.page-about {
  --ab-measure: 42rem;
  background: var(--bg);
  color: var(--fg);
  padding-bottom: 64px;
}

.page-about .breadcrumb {
  margin: 22px 0 0;
}

/* ---------- 首屏 ---------- */
.page-about .ab-hero {
  padding: 26px 0 46px;
  border-bottom: 1px solid var(--line);
}

.page-about .ab-hero__title {
  margin: 12px 0 0;
  font-size: clamp(2rem, 6vw, 3.4rem);
  font-weight: 800;
  line-height: 1.08;
  letter-spacing: -0.02em;
}

.page-about .ab-hero__intro {
  max-width: var(--ab-measure);
  margin: 18px 0 0;
  font-size: 17px;
  line-height: 1.78;
  color: var(--fg);
}

.page-about .ab-hero__intro strong {
  color: var(--grass);
  font-weight: 700;
}

.page-about .ab-facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 30px 0 0;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .ab-fact {
  display: flex;
  flex-direction: column-reverse;
  gap: 8px;
  min-width: 0;
  padding: 16px 16px 18px;
  background: var(--board);
}

.page-about .ab-fact__k {
  margin: 0;
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--muted);
}

.page-about .ab-fact__v {
  margin: 0;
  font-family: var(--font-mono);
  font-size: clamp(1.4rem, 3.4vw, 2rem);
  font-weight: 700;
  line-height: 1;
  letter-spacing: 0.02em;
  color: var(--fg);
}

.page-about .ab-fact:nth-child(2) .ab-fact__v,
.page-about .ab-fact:nth-child(4) .ab-fact__v {
  color: var(--signal);
}

/* ---------- 章节骨架 ---------- */
.page-about .ab-sec {
  padding: 50px 0;
  border-bottom: 1px solid var(--line);
}

.page-about .ab-sec:last-of-type {
  border-bottom: 0;
  padding-bottom: 24px;
}

.page-about .ab-sec__head {
  display: flex;
  align-items: baseline;
  gap: 14px;
  margin-bottom: 22px;
}

.page-about .ab-sec__idx {
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.16em;
  color: var(--grass);
}

.page-about .ab-sec__idx::after {
  content: "";
  display: inline-block;
  width: 24px;
  height: 1px;
  margin-left: 10px;
  vertical-align: middle;
  background: var(--grass);
}

.page-about .ab-sec__title {
  margin: 0;
  font-size: clamp(1.5rem, 3.6vw, 2.15rem);
  font-weight: 800;
  letter-spacing: -0.01em;
  line-height: 1.2;
}

.page-about .ab-sec__lead {
  max-width: var(--ab-measure);
  margin: 0 0 26px;
  font-size: 15px;
  color: var(--muted);
}

.page-about .ab-sec__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 30px;
}

.page-about .ab-sec__grid--after {
  margin-top: 34px;
}

.page-about .ab-sec__body {
  max-width: var(--ab-measure);
}

.page-about .ab-sec__body p {
  margin: 0 0 18px;
  font-size: 17px;
  line-height: 1.78;
  color: var(--fg);
}

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

.page-about .ab-sec__body strong {
  color: var(--grass);
  font-weight: 700;
}

.page-about .ab-inline-cta {
  margin: 22px 0 0 !important;
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

/* ---------- 旁注 ---------- */
.page-about .ab-side {
  padding-top: 18px;
  border-top: 1px solid var(--line);
}

.page-about .ab-side__k {
  margin: 0 0 10px;
  font-size: 12px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--muted);
}

.page-about .ab-side__num {
  margin: 0;
  font-family: var(--font-mono);
  font-size: clamp(2rem, 6vw, 2.8rem);
  font-weight: 700;
  line-height: 1;
  letter-spacing: 0.02em;
  color: var(--ice);
}

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

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

/* ---------- 图片 ---------- */
.page-about .ab-figure {
  margin: 30px 0 0;
}

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

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

/* ---------- 机位示意 ---------- */
.page-about .ab-camwrap {
  margin: 32px 0 0;
  padding: 20px 16px 14px;
  background: var(--board);
  border: 1px solid var(--line);
}

.page-about .ab-cam {
  display: block;
  width: 100%;
  max-width: 720px;
  height: auto;
  margin: 0 auto;
}

.page-about .ab-cam__pitch rect,
.page-about .ab-cam__pitch line,
.page-about .ab-cam__pitch circle {
  fill: none;
  stroke: var(--line);
  stroke-width: 1;
}

.page-about .ab-cam__std circle {
  fill: var(--grass);
}

.page-about .ab-cam__ext circle {
  fill: none;
  stroke: var(--signal);
  stroke-width: 1.6;
}

.page-about .ab-cam__labels text {
  fill: var(--muted);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
}

.page-about .ab-camwrap__cap {
  margin: 12px 0 0;
  font-size: 13px;
  line-height: 1.7;
  color: var(--muted);
  text-align: center;
}

/* ---------- 图例 ---------- */
.page-about .ab-legend {
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .ab-legend__item {
  position: relative;
  padding-left: 18px;
  margin-bottom: 12px;
  font-size: 14px;
  line-height: 1.7;
  color: var(--muted);
}

.page-about .ab-legend__item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.62em;
  width: 10px;
  height: 10px;
  border: 1px solid var(--line);
}

.page-about .ab-legend__item--std::before {
  background: var(--grass);
  border-color: var(--grass);
}

.page-about .ab-legend__item--ext::before {
  background: transparent;
  border-color: var(--signal);
}

/* ---------- 数据路径 ---------- */
.page-about .ab-flow {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  margin: 0;
  padding: 0;
  list-style: none;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .ab-flow__step {
  position: relative;
  padding: 20px 18px 22px;
  background: var(--board);
}

.page-about .ab-flow__num {
  display: block;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.16em;
  color: var(--grass);
}

.page-about .ab-flow__name {
  margin: 10px 0 8px;
  font-size: 17px;
  font-weight: 700;
  line-height: 1.3;
  color: var(--fg);
}

.page-about .ab-flow__text {
  margin: 0;
  font-size: 14px;
  line-height: 1.72;
  color: var(--muted);
}

/* ---------- 团队 ---------- */
.page-about .ab-crew {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  margin: 28px 0 0;
  padding: 0;
  list-style: none;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .ab-crew__item {
  padding: 22px 18px 24px;
  background: var(--steel);
}

.page-about .ab-crew__num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(2rem, 7vw, 2.75rem);
  font-weight: 700;
  line-height: 1;
  letter-spacing: 0.02em;
  color: var(--fg);
}

.page-about .ab-crew__role {
  display: inline-block;
  margin-top: 12px;
  padding: 3px 10px;
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--grass);
  border: 1px solid var(--grass-deep);
}

.page-about .ab-crew__text {
  margin: 12px 0 0;
  font-size: 14px;
  line-height: 1.72;
  color: var(--muted);
}

/* ---------- 荣誉 ---------- */
.page-about .ab-honor {
  padding: 14px 0;
  border-bottom: 1px solid var(--line);
}

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

.page-about .ab-honor__year {
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.12em;
  color: var(--grass);
}

.page-about .ab-honor__name {
  margin: 8px 0 0;
  font-size: 15px;
  line-height: 1.6;
  color: var(--fg);
}

/* ---------- 时间轴 ---------- */
.page-about .ab-timeline {
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .ab-timeline__item {
  position: relative;
  padding-left: 26px;
}

.page-about .ab-timeline__item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 1px;
  background: var(--line);
}

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

.page-about .ab-node__sum {
  position: relative;
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 10px 14px;
  padding: 18px 0 18px;
  cursor: pointer;
  list-style: none;
}

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

.page-about .ab-node__sum::before {
  content: "";
  position: absolute;
  left: -30px;
  top: 24px;
  width: 9px;
  height: 9px;
  background: var(--bg);
  border: 1px solid var(--grass-deep);
}

.page-about .ab-node[open] .ab-node__sum::before {
  background: var(--grass);
  border-color: var(--grass);
}

.page-about .ab-node__year {
  font-family: var(--font-mono);
  font-size: 20px;
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--muted);
  transition: color 160ms linear;
}

.page-about .ab-node[open] .ab-node__year {
  color: var(--grass);
}

.page-about .ab-node__name {
  font-size: 17px;
  font-weight: 700;
  color: var(--fg);
}

.page-about .ab-node__tag {
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--muted);
}

.page-about .ab-node__body {
  padding: 0 0 20px;
}

.page-about .ab-node__body p {
  max-width: var(--ab-measure);
  margin: 0;
  font-size: 15px;
  line-height: 1.78;
  color: var(--muted);
}

/* ---------- 服务承诺 ---------- */
.page-about .ab-pledge {
  margin: 0;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--line);
}

.page-about .ab-pledge__row {
  display: grid;
  grid-template-columns: 1fr;
  gap: 6px;
  padding: 18px 0;
  border-bottom: 1px solid var(--line);
}

.page-about .ab-pledge__v {
  font-family: var(--font-mono);
  font-size: 20px;
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--signal);
}

.page-about .ab-pledge__k {
  font-size: 15px;
  line-height: 1.72;
  color: var(--muted);
}

.page-about .ab-pledge__foot {
  max-width: var(--ab-measure);
  margin: 26px 0 0;
  font-size: 15px;
  line-height: 1.78;
  color: var(--muted);
}

/* ---------- 响应式 ---------- */
@media (min-width: 640px) {
  .page-about .ab-facts {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

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

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

@media (min-width: 1000px) {
  .page-about .ab-hero {
    padding: 34px 0 54px;
  }

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

  .page-about .ab-sec {
    padding: 64px 0;
  }

  .page-about .ab-sec__grid {
    grid-template-columns: minmax(0, 620px) minmax(220px, 1fr);
    gap: 64px;
    align-items: start;
  }

  .page-about .ab-sec__grid--after {
    margin-top: 44px;
  }

  .page-about .ab-side {
    position: sticky;
    top: 34px;
  }

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

  .page-about .ab-camwrap {
    padding: 28px 28px 18px;
    margin-top: 40px;
  }

  .page-about .ab-pledge__row {
    grid-template-columns: 190px minmax(0, 1fr);
    align-items: baseline;
    gap: 24px;
    padding: 20px 0;
  }

  .page-about .ab-pledge__v {
    font-size: 24px;
  }

  .page-about .ab-node__sum {
    padding: 20px 0;
  }
}

@media (min-width: 1280px) {
  .page-about .ab-hero__title {
    max-width: 22ch;
  }
}