margin: var(--sp-5) 0 0;
  padding: 0;
  display: grid;
  gap: var(--sp-3);
}

.page-about .ab-cta__list li {
  position: relative;
  padding-left: var(--sp-5);
  font-size: 15px;
  color: var(--paper-50);
}

.page-about .ab-cta__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .65em;
  width: 12px;
  height: 3px;
  background: var(--orange-500);
}

.page-about .ab-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--sp-3);
}

/* ---------- 延伸阅读 ---------- */

.page-about .ab-next {
  background: var(--paper-50);
  padding: clamp(40px, 7vw, 72px) 0;
  border-top: var(--rule-light);
}

.page-about .ab-next__title {
  margin: 0 0 var(--sp-5);
  font-family: var(--font-display);
  font-size: 18px;
  font-weight: 700;
}

.page-about .ab-next__title .index-tag {
  margin-right: var(--sp-3);
  color: var(--orange-500);
}

.page-about .ab-next__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0;
  border-top: var(--rule-light);
}

.page-about .ab-next__item a {
  display: grid;
  grid-template-columns: auto 1fr;
  grid-template-areas:
    "num label"
    "num desc";
  gap: 2px var(--sp-4);
  padding: var(--sp-4) var(--sp-2);
  border-bottom: var(--rule-light);
  border-left: 3px solid transparent;
  color: inherit;
  text-decoration: none;
  transition: border-color 160ms var(--ease-out), background-color 160ms var(--ease-out);
}

.page-about .ab-next__item a:hover {
  border-left-color: var(--orange-500);
  background: var(--mint-100);
}

.page-about .ab-next__num {
  grid-area: num;
  align-self: start;
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--lead-500);
  padding-top: 4px;
}

.page-about .ab-next__label {
  grid-area: label;
  font-family: var(--font-display);
  font-size: 20px;
  font-weight: 700;
}

.page-about .ab-next__desc {
  grid-area: desc;
  font-size: 14px;
  color: var(--lead-500);
}

/* ---------- 响应式 ---------- */

@media (min-width: 720px) {
  .page-about .ab-lines {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .ab-figures {
    grid-template-columns: 1fr;
  }

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

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

  .page-about .ab-next__item a {
    border-bottom: 0;
    border-right: var(--rule-light);
    height: 100%;
  }

  .page-about .ab-next__item:last-child a {
    border-right: 0;
  }
}

@media (min-width: 900px) {
  .page-about .ab-hero {
    padding: var(--sp-6) 0 clamp(72px, 8vw, 112px);
  }

  .page-about .ab-hero__slash {
    inset: -12% -6% 18% 46%;
    height: auto;
    clip-path: polygon(20% 0, 100% 0, 100% 100%, 0 100%);
  }

  .page-about .ab-hero__inner {
    display: grid;
    grid-template-columns: 7fr 5fr;
    column-gap: var(--sp-7);
  }

  .page-about .ab-hero__inner > * {
    grid-column: 1 / 2;
  }

  .page-about .ab-hero__stats {
    grid-column: 1 / -1;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    margin-top: var(--sp-7);
  }

  .page-about .ab-hero__title {
    font-size: clamp(52px, 5.6vw, 78px);
  }

  .page-about .ab-body--7-5 {
    grid-template-columns: 7fr 5fr;
  }

  .page-about .ab-body--8-4 {
    grid-template-columns: 8fr 4fr;
  }

  .page-about .ab-body--3-9 {
    grid-template-columns: 3fr 9fr;
  }

  .page-about .ab-cta {
    grid-template-columns: 8fr 4fr;
    align-items: start;
  }

  .page-about .ab-cta__actions {
    flex-direction: column;
    align-items: flex-start;
  }

  .page-about .ab-timeline {
    margin-bottom: var(--sp-5);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-pill,
  .page-about .ab-next__item a,
  .page-about .ab-node__summary {
    transition: none;
  }
}