.page-about {
  --ab-cut: 14px;
  --ab-gap: clamp(28px, 5vw, 72px);
  background: var(--kt-ink);
  color: var(--kt-cream);
  font-family: var(--kt-font-sans);
  overflow-x: clip;
  padding-bottom: clamp(48px, 8vw, 96px);
}

.page-about *,
.page-about *::before,
.page-about *::after {
  box-sizing: border-box;
}

/* ---------- 首屏 ---------- */
.page-about .ab-mast {
  position: relative;
  isolation: isolate;
  padding-top: clamp(52px, 9vw, 104px);
  padding-bottom: clamp(36px, 6vw, 72px);
  background:
    radial-gradient(120% 90% at 88% 0%, rgba(11, 30, 58, 0.95), transparent 62%),
    linear-gradient(180deg, var(--kt-ink) 0%, #04120f 100%);
  border-bottom: 1px solid var(--kt-line-soft);
  overflow: hidden;
}

.page-about .ab-mast::after {
  content: "";
  position: absolute;
  top: 0;
  right: -12%;
  width: 52%;
  height: 100%;
  background: linear-gradient(180deg, rgba(18, 61, 50, 0.9), rgba(6, 27, 23, 0));
  clip-path: polygon(30% 0, 100% 0, 100% 100%, 0 100%);
  opacity: 0.6;
  pointer-events: none;
  z-index: -1;
}

.page-about .ab-mast .kt-crumbs {
  margin-bottom: clamp(18px, 3vw, 34px);
}

.page-about .ab-mast__grid {
  display: grid;
  gap: clamp(22px, 4vw, 52px);
}

.page-about .ab-h1 {
  margin: 0;
  font-size: clamp(2.2rem, 6.6vw, 5rem);
  line-height: 1.02;
  font-weight: 900;
  letter-spacing: -0.03em;
}

.page-about .ab-h1 em {
  display: block;
  font-style: normal;
  color: var(--kt-lime);
}

.page-about .ab-mast__lede {
  margin: 0 0 clamp(16px, 2.5vw, 26px);
  color: var(--kt-mist);
  font-size: clamp(0.98rem, 1.4vw, 1.08rem);
  line-height: 1.8;
  max-width: 34em;
}

.page-about .ab-mast__acts {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

/* ---------- 行式轨道 ---------- */
.page-about .ab-row {
  display: grid;
  gap: clamp(14px, 2.5vw, 36px);
  padding-block: clamp(38px, 6.5vw, 84px);
  border-top: 1px solid var(--kt-line-soft);
}

.page-about .ab-row__idx {
  margin: 0;
  font-family: var(--kt-font-mono);
  font-size: 0.76rem;
  letter-spacing: 0.2em;
  color: var(--kt-lime);
  text-transform: uppercase;
}

.page-about .ab-h2 {
  margin: 0 0 0.7em;
  font-size: clamp(1.55rem, 3.2vw, 2.6rem);
  line-height: 1.15;
  font-weight: 900;
  letter-spacing: -0.02em;
}

.page-about .ab-p {
  margin: 0 0 1em;
  color: var(--kt-mist);
  line-height: 1.8;
  max-width: 40em;
}

.page-about .ab-p--tight {
  margin-top: clamp(16px, 2.5vw, 26px);
  max-width: 46em;
  font-size: 0.95rem;
  color: var(--kt-stone);
}

/* ---------- 分栏与图 ---------- */
.page-about .ab-split {
  display: grid;
  gap: clamp(20px, 3.5vw, 44px);
}

.page-about .ab-figure {
  margin: 0;
  overflow: hidden;
  background: var(--kt-night);
  border: 1px solid var(--kt-line-soft);
}

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

.page-about .ab-figure--tilt {
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 32px), calc(100% - 32px) 100%, 0 100%);
}

.page-about .ab-figure--tilt img {
  aspect-ratio: 14 / 9;
}

.page-about .ab-figure--wide {
  margin-block: clamp(20px, 3vw, 34px);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - var(--ab-cut)), calc(100% - var(--ab-cut)) 100%, 0 100%);
}

.page-about .ab-figure--wide img {
  aspect-ratio: 16 / 10;
  max-height: 420px;
}

.page-about .ab-figure--side {
  clip-path: polygon(var(--ab-cut) 0, 100% 0, 100% 100%, 0 100%, 0 var(--ab-cut));
}

.page-about .ab-figure--side img {
  aspect-ratio: 3 / 2;
}

.page-about .ab-quote {
  margin: clamp(20px, 3vw, 34px) 0 0;
  padding: 0.1em 0 0.1em clamp(14px, 2vw, 24px);
  border-left: 3px solid var(--kt-orange);
  font-size: clamp(1.2rem, 2.6vw, 1.9rem);
  font-weight: 800;
  line-height: 1.35;
  letter-spacing: -0.01em;
  color: var(--kt-cream);
  max-width: 22em;
}

/* ---------- 团队 ---------- */
.page-about .ab-team {
  display: grid;
  gap: 12px;
}

.page-about .ab-role {
  padding: clamp(16px, 2.4vw, 26px);
  background: var(--kt-moss);
  border-top: 2px solid var(--kt-lime);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - var(--ab-cut)), calc(100% - var(--ab-cut)) 100%, 0 100%);
  transition: transform var(--kt-speed) var(--kt-ease), background-color var(--kt-speed) var(--kt-ease);
}

.page-about .ab-role:nth-child(2),
.page-about .ab-role:nth-child(3) {
  background: var(--kt-night);
}

.page-about .ab-role:nth-child(2) {
  border-top-color: var(--kt-orange);
}

.page-about .ab-role:nth-child(3) {
  border-top-color: var(--kt-gold);
}

.page-about .ab-role:nth-child(4) {
  border-top-color: var(--kt-mist);
}

.page-about .ab-role:hover,
.page-about .ab-role:focus-within {
  transform: translateY(-3px);
  background: #174a3c;
}

.page-about .ab-role__name {
  margin: 0 0 0.5em;
  font-size: clamp(1.05rem, 1.8vw, 1.3rem);
  font-weight: 800;
  letter-spacing: -0.01em;
}

.page-about .ab-role__desc {
  margin: 0 0 0.9em;
  color: var(--kt-mist);
  font-size: 0.94rem;
  line-height: 1.75;
}

.page-about .ab-role__out {
  margin: 0;
  padding-top: 0.7em;
  border-top: 1px solid var(--kt-line);
  font-family: var(--kt-font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.03em;
  color: var(--kt-lime);
}

/* ---------- 流程 ---------- */
.page-about .ab-flow {
  display: grid;
  gap: clamp(20px, 3.5vw, 40px);
  margin-top: clamp(18px, 3vw, 30px);
}

.page-about .ab-flow__svg {
  display: block;
  width: 100%;
  height: auto;
  margin-bottom: clamp(10px, 2vw, 20px);
}

.page-about .ab-steps {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 14px;
  counter-reset: abstep;
}

.page-about .ab-step {
  padding: clamp(14px, 2vw, 20px) clamp(14px, 2vw, 22px);
  background: linear-gradient(180deg, rgba(11, 30, 58, 0.85), rgba(6, 27, 23, 0.9));
  border: 1px solid var(--kt-line-soft);
  border-left: 2px solid var(--kt-orange);
}

.page-about .ab-step__no {
  margin: 0 0 0.5em;
  font-family: var(--kt-font-mono);
  font-size: 0.74rem;
  letter-spacing: 0.16em;
  color: var(--kt-orange);
}

.page-about .ab-step__name {
  margin: 0 0 0.45em;
  font-size: 1.06rem;
  font-weight: 800;
}

.page-about .ab-step__desc {
  margin: 0;
  font-size: 0.92rem;
  line-height: 1.75;
  color: var(--kt-mist);
}

/* ---------- 版本轴 ---------- */
.page-about .ab-timeline {
  margin-top: clamp(16px, 3vw, 28px);
  border-bottom: 1px solid var(--kt-line);
}

.page-about .ab-stage {
  border-top: 1px solid var(--kt-line);
}

.page-about .ab-stage summary {
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: clamp(12px, 2vw, 20px);
  padding: clamp(14px, 2.2vw, 22px) 0;
  cursor: pointer;
  list-style: none;
}

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

.page-about .ab-stage summary:focus-visible {
  outline: 2px solid var(--kt-lime);
  outline-offset: 4px;
}

.page-about .ab-stage__badge {
  font-family: var(--kt-font-mono);
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--kt-ink);
  background: var(--kt-lime);
  padding: 4px 9px;
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 8px), calc(100% - 8px) 100%, 0 100%);
}

.page-about .ab-stage__title {
  font-size: clamp(1rem, 1.9vw, 1.28rem);
  font-weight: 800;
  letter-spacing: -0.01em;
}

.page-about .ab-stage__mark {
  position: relative;
  width: 18px;
  height: 18px;
  border: 1px solid var(--kt-line);
  flex: none;
}

.page-about .ab-stage__mark::before {
  content: "+";
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  font-family: var(--kt-font-mono);
  font-size: 0.85rem;
  line-height: 1;
  color: var(--kt-lime);
}

.page-about .ab-stage[open] .ab-stage__mark::before {
  content: "–";
  color: var(--kt-orange);
}

.page-about .ab-stage__body {
  padding: 0 0 clamp(16px, 2.4vw, 24px) clamp(52px, 8vw, 92px);
}

.page-about .ab-stage__body p {
  margin: 0;
  max-width: 44em;
  color: var(--kt-mist);
  font-size: 0.95rem;
  line-height: 1.8;
}

.page-about .ab-stage:hover {
  background: linear-gradient(90deg, var(--kt-lime-soft), transparent 70%);
}

/* ---------- 规模 ---------- */
.page-about .ab-stats {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(148px, 1fr));
  gap: 1px;
  margin: clamp(18px, 3vw, 30px) 0 0;
  background: var(--kt-line-soft);
  border: 1px solid var(--kt-line-soft);
}

.page-about .ab-stat {
  background: var(--kt-ink);
  padding: clamp(16px, 2.6vw, 26px);
}

.page-about .ab-stat dt {
  font-size: 0.78rem;
  letter-spacing: 0.06em;
  color: var(--kt-stone);
  margin-bottom: 0.7em;
}

.page-about .ab-stat dd {
  margin: 0;
  display: flex;
  align-items: baseline;
  gap: 4px;
}

.page-about .ab-stat b {
  font-family: var(--kt-font-mono);
  font-size: clamp(1.7rem, 3.4vw, 2.6rem);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--kt-gold);
}

.page-about .ab-stat dd span {
  font-size: 0.82rem;
  color: var(--kt-mist);
}

/* ---------- 合作 ---------- */
.page-about .ab-partners {
  list-style: none;
  margin: clamp(18px, 3vw, 28px) 0 0;
  padding: 0;
  display: grid;
  gap: 12px;
}

.page-about .ab-partner {
  padding: clamp(16px, 2.4vw, 24px);
  border-left: 2px solid var(--kt-stone);
  background: rgba(11, 30, 58, 0.6);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - var(--ab-cut)), calc(100% - var(--ab-cut)) 100%, 0 100%);
  transition: transform var(--kt-speed) var(--kt-ease);
}

.page-about .ab-partner:hover {
  transform: translateY(-2px);
}

.page-about .ab-partner--clay {
  border-left-color: var(--kt-clay);
  background: rgba(184, 107, 75, 0.14);
}

.page-about .ab-partner--moss {
  border-left-color: var(--kt-lime);
  background: rgba(18, 61, 50, 0.75);
}

.page-about .ab-partner--night {
  border-left-color: var(--kt-mist);
}

.page-about .ab-partner__k {
  margin: 0 0 0.5em;
  font-weight: 800;
  font-size: 1.02rem;
  letter-spacing: -0.01em;
}

.page-about .ab-partner__v {
  margin: 0;
  font-size: 0.92rem;
  line-height: 1.75;
  color: var(--kt-mist);
}

.page-about .ab-award {
  margin: clamp(20px, 3vw, 30px) 0 0;
  padding-left: clamp(14px, 2vw, 22px);
  border-left: 2px solid var(--kt-gold);
  max-width: 42em;
  color: var(--kt-cream);
  font-size: 0.96rem;
  line-height: 1.85;
}

/* ---------- 结尾 ---------- */
.page-about .ab-cta {
  margin-top: clamp(36px, 6vw, 72px);
  padding-block: clamp(36px, 6vw, 72px);
  background:
    linear-gradient(115deg, rgba(18, 61, 50, 0.95) 0%, rgba(11, 30, 58, 0.95) 58%, rgba(6, 27, 23, 0.98) 100%);
  border-top: 1px solid var(--kt-line-soft);
  border-bottom: 1px solid var(--kt-line-soft);
}

.page-about .ab-cta__inner {
  position: relative;
}

.page-about .ab-cta__title {
  margin-bottom: 0.6em;
}

.page-about .ab-cta__text {
  margin: 0 0 clamp(18px, 3vw, 26px);
  max-width: 42em;
  color: var(--kt-mist);
  line-height: 1.85;
}

.page-about .ab-cta__acts {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.page-about .ab-cta__note {
  margin: clamp(16px, 2.5vw, 24px) 0 0;
  font-size: 0.88rem;
  color: var(--kt-stone);
}

.page-about .ab-cta__note a {
  color: var(--kt-lime);
  text-decoration: underline;
  text-underline-offset: 3px;
}

/* ---------- 桌面 ---------- */
@media (min-width: 760px) {
  .page-about .ab-team {
    grid-template-columns: repeat(6, 1fr);
  }

  .page-about .ab-role:nth-child(1) {
    grid-column: span 4;
  }

  .page-about .ab-role:nth-child(2) {
    grid-column: span 2;
  }

  .page-about .ab-role:nth-child(3) {
    grid-column: span 2;
  }

  .page-about .ab-role:nth-child(4) {
    grid-column: span 4;
  }

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

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

@media (min-width: 900px) {
  .page-about .ab-mast__grid {
    grid-template-columns: 7fr 5fr;
    align-items: end;
  }

  .page-about .ab-mast__side {
    padding-left: clamp(16px, 3vw, 40px);
    border-left: 1px solid var(--kt-line);
    padding-bottom: 6px;
  }

  .page-about .ab-row {
    grid-template-columns: minmax(76px, 104px) minmax(0, 1fr);
  }

  .page-about .ab-row__idx {
    position: sticky;
    top: 96px;
    align-self: start;
    padding-top: 0.55em;
  }

  .page-about .ab-split {
    grid-template-columns: 6fr 5fr;
    align-items: start;
  }

  .page-about .ab-flow {
    grid-template-columns: 7fr 4fr;
    align-items: start;
  }

  .page-about .ab-flow .ab-figure--side {
    margin-top: clamp(10px, 2vw, 24px);
  }

  .page-about .ab-partners {
    grid-template-columns: repeat(4, 1fr);
  }

  .page-about .ab-partner:nth-child(1) {
    grid-column: span 2;
  }

  .page-about .ab-partner:nth-child(2) {
    grid-column: span 2;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-role,
  .page-about .ab-partner {
    transition: none;
  }

  .page-about .ab-role:hover,
  .page-about .ab-role:focus-within,
  .page-about .ab-partner:hover {
    transform: none;
  }
}