.page-about {
  --ab-toc-w: 188px;
  padding: 24px 16px 72px;
  overflow-x: hidden;
}

@media (min-width: 768px) {
  .page-about {
    padding: 40px 32px 96px;
  }
}

.page-about .ab-crumbs {
  margin-bottom: 18px;
}

.page-about .ab-crumbs__sep {
  color: var(--bv-mist);
  opacity: .6;
}

/* ---------- 首屏 ---------- */

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

.page-about .ab-hero__media {
  position: relative;
  margin: 0;
  border-radius: var(--bv-radius-l);
  overflow: hidden;
  background: var(--bv-deep);
}

.page-about .ab-hero__media img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  opacity: .82;
}

.page-about .ab-hero__media::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, rgba(10, 20, 36, .42) 0%, rgba(10, 20, 36, .06) 38%, rgba(10, 20, 36, .95) 100%);
  pointer-events: none;
}

.page-about .ab-hero__body {
  position: relative;
  z-index: 2;
  margin-top: -64px;
  padding: 0 14px;
  max-width: 940px;
}

@media (min-width: 768px) {
  .page-about .ab-hero__body {
    margin-top: -108px;
    padding: 0 40px;
  }
}

.page-about .ab-hero__title {
  margin: 12px 0 0;
  font-size: clamp(32px, 6.6vw, 64px);
  font-weight: 800;
  line-height: 1.05;
  letter-spacing: -.02em;
  color: var(--bv-ink);
  text-shadow: 0 2px 24px rgba(10, 20, 36, .7);
}

.page-about .ab-hero__lead {
  margin-top: 18px;
  max-width: 38em;
}

.page-about .ab-hero__cta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 14px;
  margin: 24px 0 0;
}

.page-about .ab-hero__cta-note {
  font-family: var(--bv-mono);
  font-size: 12px;
  line-height: 1.6;
  letter-spacing: .04em;
  color: var(--bv-mist);
  max-width: 22em;
}

/* 首屏数据牌 */

.page-about .ab-stats {
  list-style: none;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
  margin: 36px 0 0;
  padding: 0;
}

@media (min-width: 768px) {
  .page-about .ab-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 16px;
    margin-top: 52px;
  }
}

.page-about .ab-stat {
  position: relative;
  padding: 20px 16px 16px;
  min-width: 0;
  border-radius: var(--bv-radius-m);
  background: var(--bv-deep);
  border: 1px solid var(--bv-line);
  overflow: hidden;
}

.page-about .ab-stat::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 46px;
  height: 3px;
  background: var(--bv-cyan);
  border-radius: 0 0 3px 0;
}

.page-about .ab-stat__num {
  display: block;
  font-family: var(--bv-mono);
  font-size: clamp(28px, 5vw, 38px);
  font-weight: 800;
  line-height: 1;
  letter-spacing: -.02em;
  font-variant-numeric: tabular-nums;
  color: var(--bv-ink);
}

.page-about .ab-stat__label {
  display: block;
  margin-top: 10px;
  font-family: var(--bv-mono);
  font-size: 12px;
  letter-spacing: .07em;
  color: var(--bv-mist);
}

/* ---------- 骨架：目录 + 正文 ---------- */

.page-about .ab-shell {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 36px;
  margin-top: 60px;
}

@media (min-width: 1024px) {
  .page-about .ab-shell {
    grid-template-columns: var(--ab-toc-w) minmax(0, 1fr);
    gap: 56px;
    margin-top: 92px;
  }
}

.page-about .ab-body {
  min-width: 0;
}

.page-about .ab-toc__label {
  margin: 0 0 12px;
  font-family: var(--bv-mono);
  font-size: 12px;
  letter-spacing: .16em;
  color: var(--bv-mist);
}

.page-about .ab-toc__list {
  list-style: none;
  display: flex;
  flex-wrap: nowrap;
  gap: 8px;
  margin: 0;
  padding: 0 0 4px;
  overflow-x: auto;
  scrollbar-width: none;
}

.page-about .ab-toc__list::-webkit-scrollbar {
  display: none;
}

.page-about .ab-toc__link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  flex: none;
  padding: 7px 13px;
  border-radius: var(--bv-pill);
  border: 1px solid var(--bv-line);
  font-size: 14px;
  line-height: 1.2;
  color: var(--bv-mist);
  text-decoration: none;
  white-space: nowrap;
  transition: color .2s ease, background-color .2s ease, border-color .2s ease;
}

.page-about .ab-toc__link:hover,
.page-about .ab-toc__link:focus-visible {
  color: var(--bv-ink);
  background: var(--bv-panel);
}

.page-about .ab-toc__link.is-active {
  color: var(--bv-ink);
  background: var(--bv-panel);
  border-color: var(--bv-cyan);
}

.page-about .ab-toc__num {
  font-family: var(--bv-mono);
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--bv-mist);
}

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

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

@media (min-width: 1024px) {
  .page-about .ab-toc {
    position: sticky;
    top: 32px;
    align-self: start;
  }

  .page-about .ab-toc__list {
    flex-direction: column;
    flex-wrap: nowrap;
    gap: 0;
    overflow: visible;
    padding: 0;
    border-left: 1px solid var(--bv-line);
  }

  .page-about .ab-toc__link {
    display: flex;
    border: 0;
    border-left: 2px solid transparent;
    border-radius: 0 var(--bv-pill) var(--bv-pill) 0;
    padding: 10px 14px;
    margin-left: -1px;
    white-space: normal;
  }

  .page-about .ab-toc__link.is-active {
    border-left-color: var(--bv-cyan);
    box-shadow: none;
  }

  .page-about .ab-toc__more {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    margin-top: 20px;
    font-family: var(--bv-mono);
    font-size: 12px;
    letter-spacing: .06em;
    color: var(--bv-cyan);
    text-decoration: none;
    border-bottom: 1px solid transparent;
    padding-bottom: 2px;
  }

  .page-about .ab-toc__more:hover {
    border-bottom-color: var(--bv-cyan);
  }
}

/* ---------- 章节通用 ---------- */

.page-about .ab-chapter {
  padding-top: 56px;
  border-top: 1px solid var(--bv-line);
}

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

.page-about .ab-chapter + .ab-chapter {
  margin-top: 56px;
}

@media (min-width: 768px) {
  .page-about .ab-chapter + .ab-chapter {
    margin-top: 72px;
  }
}

.page-about .ab-chapter__head {
  display: flex;
  align-items: baseline;
  gap: 14px;
  margin-bottom: 22px;
}

.page-about .ab-chapter__idx {
  flex: none;
  font-family: var(--bv-mono);
  font-size: 14px;
  letter-spacing: .1em;
  color: var(--bv-cyan);
}

.page-about .ab-chapter__title {
  margin: 0;
  font-size: clamp(23px, 3.4vw, 34px);
  font-weight: 700;
  line-height: 1.26;
  letter-spacing: -.01em;
  color: var(--bv-ink);
  overflow-wrap: break-word;
}

.page-about .ab-chapter__content > p {
  margin: 0 0 18px;
  max-width: 38em;
  font-size: 17px;
  line-height: 1.78;
  color: var(--bv-ink);
}

@media (min-width: 768px) {
  .page-about .ab-chapter__content > p {
    font-size: 18px;
  }
}

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

.page-about .ab-chapter__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 26px;
}

@media (min-width: 768px) {
  .page-about .ab-chapter__grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: 36px;
    align-items: start;
  }
}

.page-about .ab-chapter__col {
  min-width: 0;
}

.page-about .ab-chapter__col > p {
  margin: 0 0 18px;
  max-width: 34em;
  font-size: 17px;
  line-height: 1.78;
  color: var(--bv-ink);
}

@media (min-width: 768px) {
  .page-about .ab-chapter__col > p {
    font-size: 18px;
  }
}

.page-about .ab-aside {
  max-width: 34em;
  margin: 26px 0 0;
  padding: 14px 18px;
  font-size: 15px;
  line-height: 1.72;
  color: var(--bv-mist);
  border-left: 2px solid var(--bv-cyan);
  border-radius: 0 var(--bv-radius-s) var(--bv-radius-s) 0;
  background: linear-gradient(90deg, rgba(44, 232, 192, .08), rgba(44, 232, 192, 0) 68%);
}

.page-about .ab-inline-link {
  margin-top: 24px;
  font-size: 16px;
  color: var(--bv-mist);
}

.page-about .ab-inline-link a {
  color: var(--bv-cyan);
  text-decoration: none;
  border-bottom: 1px solid var(--bv-line);
  padding-bottom: 1px;
}

.page-about .ab-inline-link a:hover {
  border-bottom-color: var(--bv-cyan);
}

/* ---------- 图片 ---------- */

.page-about .ab-photo {
  margin: 0;
  border-radius: var(--bv-radius-m);
  overflow: hidden;
  background: var(--bv-deep);
  border: 1px solid var(--bv-line);
}

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

.page-about .ab-photo--wide img {
  aspect-ratio: 16 / 9;
}

.page-about .ab-photo__cap {
  padding: 12px 16px 14px;
  font-size: 13px;
  line-height: 1.65;
  color: var(--bv-mist);
  background: var(--bv-panel);
  border-top: 1px solid var(--bv-line);
}

.page-about .ab-figure {
  margin-top: 30px;
}

@media (min-width: 768px) {
  .page-about .ab-chapter__grid .ab-figure {
    margin-top: 0;
  }
}

/* ---------- 数据流转 ---------- */

.page-about .ab-rail-wrap {
  margin: 24px 0 26px;
  transform: rotate(-.6deg);
}

.page-about .ab-rail {
  display: block;
  width: 100%;
  height: auto;
}

.page-about .ab-rail__line {
  stroke: var(--bv-line);
  stroke-width: 1.5;
  stroke-dasharray: 4 7;
  fill: none;
}

.page-about .ab-rail__dot {
  fill: var(--bv-cyan);
}

.page-about .ab-rail__dot--mid {
  opacity: .5;
}

.page-about .ab-steps {
  list-style: none;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 18px;
  margin: 0;
  padding: 0;
}

@media (min-width: 640px) {
  .page-about .ab-steps {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 22px;
  }
}

.page-about .ab-step {
  min-width: 0;
  padding: 20px 18px 22px;
  border-radius: var(--bv-radius-m);
  background: var(--bv-deep);
  border: 1px solid var(--bv-line);
}

.page-about .ab-step__n {
  display: block;
  font-family: var(--bv-mono);
  font-size: 13px;
  letter-spacing: .12em;
  color: var(--bv-cyan);
}

.page-about .ab-step__t {
  margin: 10px 0 8px;
  font-size: 18px;
  font-weight: 700;
  line-height: 1.3;
  color: var(--bv-ink);
}

.page-about .ab-step p {
  margin: 0;
  font-size: 15.5px;
  line-height: 1.72;
  color: var(--bv-mist);
}

/* ---------- 团队标签 ---------- */

.page-about .ab-tags {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 22px 0 0;
  padding: 0;
}

/* ---------- 内容准则 ---------- */

.page-about .ab-rules {
  list-style: none;
  margin: 28px 0 0;
  padding: 0;
  display: grid;
  gap: 18px;
}

.page-about .ab-rule {
  position: relative;
  min-width: 0;
  padding: 20px 20px 22px 22px;
  border-radius: var(--bv-radius-m);
  background: var(--bv-deep);
  border: 1px solid var(--bv-line);
  border-left: 3px solid var(--bv-line);
}

.page-about .ab-rule:hover {
  border-left-color: var(--bv-cyan);
}

.page-about .ab-rule__t {
  margin: 0 0 8px;
  font-size: 17px;
  font-weight: 700;
  line-height: 1.35;
  color: var(--bv-ink);
}

.page-about .ab-rule p {
  margin: 0;
  font-size: 15.5px;
  line-height: 1.75;
  color: var(--bv-mist);
}

/* ---------- 三个阶段 ---------- */

.page-about .ab-phases {
  list-style: none;
  position: relative;
  margin: 30px 0 0;
  padding: 0 0 0 24px;
}

.page-about .ab-phases::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 18px;
  bottom: 18px;
  width: 1px;
  background: linear-gradient(180deg, var(--bv-cyan) 0%, var(--bv-line) 42%, var(--bv-line) 100%);
}

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

.page-about .ab-phase::before {
  content: "";
  position: absolute;
  left: -24px;
  top: 20px;
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: var(--bv-night);
  border: 2px solid var(--bv-cyan);
}

.page-about .ab-phase + .ab-phase {
  margin-top: 12px;
}

.page-about .ab-phase__s {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px;
  padding: 12px 0;
  cursor: pointer;
  list-style: none;
}

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

.page-about .ab-phase__s:focus-visible {
  outline: 2px solid var(--bv-cyan);
  outline-offset: 4px;
  border-radius: var(--bv-radius-s);
}

.page-about .ab-phase__tag {
  flex: none;
  padding: 5px 12px;
  border-radius: var(--bv-pill);
  background: var(--bv-panel);
  border: 1px solid var(--bv-line);
  font-family: var(--bv-mono);
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--bv-mist);
}

.page-about .ab-phase__name {
  font-size: 18px;
  font-weight: 700;
  line-height: 1.35;
  color: var(--bv-ink);
}

.page-about .ab-phase[open] .ab-phase__tag,
.page-about .ab-phase__d[open] .ab-phase__tag {
  border-color: var(--bv-cyan);
  color: var(--bv-cyan);
}

.page-about .ab-phase__body {
  padding: 4px 0 18px;
}

.page-about .ab-phase__body p {
  margin: 0;
  max-width: 36em;
  font-size: 16px;
  line-height: 1.78;
  color: var(--bv-mist);
}

/* ---------- 合作 ---------- */

.page-about .ab-partners {
  list-style: none;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 16px;
  margin: 26px 0 0;
  padding: 0;
}

@media (min-width: 640px) {
  .page-about .ab-partners {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 20px;
  }
}

.page-about .ab-partner {
  min-width: 0;
  padding: 20px 18px 22px;
  border-radius: var(--bv-radius-m);
  background: linear-gradient(150deg, var(--bv-deep) 0%, var(--bv-panel) 140%);
  border: 1px solid var(--bv-line);
}

.page-about .ab-partner__t {
  margin: 0 0 8px;
  font-size: 17px;
  font-weight: 700;
  line-height: 1.3;
  color: var(--bv-ink);
}

.page-about .ab-partner__t::after {
  content: "";
  display: block;
  width: 26px;
  height: 2px;
  margin-top: 10px;
  border-radius: 2px;
  background: var(--bv-cyan);
  opacity: .7;
}

.page-about .ab-partner p {
  margin: 0;
  font-size: 15.5px;
  line-height: 1.75;
  color: var(--bv-mist);
}

/* ---------- 信任 ---------- */

.page-about .ab-trusts {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 16px;
  margin-top: 24px;
}

@media (min-width: 768px) {
  .page-about .ab-trusts {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 20px;
  }
}

.page-about .ab-trust {
  min-width: 0;
  padding: 20px 18px 22px;
  border-radius: var(--bv-radius-m);
  background: var(--bv-paper);
  color: var(--bv-ink-dark);
}

.page-about .ab-trust__k {
  margin: 0 0 10px;
  font-family: var(--bv-mono);
  font-size: 12px;
  letter-spacing: .14em;
  color: #4A6486;
}

.page-about .ab-trust__v {
  margin: 0;
  font-size: 15.5px;
  line-height: 1.72;
  color: var(--bv-ink-dark);
  overflow-wrap: break-word;
}

/* ---------- 尾部引导 ---------- */

.page-about .ab-next {
  margin-top: 64px;
  padding: 30px 22px 32px;
  border-radius: var(--bv-radius-l);
  background: linear-gradient(128deg, var(--bv-deep) 0%, var(--bv-panel) 100%);
  border: 1px solid var(--bv-line);
  position: relative;
  overflow: hidden;
}

.page-about .ab-next::after {
  content: "";
  position: absolute;
  right: -60px;
  bottom: -80px;
  width: 220px;
  height: 220px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(44, 232, 192, .18) 0%, rgba(44, 232, 192, 0) 72%);
  pointer-events: none;
}

@media (min-width: 768px) {
  .page-about .ab-next {
    margin-top: 88px;
    padding: 40px 44px 42px;
  }
}

.page-about .ab-next__k {
  margin: 0;
  font-family: var(--bv-mono);
  font-size: 12px;
  letter-spacing: .16em;
  color: var(--bv-cyan);
}

.page-about .ab-next__t {
  margin: 12px 0 22px;
  max-width: 34em;
  font-size: 17px;
  line-height: 1.72;
  color: var(--bv-ink);
}

@media (min-width: 768px) {
  .page-about .ab-next__t {
    font-size: 18px;
  }
}

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

/* ---------- 降低动效偏好 ---------- */

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-rail-wrap,
  .page-about .ab-toc__link,
  .page-about .ab-inline-link a {
    transition: none;
    transform: none;
  }
}