/* ===== 品牌总览 · 页面专属样式 ===== */
.page-about {
  --ab-section-y: clamp(56px, 8vw, 112px);
  --ab-bar: 0%;
  padding-bottom: clamp(48px, 7vw, 96px);
  color: var(--bo-cream);
}

/* 面包屑 */
.page-about .bo-crumbs {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 0;
  padding: 22px 0 0;
  list-style: none;
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--bo-text-faint);
}
.page-about .bo-crumbs__item {
  display: flex;
  align-items: center;
  gap: 8px;
}
.page-about .bo-crumbs__item + .bo-crumbs__item::before {
  content: "/";
  color: var(--bo-rock);
}
.page-about .bo-crumbs__link {
  color: var(--bo-ice);
  text-decoration: none;
}
.page-about .bo-crumbs__link:hover,
.page-about .bo-crumbs__link:focus-visible {
  text-decoration: underline;
  outline: 2px solid var(--bo-ice);
  outline-offset: 2px;
}
.page-about .bo-crumbs__current {
  color: var(--bo-cream);
}

/* 首屏 */
.page-about .ab-hero {
  display: grid;
  gap: clamp(14px, 2.4vw, 28px);
  padding: clamp(30px, 5vw, 60px) 0 clamp(40px, 6vw, 76px);
  border-bottom: 2px solid var(--bo-line-1);
}
.page-about .ab-hero__side {
  display: flex;
  align-items: flex-start;
}
.page-about .ab-side-note {
  font-family: var(--bo-font-mono);
  font-size: 12px;
  letter-spacing: 0.26em;
  text-transform: uppercase;
  color: var(--bo-text-faint);
}
.page-about .ab-hero__title {
  margin: 0 0 clamp(18px, 3vw, 30px);
  font-size: clamp(38px, 8.4vw, 96px);
  font-weight: 900;
  line-height: 1.03;
  letter-spacing: -0.025em;
}
.page-about .ab-hero__title em {
  display: block;
  font-style: normal;
  color: var(--bo-orange);
}
.page-about .ab-hero__lede {
  max-width: 62ch;
  margin: 0;
  font-size: clamp(16px, 1.5vw, 18px);
  line-height: 1.85;
  color: var(--bo-text-dim);
}

/* 首屏数据带 */
.page-about .ab-hero__facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: clamp(24px, 4vw, 42px) 0 0;
  padding: 0;
  background: var(--bo-line-1);
  border: 2px solid var(--bo-line-1);
}
.page-about .ab-fact {
  margin: 0;
  padding: 16px 18px 18px;
  background: var(--bo-deep);
}
.page-about .ab-fact__label {
  margin: 0 0 10px;
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--bo-text-faint);
}
.page-about .ab-fact__value {
  margin: 0;
  font-family: var(--bo-font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(26px, 3.2vw, 38px);
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--bo-lime);
}
.page-about .ab-fact__unit {
  margin-left: 5px;
  font-family: var(--bo-font-sans);
  font-size: 14px;
  color: var(--bo-text-dim);
}

/* 章节骨架 */
.page-about .ab-section {
  padding: var(--ab-section-y) 0;
  border-bottom: 2px solid var(--bo-line-1);
}
.page-about .ab-section--last {
  border-bottom: 0;
}
.page-about .ab-sec-head {
  display: grid;
  gap: 12px;
  margin-bottom: clamp(26px, 4vw, 48px);
}
.page-about .ab-kicker {
  margin: 0;
  font-family: var(--bo-font-mono);
  font-size: 12px;
  letter-spacing: 0.24em;
  text-transform: uppercase;
  color: var(--bo-orange);
}
.page-about .ab-sec-title {
  max-width: 20ch;
  margin: 0;
  font-size: clamp(28px, 5.2vw, 64px);
  font-weight: 900;
  line-height: 1.06;
  letter-spacing: -0.022em;
}

/* 链路示意图 */
.page-about .ab-flow-wrap {
  overflow-x: auto;
  padding-bottom: 8px;
  margin-bottom: clamp(26px, 4vw, 46px);
}
.page-about .ab-flow {
  display: block;
  width: 100%;
  min-width: 640px;
  height: auto;
}
.page-about .ab-flow__axis {
  stroke: var(--bo-line-1);
  stroke-width: 2;
  stroke-dasharray: 6 9;
}
.page-about .ab-flow__ring {
  fill: var(--bo-layer);
  stroke: var(--bo-ice);
  stroke-width: 2.5;
}
.page-about .ab-flow__no {
  fill: var(--bo-lime);
  font-family: var(--bo-font-mono);
  font-size: 22px;
  font-weight: 700;
  text-anchor: middle;
}
.page-about .ab-flow__label {
  fill: var(--bo-cream);
  font-size: 21px;
  font-weight: 800;
  letter-spacing: 0.04em;
  text-anchor: middle;
}
.page-about .ab-flow__sub {
  fill: rgba(242, 237, 227, 0.55);
  font-size: 14px;
  letter-spacing: 0.06em;
  text-anchor: middle;
}

/* 链路正文 */
.page-about .ab-chain__grid {
  display: grid;
  gap: clamp(22px, 3.4vw, 40px);
}
.page-about .ab-chain__steps {
  display: grid;
  gap: clamp(20px, 2.6vw, 30px);
  align-content: start;
}
.page-about .ab-chain__step {
  padding-left: 18px;
  border-left: 2px solid var(--bo-orange);
}
.page-about .ab-chain__title {
  margin: 0 0 10px;
  font-size: clamp(19px, 2.2vw, 24px);
  font-weight: 800;
  letter-spacing: -0.01em;
}
.page-about .ab-chain__text {
  margin: 0;
  font-size: 16px;
  line-height: 1.85;
  color: var(--bo-text-dim);
}
.page-about .ab-chain__figure {
  margin: 0;
}
.page-about .ab-chain__wide {
  margin: clamp(28px, 4vw, 52px) 0 0;
}

/* 覆盖版图 */
.page-about .ab-cover__lede {
  max-width: 62ch;
  margin: 0 0 clamp(20px, 3vw, 28px);
  font-size: 17px;
  line-height: 1.85;
  color: var(--bo-text-dim);
}
.page-about .ab-cover__chips {
  margin-bottom: clamp(20px, 3vw, 30px);
}
.page-about .ab-cover__list {
  display: grid;
  gap: 1px;
  margin: 0 0 clamp(26px, 4vw, 44px);
  padding: 0;
  list-style: none;
  background: var(--bo-line-1);
  border: 2px solid var(--bo-line-1);
}
.page-about .ab-cover__item {
  display: grid;
  gap: 10px;
  align-content: start;
  padding: 20px;
  background: var(--bo-deep);
  transition: background 0.2s var(--bo-ease), transform 0.2s var(--bo-ease);
}
.page-about .ab-cover__item:hover,
.page-about .ab-cover__item:focus-visible {
  background: var(--bo-layer);
  transform: translateY(-2px);
}
.page-about .ab-cover__item:focus-visible {
  outline: 2px solid var(--bo-ice);
  outline-offset: -2px;
}
.page-about .ab-cover__name {
  margin: 0;
  font-size: 22px;
  font-weight: 800;
  letter-spacing: -0.01em;
}
.page-about .ab-cover__desc {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--bo-text-dim);
}
.page-about .ab-dots {
  height: 96px;
  margin-bottom: clamp(22px, 3vw, 34px);
  border: 2px solid var(--bo-line-1);
  background-color: var(--bo-deep);
  background-image: radial-gradient(var(--bo-rock) 1.6px, transparent 1.7px);
  background-size: 20px 20px;
  background-position: 0 0;
}
.page-about .ab-cover__figure {
  margin: 0;
}

/* 团队 */
.page-about .ab-team {
  display: grid;
  gap: 1px;
  margin: 0;
  padding: 0;
  list-style: none;
  background: var(--bo-line-1);
  border: 2px solid var(--bo-line-1);
}
.page-about .ab-team__row {
  display: grid;
  grid-template-columns: 58px minmax(0, 1fr);
  gap: 4px 16px;
  align-items: start;
  padding: 18px 20px 20px;
  background: var(--bo-deep);
}
.page-about .ab-team__no {
  font-family: var(--bo-font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 28px;
  line-height: 1.1;
  color: var(--bo-lime);
}
.page-about .ab-team__name {
  margin: 0 0 6px;
  font-size: 19px;
  font-weight: 800;
}
.page-about .ab-team__desc {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--bo-text-dim);
}
.page-about .ab-team__bar {
  position: relative;
  grid-column: 2;
  display: block;
  height: 6px;
  margin-top: 12px;
  background: var(--bo-layer);
}
.page-about .ab-team__bar::after {
  content: "";
  position: absolute;
  inset: 0 auto 0 0;
  width: var(--ab-bar);
  background: linear-gradient(90deg, var(--bo-orange), var(--bo-clay));
}
.page-about .ab-team__bar--38 { --ab-bar: 40%; }
.page-about .ab-team__bar--22 { --ab-bar: 23%; }
.page-about .ab-team__bar--12 { --ab-bar: 13%; }
.page-about .ab-team__bar--15 { --ab-bar: 16%; }
.page-about .ab-team__bar--9 { --ab-bar: 9%; }
.page-about .ab-team__total {
  margin: clamp(18px, 2.4vw, 26px) 0 0;
  max-width: 70ch;
}

/* 版本时间线 */
.page-about .ab-ver__lede {
  margin: 0 0 clamp(20px, 3vw, 30px);
  font-size: 15px;
  letter-spacing: 0.02em;
  color: var(--bo-text-faint);
}
.page-about .ab-timeline {
  display: grid;
  grid-auto-flow: column;
  grid-auto-columns: minmax(232px, 80%);
  gap: 14px;
  margin: 0;
  padding: 0 0 14px;
  list-style: none;
  overflow-x: auto;
  scroll-snap-type: x mandatory;
}
.page-about .ab-timeline:focus-visible {
  outline: 2px solid var(--bo-ice);
  outline-offset: 4px;
}
.page-about .ab-timeline__item {
  position: relative;
  scroll-snap-align: start;
  padding: 34px 18px 22px;
  background: var(--bo-deep);
  border: 2px solid var(--bo-line-1);
  transition: transform 0.2s var(--bo-ease), border-color 0.2s var(--bo-ease), background 0.2s var(--bo-ease);
}
.page-about .ab-timeline__item::before {
  content: "";
  position: absolute;
  top: 15px;
  left: 18px;
  width: 26px;
  height: 2px;
  background: var(--bo-orange);
}
.page-about .ab-timeline__item:hover,
.page-about .ab-timeline__item:focus-visible {
  transform: translateY(-4px);
  border-color: var(--bo-ice);
  background: var(--bo-layer);
}
.page-about .ab-timeline__item:focus-visible {
  outline: 2px solid var(--bo-ice);
  outline-offset: 3px;
}
.page-about .ab-timeline__year {
  display: block;
  margin: 16px 0 8px;
  font-family: var(--bo-font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(25px, 2.6vw, 34px);
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--bo-cream);
}
.page-about .ab-timeline__title {
  margin: 0 0 10px;
  font-size: 18px;
  font-weight: 800;
}
.page-about .ab-timeline__desc {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--bo-text-dim);
}

/* 可信的样子 */
.page-about .ab-proof {
  display: grid;
  gap: 16px;
}
.page-about .ab-proof__card {
  display: grid;
  gap: 8px;
  align-content: start;
  padding: 20px;
  background: var(--bo-deep);
  border: 2px solid var(--bo-line-1);
  box-shadow: var(--bo-shadow-hard-sm);
}
.page-about .ab-proof__mark {
  font-family: var(--bo-font-mono);
  font-size: 12px;
  letter-spacing: 0.2em;
  color: var(--bo-orange);
}
.page-about .ab-proof__title {
  margin: 0;
  font-size: 18px;
  font-weight: 800;
  letter-spacing: -0.01em;
}
.page-about .ab-proof__desc {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--bo-text-dim);
}

/* 后续指引 */
.page-about .ab-next {
  padding: clamp(40px, 6vw, 72px) 0 clamp(20px, 3vw, 32px);
}
.page-about .ab-next__title {
  margin: 0 0 clamp(18px, 2.6vw, 28px);
  font-size: clamp(22px, 2.6vw, 30px);
  font-weight: 800;
  letter-spacing: -0.01em;
}
.page-about .ab-next__grid {
  display: grid;
  gap: 12px;
}
.page-about .ab-next__link {
  display: grid;
  gap: 6px;
  padding: 18px 22px;
  background: var(--bo-layer);
  border: 2px solid var(--bo-line-1);
  color: var(--bo-cream);
  text-decoration: none;
  transition: transform 0.18s var(--bo-ease), border-color 0.18s var(--bo-ease);
}
.page-about .ab-next__link:hover,
.page-about .ab-next__link:focus-visible {
  transform: translateY(-3px);
  border-color: var(--bo-orange);
}
.page-about .ab-next__link:focus-visible {
  outline: 2px solid var(--bo-ice);
  outline-offset: 3px;
}
.page-about .ab-next__name {
  font-size: 17px;
  font-weight: 800;
}
.page-about .ab-next__hint {
  font-size: 14px;
  line-height: 1.7;
  color: var(--bo-text-faint);
}

/* 响应式 */
@media (min-width: 700px) {
  .page-about .ab-proof {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .page-about .ab-next__grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .page-about .ab-cover__list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 880px) {
  .page-about .ab-hero {
    grid-template-columns: 84px minmax(0, 1fr);
  }
  .page-about .ab-side-note {
    writing-mode: vertical-rl;
    transform: rotate(180deg);
    padding-top: 8px;
  }
  .page-about .ab-hero__facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (min-width: 960px) {
  .page-about .ab-chain__grid {
    grid-template-columns: minmax(0, 1.1fr) minmax(0, 0.9fr);
    align-items: start;
  }
  .page-about .ab-chain__wide {
    margin-top: clamp(36px, 5vw, 64px);
  }
}

@media (min-width: 1080px) {
  .page-about .ab-cover__list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
  .page-about .ab-proof {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
  .page-about .ab-timeline {
    grid-auto-columns: minmax(0, 1fr);
    gap: 14px;
    overflow-x: visible;
    padding-bottom: 0;
  }
  .page-about .ab-timeline__item + .ab-timeline__item::after {
    content: "";
    position: absolute;
    top: 16px;
    left: -16px;
    width: 16px;
    height: 2px;
    background: var(--bo-line-1);
  }
  .page-about .ab-next__grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-cover__item,
  .page-about .ab-timeline__item,
  .page-about .ab-next__link {
    transition: none;
  }
  .page-about .ab-cover__item:hover,
  .page-about .ab-cover__item:focus-visible,
  .page-about .ab-timeline__item:hover,
  .page-about .ab-timeline__item:focus-visible,
  .page-about .ab-next__link:hover,
  .page-about .ab-next__link:focus-visible {
    transform: none;
  }
}
</main>