.page-about {
  --ab-line: rgba(95, 224, 208, 0.32);
  --ab-line-soft: rgba(95, 224, 208, 0.16);
  --ab-dim: rgba(247, 243, 234, 0.72);
  background: var(--paper);
  color: var(--ink);
  overflow-x: hidden;
}

.page-about .ab-section {
  padding: 3rem 0;
}

.page-about .ab-slate {
  display: inline-block;
  margin: 0 0 0.9rem;
  padding-left: 0.7rem;
  border-left: 2px solid var(--signal);
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.2em;
  color: var(--mist);
}

.page-about .ab-slate--light {
  color: var(--ice);
  border-left-color: var(--signal);
}

.page-about .ab-head {
  max-width: 64ch;
  margin-bottom: 2rem;
}

.page-about .ab-head h2,
.page-about .ab-origin h2,
.page-about .ab-crew h2,
.page-about .ab-stats h2,
.page-about .ab-cta h2 {
  margin: 0 0 0.8rem;
  font-size: clamp(1.5rem, 3.6vw, 2.3rem);
  font-weight: 800;
  letter-spacing: 0.03em;
  line-height: 1.28;
}

.page-about .ab-head__sub {
  margin: 0;
  font-size: 1rem;
  line-height: 1.8;
  color: #5a4f47;
}

/* ---------- 首屏 ---------- */
.page-about .ab-hero {
  position: relative;
  padding: 1.25rem 0 2.5rem;
}

.page-about .ab-hero::after {
  content: "";
  position: absolute;
  right: -12%;
  bottom: 1rem;
  width: 46%;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--ice));
  transform: rotate(-7deg);
  opacity: 0.55;
  pointer-events: none;
}

.page-about .ab-hero__grid {
  display: grid;
  gap: 2rem;
  align-items: end;
}

.page-about .ab-hero h1 {
  margin: 0.4rem 0 1.1rem;
  font-size: clamp(2rem, 6vw, 3.5rem);
  font-weight: 800;
  line-height: 1.14;
  letter-spacing: 0.02em;
}

.page-about .ab-hero__lead {
  margin: 0;
  max-width: 56ch;
  font-size: 1.0625rem;
  line-height: 1.85;
  color: #3d332d;
}

.page-about .ab-hero__marks {
  list-style: none;
  margin: 1.6rem 0 0;
  padding: 0;
  display: grid;
  gap: 0.6rem;
  font-size: 0.9rem;
  color: #4c423b;
}

.page-about .ab-hero__marks li {
  display: flex;
  align-items: baseline;
  gap: 0.7rem;
}

.page-about .ab-hero__mk {
  flex: 0 0 auto;
  font-family: var(--font-mono);
  font-size: 0.82rem;
  letter-spacing: 0.06em;
  color: var(--polar);
  background: var(--ice-soft);
  padding: 0.18rem 0.5rem;
  border-radius: 2px;
}

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

.page-about .ab-hero__figure .media-frame {
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 22px), calc(100% - 22px) 100%, 0 100%);
  border: 1px solid var(--ab-line);
}

.page-about .ab-hero__figure figcaption {
  margin-top: 0.65rem;
  font-size: 0.78rem;
  letter-spacing: 0.04em;
  color: var(--mist);
  text-align: right;
}

/* ---------- 起点与代号 ---------- */
.page-about .ab-origin {
  display: grid;
  gap: 1.75rem;
}

.page-about .ab-origin__text p {
  margin: 0 0 1rem;
  font-size: 1rem;
  line-height: 1.85;
  color: #3d332d;
}

.page-about .ab-code {
  align-self: start;
  padding: 1.5rem 1.4rem 1.7rem;
  background: linear-gradient(150deg, var(--polar), var(--night) 70%);
  color: var(--paper);
  clip-path: polygon(0 0, calc(100% - 20px) 0, 100% 20px, 100% 100%, 0 100%);
  border-left: 3px solid var(--signal);
}

.page-about .ab-code__tag {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.22em;
  color: var(--ice);
}

.page-about .ab-code__word {
  margin: 0.35rem 0 1.2rem;
  font-family: var(--font-mono);
  font-size: clamp(2rem, 8vw, 2.9rem);
  font-weight: 700;
  letter-spacing: 0.14em;
  color: var(--paper);
}

.page-about .ab-code__list {
  margin: 0;
  display: grid;
  gap: 0.85rem;
}

.page-about .ab-code__list div {
  padding-top: 0.7rem;
  border-top: 1px solid var(--ab-line-soft);
}

.page-about .ab-code__list dt {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.14em;
  color: var(--ice);
  margin-bottom: 0.28rem;
}

.page-about .ab-code__list dd {
  margin: 0;
  font-size: 0.9rem;
  line-height: 1.65;
  color: var(--ab-dim);
}

/* ---------- 时间轴 ---------- */
.page-about .ab-section--tl {
  padding-top: 1rem;
}

.page-about .ab-tl {
  --tl-dot: 0.85rem;
  --tl-shift: -2.25rem;
  --tl-x: 0.62rem;
  position: relative;
  list-style: none;
  margin: 0;
  padding: 0 0 0 2.25rem;
}

.page-about .ab-tl::before {
  content: "";
  position: absolute;
  left: var(--tl-x);
  top: 0.6rem;
  bottom: 1.5rem;
  width: 1px;
  background: linear-gradient(180deg, var(--glacier), var(--ice) 55%, var(--ab-line-soft));
}

.page-about .ab-tl__item {
  position: relative;
  padding-bottom: 2.25rem;
}

.page-about .ab-tl__item::before {
  content: "";
  position: absolute;
  left: calc(var(--tl-shift) + var(--tl-x) - var(--tl-dot) / 2);
  top: 0.85rem;
  width: var(--tl-dot);
  height: var(--tl-dot);
  border-radius: 50%;
  border: 2px solid var(--glacier);
  background: var(--paper);
  transition: border-color 200ms var(--ease), box-shadow 200ms var(--ease);
}

.page-about .ab-tl__item:hover::before,
.page-about .ab-tl__item:focus-within::before {
  border-color: var(--signal);
  box-shadow: 0 0 0 4px rgba(255, 122, 61, 0.16);
}

.page-about .ab-tl__year {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(1.75rem, 6vw, 3.2rem);
  font-weight: 700;
  line-height: 1;
  letter-spacing: 0.02em;
  color: var(--polar);
  margin-bottom: 0.6rem;
}

.page-about .ab-tl__body h3 {
  margin: 0 0 0.55rem;
  font-size: 1.1rem;
  font-weight: 700;
  letter-spacing: 0.02em;
}

.page-about .ab-tl__body p {
  margin: 0;
  font-size: 0.97rem;
  line-height: 1.8;
  color: #3d332d;
}

.page-about .ab-tl__note {
  margin-top: 0.75rem;
  padding-left: 0.7rem;
  border-left: 2px solid var(--ab-line);
  font-size: 0.82rem;
  letter-spacing: 0.03em;
  color: var(--mist);
  opacity: 0;
  max-height: 0;
  overflow: hidden;
  transition: opacity 220ms var(--ease), max-height 260ms var(--ease), border-color 220ms var(--ease);
}

.page-about .ab-tl__item:hover .ab-tl__note,
.page-about .ab-tl__item:focus-within .ab-tl__note {
  opacity: 1;
  max-height: 8rem;
  border-left-color: var(--signal);
}

/* ---------- 团队 ---------- */
.page-about .ab-crew {
  padding: 3rem 0;
  background: linear-gradient(165deg, var(--polar), var(--night) 82%);
  color: var(--paper);
}

.page-about .ab-crew__grid {
  display: grid;
  gap: 2rem;
}

.page-about .ab-crew__intro p {
  margin: 0;
  font-size: 0.98rem;
  line-height: 1.85;
  color: var(--ab-dim);
  max-width: 52ch;
}

.page-about .ab-crew__cols {
  display: grid;
  gap: 1px;
  background: var(--ab-line-soft);
  border-top: 1px solid var(--ab-line-soft);
  border-bottom: 1px solid var(--ab-line-soft);
}

.page-about .ab-crew__col {
  padding: 1.35rem 1.1rem;
  background: rgba(10, 27, 51, 0.55);
}

.page-about .ab-crew__num {
  display: block;
  font-family: var(--font-mono);
  font-size: 1.9rem;
  font-weight: 700;
  line-height: 1;
  color: var(--signal);
  margin-bottom: 0.55rem;
}

.page-about .ab-crew__col h3 {
  margin: 0 0 0.45rem;
  font-size: 1rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--paper);
}

.page-about .ab-crew__col p {
  margin: 0;
  font-size: 0.88rem;
  line-height: 1.75;
  color: var(--ab-dim);
}

.page-about .ab-crew__media {
  margin-top: 2.25rem;
  display: grid;
  gap: 1.5rem;
}

.page-about .ab-crew__media .media-frame {
  border: 1px solid var(--ab-line-soft);
}

.page-about .ab-crew__rules {
  display: grid;
  gap: 0.85rem;
  align-content: start;
}

.page-about .ab-crew__rules p {
  margin: 0;
  padding-left: 0.85rem;
  border-left: 1px solid var(--ab-line-soft);
  font-size: 0.9rem;
  line-height: 1.75;
  color: var(--ab-dim);
}

.page-about .ab-crew__k {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.16em;
  color: var(--ice);
  margin-bottom: 0.2rem;
}

/* ---------- 序号体系 ---------- */
.page-about .ab-idx {
  display: grid;
  gap: 1.75rem;
}

.page-about .ab-idx__list {
  display: grid;
  gap: 0.75rem;
}

.page-about .ab-idx__item {
  display: grid;
  grid-template-columns: auto 1fr;
  grid-template-areas:
    "no title"
    "no desc";
  column-gap: 0.9rem;
  padding: 1rem 1.1rem;
  background: #fffdf8;
  border: 1px solid rgba(33, 26, 23, 0.12);
  border-top: 3px solid var(--signal);
  text-decoration: none;
  color: inherit;
  transition: transform 200ms var(--ease), border-color 200ms var(--ease), box-shadow 200ms var(--ease);
}

.page-about .ab-idx__item:hover {
  transform: translateY(-4px);
  border-color: var(--glacier);
  box-shadow: 0 10px 24px rgba(10, 27, 51, 0.1);
}

.page-about .ab-idx__no {
  grid-area: no;
  align-self: center;
  font-family: var(--font-mono);
  font-size: 1.45rem;
  font-weight: 700;
  color: var(--glacier);
  letter-spacing: 0.04em;
}

.page-about .ab-idx__title {
  grid-area: title;
  font-size: 1rem;
  font-weight: 700;
  letter-spacing: 0.03em;
}

.page-about .ab-idx__desc {
  grid-area: desc;
  margin-top: 0.25rem;
  font-size: 0.86rem;
  line-height: 1.7;
  color: #5a4f47;
}

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

.page-about .ab-idx__figure .media-frame {
  border: 1px solid var(--ab-line);
}

.page-about .ab-idx__figure figcaption {
  margin-top: 0.6rem;
  font-size: 0.78rem;
  letter-spacing: 0.04em;
  color: var(--mist);
}

/* ---------- 统计 ---------- */
.page-about .ab-stats {
  padding: 2.75rem 0 3rem;
  background: var(--night);
  color: var(--paper);
  border-top: 1px solid var(--ab-line-soft);
  border-bottom: 1px solid var(--ab-line-soft);
}

.page-about .ab-stats h2 {
  color: var(--paper);
}

.page-about .ab-stats__head {
  max-width: 56ch;
  margin-bottom: 1.75rem;
}

.page-about .ab-stats__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--ab-line-soft);
  border: 1px solid var(--ab-line-soft);
}

.page-about .ab-stats__item {
  background: rgba(10, 27, 51, 0.72);
  padding: 1.25rem 1rem;
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.page-about .ab-stats__num {
  font-family: var(--font-mono);
  font-size: clamp(1.9rem, 6vw, 2.6rem);
  font-weight: 700;
  line-height: 1;
  color: var(--signal);
  letter-spacing: 0.02em;
}

.page-about .ab-stats__unit {
  font-size: 0.6em;
  margin-left: 0.15em;
  color: var(--ice);
}

.page-about .ab-stats__label {
  font-size: 0.84rem;
  line-height: 1.6;
  color: var(--ab-dim);
}

/* ---------- 技术底座 ---------- */
.page-about .ab-trust {
  margin-top: 0.5rem;
}

.page-about .ab-trust__card h3 {
  margin: 0.6rem 0 0.5rem;
  font-size: 1.02rem;
  font-weight: 700;
  letter-spacing: 0.02em;
  line-height: 1.45;
}

.page-about .ab-trust__card p {
  margin: 0;
  font-size: 0.9rem;
  line-height: 1.75;
  color: #4c423b;
}

/* ---------- 收束 ---------- */
.page-about .ab-cta {
  padding: 2.75rem 0 3.25rem;
  background: linear-gradient(140deg, var(--polar), #061224 78%);
  color: var(--paper);
}

.page-about .ab-cta__inner {
  display: grid;
  gap: 1.5rem;
  align-items: center;
}

.page-about .ab-cta h2 {
  font-size: clamp(1.35rem, 3.4vw, 1.9rem);
  color: var(--paper);
  margin-bottom: 0.6rem;
}

.page-about .ab-cta p {
  margin: 0;
  max-width: 46ch;
  font-size: 0.94rem;
  line-height: 1.8;
  color: var(--ab-dim);
}

.page-about .ab-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}

/* ---------- 响应式 ---------- */
@media (min-width: 720px) {
  .page-about .ab-section {
    padding: 4rem 0;
  }

  .page-about .ab-hero__marks {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 0.9rem;
  }

  .page-about .ab-hero__marks li {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.35rem;
  }

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

  .page-about .ab-crew__media {
    grid-template-columns: 1.15fr 0.85fr;
    align-items: start;
    gap: 2rem;
  }

  .page-about .ab-stats__list {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .ab-cta__inner {
    grid-template-columns: 1fr auto;
    gap: 2.5rem;
  }
}

@media (min-width: 900px) {
  .page-about .ab-hero {
    padding: 2rem 0 3.5rem;
  }

  .page-about .ab-hero__grid {
    grid-template-columns: 1.08fr 0.92fr;
    gap: 3.25rem;
  }

  .page-about .ab-origin {
    grid-template-columns: 1.45fr 0.9fr;
    gap: 3rem;
  }

  .page-about .ab-crew {
    padding: 4rem 0;
  }

  .page-about .ab-crew__grid {
    grid-template-columns: 0.85fr 1.15fr;
    gap: 3rem;
    align-items: start;
  }

  .page-about .ab-crew__cols {
    border-top: 0;
    border-bottom: 0;
  }

  .page-about .ab-idx {
    grid-template-columns: 1.05fr 0.95fr;
    gap: 2.75rem;
    align-items: start;
  }

  .page-about .ab-tl {
    --tl-shift: 0rem;
    --tl-x: 11.5rem;
    padding-left: 0;
  }

  .page-about .ab-tl__item {
    display: grid;
    grid-template-columns: 10.5rem 1fr;
    column-gap: 2.5rem;
    padding-bottom: 2.75rem;
  }

  .page-about .ab-tl__item::before {
    top: 1rem;
  }

  .page-about .ab-tl__year {
    margin-bottom: 0;
    text-align: right;
    padding-right: 0.5rem;
  }

  .page-about .ab-tl__note {
    max-height: none;
    opacity: 0;
    max-height: 0;
  }

  .page-about .ab-tl__item:hover .ab-tl__note,
  .page-about .ab-tl__item:focus-within .ab-tl__note {
    max-height: 8rem;
    opacity: 1;
  }
}

@media (max-width: 719px) {
  .page-about .ab-tl__note {
    opacity: 1;
    max-height: none;
    overflow: visible;
  }
}

@media (min-width: 1120px) {
  .page-about .ab-hero h1 {
    font-size: 3.55rem;
  }
}
<<<END>>>