.page-about {
  --ab-rail: clamp(96px, 12vw, 168px);
  --ab-pad-y: clamp(44px, 6.5vw, 92px);
}

/* ---------- 面包屑 ---------- */
.page-about .yw-crumb {
  margin: clamp(20px, 3vw, 34px) 0 clamp(12px, 2vw, 20px);
}

/* ---------- 首屏 ---------- */
.page-about .ab-hero {
  padding: clamp(6px, 1.5vw, 18px) 0 clamp(30px, 4.5vw, 62px);
}

.page-about .ab-hero__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(26px, 4vw, 54px);
  align-items: center;
}

.page-about .ab-hero__kicker {
  display: block;
  margin: 0 0 14px;
  color: var(--yw-signal);
}

.page-about .ab-hero__title {
  margin: 0 0 20px;
  font-size: clamp(29px, 5.2vw, 56px);
  line-height: 1.12;
  letter-spacing: -0.02em;
  color: var(--yw-paper);
}

.page-about .ab-hero__lead {
  margin: 0;
  max-width: 46ch;
  font-size: clamp(15px, 1.3vw, 17px);
  line-height: 1.78;
  color: var(--yw-muted);
}

.page-about .ab-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 28px;
}

.page-about .ab-fig {
  margin: 0;
  position: relative;
  overflow: hidden;
  background: var(--yw-graphite-2);
  border: 1px solid var(--yw-line);
  border-radius: var(--yw-radius);
}

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

.page-about .ab-fig--3x2 { aspect-ratio: 3 / 2; }
.page-about .ab-fig--4x3 { aspect-ratio: 4 / 3; }

.page-about .ab-fig__cap {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  margin: 0;
  padding: 12px 16px;
  font-family: var(--yw-font-mono);
  font-size: 12.5px;
  line-height: 1.6;
  letter-spacing: 0.02em;
  color: var(--yw-paper);
  background: linear-gradient(180deg, rgba(18, 21, 26, 0) 0%, rgba(18, 21, 26, 0.88) 55%);
}

@media (min-width: 940px) {
  .page-about .ab-hero__grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: clamp(34px, 5vw, 72px);
  }
  .page-about .ab-hero__media {
    transform: translateY(12px);
  }
}

/* ---------- 年份索引条 ---------- */
.page-about .ab-axis {
  border-top: 1px solid var(--yw-line);
  border-bottom: 1px solid var(--yw-line);
  background: var(--yw-graphite-2);
}

.page-about .ab-axis__rail {
  display: flex;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: thin;
}

.page-about .ab-axis__item {
  flex: 1 0 auto;
  min-width: 88px;
  padding: 13px 16px;
  font-family: var(--yw-font-mono);
  font-size: 14px;
  letter-spacing: 0.08em;
  text-align: center;
  text-decoration: none;
  color: var(--yw-muted);
  border-right: 1px solid var(--yw-line);
  white-space: nowrap;
  transition: color 160ms ease, background-color 160ms ease;
}

.page-about .ab-axis__item:last-child { border-right: 0; }

.page-about .ab-axis__item:hover,
.page-about .ab-axis__item:focus-visible {
  color: var(--yw-paper);
  background: var(--yw-graphite-3);
}

.page-about .ab-axis__item.is-active {
  color: var(--yw-signal);
  box-shadow: inset 0 -2px 0 var(--yw-signal);
}

/* ---------- 章节骨架 ---------- */
.page-about .ab-sec {
  padding: var(--ab-pad-y) 0;
  border-bottom: 1px solid var(--yw-line);
}

.page-about .ab-sec__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(16px, 3vw, 36px);
}

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

.page-about .yw-num {
  display: block;
  font-family: var(--yw-font-mono);
  font-weight: 800;
  font-size: clamp(50px, 13vw, 76px);
  line-height: 0.9;
  letter-spacing: -0.03em;
  color: var(--yw-graphite-3);
  -webkit-text-stroke: 1px var(--yw-signal);
}

.page-about .ab-sec__kicker {
  display: block;
  margin: 0 0 12px;
  color: var(--yw-electric);
}

.page-about .ab-sec__title {
  margin: 0 0 20px;
  font-size: clamp(23px, 3.4vw, 37px);
  line-height: 1.22;
  letter-spacing: -0.015em;
  color: var(--yw-paper);
}

.page-about .ab-sec__prose {
  color: var(--yw-muted);
  font-size: 16px;
  line-height: 1.8;
}

.page-about .ab-sec__prose p {
  margin: 0 0 14px;
}

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

.page-about .ab-sec__prose--after {
  margin-top: 28px;
}

.page-about .ab-sec__link {
  margin: 26px 0 0;
}

@media (min-width: 900px) {
  .page-about .ab-sec__grid {
    grid-template-columns: var(--ab-rail) minmax(0, 1fr);
    gap: clamp(26px, 4vw, 64px);
  }
  .page-about .ab-sec__num {
    position: sticky;
    top: calc(var(--yw-header-h) + 26px);
    align-self: start;
  }
  .page-about .yw-num {
    font-size: clamp(44px, 6vw, 84px);
  }
  .page-about .ab-sec--offset .ab-sec__grid {
    padding-left: clamp(0px, 2.4vw, 38px);
  }
}

/* ---------- 三条产品线 ---------- */
.page-about .ab-lines {
  list-style: none;
  margin: 32px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 0;
}

.page-about .ab-line {
  border-top: 1px solid var(--yw-line);
  padding: 20px 0 22px;
}

.page-about .ab-line__tag {
  display: inline-block;
  margin-bottom: 12px;
  padding: 4px 10px;
  font-family: var(--yw-font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--yw-electric);
  border: 1px solid var(--yw-line);
  border-radius: var(--yw-radius);
}

.page-about .ab-line__title {
  margin: 0 0 8px;
  font-family: var(--yw-font-serif);
  font-size: 18px;
  font-weight: 600;
  line-height: 1.45;
  color: var(--yw-paper);
}

.page-about .ab-line p {
  margin: 0;
  font-size: 15px;
  line-height: 1.75;
  color: var(--yw-muted);
}

@media (min-width: 760px) {
  .page-about .ab-lines {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: clamp(18px, 2.6vw, 34px);
  }
  .page-about .ab-line {
    padding: 20px 0 6px;
  }
}

/* ---------- 图带 ---------- */
.page-about .ab-figure-band {
  padding: clamp(26px, 4vw, 52px) 0 clamp(8px, 1.5vw, 20px);
}

/* ---------- 年份时间线 ---------- */
.page-about .ab-years {
  margin-top: 8px;
  border-bottom: 1px solid var(--yw-line);
}

.page-about .ab-year {
  display: grid;
  grid-template-columns: 1fr;
  gap: 6px;
  padding: 22px 0 24px;
  border-top: 1px solid var(--yw-line);
  scroll-margin-top: calc(var(--yw-header-h) + 24px);
}

.page-about .ab-year__k {
  font-family: var(--yw-font-mono);
  font-size: clamp(22px, 2.6vw, 30px);
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: -0.02em;
  color: var(--yw-signal);
}

.page-about .ab-year__title {
  margin: 0 0 8px;
  font-family: var(--yw-font-serif);
  font-size: 17.5px;
  font-weight: 600;
  line-height: 1.5;
  color: var(--yw-paper);
}

.page-about .ab-year__body p {
  margin: 0;
  font-size: 15.5px;
  line-height: 1.78;
  color: var(--yw-muted);
}

@media (min-width: 760px) {
  .page-about .ab-year {
    grid-template-columns: 108px minmax(0, 1fr);
    gap: clamp(20px, 3vw, 44px);
    padding: 26px 0 30px;
  }
}

/* ---------- 专利构成 ---------- */
.page-about .ab-patent {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(24px, 3.6vw, 44px);
  align-items: center;
  margin-top: 30px;
}

.page-about .ab-patent__fig {
  display: flex;
  justify-content: center;
}

.page-about .ab-donut {
  width: min(240px, 68vw);
  height: auto;
}

.page-about .ab-donut__track,
.page-about .ab-donut__seg {
  fill: none;
  stroke-width: 20;
}

.page-about .ab-donut__track { stroke: var(--yw-graphite-3); }
.page-about .ab-donut__seg--u { stroke: var(--yw-signal); }
.page-about .ab-donut__seg--d { stroke: var(--yw-electric); }
.page-about .ab-donut__seg--i { stroke: var(--yw-paper); }

.page-about .ab-donut__num {
  font-family: var(--yw-font-mono);
  font-size: 26px;
  font-weight: 700;
  fill: var(--yw-paper);
}

.page-about .ab-donut__cap {
  font-family: var(--yw-font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  fill: var(--yw-muted);
}

.page-about .ab-patent__list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .ab-patent__item {
  display: grid;
  grid-template-columns: 12px minmax(0, 1fr) auto auto;
  align-items: center;
  gap: 12px;
  padding: 14px 0;
  border-top: 1px solid var(--yw-line);
}

.page-about .ab-patent__item:last-child {
  border-bottom: 1px solid var(--yw-line);
}

.page-about .ab-patent__dot {
  width: 10px;
  height: 10px;
  border-radius: 2px;
  display: block;
}

.page-about .ab-patent__dot--u { background: var(--yw-signal); }
.page-about .ab-patent__dot--d { background: var(--yw-electric); }
.page-about .ab-patent__dot--i { background: var(--yw-paper); }

.page-about .ab-patent__name {
  font-size: 15.5px;
  color: var(--yw-paper);
}

.page-about .ab-patent__val {
  font-size: 14px;
  color: var(--yw-muted);
}

.page-about .ab-patent__pct {
  font-size: 14px;
  font-weight: 700;
  color: var(--yw-signal);
  min-width: 52px;
  text-align: right;
}

@media (min-width: 760px) {
  .page-about .ab-patent {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
  }
  .page-about .ab-patent__fig {
    justify-content: flex-start;
  }
}

/* ---------- 团队 ---------- */
.page-about .ab-team {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(24px, 3.6vw, 44px);
  align-items: start;
}

@media (min-width: 860px) {
  .page-about .ab-team {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
  }
}

/* ---------- 核对清单 ---------- */
.page-about .ab-checks {
  list-style: none;
  margin: 24px 0 0;
  padding: 0;
}

.page-about .ab-checks li {
  position: relative;
  padding: 12px 0 12px 26px;
  font-size: 15px;
  line-height: 1.7;
  border-top: 1px solid var(--yw-line);
}

.page-about .ab-checks li:last-child {
  border-bottom: 1px solid var(--yw-line);
}

.page-about .ab-checks li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 19px;
  width: 12px;
  height: 2px;
  background: var(--yw-signal);
}

.page-about .ab-checks--dark li {
  color: var(--yw-muted);
}

.page-about .ab-checks--paper li {
  color: var(--yw-paper-muted);
  border-top-color: var(--yw-paper-line);
}

.page-about .ab-checks--paper li:last-child {
  border-bottom-color: var(--yw-paper-line);
}

.page-about .ab-checks--paper li::before {
  background: var(--yw-signal-deep);
}

/* ---------- 数据锚点 ---------- */
.page-about .ab-stats {
  list-style: none;
  margin: 28px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0;
  border-top: 1px solid var(--yw-line);
}

.page-about .ab-stat {
  padding: 20px 16px 22px 0;
  border-bottom: 1px solid var(--yw-line);
}

.page-about .ab-stat__num {
  display: block;
  font-size: clamp(34px, 5vw, 52px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.03em;
  color: var(--yw-signal);
}

.page-about .ab-stat__label {
  display: block;
  margin-top: 10px;
  font-size: 13.5px;
  line-height: 1.6;
  color: var(--yw-muted);
}

@media (min-width: 860px) {
  .page-about .ab-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 0 clamp(18px, 2.4vw, 32px);
  }
}

/* ---------- 纸感章节 ---------- */
.page-about .ab-sec--paper {
  background: var(--yw-paper);
  color: var(--yw-ink);
  border-bottom-color: var(--yw-paper-line);
}

.page-about .ab-sec--paper .ab-sec__kicker {
  color: var(--yw-signal-deep);
}

.page-about .ab-sec--paper .ab-sec__title {
  color: var(--yw-ink);
}

.page-about .ab-sec--paper .ab-sec__prose {
  color: var(--yw-paper-muted);
}

.page-about .ab-sec--paper .yw-num {
  color: transparent;
  -webkit-text-stroke: 1px var(--yw-signal-deep);
}

/* ---------- 收尾 ---------- */
.page-about .ab-cta {
  padding: clamp(40px, 6vw, 84px) 0 clamp(52px, 7vw, 96px);
}

.page-about .ab-cta__box {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(22px, 3vw, 40px);
  align-items: center;
  padding: clamp(26px, 4vw, 52px);
  background: var(--yw-graphite-2);
  border: 1px solid var(--yw-line);
  border-left: 3px solid var(--yw-signal);
  border-radius: var(--yw-radius);
}

.page-about .ab-cta__title {
  margin: 0 0 14px;
  font-size: clamp(21px, 2.9vw, 32px);
  line-height: 1.25;
  letter-spacing: -0.015em;
  color: var(--yw-paper);
}

.page-about .ab-cta__lead {
  margin: 0;
  max-width: 52ch;
  font-size: 15.5px;
  line-height: 1.8;
  color: var(--yw-muted);
}

.page-about .ab-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

@media (min-width: 860px) {
  .page-about .ab-cta__box {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
  }
  .page-about .ab-cta__actions {
    justify-content: flex-end;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-axis__item,
  .page-about .ab-hero__media {
    transition: none;
    transform: none;
  }
}