.page-about {
  --ab-line: #1D3E5C;
  --ab-panel: #14304A;
  --ab-glass: rgba(20, 48, 74, 0.44);
  --ab-orange-a: rgba(255, 107, 26, 0.42);
  display: block;
  overflow-x: clip;
  color: var(--text);
}

.page-about .ab-top {
  padding: 18px 0 0;
}

/* ---------- 首屏 ---------- */

.page-about .ab-hero {
  padding: 26px 0 0;
}

.page-about .ab-hero__kicker {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--orange);
}

.page-about .ab-hero__dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--orange);
  box-shadow: 0 0 0 5px rgba(255, 107, 26, 0.16);
}

.page-about .ab-hero__title {
  margin: 16px 0 0;
  max-width: 20ch;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(30px, 8.4vw, 58px);
  line-height: 1.08;
  letter-spacing: -0.02em;
  color: var(--text);
}

.page-about .ab-hero__lede {
  margin: 18px 0 0;
  max-width: 64ch;
  font-size: 16px;
  line-height: 1.82;
  color: var(--text-2);
}

.page-about .ab-hero__figure {
  margin: 28px 0 0;
  border: 1px solid var(--ab-line);
  border-radius: var(--radius-l);
  overflow: hidden;
}

/* ---------- 章节骨架 ---------- */

.page-about .ab-chapter {
  margin: 58px 0 0;
}

.page-about .ab-chapter--last {
  margin-bottom: 64px;
}

.page-about .ab-chapter__head {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 14px;
  align-items: start;
  padding-bottom: 18px;
  border-bottom: 1px solid var(--ab-line);
}

.page-about .ab-num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 26px;
  border-radius: 6px;
  background: var(--orange);
  color: #0B1B2B;
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.08em;
}

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

.page-about .ab-chapter__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(22px, 5.4vw, 34px);
  line-height: 1.22;
  letter-spacing: -0.01em;
  color: var(--text);
}

.page-about .ab-chapter__lede {
  margin: 10px 0 0;
  max-width: 62ch;
  font-size: 15px;
  line-height: 1.78;
  color: var(--text-2);
}

.page-about .ab-chapter__note {
  margin: 22px 0 0;
  padding: 16px 18px;
  border-left: 3px solid var(--orange);
  background: var(--ab-glass);
  border-radius: 0 var(--radius-m) var(--radius-m) 0;
  font-size: 15px;
  line-height: 1.78;
  color: var(--text-2);
}

/* ---------- 时间轴 ---------- */

.page-about .ab-timeline {
  margin: 28px 0 0;
  padding: 0 0 0 30px;
  list-style: none;
  position: relative;
}

.page-about .ab-timeline::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 10px;
  bottom: 10px;
  width: 2px;
  border-radius: 2px;
  background: linear-gradient(180deg, #FF6B1A 0%, #FF8A47 42%, #1D3E5C 100%);
}

.page-about .ab-timeline__item {
  position: relative;
  list-style: none;
  margin: 0 0 14px;
}

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

.page-about .ab-timeline__item::before {
  content: "";
  position: absolute;
  left: -28px;
  top: 20px;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--orange);
  box-shadow: 0 0 0 5px rgba(255, 107, 26, 0.14);
}

.page-about .ab-stage {
  border: 1px solid var(--ab-line);
  border-radius: var(--radius-m);
  background: var(--ab-glass);
  overflow: hidden;
  transition: border-color 0.2s ease, background 0.2s ease;
}

.page-about .ab-stage[open] {
  background: var(--ab-panel);
  border-color: var(--ab-orange-a);
}

.page-about .ab-stage__summary {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding: 16px 18px;
  cursor: pointer;
  list-style: none;
}

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

.page-about .ab-stage__summary::after {
  content: "+";
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 18px;
  line-height: 1;
  color: var(--orange);
}

.page-about .ab-stage[open] .ab-stage__summary::after {
  content: "–";
}

.page-about .ab-stage__summary:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: -2px;
}

.page-about .ab-stage__idx {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--orange);
}

.page-about .ab-stage__name {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 18px;
  color: var(--text);
}

.page-about .ab-stage__panel {
  padding: 4px 18px 18px;
  border-top: 1px solid var(--ab-line);
}

.page-about .ab-stage__panel p {
  margin: 14px 0 0;
  font-size: 15px;
  line-height: 1.78;
  color: var(--text-2);
}

.page-about .ab-stage__list {
  margin: 14px 0 0;
  padding: 0;
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.page-about .ab-stage__list li {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  padding: 7px 11px;
  border-radius: 999px;
  border: 1px solid var(--ab-line);
  color: var(--text-2);
}

/* ---------- 数据生产 ---------- */

.page-about .ab-split {
  display: grid;
  gap: 24px;
  margin-top: 28px;
}

.page-about .ab-split__main,
.page-about .ab-split__side {
  min-width: 0;
}

.page-about .ab-flow {
  display: block;
  width: 100%;
  height: auto;
}

.page-about .ab-flow__num {
  font-family: var(--font-mono);
  font-size: 17px;
  letter-spacing: 0.04em;
  fill: #E8EEF4;
}

.page-about .ab-steps {
  margin: 22px 0 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 12px;
}

.page-about .ab-step {
  padding: 18px;
  border: 1px solid var(--ab-line);
  border-radius: var(--radius-m);
  background: var(--ab-glass);
}

.page-about .ab-step__no {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--orange);
}

.page-about .ab-step__title {
  margin: 8px 0 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 17px;
  line-height: 1.4;
  color: var(--text);
}

.page-about .ab-step__body {
  margin: 8px 0 0;
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--text-2);
}

.page-about .ab-step__catch {
  margin: 12px 0 0;
  padding-left: 10px;
  border-left: 2px solid var(--orange);
  font-size: 13px;
  line-height: 1.6;
  color: var(--text);
}

.page-about .ab-side-figure {
  margin: 0;
  border: 1px solid var(--ab-line);
  border-radius: var(--radius-l);
  overflow: hidden;
}

/* ---------- 团队 ---------- */

.page-about .ab-team-figure {
  margin: 26px 0 0;
  border: 1px solid var(--ab-line);
  border-radius: var(--radius-l);
  overflow: hidden;
}

.page-about .ab-tagwall {
  margin: 22px 0 0;
  padding: 0;
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.page-about .ab-tagwall__item {
  padding: 10px 15px;
  border-radius: 999px;
  border: 1px solid var(--ab-line);
  background: var(--ab-glass);
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.04em;
  color: var(--text-2);
}

.page-about .ab-tagwall__item--solid {
  background: var(--ab-panel);
  border-color: var(--ab-orange-a);
  color: var(--text);
}

.page-about .ab-shifts {
  margin: 24px 0 0;
  display: grid;
  gap: 1px;
  background: var(--ab-line);
  border: 1px solid var(--ab-line);
  border-radius: var(--radius-m);
  overflow: hidden;
}

.page-about .ab-shift {
  padding: 16px 18px;
  background: #0F2438;
}

.page-about .ab-shift__time {
  display: block;
  font-family: var(--font-mono);
  font-size: 14px;
  letter-spacing: 0.06em;
  color: var(--cyan);
}

.page-about .ab-shift__desc {
  margin: 8px 0 0;
  font-size: 14.5px;
  line-height: 1.72;
  color: var(--text-2);
}

/* ---------- 覆盖能力 ---------- */

.page-about .ab-stats {
  margin: 28px 0 0;
  display: grid;
  gap: 12px;
}

.page-about .ab-stat {
  position: relative;
  padding: 22px 20px;
  border: 1px solid var(--ab-line);
  border-radius: var(--radius-m);
  background: linear-gradient(155deg, rgba(255, 107, 26, 0.12) 0%, rgba(20, 48, 74, 0.72) 52%);
}

.page-about .ab-stat__figure {
  display: flex;
  align-items: baseline;
  gap: 6px;
}

.page-about .ab-stat__num {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(36px, 10vw, 54px);
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--text);
}

.page-about .ab-stat__unit {
  font-size: 15px;
  color: var(--orange);
}

.page-about .ab-stat__label {
  margin: 12px 0 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--text-2);
}

/* ---------- 合作生态 ---------- */

.page-about .ab-coop {
  margin: 26px 0 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 12px;
}

.page-about .ab-coop__item {
  display: grid;
  gap: 8px;
  padding: 16px 18px;
  border: 1px solid var(--ab-line);
  border-radius: var(--radius-m);
  background: var(--ab-glass);
}

.page-about .ab-coop__key {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.14em;
  color: var(--gold);
}

.page-about .ab-coop__val {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.76;
  color: var(--text-2);
}

/* ---------- 承诺与出口 ---------- */

.page-about .ab-pledges {
  margin: 26px 0 0;
  display: grid;
  gap: 12px;
}

.page-about .ab-pledge {
  padding: 20px 18px;
  border: 1px solid var(--ab-line);
  border-radius: var(--radius-m);
  background: linear-gradient(160deg, rgba(255, 107, 26, 0.14) 0%, rgba(20, 48, 74, 0.66) 58%);
}

.page-about .ab-pledge__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 18px;
  color: var(--text);
}

.page-about .ab-pledge__body {
  margin: 10px 0 0;
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--text-2);
}

.page-about .ab-next {
  margin: 30px 0 0;
  padding: 22px 20px;
  border: 1px solid var(--ab-orange-a);
  border-radius: var(--radius-l);
  background: rgba(15, 36, 56, 0.86);
}

.page-about .ab-next__text {
  margin: 0;
  font-size: 15px;
  line-height: 1.78;
  color: var(--text);
}

.page-about .ab-next__links {
  margin: 18px 0 0;
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

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

/* ---------- 响应式 ---------- */

@media (min-width: 600px) {
  .page-about .ab-steps {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

@media (min-width: 820px) {
  .page-about .ab-hero {
    padding-top: 34px;
  }

  .page-about .ab-chapter {
    margin-top: 76px;
  }

  .page-about .ab-split {
    grid-template-columns: minmax(0, 1.2fr) minmax(0, 0.8fr);
    gap: 32px;
    align-items: start;
  }

  .page-about .ab-stats {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 16px;
  }

  .page-about .ab-pledges {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 16px;
  }

  .page-about .ab-timeline {
    padding-left: 38px;
  }

  .page-about .ab-timeline::before {
    left: 9px;
  }

  .page-about .ab-timeline__item::before {
    left: -35px;
    top: 22px;
  }

  .page-about .ab-next {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 24px;
    padding: 26px 28px;
  }

  .page-about .ab-next__text {
    max-width: 46ch;
  }

  .page-about .ab-next__links {
    margin: 0;
    justify-content: flex-end;
  }
}

@media (min-width: 1080px) {
  .page-about .ab-chapter__head {
    gap: 20px;
  }

  .page-about .ab-flow {
    margin-top: 6px;
  }
}