.page-about {
  --ab-rail-w: 236px;
  --ab-rail-gap: 44px;
  --ab-r: 3px;
  color: var(--text);
}

/* ============ 首屏 ============ */
.page-about .ab-hero {
  position: relative;
  overflow: hidden;
  border-bottom: 1px solid var(--line);
  background:
    radial-gradient(880px 420px at 80% 8%, rgba(168, 85, 247, .22), transparent 62%),
    radial-gradient(700px 380px at 8% 96%, rgba(56, 189, 248, .15), transparent 60%),
    linear-gradient(180deg, var(--ink) 0%, var(--ink-2) 58%, var(--ink) 100%);
}

.page-about .ab-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  opacity: .32;
  background-image:
    linear-gradient(to right, rgba(46, 42, 68, .7) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(46, 42, 68, .7) 1px, transparent 1px);
  background-size: 96px 96px;
}

.page-about .ab-crumb {
  position: relative;
  z-index: 1;
  padding-top: 20px;
  font-size: 12px;
}

.page-about .ab-hero__grid {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: 1fr;
  gap: 30px;
  padding: 26px 0 44px;
}

.page-about .ab-hero__eyebrow {
  margin: 0;
  font-size: 12px;
  letter-spacing: .16em;
  color: var(--blue);
}

.page-about .ab-hero__title {
  margin: 10px 0 16px;
  font-size: clamp(30px, 6.6vw, 54px);
  font-weight: 800;
  line-height: 1.08;
  letter-spacing: -.02em;
}

.page-about .ab-hero__lead {
  max-width: 40em;
  margin: 0;
  color: var(--text);
  font-size: 15px;
  line-height: 1.85;
}

.page-about .ab-chips {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 22px 0 0;
  padding: 0;
}

.page-about .ab-chip {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 5px 11px;
  border: 1px solid var(--line);
  border-radius: var(--ab-r);
  background: rgba(94, 234, 212, .05);
  color: var(--muted);
  font-size: 12px;
}

.page-about .ab-chip::before {
  content: "";
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--teal);
}

.page-about .ab-hero__aside {
  border: 1px solid var(--line);
  border-left: 3px solid var(--violet);
  background: rgba(11, 10, 24, .66);
  padding: 16px 16px 18px;
}

.page-about .ab-stairs {
  display: block;
  width: 100%;
  height: auto;
  margin-bottom: 14px;
  opacity: .85;
}

.page-about .ab-hero__cap {
  margin: 0 0 10px;
  font-size: 11px;
  letter-spacing: .16em;
  color: var(--blue);
}

.page-about .ab-facts {
  display: grid;
  gap: 1px;
  margin: 0;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .ab-fact {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 14px;
  padding: 11px 12px;
  background: rgba(15, 10, 34, .94);
}

.page-about .ab-fact__k {
  font-size: 11px;
  letter-spacing: .08em;
  color: var(--muted);
}

.page-about .ab-fact__v {
  margin: 0;
  font-size: 13px;
  color: var(--muted);
  text-align: right;
}

.page-about .ab-fact__v b {
  color: var(--text);
  font-size: 15px;
  font-weight: 800;
  margin-right: 5px;
}

/* ============ 主体容器 ============ */
.page-about .ab-body {
  padding-top: 4px;
  padding-bottom: 56px;
}

/* ============ 锚点索引条 ============ */
.page-about .ab-anchorbar {
  display: flex;
  gap: 6px;
  padding: 12px 0;
  overflow-x: auto;
  scrollbar-width: none;
  -webkit-overflow-scrolling: touch;
  border-bottom: 1px solid var(--line);
}

.page-about .ab-anchorbar::-webkit-scrollbar {
  display: none;
}

.page-about .mgm-anchorbar__link {
  flex: 0 0 auto;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 7px 12px;
  border: 1px solid var(--line);
  border-radius: var(--ab-r);
  background: rgba(27, 16, 53, .5);
  color: var(--muted);
  font-size: 12px;
  white-space: nowrap;
  text-decoration: none;
  transition: border-color .18s var(--ease), color .18s var(--ease), background-color .18s var(--ease);
}

.page-about .mgm-anchorbar__link:hover,
.page-about .mgm-anchorbar__link.is-active {
  color: var(--text);
  border-color: var(--violet);
  background: rgba(168, 85, 247, .12);
}

.page-about .mgm-anchorbar__no {
  font-size: 11px;
  color: var(--blue);
}

/* ============ 档案册双栏 ============ */
.page-about .ab-archive {
  display: grid;
  grid-template-columns: 1fr;
  gap: 30px;
  padding-top: 32px;
}

/* ---- 左栏坐标索引 ---- */
.page-about .ab-rail {
  border: 1px solid var(--line);
  background: linear-gradient(180deg, rgba(27, 16, 53, .88), rgba(11, 10, 24, .62));
  padding: 16px 14px 14px;
  box-shadow: 5px 5px 0 0 rgba(46, 42, 68, .5);
}

.page-about .ab-rail__cap {
  margin: 0 0 14px;
  font-size: 11px;
  letter-spacing: .16em;
  color: var(--blue);
}

.page-about .ab-rail__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 2px;
}

.page-about .ab-rail__item {
  position: relative;
  padding-left: 15px;
}

.page-about .ab-rail__item::before {
  content: "";
  position: absolute;
  left: 2px;
  top: 50%;
  transform: translateY(-50%);
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--ink);
  border: 1px solid var(--line);
  transition: background-color .18s var(--ease), border-color .18s var(--ease);
}

.page-about .ab-rail__item:hover::before,
.page-about .ab-rail__item:has(.is-active)::before {
  background: var(--violet);
  border-color: var(--violet);
}

.page-about .ab-rail__link {
  display: flex;
  align-items: baseline;
  gap: 10px;
  padding: 9px 8px 9px 12px;
  border-left: 2px solid transparent;
  color: var(--muted);
  font-size: 14px;
  text-decoration: none;
  transition: color .18s var(--ease), border-color .18s var(--ease), background-color .18s var(--ease);
}

.page-about .ab-rail__link:hover {
  color: var(--text);
  background: rgba(56, 189, 248, .07);
}

.page-about .ab-rail__link.is-active {
  color: var(--teal);
  border-left-color: var(--violet);
  background: rgba(168, 85, 247, .1);
}

.page-about .ab-rail__no {
  font-size: 11px;
  color: var(--blue);
}

.page-about .ab-rail__note {
  margin: 16px 0 0;
  padding-top: 12px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 12px;
  line-height: 1.7;
}

/* ---- 右栏画板流 ---- */
.page-about .ab-flow {
  display: grid;
  gap: 34px;
  min-width: 0;
}

.page-about .ab-card {
  position: relative;
  border: 1px solid var(--line);
  border-left: 3px solid var(--violet);
  background: linear-gradient(158deg, rgba(27, 16, 53, .92) 0%, rgba(15, 10, 34, .88) 100%);
  padding: 22px 18px 18px;
  box-shadow: 6px 6px 0 0 rgba(46, 42, 68, .5);
  transition: border-color .18s var(--ease), box-shadow .18s var(--ease), transform .18s var(--ease);
}

.page-about .ab-card:hover {
  border-color: rgba(168, 85, 247, .6);
  transform: translateY(-2px);
  box-shadow: 6px 8px 0 0 rgba(46, 42, 68, .62);
}

.page-about .ab-card__head {
  display: grid;
  gap: 8px;
  margin-bottom: 18px;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--line);
}

.page-about .ab-card__no {
  font-size: 11px;
  letter-spacing: .14em;
  color: var(--violet);
}

.page-about .ab-card__title {
  margin: 0;
  font-size: clamp(20px, 4.2vw, 27px);
  font-weight: 800;
  line-height: 1.28;
  letter-spacing: -.01em;
}

.page-about .ab-card__body > p {
  margin: 0 0 18px;
  max-width: 42em;
  font-size: 15px;
  line-height: 1.85;
}

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

.page-about .ab-card__foot {
  margin-top: 20px;
  padding-top: 11px;
  border-top: 1px solid var(--line);
  font-size: 11px;
  letter-spacing: .08em;
  color: var(--muted);
}

.page-about .ab-aside-note {
  margin: 16px 0 0;
  padding-left: 12px;
  border-left: 2px solid var(--blue);
  color: var(--muted) !important;
  font-size: 13px;
}

/* ============ 版本阶梯 ============ */
.page-about .ab-steps {
  list-style: none;
  display: grid;
  gap: 10px;
  margin: 0 0 26px;
  padding: 0;
}

.page-about .ab-step {
  display: flex;
  align-items: flex-start;
  gap: 14px;
  padding: 13px 15px;
  border: 1px solid var(--line);
  border-left: 2px solid var(--line);
  background: rgba(168, 85, 247, .04);
  transition: border-color .18s var(--ease), background-color .18s var(--ease), transform .18s var(--ease);
}

.page-about .ab-step:hover {
  border-color: var(--violet);
  background: rgba(168, 85, 247, .11);
  transform: translateY(-2px);
}

.page-about .ab-step__no {
  flex: 0 0 auto;
  padding-top: 3px;
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--teal);
}

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

.page-about .ab-step__name {
  margin: 0 0 6px;
  font-size: 15px;
  font-weight: 700;
  color: var(--text);
}

.page-about .ab-step__text p {
  margin: 0;
  font-size: 13.5px;
  line-height: 1.8;
  color: var(--muted);
}

/* ============ 通道列表 ============ */
.page-about .ab-lanes {
  list-style: none;
  display: grid;
  gap: 10px;
  margin: 0;
  padding: 0;
}

.page-about .ab-lane {
  padding: 14px 15px;
  border: 1px solid var(--line);
  border-left: 2px solid var(--line);
  background: rgba(56, 189, 248, .04);
  transition: border-color .18s var(--ease), background-color .18s var(--ease), transform .18s var(--ease);
}

.page-about .ab-lane:hover {
  transform: translateY(-2px);
  background: rgba(56, 189, 248, .1);
  border-color: var(--blue);
}

.page-about .ab-lane--legacy {
  border-left-color: var(--violet);
  background: rgba(168, 85, 247, .06);
}

.page-about .ab-lane--legacy:hover {
  background: rgba(168, 85, 247, .13);
  border-color: var(--violet);
}

.page-about .ab-lane--fast {
  border-left-color: var(--teal);
}

.page-about .ab-lane__head {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 9px;
  margin-bottom: 8px;
}

.page-about .ab-lane__code {
  font-size: 11px;
  letter-spacing: .08em;
  color: var(--blue);
}

.page-about .ab-lane__name {
  margin: 0;
  font-size: 15px;
  font-weight: 700;
}

.page-about .ab-lane__desc {
  margin: 0;
  font-size: 13.5px;
  line-height: 1.8;
  color: var(--muted);
}

/* ============ 团队分工 ============ */
.page-about .ab-split {
  display: grid;
  grid-template-columns: 1fr;
  gap: 22px;
  margin-bottom: 22px;
}

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

.page-about .ab-role {
  padding: 14px 15px;
  border: 1px solid var(--line);
  background: rgba(27, 16, 53, .5);
  transition: border-color .18s var(--ease);
}

.page-about .ab-role:hover {
  border-color: var(--violet);
}

.page-about .ab-role__tag {
  display: inline-block;
  margin-bottom: 8px;
  font-size: 10px;
  letter-spacing: .12em;
  color: var(--teal);
}

.page-about .ab-role__name {
  margin: 0 0 7px;
  font-size: 15px;
  font-weight: 700;
}

.page-about .ab-role__desc {
  margin: 0;
  font-size: 13.5px;
  line-height: 1.8;
  color: var(--muted);
}

/* ============ 地区说明 ============ */
.page-about .ab-notes {
  list-style: none;
  display: grid;
  gap: 1px;
  margin: 0 0 26px;
  padding: 0;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .ab-note {
  display: grid;
  grid-template-columns: 1fr;
  gap: 6px;
  padding: 14px 15px;
  background: rgba(15, 10, 34, .9);
  transition: background-color .18s var(--ease);
}

.page-about .ab-note:hover {
  background: rgba(27, 16, 53, .95);
}

.page-about .ab-note__k {
  font-size: 11px;
  letter-spacing: .1em;
  color: var(--blue);
}

.page-about .ab-note p {
  margin: 0;
  font-size: 13.5px;
  line-height: 1.8;
  color: var(--muted);
}

/* ============ 图片容器 ============ */
.page-about .ab-figure {
  margin: 0;
}

.page-about .ab-frame {
  position: relative;
  overflow: hidden;
  width: 100%;
  border: 1px solid var(--line);
  background: linear-gradient(140deg, var(--ink-2), var(--panel));
}

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

.page-about .ab-frame--wide {
  aspect-ratio: 2 / 1;
}

.page-about .ab-frame--team {
  aspect-ratio: 3 / 2;
}

.page-about .ab-frame--grid {
  aspect-ratio: 10 / 7;
}

.page-about .ab-figure .mgm-figure__caption {
  margin-top: 10px;
  font-size: 12px;
  line-height: 1.7;
  color: var(--muted);
}

.page-about .ab-figure .mgm-figure__badge {
  position: absolute;
  right: 10px;
  bottom: 10px;
  padding: 4px 9px;
  border: 1px solid var(--line);
  border-radius: var(--ab-r);
  background: rgba(11, 10, 24, .85);
  color: var(--gold);
  font-size: 10px;
  letter-spacing: .08em;
}

/* ============ 折叠面板 ============ */
.page-about .ab-fold {
  margin-top: 12px;
  border: 0;
  background: none;
}

.page-about .ab-fold > summary {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding: 12px 14px;
  border: 1px solid var(--line);
  background: rgba(56, 189, 248, .05);
  cursor: pointer;
  list-style: none;
  font-size: 14px;
  color: var(--text);
  transition: border-color .18s var(--ease), background-color .18s var(--ease);
}

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

.page-about .ab-fold > summary:hover {
  border-color: var(--violet);
}

.page-about .ab-fold[open] > summary {
  border-color: var(--violet);
  background: rgba(168, 85, 247, .1);
}

.page-about .ab-fold > summary::after {
  content: "+";
  margin-left: auto;
  color: var(--blue);
  font-family: var(--mono);
  font-size: 14px;
}

.page-about .ab-fold[open] > summary::after {
  content: "–";
  color: var(--violet);
}

.page-about .mgm-fold__no {
  flex: 0 0 auto;
  font-size: 11px;
  letter-spacing: .08em;
  color: var(--blue);
}

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

.page-about .ab-fold .mgm-fold__body {
  padding: 14px 16px 16px;
  border: 1px solid var(--line);
  border-top: 0;
  background: rgba(11, 10, 24, .55);
}

.page-about .ab-fold .mgm-fold__body p {
  margin: 0;
  max-width: 42em;
  font-size: 13.5px;
  line-height: 1.85;
  color: var(--muted);
}

/* ============ 口径双栏 ============ */
.page-about .ab-duo {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  margin-bottom: 20px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .ab-duo__cell {
  padding: 16px 15px;
  background: rgba(15, 10, 34, .9);
}

.page-about .ab-duo__cell--blue {
  border-top: 2px solid var(--blue);
}

.page-about .ab-duo__cell--violet {
  border-top: 2px solid var(--violet);
}

.page-about .ab-duo__k {
  display: block;
  margin-bottom: 8px;
  font-size: 10px;
  letter-spacing: .14em;
  color: var(--muted);
}

.page-about .ab-duo__title {
  margin: 0 0 8px;
  font-size: 15px;
  font-weight: 700;
}

.page-about .ab-duo__cell p {
  margin: 0;
  font-size: 13.5px;
  line-height: 1.8;
  color: var(--muted);
}

/* ============ 行动按钮组 ============ */
.page-about .ab-cta {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 22px;
}

/* ============ 响应式 ============ */
@media (min-width: 620px) {
  .page-about .ab-note {
    grid-template-columns: 96px minmax(0, 1fr);
    align-items: baseline;
    gap: 14px;
  }

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

  .page-about .ab-step:nth-child(2) {
    margin-left: 16px;
  }

  .page-about .ab-step:nth-child(3) {
    margin-left: 32px;
  }

  .page-about .ab-step:nth-child(4) {
    margin-left: 48px;
  }
}

@media (min-width: 900px) {
  .page-about .ab-hero__grid {
    grid-template-columns: minmax(0, 1.42fr) minmax(0, 1fr);
    gap: 48px;
    align-items: end;
    padding: 42px 0 72px;
  }

  .page-about .ab-card {
    padding: 28px 26px 22px;
  }

  .page-about .ab-split {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 1fr);
    gap: 26px;
    align-items: start;
  }
}

@media (min-width: 1000px) {
  .page-about .ab-anchorbar {
    position: sticky;
    top: 78px;
    z-index: 6;
    flex-wrap: wrap;
    overflow: visible;
    gap: 8px;
    background: rgba(11, 10, 24, .94);
    backdrop-filter: blur(8px);
  }

  .page-about .ab-archive {
    grid-template-columns: var(--ab-rail-w) minmax(0, 1fr);
    gap: var(--ab-rail-gap);
    align-items: start;
    padding-top: 40px;
  }

  .page-about .ab-rail {
    position: sticky;
    top: 148px;
    padding: 20px 18px 16px;
  }

  .page-about .ab-flow {
    gap: 46px;
  }

  .page-about .ab-flow > :nth-child(4) {
    margin-top: 14px;
  }

  .page-about .ab-flow > :nth-child(5) {
    margin-top: 30px;
  }

  .page-about .ab-flow > :nth-child(6) {
    margin-top: 44px;
  }

  .page-about .ab-card--airy {
    padding-top: 34px;
    padding-bottom: 30px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-card,
  .page-about .ab-step,
  .page-about .ab-lane,
  .page-about .mgm-anchorbar__link,
  .page-about .ab-rail__link,
  .page-about .ab-rail__item::before,
  .page-about .ab-fold > summary {
    transition: none;
  }

  .page-about .ab-card:hover,
  .page-about .ab-step:hover,
  .page-about .ab-lane:hover {
    transform: none;
  }
}