.page-about {
  --ab-gap: clamp(1.6rem, 4vw, 3rem);
  --ab-hair: rgba(232, 200, 138, 0.18);
  position: relative;
  background: var(--c-night);
  color: var(--c-snow);
  font-family: var(--f-body);
  overflow-x: clip;
}

/* ---------- 首屏 ---------- */
.page-about .ab-hero {
  position: relative;
  overflow: hidden;
  padding: clamp(1.4rem, 4vw, 2.2rem) 0 clamp(2rem, 6vw, 3.4rem);
  background:
    radial-gradient(120% 82% at 90% 0%, rgba(34, 227, 210, 0.15), transparent 58%),
    radial-gradient(92% 70% at 2% 100%, rgba(255, 106, 26, 0.13), transparent 62%),
    linear-gradient(166deg, var(--c-indigo) 0%, var(--c-night) 70%);
  border-bottom: 1px solid var(--c-line);
}

.page-about .ab-hero::after {
  content: "";
  position: absolute;
  right: -10%;
  bottom: -34%;
  width: 48%;
  height: 72%;
  background: linear-gradient(120deg, rgba(217, 164, 65, 0.16), rgba(34, 227, 210, 0.09));
  transform: rotate(-14deg);
  pointer-events: none;
}

.page-about .ab-hero__inner {
  position: relative;
  z-index: 2;
  display: grid;
  gap: clamp(1.4rem, 4vw, 2.4rem);
}

.page-about .ab-hero__lead .breadcrumb {
  margin-bottom: 0.9rem;
  font-size: 0.82rem;
  letter-spacing: 0.02em;
  color: rgba(244, 247, 251, 0.55);
}

.page-about .ab-hero__lead .breadcrumb a {
  color: rgba(244, 247, 251, 0.72);
  text-decoration: none;
}

.page-about .ab-hero__lead .breadcrumb a:hover,
.page-about .ab-hero__lead .breadcrumb a:focus-visible {
  color: var(--c-orange);
}

.page-about .ab-hero__title {
  margin: 0.45rem 0 0;
  font-family: var(--f-display);
  font-size: clamp(2rem, 8.4vw, 4.3rem);
  font-weight: 800;
  line-height: 1.05;
  letter-spacing: -0.025em;
  color: var(--c-snow);
  text-wrap: balance;
}

.page-about .ab-hero__lede {
  margin: 1rem 0 0;
  max-width: 48ch;
  font-size: clamp(0.98rem, 2.6vw, 1.08rem);
  line-height: 1.78;
  color: rgba(244, 247, 251, 0.78);
}

.page-about .ab-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.7rem;
  margin-top: clamp(1.2rem, 3.4vw, 1.8rem);
}

.page-about .ab-hero__brandmark {
  display: flex;
  justify-content: flex-start;
}

.page-about .ab-seal {
  position: relative;
  width: clamp(116px, 30vw, 168px);
  aspect-ratio: 1 / 1;
  border-radius: 50%;
  border: 1px dashed rgba(217, 164, 65, 0.6);
  display: grid;
  place-content: center;
  gap: 0.18rem;
  text-align: center;
  background:
    radial-gradient(circle at 50% 50%, rgba(255, 106, 26, 0.2), transparent 68%),
    rgba(255, 255, 255, 0.03);
  transform: rotate(-7deg);
}

.page-about .ab-seal::before {
  content: "";
  position: absolute;
  inset: 9px;
  border-radius: 50%;
  border: 1px solid rgba(34, 227, 210, 0.34);
}

.page-about .ab-seal__core {
  font-family: var(--f-serif);
  font-size: clamp(1.35rem, 5vw, 1.85rem);
  letter-spacing: 0.22em;
  text-indent: 0.22em;
  color: var(--c-snow);
}

.page-about .ab-seal__sub {
  font-family: var(--f-mono);
  font-size: 0.66rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--c-sand);
}

.page-about .ab-facts {
  list-style: none;
  margin: clamp(1.8rem, 4.6vw, 2.8rem) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--ab-hair);
  border: 1px solid var(--ab-hair);
  border-radius: var(--r-md);
  overflow: hidden;
}

.page-about .ab-fact {
  display: grid;
  gap: 0.2rem;
  padding: 0.85rem 0.9rem;
  background: rgba(11, 20, 48, 0.9);
}

.page-about .ab-fact__v {
  font-family: var(--f-mono);
  font-size: clamp(1.25rem, 4.4vw, 1.7rem);
  font-weight: 700;
  line-height: 1;
  color: var(--c-orange);
}

.page-about .ab-fact__k {
  font-size: 0.78rem;
  letter-spacing: 0.04em;
  color: rgba(244, 247, 251, 0.62);
}

/* ---------- 主体框架 ---------- */
.page-about .ab-frame {
  padding-top: clamp(2rem, 5vw, 3.2rem);
  padding-bottom: clamp(2.4rem, 6vw, 4rem);
}

.page-about .ab-rail {
  display: none;
}

.page-about .ab-flow {
  display: block;
  min-width: 0;
}

/* ---------- 章节 ---------- */
.page-about .ab-chapter {
  padding: clamp(1.8rem, 4.6vw, 3rem) 0;
  border-top: 1px solid rgba(232, 200, 138, 0.14);
}

.page-about .ab-chapter:first-child {
  border-top: 0;
  padding-top: 0;
}

.page-about .ab-chapter__head {
  max-width: 62ch;
  margin-bottom: clamp(1.1rem, 3vw, 1.7rem);
}

.page-about .ab-chapter__head h2 {
  margin: 0.4rem 0 0;
  font-family: var(--f-display);
  font-size: clamp(1.5rem, 5.6vw, 2.5rem);
  font-weight: 800;
  line-height: 1.12;
  letter-spacing: -0.02em;
  color: var(--c-snow);
  text-wrap: balance;
}

.page-about .ab-chapter__intro {
  margin: 0.6rem 0 0;
  font-size: 0.92rem;
  line-height: 1.7;
  color: rgba(244, 247, 251, 0.6);
}

.page-about .ab-prose p {
  max-width: 68ch;
  margin: 0 0 0.85rem;
  font-size: 1rem;
  line-height: 1.78;
  color: rgba(244, 247, 251, 0.78);
}

.page-about .ab-reach__body .ab-prose {
  margin-bottom: 1rem;
}

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

.page-about .ab-pull {
  margin: clamp(1.3rem, 3.4vw, 2rem) 0 0;
  padding-left: 1.1rem;
  border-left: 2px solid var(--c-orange);
  max-width: 54ch;
  font-family: var(--f-serif);
  font-size: clamp(1rem, 3.6vw, 1.24rem);
  line-height: 1.62;
  color: var(--c-sand);
}

.page-about .ab-note {
  margin: 1rem 0 0;
  max-width: 64ch;
  font-size: 0.88rem;
  line-height: 1.72;
  color: rgba(244, 247, 251, 0.58);
}

.page-about .ab-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0.6rem;
}

.page-about .ab-list li {
  position: relative;
  padding-left: 1.15rem;
  font-size: 0.93rem;
  line-height: 1.7;
  color: rgba(244, 247, 251, 0.74);
}

.page-about .ab-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.68em;
  width: 7px;
  height: 1px;
  background: var(--c-cyan);
}

/* ---------- 时间带 ---------- */
.page-about .ab-band {
  margin: 0 0 clamp(1.4rem, 3.6vw, 2rem);
  border-radius: var(--r-lg);
  overflow: hidden;
}

.page-about .ab-timeline {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0.85rem;
}

.page-about .ab-node {
  position: relative;
  padding: 0.85rem 0.95rem 0.95rem 1.5rem;
  border-left: 1px solid rgba(217, 164, 65, 0.42);
  border-radius: 0 var(--r-md) var(--r-md) 0;
  background: linear-gradient(160deg, rgba(22, 32, 74, 0.8), rgba(11, 20, 48, 0.55));
  transition: border-color 0.3s var(--ease), background 0.3s var(--ease);
}

.page-about .ab-node::before {
  content: "";
  position: absolute;
  left: -4.5px;
  top: 1.2rem;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--c-night);
  border: 2px solid var(--c-sand);
  transition: border-color 0.3s var(--ease), background 0.3s var(--ease);
}

.page-about .ab-node:hover,
.page-about .ab-node:focus-within {
  border-color: var(--c-orange);
}

.page-about .ab-node:hover::before,
.page-about .ab-node:focus-within::before {
  border-color: var(--c-orange);
  background: var(--c-orange);
}

.page-about .ab-node:focus-visible {
  outline: 2px solid var(--c-cyan);
  outline-offset: 3px;
}

.page-about .ab-node__year {
  display: block;
  font-family: var(--f-mono);
  font-size: clamp(1rem, 3.4vw, 1.28rem);
  font-weight: 700;
  letter-spacing: 0.05em;
  color: var(--c-cyan);
}

.page-about .ab-node__title {
  margin: 0.24rem 0 0.34rem;
  font-family: var(--f-display);
  font-size: 1rem;
  font-weight: 700;
  line-height: 1.3;
  color: var(--c-snow);
}

.page-about .ab-node__text {
  margin: 0;
  font-size: 0.88rem;
  line-height: 1.68;
  color: rgba(244, 247, 251, 0.66);
}

.page-about .ab-node__key {
  display: inline-block;
  margin-top: 0.6rem;
  padding: 0.14rem 0.5rem;
  border: 1px solid rgba(217, 164, 65, 0.42);
  border-radius: 999px;
  font-family: var(--f-mono);
  font-size: 0.68rem;
  letter-spacing: 0.12em;
  color: var(--c-poplar);
  opacity: 0.6;
  transition: opacity 0.25s var(--ease), color 0.25s var(--ease), border-color 0.25s var(--ease);
}

.page-about .ab-node:hover .ab-node__key,
.page-about .ab-node:focus-within .ab-node__key {
  opacity: 1;
  color: var(--c-cyan);
  border-color: rgba(34, 227, 210, 0.6);
}

/* ---------- 团队 ---------- */
.page-about .ab-team {
  display: grid;
  gap: clamp(1.2rem, 3.4vw, 1.8rem);
}

.page-about .ab-team__fig {
  margin: 0;
  border-radius: var(--r-lg);
  overflow: hidden;
}

.page-about .ab-roles {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0.85rem;
}

.page-about .ab-role {
  padding: 0.85rem 1rem;
  border: 1px solid var(--ab-hair);
  border-radius: var(--r-md);
  background: linear-gradient(158deg, rgba(22, 32, 74, 0.85), rgba(11, 20, 48, 0.6));
}

.page-about .ab-role__name {
  display: block;
  font-family: var(--f-display);
  font-size: 0.98rem;
  font-weight: 700;
  color: var(--c-snow);
}

.page-about .ab-role__text {
  margin: 0.34rem 0 0;
  font-size: 0.88rem;
  line-height: 1.72;
  color: rgba(244, 247, 251, 0.68);
}

/* ---------- 覆盖 ---------- */
.page-about .ab-reach {
  display: grid;
  gap: clamp(1.2rem, 3.4vw, 1.8rem);
}

.page-about .ab-reach__fig {
  margin: 0;
  border-radius: var(--r-lg);
  overflow: hidden;
}

/* ---------- 能力底座 ---------- */
.page-about .ab-stack {
  position: relative;
  display: grid;
  gap: 0.9rem;
}

.page-about .ab-cell {
  position: relative;
  padding: 0.95rem 1.05rem;
  border: 1px solid var(--ab-hair);
  border-radius: var(--r-md);
  background: linear-gradient(158deg, rgba(22, 32, 74, 0.92), rgba(11, 20, 48, 0.82));
  transition: border-color 0.3s var(--ease), transform 0.3s var(--ease);
}

.page-about .ab-cell:hover,
.page-about .ab-cell[open] {
  border-color: rgba(255, 106, 26, 0.62);
}

.page-about .ab-cell__head {
  display: grid;
  gap: 0.24rem;
  list-style: none;
  cursor: pointer;
}

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

.page-about .ab-cell__head::marker {
  content: "";
}

.page-about .ab-cell__idx {
  font-family: var(--f-mono);
  font-size: 0.72rem;
  letter-spacing: 0.16em;
  color: var(--c-poplar);
}

.page-about .ab-cell__name {
  font-family: var(--f-display);
  font-size: 1.02rem;
  font-weight: 700;
  line-height: 1.3;
  color: var(--c-snow);
}

.page-about .ab-cell__body {
  margin: 0.6rem 0 0;
  padding-top: 0.6rem;
  border-top: 1px dashed rgba(232, 200, 138, 0.28);
  font-size: 0.87rem;
  line-height: 1.72;
  color: rgba(244, 247, 251, 0.7);
}

/* ---------- 合作生态 ---------- */
.page-about .ab-partners {
  display: grid;
  gap: 0.9rem;
}

.page-about .ab-partner {
  padding: 1rem 1.05rem;
  border: 1px solid var(--ab-hair);
  border-left: 3px solid var(--c-poplar);
  border-radius: 0 var(--r-md) var(--r-md) 0;
  background: rgba(22, 32, 74, 0.5);
}

.page-about .ab-partner__num {
  display: block;
  font-family: var(--f-mono);
  font-size: clamp(1.6rem, 6vw, 2.2rem);
  font-weight: 700;
  line-height: 1;
  color: var(--c-snow);
}

.page-about .ab-partner__name {
  margin: 0.3rem 0 0.4rem;
  font-family: var(--f-display);
  font-size: 0.98rem;
  font-weight: 700;
  color: var(--c-poplar);
}

.page-about .ab-partner__text {
  margin: 0;
  font-size: 0.87rem;
  line-height: 1.72;
  color: rgba(244, 247, 251, 0.66);
}

/* ---------- 下一步 ---------- */
.page-about .ab-next {
  border-top: 0;
  padding-top: clamp(2rem, 5vw, 3rem);
}

.page-about .ab-next__inner {
  position: relative;
  overflow: hidden;
  padding: clamp(1.5rem, 4.4vw, 2.6rem);
  border-radius: var(--r-lg);
  background:
    radial-gradient(110% 90% at 100% 0%, rgba(255, 106, 26, 0.24), transparent 60%),
    linear-gradient(150deg, var(--c-indigo), var(--c-void));
  border: 1px solid rgba(255, 106, 26, 0.32);
}

.page-about .ab-next__inner h2 {
  margin: 0.4rem 0 0;
  font-family: var(--f-display);
  font-size: clamp(1.5rem, 5.4vw, 2.2rem);
  font-weight: 800;
  line-height: 1.14;
  letter-spacing: -0.02em;
  color: var(--c-snow);
}

.page-about .ab-next__inner p {
  margin: 0.85rem 0 0;
  max-width: 58ch;
  font-size: 0.95rem;
  line-height: 1.76;
  color: rgba(244, 247, 251, 0.76);
}

.page-about .ab-next__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.7rem;
  margin-top: clamp(1.1rem, 3vw, 1.6rem);
}

/* ---------- 平板与桌面 ---------- */
@media (min-width: 700px) {
  .page-about .ab-facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

  .page-about .ab-node {
    padding: 0.95rem 1.1rem 1.05rem 1.7rem;
  }
}

@media (min-width: 860px) {
  .page-about .ab-timeline {
    grid-template-columns: repeat(5, minmax(0, 1fr));
    gap: 0.9rem;
  }

  .page-about .ab-node {
    padding: 2.3rem 0.85rem 1rem 0.85rem;
    border-left: 0;
    border-top: 1px solid rgba(217, 164, 65, 0.42);
    border-radius: 0 0 var(--r-md) var(--r-md);
  }

  .page-about .ab-node::before {
    left: 0.85rem;
    top: -4.5px;
  }
}

@media (min-width: 900px) {
  .page-about .ab-hero__inner {
    grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
    align-items: end;
  }

  .page-about .ab-hero__brandmark {
    justify-content: flex-end;
  }

  .page-about .ab-team {
    grid-template-columns: minmax(0, 5fr) minmax(0, 6fr);
    align-items: start;
  }

  .page-about .ab-reach {
    grid-template-columns: minmax(0, 6fr) minmax(0, 5fr);
    align-items: start;
  }

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

  .page-about .ab-stack::before {
    content: "";
    position: absolute;
    inset: 12% 10%;
    pointer-events: none;
    background:
      linear-gradient(48deg, transparent calc(50% - 1px), rgba(232, 200, 138, 0.3) calc(50% - 1px), rgba(232, 200, 138, 0.3) calc(50% + 1px), transparent calc(50% + 1px)),
      linear-gradient(-48deg, transparent calc(50% - 1px), rgba(232, 200, 138, 0.3) calc(50% - 1px), rgba(232, 200, 138, 0.3) calc(50% + 1px), transparent calc(50% + 1px));
  }

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

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

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

  .page-about .ab-cell:nth-child(4) {
    grid-column: 2;
    grid-row: 3;
  }
}

@media (min-width: 1024px) {
  .page-about .ab-frame {
    display: grid;
    grid-template-columns: 116px minmax(0, 1fr);
    gap: clamp(2rem, 4vw, 3.4rem);
    align-items: start;
  }

  .page-about .ab-rail {
    display: grid;
    gap: 0.1rem;
    position: sticky;
    top: calc(var(--header-h) + 1.6rem);
    padding-left: 0.8rem;
    border-left: 1px solid rgba(232, 200, 138, 0.22);
  }

  .page-about .ab-rail__item {
    display: grid;
    gap: 0.08rem;
    padding: 0.34rem 0.2rem;
    text-decoration: none;
    color: rgba(244, 247, 251, 0.5);
    transition: color 0.25s var(--ease), padding-left 0.25s var(--ease);
  }

  .page-about .ab-rail__item:hover,
  .page-about .ab-rail__item:focus-visible {
    color: var(--c-snow);
    padding-left: 0.42rem;
  }

  .page-about .ab-rail__idx {
    font-family: var(--f-mono);
    font-size: 0.66rem;
    letter-spacing: 0.12em;
    color: var(--c-poplar);
  }

  .page-about .ab-rail__name {
    font-size: 0.84rem;
    letter-spacing: 0.04em;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-node,
  .page-about .ab-node::before,
  .page-about .ab-node__key,
  .page-about .ab-cell,
  .page-about .ab-rail__item {
    transition: none;
  }
}