.page-about {
  --ab-line: rgba(58, 90, 80, .45);
  --ab-wrap: clamp(56px, 8vw, 104px);
}

/* ── 首屏 ─────────────────────────────────── */
.page-about .ab-hero {
  position: relative;
  padding: clamp(28px, 5vw, 56px) 0 clamp(48px, 7vw, 96px);
  overflow: hidden;
}
.page-about .ab-hero::before {
  content: "";
  position: absolute;
  right: -14%;
  top: -34%;
  width: 70%;
  height: 150%;
  background: linear-gradient(158deg, rgba(216, 245, 60, .12) 0%, rgba(216, 245, 60, 0) 58%);
  transform: rotate(-10deg);
  pointer-events: none;
}
.page-about .ab-hero::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 1px;
  background: linear-gradient(90deg, var(--ky-volt) 0%, rgba(216, 245, 60, 0) 46%);
}
.page-about .ab-hero .ky-shell { position: relative; z-index: 1; }

.page-about .ab-hero__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(28px, 4vw, 48px);
  margin-top: clamp(24px, 4vw, 44px);
}

.page-about .ab-hero__title {
  margin: 14px 0 0;
  max-width: 900px;
  font-family: var(--ky-serif);
  font-weight: 800;
  font-size: clamp(30px, 5.6vw, 66px);
  line-height: 1.08;
  letter-spacing: .015em;
  color: var(--ky-white);
  text-wrap: balance;
}

.page-about .ab-hero__lead {
  margin: clamp(18px, 2.4vw, 28px) 0 0;
  max-width: 60ch;
  font-size: clamp(15px, 1.5vw, 17px);
  line-height: 1.85;
  color: var(--ky-white);
}

.page-about .ab-hero__aside {
  padding-top: 18px;
  border-top: 2px solid var(--ky-volt);
}
.page-about .ab-hero__stamp {
  margin: 0 0 14px;
  font-family: var(--ky-mono);
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--ky-volt);
}
.page-about .ab-hero__stamp-note {
  margin: 0 0 10px;
  font-size: 13.5px;
  line-height: 1.7;
  color: var(--ky-muted);
}

.page-about .ab-stats {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(126px, 1fr));
  gap: clamp(16px, 3vw, 40px);
  margin: clamp(34px, 5vw, 60px) 0 0;
  padding: 0;
  list-style: none;
}
.page-about .ab-stats__item {
  position: relative;
  padding-top: 16px;
}
.page-about .ab-stats__item::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 36px;
  height: 2px;
  background: var(--ky-volt);
}
.page-about .ab-stats__num {
  display: block;
  font-family: var(--ky-cond);
  font-weight: 700;
  font-size: clamp(28px, 4.2vw, 46px);
  line-height: .96;
  letter-spacing: .01em;
  color: var(--ky-white);
}
.page-about .ab-stats__key {
  display: block;
  margin-top: 8px;
  font-family: var(--ky-mono);
  font-size: 12px;
  letter-spacing: .04em;
  color: var(--ky-muted);
}

/* ── 主体两栏 ─────────────────────────────── */
.page-about .ab-layout {
  display: grid;
  grid-template-columns: 1fr;
}

.page-about .ab-rail {
  padding: clamp(24px, 4vw, 40px) 0 0;
}
.page-about .ab-rail__title {
  margin: 0 0 10px;
  font-family: var(--ky-mono);
  font-size: 11px;
  letter-spacing: .22em;
  text-transform: uppercase;
  color: var(--ky-muted);
}
.page-about .ab-rail__list {
  display: flex;
  flex-wrap: wrap;
  gap: 4px 18px;
  margin: 0;
  padding: 0;
  list-style: none;
}
.page-about .ab-rail__link {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  padding: 5px 0;
  border-bottom: 1px solid transparent;
  font-size: 13.5px;
  color: var(--ky-muted);
  text-decoration: none;
  transition: color .25s var(--ky-ease), border-color .25s var(--ky-ease);
}
.page-about .ab-rail__num {
  font-family: var(--ky-mono);
  font-size: 11px;
  color: var(--ky-archive);
}
.page-about .ab-rail__link:hover,
.page-about .ab-rail__link:focus-visible {
  color: var(--ky-volt);
  border-bottom-color: var(--ky-volt);
}

.page-about .ab-flow { display: block; }

.page-about .ab-block {
  padding: clamp(44px, 6vw, 82px) 0;
}
.page-about .ab-block + .ab-block {
  border-top: 1px solid var(--ab-line);
}
.page-about .ab-block--last {
  padding-bottom: clamp(72px, 12vw, 150px);
}

.page-about .ab-h2 {
  margin: 14px 0 clamp(20px, 3vw, 32px);
  max-width: 22ch;
  font-family: var(--ky-serif);
  font-weight: 800;
  font-size: clamp(23px, 3.3vw, 38px);
  line-height: 1.2;
  letter-spacing: .015em;
  color: var(--ky-white);
}
.page-about .ab-block p {
  max-width: 62ch;
  font-size: 15.5px;
  line-height: 1.82;
  color: var(--ky-white);
}
.page-about .ab-more {
  margin-top: clamp(20px, 2.6vw, 30px) !important;
}
.page-about .ab-more .ky-link { font-size: 14.5px; }

/* ── 01 从本地看台出发 ─────────────────────── */
.page-about .ab-cols {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(24px, 3.4vw, 44px);
  align-items: start;
}
.page-about .ab-cols__text p + p { margin-top: 16px; }
.page-about .ab-cols__figure { margin: 0; }
.page-about .ab-cols__figure .ky-figure__cap {
  font-family: var(--ky-mono);
  font-size: 11.5px;
  letter-spacing: .03em;
}

.page-about .ab-quote {
  margin: clamp(28px, 4.5vw, 52px) 0 0;
  max-width: 22ch;
  padding: clamp(24px, 3.6vw, 42px);
  background: var(--ky-cream);
  color: var(--ky-night);
  font-family: var(--ky-serif);
  font-weight: 800;
  font-size: clamp(21px, 2.9vw, 32px);
  line-height: 1.34;
  letter-spacing: .02em;
}

/* ── 02 四条内容线 ─────────────────────────── */
.page-about .ab-lines {
  margin: 0;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--ab-line);
}
.page-about .ab-line {
  display: grid;
  grid-template-columns: 46px minmax(0, 1fr);
  gap: 14px;
  padding: clamp(20px, 2.8vw, 30px) 0;
  border-bottom: 1px solid var(--ab-line);
  transition: background-color .3s var(--ky-ease);
}
.page-about .ab-line__num {
  padding-top: 5px;
  font-family: var(--ky-mono);
  font-size: 11.5px;
  letter-spacing: .1em;
  color: var(--ky-archive);
}
.page-about .ab-line__title {
  margin: 0 0 8px;
  font-family: var(--ky-serif);
  font-weight: 700;
  font-size: clamp(17px, 1.9vw, 21px);
  letter-spacing: .02em;
  color: var(--ky-volt);
}
.page-about .ab-line__body p {
  max-width: 58ch;
  font-size: 15px;
  margin: 0;
}

/* ── 03 协作流程 ───────────────────────────── */
.page-about .ab-steps {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(100%, 210px), 1fr));
  gap: clamp(20px, 2.8vw, 34px);
  margin: 0;
  padding: 0;
  list-style: none;
}
.page-about .ab-step {
  padding-top: 16px;
  border-top: 1px solid var(--ky-grid);
}
.page-about .ab-step__num {
  display: block;
  font-family: var(--ky-mono);
  font-size: 10.5px;
  letter-spacing: .16em;
  color: var(--ky-archive);
}
.page-about .ab-step__title {
  margin: 8px 0 10px;
  font-family: var(--ky-serif);
  font-weight: 700;
  font-size: 18px;
  letter-spacing: .02em;
  color: var(--ky-white);
}
.page-about .ab-step p {
  margin: 0;
  font-size: 14px;
  line-height: 1.78;
  color: var(--ky-muted);
}

/* ── 04 版本时间线 ─────────────────────────── */
.page-about .ab-versions__wrap {
  position: relative;
  padding: clamp(20px, 3vw, 36px) 0;
}
.page-about .ab-versions__bg {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: .14;
  pointer-events: none;
}
.page-about .ab-timeline {
  position: relative;
  z-index: 1;
  margin: 0;
  padding: 0;
  list-style: none;
}
.page-about .ab-timeline::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 14px;
  bottom: 14px;
  width: 1px;
  background: var(--ky-grid);
}
.page-about .ab-timeline__item {
  position: relative;
  display: grid;
  grid-template-columns: 22px 44px minmax(0, 1fr);
  gap: 12px;
  padding: 15px 0;
  align-items: start;
  outline: none;
}
.page-about .ab-timeline__node {
  width: 15px;
  height: 15px;
  margin-top: 3px;
  background: var(--ky-archive);
  transition: background-color .25s var(--ky-ease), transform .25s var(--ky-ease);
}
.page-about .ab-timeline__item--current .ab-timeline__node {
  background: var(--ky-volt);
  box-shadow: 0 0 0 4px rgba(216, 245, 60, .16);
}
.page-about .ab-timeline__ver {
  padding-top: 2px;
  font-family: var(--ky-mono);
  font-size: 13px;
  letter-spacing: .08em;
  color: var(--ky-volt);
}
.page-about .ab-timeline__name {
  padding-top: 1px;
  font-family: var(--ky-serif);
  font-weight: 700;
  font-size: 17px;
  letter-spacing: .02em;
  color: var(--ky-white);
}
.page-about .ab-timeline__desc {
  grid-column: 3;
  max-height: 0;
  margin: 0;
  overflow: hidden;
  opacity: 0;
  font-size: 14px;
  line-height: 1.76;
  color: var(--ky-muted);
  transition: max-height .38s var(--ky-ease), opacity .28s var(--ky-ease), margin-top .28s var(--ky-ease);
}
.page-about .ab-timeline__item:hover .ab-timeline__desc,
.page-about .ab-timeline__item:focus .ab-timeline__desc {
  max-height: 150px;
  margin-top: 8px;
  opacity: 1;
}
.page-about .ab-timeline__item:hover .ab-timeline__node,
.page-about .ab-timeline__item:focus .ab-timeline__node {
  background: var(--ky-volt);
}
.page-about .ab-timeline__item:hover,
.page-about .ab-timeline__item:focus { outline: none; }

/* ── 05 团队与规模 ─────────────────────────── */
.page-about .ab-team {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(24px, 3.4vw, 44px);
  align-items: start;
}
.page-about .ab-team__figure { margin: 0; }
.page-about .ab-team__figure .ky-figure__cap {
  font-family: var(--ky-mono);
  font-size: 11.5px;
  letter-spacing: .03em;
}
.page-about .ab-team__body p {
  max-width: 60ch;
}

.page-about .ab-bar {
  display: flex;
  width: 100%;
  height: 58px;
  margin: clamp(22px, 3vw, 34px) 0 12px;
}
.page-about .ab-bar__seg {
  position: relative;
  display: grid;
  place-items: center;
  cursor: default;
  transition: filter .25s var(--ky-ease), transform .25s var(--ky-ease);
}
.page-about .ab-bar__seg--edit {
  flex: 18 1 0;
  background: var(--ky-volt);
  color: var(--ky-night);
}
.page-about .ab-bar__seg--proof {
  flex: 6 1 0;
  background: var(--ky-ember);
  color: var(--ky-white);
}
.page-about .ab-bar__seg--tech {
  flex: 22 1 0;
  background: var(--ky-azure);
  color: var(--ky-white);
}
.page-about .ab-bar__num,
.page-about .ab-bar__name {
  grid-area: 1 / 1;
  font-family: var(--ky-mono);
  font-size: 13px;
  letter-spacing: .06em;
  transition: opacity .22s var(--ky-ease);
}
.page-about .ab-bar__name {
  font-size: 11.5px;
  opacity: 0;
}
.page-about .ab-bar__seg:hover .ab-bar__num,
.page-about .ab-bar__seg:focus .ab-bar__num { opacity: 0; }
.page-about .ab-bar__seg:hover .ab-bar__name,
.page-about .ab-bar__seg:focus .ab-bar__name { opacity: 1; }
.page-about .ab-bar__seg:hover,
.page-about .ab-bar__seg:focus {
  filter: brightness(1.12);
  outline: none;
}
.page-about .ab-team__note {
  margin: 0;
  font-family: var(--ky-mono);
  font-size: 11.5px;
  letter-spacing: .04em;
  color: var(--ky-muted) !important;
}

/* ── 06 合作生态 ───────────────────────────── */
.page-about .ab-partners {
  margin: 0;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--ab-line);
}
.page-about .ab-partners__row {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: clamp(18px, 3vw, 40px);
  align-items: baseline;
  padding: clamp(20px, 2.6vw, 30px) 0;
  border-bottom: 1px solid var(--ab-line);
}
.page-about .ab-partners__num {
  font-family: var(--ky-cond);
  font-weight: 700;
  font-size: clamp(32px, 5vw, 54px);
  line-height: .9;
  letter-spacing: .02em;
  color: var(--ky-volt);
}
.page-about .ab-partners__title {
  margin: 0 0 8px;
  font-family: var(--ky-serif);
  font-weight: 700;
  font-size: clamp(16px, 1.8vw, 19px);
  letter-spacing: .02em;
  color: var(--ky-white);
}
.page-about .ab-partners__body p {
  margin: 0;
  max-width: 56ch;
  font-size: 14.5px;
}
.page-about .ab-partners__note {
  margin: clamp(22px, 3vw, 32px) 0 0;
  padding-left: 16px;
  border-left: 2px solid var(--ky-archive);
  max-width: 62ch;
  font-size: 14.5px;
}

/* ── 07 长期承诺 ───────────────────────────── */
.page-about .ab-pledge {
  position: relative;
  margin: clamp(4px, 1vw, 12px) 0 clamp(24px, 3.2vw, 38px);
  padding-left: clamp(28px, 5vw, 76px);
}
.page-about .ab-pledge__mark {
  position: absolute;
  left: 0;
  top: -0.28em;
  font-family: var(--ky-serif);
  font-size: clamp(58px, 9vw, 116px);
  line-height: 1;
  color: rgba(216, 245, 60, .34);
  pointer-events: none;
}
.page-about .ab-pledge__text {
  margin: 0;
  max-width: 46ch;
  font-family: var(--ky-serif);
  font-size: clamp(16px, 1.9vw, 20px);
  line-height: 1.78;
  letter-spacing: .01em;
  color: var(--ky-white);
}

.page-about .ab-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: clamp(26px, 3.4vw, 40px);
}

/* ── 响应式 ───────────────────────────────── */
@media (min-width: 720px) {
  .page-about .ab-cols { grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); }
  .page-about .ab-team { grid-template-columns: minmax(180px, .62fr) minmax(0, 1.38fr); }
}

@media (min-width: 960px) {
  .page-about .ab-hero__grid {
    grid-template-columns: minmax(0, 1fr) 300px;
    align-items: end;
    gap: clamp(36px, 5vw, 64px);
  }
  .page-about .ab-hero__aside { padding-top: 22px; }
}

@media (min-width: 1040px) {
  .page-about .ab-layout {
    grid-template-columns: 208px minmax(0, 1fr);
    gap: clamp(40px, 5vw, 84px);
  }
  .page-about .ab-rail {
    position: sticky;
    top: 112px;
    align-self: start;
    padding-top: clamp(48px, 6vw, 82px);
  }
  .page-about .ab-rail__list { flex-direction: column; gap: 0; }
  .page-about .ab-rail__link {
    width: 100%;
    padding: 9px 0;
    border-bottom: 1px solid transparent;
  }
}

@media (min-width: 1240px) {
  .page-about .ab-block { padding: clamp(56px, 6vw, 96px) 0; }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-timeline__desc,
  .page-about .ab-timeline__node,
  .page-about .ab-bar__seg,
  .page-about .ab-bar__num,
  .page-about .ab-bar__name,
  .page-about .ab-rail__link,
  .page-about .ab-line {
    transition: none;
  }
}
</main>