.page-about {
  --ab-tick-col: 3.5rem;
  --ab-gap: 1rem;
  background: var(--ink-900);
  color: var(--paper);
  overflow-x: clip;
}

.page-about .ab-crumb {
  padding-block: 1rem 0;
}

/* ---------- 首屏 ---------- */
.page-about .ab-hero {
  position: relative;
  padding-block: 1.5rem 2.75rem;
}

.page-about .ab-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background:
    radial-gradient(58% 46% at 88% 2%, rgba(40, 211, 196, 0.16), transparent 72%),
    radial-gradient(52% 44% at 2% 96%, rgba(246, 196, 83, 0.1), transparent 70%);
  pointer-events: none;
}

.page-about .ab-hero-grid {
  position: relative;
  display: grid;
  gap: 2rem;
  align-items: start;
}

.page-about .ab-h1 {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(2.05rem, 8.6vw, 4.3rem);
  line-height: 1.06;
  letter-spacing: 0.04em;
  margin: 0.75rem 0 1.1rem;
  color: var(--paper);
}

.page-about .ab-h1 span {
  display: block;
  color: var(--cyan);
}

.page-about .ab-hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.7rem;
  margin-top: 1.6rem;
}

.page-about .ab-hero-stats {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 0.5rem;
  margin: 1.9rem 0 0;
  padding-top: 1.15rem;
  border-top: 1px solid var(--line);
}

.page-about .ab-hero-stats dt {
  font-size: 0.68rem;
  letter-spacing: 0.12em;
  color: var(--silver);
  line-height: 1.5;
}

.page-about .ab-hero-stats dd {
  margin: 0.4rem 0 0;
  font-family: var(--font-mono);
  font-size: clamp(1.3rem, 5vw, 1.85rem);
  font-weight: 600;
  line-height: 1;
  color: var(--yellow);
}

.page-about .ab-hero-stats > div:nth-child(n + 2) dd {
  color: var(--cyan);
}

.page-about .ab-hero-figure {
  margin: 0;
  position: relative;
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  background: var(--ink-700);
  overflow: hidden;
  aspect-ratio: 14 / 9;
}

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

.page-about .ab-hero-figure figcaption {
  position: absolute;
  inset: auto 0 0 0;
  padding: 0.85rem 1rem 0.7rem;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.09em;
  color: var(--paper);
  background: linear-gradient(to top, rgba(6, 16, 31, 0.94), rgba(6, 16, 31, 0));
}

/* ---------- 起点 ---------- */
.page-about .ab-origin {
  padding-block: 2.75rem;
  border-top: 1px solid var(--line);
}

.page-about .ab-origin-grid {
  display: grid;
  gap: 1.75rem;
}

.page-about .ab-origin-lead h2,
.page-about .ab-team-copy h2,
.page-about .ab-outro-copy h2 {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(1.5rem, 5.4vw, 2.3rem);
  line-height: 1.24;
  letter-spacing: 0.03em;
  margin: 0.6rem 0 0;
  color: var(--paper);
}

.page-about .ab-ruler {
  position: relative;
  height: 42px;
  margin-top: 1.6rem;
  border-bottom: 1px solid var(--line);
  background-image: repeating-linear-gradient(to right, var(--line) 0 1px, transparent 1px 100%);
  background-size: calc(100% / 38) 100%;
}

.page-about .ab-ruler-fill {
  position: absolute;
  left: 0;
  bottom: 0;
  width: 68%;
  height: 5px;
  border-radius: var(--r-pill);
  background: linear-gradient(90deg, var(--cyan-deep), var(--cyan));
}

.page-about .ab-ruler-fill::after {
  content: "";
  position: absolute;
  right: -4px;
  top: 50%;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--yellow);
  transform: translateY(-50%);
  box-shadow: 0 0 0 4px rgba(246, 196, 83, 0.16);
}

.page-about .ab-ruler-cap {
  display: flex;
  justify-content: space-between;
  margin: 0.55rem 0 0;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.12em;
  color: var(--silver);
}

.page-about .ab-origin-body p {
  margin: 0 0 1rem;
  font-size: 1rem;
  line-height: 1.85;
  color: var(--silver);
}

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

/* ---------- 时间线 ---------- */
.page-about .ab-timeline-sec {
  padding-block: 3rem;
  background: var(--ink-800);
  border-block: 1px solid var(--line);
}

.page-about .ab-head {
  max-width: 44rem;
}

.page-about .ab-head h2 {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(1.5rem, 5.4vw, 2.35rem);
  line-height: 1.26;
  letter-spacing: 0.03em;
  margin: 0.6rem 0 0.7rem;
  color: var(--paper);
}

.page-about .ab-timeline {
  position: relative;
  list-style: none;
  margin: 2.25rem 0 0;
  padding: 0;
}

.page-about .ab-timeline::before {
  content: "";
  position: absolute;
  top: 0.5rem;
  bottom: 1rem;
  left: calc(var(--ab-tick-col) - 1px);
  width: 2px;
  background: linear-gradient(to bottom, var(--cyan-deep), var(--line) 88%);
}

.page-about .ab-node {
  position: relative;
  display: grid;
  grid-template-columns: var(--ab-tick-col) minmax(0, 1fr);
  gap: 0.9rem;
  padding-bottom: 1.9rem;
}

.page-about .ab-node:last-child {
  padding-bottom: 0;
}

.page-about .ab-node::before {
  content: "";
  position: absolute;
  top: 0.4rem;
  left: var(--ab-tick-col);
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--ink-800);
  border: 2px solid var(--cyan-deep);
  transform: translate(-50%, 0);
  z-index: 2;
}

.page-about .ab-node-mark {
  padding-top: 0.15rem;
  text-align: right;
  padding-right: 0.6rem;
}

.page-about .ab-year {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.01em;
  color: var(--cyan);
  transition: color 0.4s ease;
}

.page-about .ab-card {
  background: var(--ink-700);
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  padding: 1rem 1.05rem 1.15rem;
}

.page-about .ab-card h3,
.page-about .ab-flow h3,
.page-about .ab-principles h3 {
  font-family: var(--font-display);
  font-size: 1.1rem;
  font-weight: 700;
  letter-spacing: 0.03em;
  line-height: 1.4;
  margin: 0.55rem 0 0.5rem;
  color: var(--paper);
}

.page-about .ab-card p {
  margin: 0;
  font-size: 0.94rem;
  line-height: 1.78;
  color: var(--silver);
}

.page-about .ab-more {
  margin-top: 0.85rem;
  padding-top: 0.7rem;
  border-top: 1px dashed var(--line);
}

.page-about .ab-more summary {
  cursor: pointer;
  list-style: none;
  font-size: 0.78rem;
  letter-spacing: 0.1em;
  color: var(--cyan);
}

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

.page-about .ab-more summary::before {
  content: "＋ ";
}

.page-about .ab-more[open] summary::before {
  content: "－ ";
}

.page-about .ab-more p {
  margin: 0.55rem 0 0;
  font-size: 0.88rem;
  line-height: 1.75;
  color: var(--silver);
}

.page-about .ab-node--media {
  grid-template-columns: minmax(0, 1fr);
}

.page-about .ab-node--media::before {
  display: none;
}

.page-about .ab-mid-figure {
  margin: 0 0 0.4rem;
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  overflow: hidden;
  background: var(--ink-700);
}

.page-about .ab-mid-figure img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: cover;
  aspect-ratio: 2 / 1;
}

.page-about .ab-mid-figure figcaption {
  padding: 0.65rem 0.9rem 0.75rem;
  font-size: 0.76rem;
  letter-spacing: 0.05em;
  color: var(--silver);
  border-top: 1px solid var(--line);
}

.page-about .ab-node--now .ab-card {
  border-color: rgba(246, 196, 83, 0.55);
  background: linear-gradient(158deg, rgba(246, 196, 83, 0.14), var(--ink-700) 64%);
}

.page-about .ab-node--now::before {
  background: var(--yellow);
  border-color: var(--yellow);
  box-shadow: 0 0 0 4px rgba(246, 196, 83, 0.16);
}

.page-about .ab-node--now .ab-year {
  color: var(--yellow);
}

.page-about .ab-node.is-in .ab-year {
  color: var(--yellow-hi);
}

.page-about .ab-node--now.is-in .ab-year {
  color: var(--yellow);
}

/* ---------- 团队 ---------- */
.page-about .ab-team-sec {
  padding-block: 3rem;
}

.page-about .ab-team-grid {
  display: grid;
  gap: 1.75rem;
  align-items: center;
}

.page-about .ab-team-copy p {
  margin: 0.9rem 0 0;
  font-size: 0.98rem;
  line-height: 1.85;
  color: var(--silver);
}

.page-about .ab-team-figure {
  margin: 0;
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  overflow: hidden;
  background: var(--ink-700);
}

.page-about .ab-team-figure img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: cover;
  aspect-ratio: 3 / 2;
}

.page-about .ab-team-figure figcaption {
  padding: 0.7rem 1rem 0.8rem;
  font-size: 0.76rem;
  letter-spacing: 0.05em;
  color: var(--silver);
  border-top: 1px solid var(--line);
}

.page-about .ab-numbers {
  margin-top: 2.25rem;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  overflow: hidden;
}

.page-about .ab-num {
  position: relative;
  background: var(--ink-800);
  padding: 1.15rem 1rem 1.25rem;
}

.page-about .ab-num::after {
  content: "";
  position: absolute;
  top: 0.6rem;
  right: 0.6rem;
  width: 44px;
  height: 44px;
  background-image: radial-gradient(circle, rgba(40, 211, 196, 0.5) 1px, transparent 1.6px);
  background-size: 8px 8px;
  opacity: 0.65;
}

.page-about .ab-num-v {
  display: block;
  font-family: var(--font-mono);
  font-weight: 600;
  font-size: clamp(1.8rem, 7vw, 2.5rem);
  line-height: 1;
  color: var(--cyan);
}

.page-about .ab-num:first-child .ab-num-v {
  color: var(--yellow);
}

.page-about .ab-num-l {
  display: block;
  margin-top: 0.6rem;
  font-size: 0.76rem;
  letter-spacing: 0.08em;
  color: var(--silver);
}

/* ---------- 归档流程 ---------- */
.page-about .ab-flow-sec {
  padding-block: 3rem;
  background: var(--ink-800);
  border-block: 1px solid var(--line);
}

.page-about .ab-flow {
  list-style: none;
  margin: 2rem 0 0;
  padding: 0;
  display: grid;
  gap: 1rem;
}

.page-about .ab-flow li {
  position: relative;
  background: var(--ink-700);
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  padding: 1.15rem 1.1rem 1.25rem;
}

.page-about .ab-flow-num {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.76rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  color: var(--ink-900);
  background: var(--cyan);
  border-radius: var(--r-pill);
  padding: 0.12rem 0.55rem;
}

.page-about .ab-flow h3 {
  margin-top: 0.7rem;
}

.page-about .ab-flow p {
  margin: 0;
  font-size: 0.92rem;
  line-height: 1.78;
  color: var(--silver);
}

.page-about .ab-promise {
  margin-top: 1.5rem;
  display: grid;
  gap: 0.9rem;
}

.page-about .ab-promise > div {
  padding-left: 0.85rem;
  border-left: 2px solid var(--cyan-deep);
}

.page-about .ab-promise strong {
  display: block;
  font-family: var(--font-mono);
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--paper);
  letter-spacing: 0.02em;
}

.page-about .ab-promise span {
  display: block;
  margin-top: 0.25rem;
  font-size: 0.78rem;
  letter-spacing: 0.06em;
  color: var(--silver);
}

/* ---------- 服务原则 ---------- */
.page-about .ab-principles-sec {
  padding-block: 3rem;
}

.page-about .ab-principles {
  list-style: none;
  counter-reset: pr;
  margin: 1.9rem 0 0;
  padding: 0;
  display: grid;
  gap: 1rem;
}

.page-about .ab-principles li {
  counter-increment: pr;
  padding: 1.35rem 1.2rem 1.45rem;
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  background: linear-gradient(150deg, rgba(40, 211, 196, 0.09), transparent 62%);
}

.page-about .ab-principles li::before {
  content: counter(pr, decimal-leading-zero);
  display: block;
  font-family: var(--font-mono);
  font-size: 0.82rem;
  font-weight: 600;
  letter-spacing: 0.14em;
  color: var(--yellow);
}

.page-about .ab-principles h3 {
  margin-top: 0.75rem;
}

.page-about .ab-principles p {
  margin: 0;
  font-size: 0.93rem;
  line-height: 1.8;
  color: var(--silver);
}

/* ---------- 运营与联系 ---------- */
.page-about .ab-outro {
  padding-block: 2.75rem 3.5rem;
  border-top: 1px solid var(--line);
}

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

.page-about .ab-outro-copy p {
  margin: 0.9rem 0 0;
  font-size: 0.98rem;
  line-height: 1.85;
  color: var(--silver);
}

.page-about .ab-outro-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.7rem;
  margin-top: 1.5rem;
}

.page-about .ab-facts {
  margin: 0;
  display: grid;
  gap: 0;
}

.page-about .ab-facts > div {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: 0.35rem 1rem;
  padding: 0.75rem 0;
  border-bottom: 1px solid var(--line);
}

.page-about .ab-facts > div:first-child {
  border-top: 1px solid var(--line);
}

.page-about .ab-facts dt {
  font-size: 0.76rem;
  letter-spacing: 0.1em;
  color: var(--silver);
  flex: 0 0 auto;
}

.page-about .ab-facts dd {
  margin: 0;
  min-width: 0;
  font-family: var(--font-mono);
  font-size: 0.84rem;
  line-height: 1.6;
  color: var(--paper);
  text-align: right;
  overflow-wrap: anywhere;
}

/* ---------- 响应式 ---------- */
@media (min-width: 640px) {
  .page-about .ab-promise {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 1.25rem;
  }
}

@media (min-width: 760px) {
  .page-about .ab-numbers {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (min-width: 820px) {
  .page-about .ab-flow {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

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

@media (min-width: 900px) {
  .page-about {
    --ab-tick-col: 4.5rem;
  }

  .page-about .ab-hero {
    padding-block: 2.25rem 4rem;
  }

  .page-about .ab-hero-grid {
    grid-template-columns: minmax(0, 1.06fr) minmax(0, 0.94fr);
    gap: 3rem;
    align-items: end;
  }

  .page-about .ab-origin {
    padding-block: 4rem;
  }

  .page-about .ab-origin-grid {
    grid-template-columns: minmax(0, 0.9fr) minmax(0, 1.1fr);
    gap: 3.5rem;
  }

  .page-about .ab-timeline-sec,
  .page-about .ab-flow-sec,
  .page-about .ab-principles-sec {
    padding-block: 4.25rem;
  }

  .page-about .ab-team-sec {
    padding-block: 4.25rem;
  }

  .page-about .ab-team-grid {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
    gap: 3rem;
  }

  .page-about .ab-node {
    gap: 1.4rem;
    padding-bottom: 2.4rem;
  }

  .page-about .ab-node:nth-child(even) .ab-card,
  .page-about .ab-node:nth-child(even) .ab-mid-figure {
    margin-left: 2.5rem;
  }

  .page-about .ab-node--media {
    padding-left: var(--ab-tick-col);
  }

  .page-about .ab-card {
    padding: 1.25rem 1.35rem 1.5rem;
  }

  .page-about .ab-mid-figure {
    margin-top: 0;
  }

  .page-about .ab-outro {
    padding-block: 3.5rem 4.5rem;
  }

  .page-about .ab-outro-grid {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    gap: 3.5rem;
    align-items: start;
  }
}

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