.page-about {
  --ab-track: 74px;
  --ab-pad: 18px;
  position: relative;
  display: block;
  max-width: 1360px;
  margin-inline: auto;
  padding: 20px var(--ab-pad) 96px;
  color: var(--chalk);
  font-family: var(--sans);
  font-size: 15px;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
}

.page-about img {
  display: block;
  max-width: 100%;
  height: auto;
}

.page-about a {
  color: inherit;
}

.page-about .section {
  margin-top: 64px;
}

.page-about .eyebrow {
  font-family: var(--cond);
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

.page-about .section__title {
  font-family: var(--cond);
  font-weight: 800;
  letter-spacing: 0.01em;
  line-height: 1.08;
}

.page-about .ab-text {
  max-width: 62ch;
  margin: 14px 0 0;
  color: var(--steel);
}

.page-about .ab-text--tight {
  max-width: 58ch;
  margin-top: 16px;
}

.page-about .meta {
  margin: 14px 0 0;
  color: var(--steel);
  font-size: 12.5px;
}

/* ---------- 面包屑 ---------- */
.page-about .crumb {
  margin-bottom: 26px;
}

/* ---------- 首屏 ---------- */
.page-about .ab-hero {
  position: relative;
  display: grid;
  gap: 24px;
  padding-top: 4px;
}

.page-about .ab-hero__cut {
  position: absolute;
  z-index: 0;
  top: -14px;
  right: -8px;
  width: 132px;
  height: 88px;
  background: var(--ink-600);
  clip-path: polygon(10% 0, 100% 0, 100% 100%, 0 74%);
  pointer-events: none;
}

.page-about .ab-hero__cut::before {
  content: "";
  position: absolute;
  left: 30px;
  bottom: 16px;
  width: 74px;
  height: 8px;
  background: var(--orange);
  transform: skewX(-26deg);
}

.page-about .ab-hero__copy {
  position: relative;
  z-index: 1;
}

.page-about .ab-hero__title {
  margin: 12px 0 14px;
  font-family: var(--cond);
  font-weight: 800;
  font-size: clamp(27px, 7.4vw, 50px);
  line-height: 1.06;
  letter-spacing: 0.005em;
  max-width: 24ch;
}

.page-about .ab-hero__lede {
  max-width: 48ch;
  margin: 0;
  color: var(--steel);
}

.page-about .ab-hero__fig {
  position: relative;
  z-index: 1;
  margin: 0;
  clip-path: polygon(0 4%, 100% 0, 100% 100%, 0 96%);
}

.page-about .ab-hero__fig img {
  filter: saturate(0.72) contrast(1.06) brightness(0.86);
}

/* ---------- 关键数字带 ---------- */
.page-about .ab-metrics {
  list-style: none;
  margin: 42px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  border-top: 2px solid var(--ink-600);
  border-left: 2px solid var(--ink-600);
}

.page-about .ab-metric {
  padding: 16px 14px 18px;
  border-right: 2px solid var(--ink-600);
  border-bottom: 2px solid var(--ink-600);
  background: var(--ink-800);
}

.page-about .ab-metric__num {
  display: block;
  font-family: var(--mono);
  font-weight: 800;
  font-size: 32px;
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--chalk);
}

.page-about .ab-metric:nth-child(3) .ab-metric__num {
  color: var(--cyan);
}

.page-about .ab-metric__label {
  display: block;
  margin-top: 10px;
  font-family: var(--cond);
  font-size: 15px;
  letter-spacing: 0.04em;
  color: var(--chalk);
}

.page-about .ab-metric__note {
  display: block;
  margin-top: 3px;
  font-size: 12px;
  line-height: 1.5;
  color: var(--steel);
}

/* ---------- 布局骨架 ---------- */
.page-about .ab-layout {
  display: grid;
  gap: 40px;
}

/* ---------- 参数清单 ---------- */
.page-about .ab-params {
  list-style: none;
  margin: 24px 0 0;
  padding: 0;
  border-top: 2px solid var(--ink-600);
  max-width: 62ch;
}

.page-about .ab-param {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 2px;
  padding: 13px 0;
  border-bottom: 2px solid var(--ink-600);
}

.page-about .ab-param__k {
  font-size: 13px;
  letter-spacing: 0.03em;
  color: var(--steel);
}

.page-about .ab-param__v {
  font-family: var(--mono);
  font-weight: 800;
  font-size: 18px;
  letter-spacing: -0.01em;
  color: var(--chalk);
}

/* ---------- 时间轴 ---------- */
.page-about .ab-timeline {
  list-style: none;
  margin: 10px 0 0;
  padding: 0;
}

.page-about .ab-tl {
  position: relative;
  display: grid;
  grid-template-columns: 54px 20px minmax(0, 1fr);
  column-gap: 10px;
  padding-block: 18px;
}

.page-about .ab-tl::before {
  content: "";
  position: absolute;
  top: 0;
  bottom: 0;
  left: calc(var(--ab-track) - 1px);
  width: 2px;
  background: var(--ink-600);
}

.page-about .ab-tl:last-child::before {
  bottom: auto;
  height: 34px;
}

.page-about .ab-tl__dot {
  position: absolute;
  top: 22px;
  left: calc(var(--ab-track) - 6px);
  width: 12px;
  height: 12px;
  border: 2px solid var(--ink-600);
  border-radius: 50%;
  background: var(--ink-900);
  z-index: 1;
  transition: background-color 120ms linear, border-color 120ms linear;
}

.page-about .ab-tl:hover .ab-tl__dot,
.page-about .ab-tl:focus-within .ab-tl__dot,
.page-about .ab-tl:has(.ab-tl__body[open]) .ab-tl__dot {
  background: var(--cyan);
  border-color: var(--cyan);
}

.page-about .ab-tl__year {
  grid-column: 1;
  padding-top: 2px;
  font-family: var(--mono);
  font-weight: 800;
  font-size: 17px;
  line-height: 1.3;
  letter-spacing: -0.02em;
  color: var(--steel);
  transition: color 120ms linear;
}

.page-about .ab-tl:hover .ab-tl__year,
.page-about .ab-tl:has(.ab-tl__body[open]) .ab-tl__year {
  color: var(--cyan);
}

.page-about .ab-tl__body {
  grid-column: 3;
  min-width: 0;
}

.page-about .ab-tl__summary {
  display: flex;
  align-items: baseline;
  gap: 12px;
  cursor: pointer;
  list-style: none;
}

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

.page-about .ab-tl__summary:focus-visible {
  outline: 2px solid var(--orange);
  outline-offset: 4px;
}

.page-about .ab-tl__title {
  margin: 0;
  font-family: var(--cond);
  font-size: 19px;
  font-weight: 700;
  line-height: 1.25;
  letter-spacing: 0.015em;
  color: var(--chalk);
}

.page-about .ab-tl__cue {
  flex: none;
  margin-left: auto;
  min-width: 22px;
  padding: 1px 5px;
  border: 2px solid var(--ink-600);
  font-family: var(--mono);
  font-size: 12px;
  line-height: 1.4;
  text-align: center;
  color: var(--steel);
  transition: background-color 120ms linear, border-color 120ms linear, color 120ms linear;
}

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

.page-about .ab-tl__body[open] .ab-tl__cue {
  background: var(--cyan);
  border-color: var(--cyan);
  color: var(--ink-950);
}

.page-about .ab-tl__body[open] .ab-tl__cue::before {
  content: "−";
}

.page-about .ab-tl__text {
  max-width: 58ch;
  margin: 10px 0 0;
  color: var(--steel);
}

/* ---------- 核对机制 ---------- */
.page-about .ab-verify {
  display: grid;
  gap: 24px;
  margin-top: 8px;
}

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

.page-about .ab-verify__fig img {
  filter: saturate(0.7) contrast(1.08) brightness(0.85);
}

.page-about .ab-steps {
  list-style: none;
  counter-reset: ab-step;
  margin: 0;
  padding: 0;
  border-top: 2px solid var(--ink-600);
}

.page-about .ab-steps li {
  position: relative;
  padding: 16px 0 16px 48px;
  border-bottom: 2px solid var(--ink-600);
  color: var(--steel);
}

.page-about .ab-steps li::before {
  counter-increment: ab-step;
  content: counter(ab-step, decimal-leading-zero);
  position: absolute;
  left: 0;
  top: 17px;
  padding: 1px 5px;
  border: 2px solid var(--ink-600);
  font-family: var(--mono);
  font-weight: 800;
  font-size: 12px;
  line-height: 1.4;
  color: var(--cyan);
}

.page-about .ab-steps strong {
  color: var(--chalk);
  font-weight: 700;
}

/* ---------- 团队 ---------- */
.page-about .ab-team {
  position: relative;
  overflow: hidden;
  padding: 24px 18px 26px;
  border: 2px solid var(--ink-600);
  background: var(--ink-800);
  box-shadow: 4px 6px 0 var(--ink-950);
}

.page-about .ab-team__bg {
  position: absolute;
  inset: 0;
  z-index: 0;
  opacity: 0.16;
  pointer-events: none;
}

.page-about .ab-team__bg img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: saturate(0.5) contrast(1.1);
}

.page-about .ab-team > *:not(.ab-team__bg) {
  position: relative;
  z-index: 1;
}

.page-about .ab-roles {
  list-style: none;
  margin: 22px 0 0;
  padding: 0;
  border-top: 2px solid var(--ink-600);
}

.page-about .ab-role {
  display: grid;
  gap: 4px;
  padding: 15px 0;
  border-bottom: 2px solid var(--ink-600);
}

.page-about .ab-role__name {
  margin: 0;
  font-family: var(--cond);
  font-size: 17px;
  font-weight: 700;
  letter-spacing: 0.06em;
  color: var(--cyan);
}

.page-about .ab-role p {
  margin: 0;
  max-width: 60ch;
  color: var(--steel);
}

/* ---------- 覆盖与边界 ---------- */
.page-about .ab-scope {
  display: grid;
  margin-top: 8px;
  border: 2px solid var(--ink-600);
  background: var(--ink-800);
  box-shadow: 4px 6px 0 var(--ink-950);
}

.page-about .ab-scope__col {
  padding: 20px 18px 22px;
}

.page-about .ab-scope__col + .ab-scope__col {
  border-top: 2px solid var(--ink-600);
}

.page-about .ab-scope__title {
  margin: 0;
  font-family: var(--cond);
  font-size: 18px;
  font-weight: 700;
  letter-spacing: 0.05em;
  color: var(--chalk);
}

.page-about .ab-list {
  list-style: none;
  margin: 14px 0 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .ab-list li {
  position: relative;
  padding-left: 18px;
  color: var(--steel);
  font-size: 14.5px;
  line-height: 1.7;
}

.page-about .ab-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.72em;
  width: 9px;
  height: 2px;
  background: var(--cyan);
}

.page-about .ab-list--no li::before {
  background: var(--orange);
}

/* ---------- 合规 ---------- */
.page-about .ab-comp {
  margin-top: 8px;
  border: 2px solid var(--ink-600);
  background: var(--ink-800);
}

.page-about .ab-comp__row {
  display: grid;
  gap: 3px;
  padding: 14px 16px;
  border-bottom: 2px solid var(--ink-600);
}

.page-about .ab-comp__row:last-child {
  border-bottom: 0;
}

.page-about .ab-comp__k {
  font-family: var(--cond);
  font-size: 14px;
  letter-spacing: 0.06em;
  color: var(--steel);
}

.page-about .ab-comp__v {
  font-family: var(--mono);
  font-weight: 700;
  font-size: 15px;
  letter-spacing: -0.01em;
  color: var(--chalk);
  overflow-wrap: anywhere;
}

.page-about .ab-links {
  list-style: none;
  margin: 22px 0 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .ab-links a {
  display: block;
  padding: 12px 14px;
  border: 2px solid var(--ink-600);
  background: var(--ink-800);
  font-family: var(--cond);
  font-size: 15px;
  letter-spacing: 0.03em;
  text-decoration: none;
  color: var(--chalk);
  transition: border-color 120ms linear, color 120ms linear;
}

.page-about .ab-links a:hover {
  border-color: var(--cyan);
  color: var(--cyan);
}

.page-about .ab-links a:focus-visible {
  outline: 2px solid var(--orange);
  outline-offset: 3px;
}

/* ---------- 章节目录 ---------- */
.page-about .ab-toc {
  border: 2px solid var(--ink-600);
  background: var(--ink-800);
  padding: 16px 16px 18px;
}

.page-about .toc__title {
  margin: 0 0 12px;
  font-family: var(--cond);
  font-size: 13px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--steel);
}

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

.page-about .toc__link {
  display: block;
  padding: 7px 0 7px 12px;
  border-left: 2px solid var(--ink-600);
  font-size: 14px;
  text-decoration: none;
  color: var(--steel);
  transition: color 120ms linear, border-color 120ms linear;
}

.page-about .toc__link:hover {
  color: var(--chalk);
  border-color: var(--cyan);
}

.page-about .toc__link:focus-visible {
  outline: 2px solid var(--orange);
  outline-offset: 2px;
}

.page-about .toc__link.is-active {
  color: var(--cyan);
  border-color: var(--cyan);
}

/* ---------- 返回顶部 ---------- */
.page-about .to-top {
  position: fixed;
  right: 16px;
  bottom: 16px;
  z-index: 40;
  width: 46px;
  height: 46px;
  display: grid;
  place-items: center;
  border: 2px solid var(--ink-600);
  background: var(--ink-800);
  color: var(--chalk);
  cursor: pointer;
  box-shadow: 4px 6px 0 var(--ink-950);
}

.page-about .to-top:hover {
  border-color: var(--cyan);
  color: var(--cyan);
}

.page-about .to-top:focus-visible {
  outline: 2px solid var(--orange);
  outline-offset: 3px;
}

.page-about .to-top__ring {
  position: absolute;
  inset: 5px;
  border: 2px solid var(--ink-600);
  pointer-events: none;
}

.page-about .to-top__arrow {
  position: relative;
  font-family: var(--mono);
  font-weight: 800;
  font-size: 16px;
  line-height: 1;
}

/* ---------- 中等屏幕 ---------- */
@media (min-width: 560px) {
  .page-about .ab-param {
    grid-template-columns: 172px minmax(0, 1fr);
    align-items: baseline;
    gap: 16px;
  }

  .page-about .ab-role {
    grid-template-columns: 128px minmax(0, 1fr);
    align-items: baseline;
    gap: 18px;
  }
}

@media (min-width: 768px) {
  .page-about {
    --ab-pad: 32px;
    padding-top: 32px;
    padding-bottom: 120px;
    font-size: 16px;
  }

  .page-about .section {
    margin-top: 92px;
  }

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

  .page-about .ab-scope {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .ab-scope__col + .ab-scope__col {
    border-top: 0;
    border-left: 2px solid var(--ink-600);
  }

  .page-about .ab-links {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .ab-team {
    padding: 32px 28px 34px;
  }
}

@media (min-width: 900px) {
  .page-about {
    --ab-track: 110px;
  }

  .page-about .ab-tl {
    grid-template-columns: 84px 24px minmax(0, 1fr);
    column-gap: 14px;
    padding-block: 22px;
  }

  .page-about .ab-tl__year {
    font-size: 19px;
  }

  .page-about .ab-tl__title {
    font-size: 21px;
  }

  .page-about .ab-verify {
    grid-template-columns: minmax(0, 1fr) 320px;
    gap: 34px;
  }
}

@media (min-width: 1024px) {
  .page-about {
    padding-left: calc(var(--rail) + 34px);
    padding-right: 40px;
    padding-top: 38px;
  }
}

@media (min-width: 1120px) {
  .page-about .ab-layout {
    grid-template-columns: minmax(0, 1fr) 216px;
    gap: 56px;
    align-items: start;
  }

  .page-about .ab-main {
    grid-column: 1;
    grid-row: 1;
    min-width: 0;
  }

  .page-about .ab-toc {
    grid-column: 2;
    grid-row: 1;
    position: sticky;
    top: 88px;
  }

  .page-about .ab-hero {
    grid-template-columns: repeat(12, minmax(0, 1fr));
    gap: 0 24px;
    align-items: end;
  }

  .page-about .ab-hero__copy {
    grid-column: 1 / span 4;
    grid-row: 1;
    padding-bottom: 12px;
  }

  .page-about .ab-hero__fig {
    grid-column: 5 / span 8;
    grid-row: 1;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about *,
  .page-about *::before,
  .page-about *::after {
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
  }
}