.page-about {
  --about-railw: 236px;
  --about-num: rgba(47, 243, 214, 0.13);
  background: var(--bv-deep);
  color: var(--bv-chalk);
  padding-bottom: clamp(56px, 8vw, 104px);
}

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

/* 首屏 */
.page-about .about-head {
  padding-top: clamp(28px, 5vw, 56px);
  padding-bottom: clamp(26px, 4.5vw, 48px);
  border-bottom: 1px solid var(--bv-hair);
}

.page-about .about-head .crumbs {
  font-size: 12.5px;
  letter-spacing: 0.06em;
  color: var(--bv-mist);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
}

.page-about .about-head .crumbs a {
  color: var(--bv-mist-lit);
  text-decoration: none;
  border-bottom: 1px solid transparent;
}

.page-about .about-head .crumbs a:hover {
  color: var(--bv-signal);
  border-bottom-color: var(--bv-signal);
}

.page-about .about-head .eyebrow {
  margin: 20px 0 0;
  font-family: var(--font-num);
  font-size: 11.5px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--bv-signal);
}

.page-about .about-head h1 {
  margin: 12px 0 18px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(30px, 5.6vw, 56px);
  line-height: 1.14;
  letter-spacing: 0.02em;
  max-width: 16em;
}

.page-about .about-head .lead {
  margin: 0;
  max-width: 42em;
  font-size: clamp(15px, 1.9vw, 18px);
  line-height: 1.9;
  color: var(--bv-mist-lit);
}

.page-about .about-facts {
  list-style: none;
  margin: 30px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px 18px;
}

.page-about .about-facts li {
  border-top: 1px solid var(--bv-hair-strong);
  padding-top: 10px;
}

.page-about .about-facts b {
  display: block;
  font-family: var(--font-num);
  font-size: clamp(20px, 3.2vw, 28px);
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--bv-signal);
  line-height: 1.2;
}

.page-about .about-facts span {
  display: block;
  margin-top: 4px;
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--bv-mist);
}

@media (min-width: 760px) {
  .page-about .about-facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 18px;
  }
}

/* 档案双栏 */
.page-about .about-body {
  display: grid;
  gap: clamp(26px, 4vw, 44px);
  padding-top: clamp(26px, 4.5vw, 52px);
}

@media (min-width: 920px) {
  .page-about .about-body {
    grid-template-columns: var(--about-railw) minmax(0, 1fr);
    gap: clamp(32px, 5vw, 72px);
  }
}

/* 左窄栏 */
.page-about .about-rail {
  border: 1px solid var(--bv-hair);
  border-radius: 2px;
  padding: 18px 18px 20px;
  background: rgba(7, 26, 23, 0.55);
}

@media (min-width: 920px) {
  .page-about .about-rail {
    position: sticky;
    top: 108px;
    align-self: start;
    background: transparent;
    border: 0;
    border-left: 1px solid var(--bv-hair);
    border-radius: 0;
    padding: 4px 0 4px 20px;
  }
}

.page-about .about-rail__group + .about-rail__group {
  margin-top: 26px;
}

.page-about .about-rail__label {
  margin: 0;
  font-family: var(--font-num);
  font-size: 11px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--bv-mist);
}

.page-about .tl {
  list-style: none;
  margin: 14px 0 0;
  padding: 0 0 0 18px;
  position: relative;
}

.page-about .tl::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 8px;
  bottom: 8px;
  width: 1px;
  background: linear-gradient(var(--bv-signal), rgba(215, 220, 212, 0.12));
}

.page-about .tl__item {
  position: relative;
  margin-bottom: 16px;
}

.page-about .tl__item:last-child {
  margin-bottom: 0;
}

.page-about .tl__item::before {
  content: "";
  position: absolute;
  left: -18px;
  top: 6px;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--bv-signal);
  box-shadow: 0 0 0 3px rgba(47, 243, 214, 0.12);
}

.page-about .tl__item--lg::before {
  width: 11px;
  height: 11px;
  top: 4px;
  left: -20px;
  box-shadow: 0 0 0 4px rgba(255, 107, 53, 0.22);
  background: var(--bv-track-soft);
}

.page-about .tl__link {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 4px 8px;
  text-decoration: none;
  color: var(--bv-mist-lit);
}

.page-about .tl__link:hover .tl__name {
  color: var(--bv-signal);
}

.page-about .tl__year {
  font-family: var(--font-num);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.06em;
  color: var(--bv-chalk);
}

.page-about .tl__name {
  font-size: 13px;
  letter-spacing: 0.02em;
  transition: color 0.2s var(--ease);
}

.page-about .codes {
  list-style: none;
  margin: 12px 0 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 7px;
}

.page-about .codes a {
  display: inline-block;
  font-family: var(--font-num);
  font-size: 11.5px;
  letter-spacing: 0.06em;
  padding: 5px 8px;
  border: 1px solid var(--bv-hair-strong);
  border-radius: 2px;
  color: var(--bv-mist-lit);
  text-decoration: none;
  transition: border-color 0.2s var(--ease), color 0.2s var(--ease);
}

.page-about .codes a:hover {
  border-color: var(--bv-signal);
  color: var(--bv-signal);
}

.page-about .about-rail__note {
  margin: 24px 0 0;
  padding-top: 14px;
  border-top: 1px solid var(--bv-hair);
  font-size: 12px;
  line-height: 1.8;
  letter-spacing: 0.02em;
  color: var(--bv-mist);
}

/* 段落档案块 */
.page-about .about-block {
  position: relative;
  margin-bottom: clamp(44px, 7vw, 76px);
  padding-top: clamp(18px, 3vw, 30px);
}

.page-about .about-block:last-child {
  margin-bottom: 0;
}

.page-about .about-block__head {
  position: relative;
}

.page-about .about-block__num {
  position: absolute;
  left: -0.06em;
  top: -0.46em;
  font-family: var(--font-num);
  font-weight: 700;
  font-size: clamp(64px, 12vw, 104px);
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--about-num);
  pointer-events: none;
  user-select: none;
  z-index: 0;
}

.page-about .about-block h2 {
  position: relative;
  z-index: 1;
  margin: 0 0 16px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(21px, 3.2vw, 30px);
  line-height: 1.34;
  letter-spacing: 0.03em;
  color: var(--bv-chalk);
}

.page-about .about-block p {
  margin: 0 0 14px;
  max-width: 40em;
  font-size: 16px;
  line-height: 1.9;
  color: rgba(246, 242, 232, 0.86);
}

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

.page-about .about-flow a {
  color: var(--bv-signal);
  text-decoration: none;
  border-bottom: 1px solid rgba(47, 243, 214, 0.38);
}

.page-about .about-flow a:hover {
  border-bottom-color: var(--bv-signal);
}

/* 浅底工序块 */
.page-about .about-block--chalk {
  margin-top: clamp(8px, 2vw, 16px);
  padding: clamp(22px, 4vw, 38px);
  background: var(--bv-chalk);
  border-radius: 2px;
}

.page-about .about-block--chalk h2 {
  color: var(--bv-ink);
}

.page-about .about-block--chalk .about-block__num {
  color: rgba(12, 43, 38, 0.1);
}

.page-about .about-block--chalk p {
  color: #2b332e;
}

.page-about .about-block--chalk a {
  color: #0C2B26;
  border-bottom-color: rgba(12, 43, 38, 0.35);
}

.page-about .steps {
  list-style: none;
  counter-reset: step;
  margin: 20px 0 18px;
  padding: 0;
}

.page-about .steps li {
  counter-increment: step;
  position: relative;
  padding: 15px 0 15px 44px;
  border-top: 1px solid rgba(16, 22, 19, 0.14);
}

.page-about .steps li:last-child {
  border-bottom: 1px solid rgba(16, 22, 19, 0.14);
}

.page-about .steps li::before {
  content: counter(step, decimal-leading-zero);
  position: absolute;
  left: 0;
  top: 17px;
  font-family: var(--font-num);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.06em;
  color: #0C2B26;
  opacity: 0.62;
}

.page-about .steps strong {
  display: block;
  margin-bottom: 4px;
  font-size: 16px;
  letter-spacing: 0.04em;
  color: var(--bv-ink);
}

.page-about .steps p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.85;
}

.page-about .steps__tail {
  font-size: 15px;
  line-height: 1.85;
  padding-left: 16px;
  border-left: 3px solid var(--bv-signal);
  max-width: 38em;
}

/* 引用 */
.page-about .pull {
  margin: 24px 0 0;
  padding: 2px 0 2px 18px;
  border-left: 3px solid var(--bv-signal);
}

.page-about .pull p {
  margin: 0;
  max-width: 32em;
  font-size: clamp(16px, 2.2vw, 19px);
  line-height: 1.8;
  color: var(--bv-mist-lit);
}

/* 分区条带 */
.page-about .zones {
  display: flex;
  gap: 12px;
  margin: 22px 0 0;
  padding: 4px 0 16px;
  overflow-x: auto;
  scroll-snap-type: x proximity;
  -webkit-overflow-scrolling: touch;
}

.page-about .zones:focus-visible {
  outline: 2px solid var(--bv-signal);
  outline-offset: 2px;
}

.page-about .zones::-webkit-scrollbar {
  height: 6px;
}

.page-about .zones::-webkit-scrollbar-thumb {
  background: var(--bv-hair-strong);
  border-radius: 3px;
}

.page-about .zone {
  flex: 0 0 clamp(226px, 74vw, 288px);
  scroll-snap-align: start;
  padding: 16px 16px 18px;
  background: var(--bv-step);
  border: 1px solid var(--bv-hair);
  border-radius: 2px;
}

.page-about .zone__code {
  margin: 0;
  font-family: var(--font-num);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.18em;
  color: var(--bv-signal);
}

.page-about .zone__name {
  margin: 8px 0 8px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 20px;
  letter-spacing: 0.04em;
  color: var(--bv-chalk);
}

.page-about .zone p {
  margin: 0 0 12px;
  font-size: 13.5px;
  line-height: 1.75;
  color: var(--bv-mist-lit);
  max-width: none;
}

.page-about .zone ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.page-about .zone li {
  font-size: 11.5px;
  letter-spacing: 0.04em;
  padding: 3px 7px;
  border: 1px solid var(--bv-hair-strong);
  border-radius: 2px;
  color: var(--bv-chalk);
}

.page-about .zones__note {
  font-size: 13.5px;
  letter-spacing: 0.02em;
  color: var(--bv-mist);
  max-width: 42em;
}

/* 图片 */
.page-about .about-figure {
  margin: 0 0 18px;
}

.page-about .about-figure img {
  display: block;
  width: 100%;
  height: auto;
  border-radius: 2px;
  border: 1px solid var(--bv-hair);
  object-fit: cover;
}

.page-about .about-figure figcaption {
  margin-top: 8px;
  font-size: 12px;
  line-height: 1.7;
  letter-spacing: 0.04em;
  color: var(--bv-mist);
}

.page-about .about-split {
  display: grid;
  gap: 20px;
}

.page-about .about-split .about-figure {
  margin-bottom: 0;
}

@media (min-width: 760px) {
  .page-about .about-split {
    grid-template-columns: 1.12fr 0.88fr;
    gap: 28px;
    align-items: start;
  }

  .page-about .about-split--square {
    grid-template-columns: 232px minmax(0, 1fr);
    gap: 28px;
  }
}

.page-about .about-band {
  margin: clamp(20px, 4vw, 34px) 0 clamp(40px, 7vw, 68px);
}

.page-about .about-band img {
  display: block;
  width: 100%;
  height: auto;
  border-radius: 2px;
  border: 1px solid var(--bv-hair);
  object-fit: cover;
}

.page-about .about-band figcaption {
  margin-top: 10px;
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--bv-mist);
}

@media (min-width: 920px) {
  .page-about .about-band--bleed {
    margin-left: calc(-1 * (var(--about-railw) + clamp(32px, 5vw, 72px)));
  }
}

/* 编号示例 */
.page-about .code-demo {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin: 18px 0 18px;
  font-family: var(--font-num);
}

.page-about .code-demo span {
  padding: 8px 12px;
  border: 1px solid var(--bv-hair-strong);
  border-radius: 2px;
  background: rgba(47, 243, 214, 0.07);
  color: var(--bv-signal);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.12em;
}

.page-about .code-demo span:last-child {
  color: var(--bv-track-soft);
  background: rgba(255, 107, 53, 0.1);
  border-color: rgba(255, 176, 138, 0.4);
}

@media (prefers-reduced-motion: reduce) {
  .page-about .tl__name,
  .page-about .codes a {
    transition: none;
  }
}
<<<END>>>