.page-about {
  --about-rail: 76px;
  --about-pad: 56px;
  background: var(--ink);
  color: var(--ice);
  overflow-x: hidden;
}

.page-about .about-link {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(31, 227, 188, .45);
  padding-bottom: 1px;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .about-link:hover,
.page-about .about-link:focus-visible {
  color: var(--mint);
  border-bottom-color: var(--mint);
}

/* ---------- 首屏 ---------- */

.page-about .about-hero {
  position: relative;
  padding: 32px 0 56px;
  background:
    radial-gradient(72% 62% at 84% 4%, rgba(31, 227, 188, .17), transparent 68%),
    radial-gradient(52% 48% at 6% 96%, rgba(255, 83, 38, .1), transparent 72%),
    var(--ink);
  overflow: hidden;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(31, 227, 188, .07) 1px, transparent 1px),
    linear-gradient(90deg, rgba(31, 227, 188, .07) 1px, transparent 1px);
  background-size: 56px 56px;
  -webkit-mask-image: radial-gradient(72% 72% at 72% 18%, #000, transparent 86%);
  mask-image: radial-gradient(72% 72% at 72% 18%, #000, transparent 86%);
  pointer-events: none;
}

.page-about .about-hero__in {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: 1fr;
  gap: 32px;
}

.page-about .about-hero__title {
  margin: 12px 0 0;
  font-size: clamp(2.1rem, 7vw, 4.2rem);
  line-height: 1.12;
  letter-spacing: -.03em;
  font-weight: 900;
}

.page-about .about-hero__title em {
  font-style: normal;
  color: var(--cyan);
  display: inline-block;
}

.page-about .about-hero__lead {
  margin: 20px 0 0;
  max-width: 40ch;
  color: var(--ice);
  opacity: .9;
}

.page-about .about-hero__facts {
  margin: 32px 0 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
}

.page-about .about-hero__fact {
  padding: 14px 16px;
  border-left: 2px solid var(--cyan);
  background: linear-gradient(90deg, rgba(31, 227, 188, .08), transparent 88%);
  border-radius: 0 var(--r-sm) var(--r-sm) 0;
}

.page-about .about-hero__fact dt {
  font-size: 12px;
  letter-spacing: .22em;
  color: var(--mist);
}

.page-about .about-hero__fact dd {
  margin: 6px 0 0;
  font-size: 15px;
  color: var(--ice);
  line-height: 1.55;
}

.page-about .about-hero__index {
  align-self: start;
  padding: 20px 20px 12px;
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  background: linear-gradient(170deg, rgba(18, 51, 43, .92), rgba(11, 31, 25, .92));
  box-shadow: 0 24px 60px -30px rgba(0, 0, 0, .9);
}

.page-about .about-hero__index-t {
  margin: 0 0 6px;
  font-size: 11px;
  letter-spacing: .34em;
  color: var(--mist);
}

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

.page-about .about-hero__list li + li {
  border-top: 1px dashed var(--line-soft);
}

.page-about .about-hero__list a {
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding: 12px 4px;
  color: var(--ice);
  text-decoration: none;
  font-size: 15px;
  transition: color var(--dur) var(--ease), padding-left var(--dur) var(--ease);
}

.page-about .about-hero__list a .bsx-num {
  font-size: 12px;
  color: var(--cyan-deep);
  letter-spacing: .1em;
}

.page-about .about-hero__list a:hover,
.page-about .about-hero__list a:focus-visible {
  color: var(--cyan);
  padding-left: 12px;
}

/* ---------- 章节骨架 ---------- */

.page-about .about-sec {
  position: relative;
  padding: var(--about-pad) 0;
}

.page-about .about-sec--deck {
  background: var(--deck);
  border-top: 1px solid rgba(31, 227, 188, .08);
  border-bottom: 1px solid rgba(31, 227, 188, .08);
}

.page-about .about-sec__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 20px;
}

.page-about .about-sec__rail {
  display: none;
  position: relative;
  padding-top: 6px;
}

.page-about .about-sec__no {
  display: block;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .3em;
  color: var(--mist);
  writing-mode: vertical-rl;
  text-orientation: mixed;
}

.page-about .about-sec__body {
  min-width: 0;
}

.page-about .about-sec__body .bsx-h2 {
  margin: 0 0 18px;
  font-size: clamp(1.5rem, 4.6vw, 2.3rem);
  line-height: 1.24;
  letter-spacing: -.02em;
}

.page-about .about-sec__intro {
  margin-top: 0;
}

.page-about .about-sec__body .bsx-prose + .bsx-prose {
  margin-top: 16px;
}

.page-about .about-sec__body strong {
  color: var(--cyan);
  font-weight: 700;
}

/* ---------- 引言块 ---------- */

.page-about .about-quote {
  margin: 28px 0;
  padding: 20px 22px;
  border-radius: var(--r-md);
  border: 1px solid var(--line);
  border-left: 3px solid var(--cyan);
  background: linear-gradient(100deg, rgba(31, 227, 188, .12), rgba(11, 31, 25, .3) 70%);
}

.page-about .about-quote p {
  margin: 0;
  font-size: clamp(1rem, 2.6vw, 1.15rem);
  line-height: 1.75;
  color: var(--mint);
}

/* ---------- 工序列 ---------- */

.page-about .about-steps {
  counter-reset: aboutstep;
  list-style: none;
  margin: 28px 0 0;
  padding: 0;
  display: grid;
  gap: 14px;
}

.page-about .about-steps__item {
  counter-increment: aboutstep;
  position: relative;
  padding: 20px 20px 20px 62px;
  border-radius: var(--r-md);
  background: var(--raise);
  border: 1px solid rgba(31, 227, 188, .14);
}

.page-about .about-steps__item::before {
  content: counter(aboutstep, decimal-leading-zero);
  position: absolute;
  left: 20px;
  top: 20px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .08em;
  color: var(--amber);
}

.page-about .about-steps__t {
  margin: 0 0 8px;
  font-size: 1.02rem;
  font-weight: 700;
  color: var(--mint);
  letter-spacing: .04em;
}

.page-about .about-steps__item p {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--ice);
  opacity: .88;
}

.page-about .about-steps__item .bsx-num {
  color: var(--cyan);
}

/* ---------- 图片容器 ---------- */

.page-about .about-fig {
  margin: 32px 0;
}

.page-about .about-fig--wide {
  margin-top: 24px;
}

.page-about .about-media {
  border-radius: var(--r-lg);
  overflow: hidden;
  border: 1px solid var(--line);
  background: var(--raise);
  aspect-ratio: 16 / 9;
}

.page-about .about-media--wide {
  aspect-ratio: 16 / 9;
}

.page-about .about-media--tall {
  aspect-ratio: 3 / 2;
}

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

.page-about .about-fig .bsx-figure {
  margin: 12px 0 0;
  font-size: 12.5px;
  line-height: 1.7;
  color: var(--mist);
}

/* ---------- 版本时间轴 ---------- */

.page-about .about-vers {
  position: relative;
  list-style: none;
  margin: 28px 0 0;
  padding: 0;
}

.page-about .about-vers::before {
  content: "";
  position: absolute;
  left: 11px;
  top: 10px;
  bottom: 10px;
  width: 1px;
  background: linear-gradient(180deg, var(--cyan) 0%, rgba(31, 227, 188, .35) 45%, rgba(31, 227, 188, .06) 100%);
}

.page-about .about-vers__item {
  position: relative;
  padding-left: 38px;
}

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

.page-about .about-vers__item::before {
  content: "";
  position: absolute;
  left: 4px;
  top: 16px;
  width: 13px;
  height: 13px;
  border-radius: 50%;
  background: var(--ink);
  border: 2px solid var(--cyan);
  box-shadow: 0 0 0 4px rgba(31, 227, 188, .12);
  z-index: 1;
  transition: background var(--dur) var(--ease), box-shadow var(--dur) var(--ease);
}

.page-about .about-vers__item:has(details[open])::before {
  background: var(--cyan);
  box-shadow: 0 0 0 6px rgba(31, 227, 188, .18);
}

.page-about .about-vers__node {
  border-radius: var(--r-md);
  border: 1px solid var(--line-soft);
  background: var(--deck);
  overflow: hidden;
  transition: border-color var(--dur) var(--ease);
}

.page-about .about-vers__node[open] {
  border-color: rgba(31, 227, 188, .42);
}

.page-about .about-vers__node > summary {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 14px 16px;
  cursor: pointer;
  list-style: none;
}

.page-about .about-vers__node > summary::-webkit-details-marker {
  display: none;
}

.page-about .about-vers__node > summary:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: -2px;
}

.page-about .about-vers__v {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--amber);
  letter-spacing: .02em;
  flex: none;
}

.page-about .about-vers__label {
  flex: 1 1 auto;
  min-width: 0;
  font-size: 14.5px;
  color: var(--ice);
  line-height: 1.5;
}

.page-about .about-vers__sign {
  position: relative;
  flex: none;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  border: 1px solid var(--cyan-deep);
}

.page-about .about-vers__sign::before,
.page-about .about-vers__sign::after {
  content: "";
  position: absolute;
  left: 50%;
  top: 50%;
  background: var(--cyan);
  transform: translate(-50%, -50%);
  transition: opacity var(--dur) var(--ease);
}

.page-about .about-vers__sign::before {
  width: 8px;
  height: 1px;
}

.page-about .about-vers__sign::after {
  width: 1px;
  height: 8px;
}

.page-about .about-vers__node[open] .about-vers__sign::after {
  opacity: 0;
}

.page-about .about-vers__list {
  margin: 0;
  padding: 0 16px 16px;
  list-style: none;
}

.page-about .about-vers__list li {
  position: relative;
  padding-left: 16px;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--ice);
  opacity: .86;
}

.page-about .about-vers__list li + li {
  margin-top: 8px;
}

.page-about .about-vers__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 11px;
  width: 6px;
  height: 6px;
  border-radius: 2px;
  background: var(--cyan-deep);
}

/* ---------- 团队 ---------- */

.page-about .about-team {
  margin-top: 28px;
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
}

.page-about .about-team__card {
  position: relative;
  padding: 20px;
  border-radius: var(--r-md);
  background: var(--raise);
  border: 1px solid rgba(31, 227, 188, .14);
  transition: transform var(--dur) var(--ease), border-color var(--dur) var(--ease), background var(--dur) var(--ease);
}

.page-about .about-team__card:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 3px;
}

.page-about .about-team__role {
  margin: 0;
  font-size: 11.5px;
  letter-spacing: .26em;
  color: var(--mist);
}

.page-about .about-team__n {
  margin: 10px 0 0;
  font-size: 2rem;
  font-weight: 700;
  line-height: 1;
  color: var(--cyan);
  letter-spacing: -.02em;
}

.page-about .about-team__t {
  margin: 8px 0 10px;
  font-size: 1rem;
  font-weight: 700;
  color: var(--mint);
}

.page-about .about-team__card p:last-child {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--ice);
  opacity: .84;
}

@media (hover: hover) {
  .page-about .about-team:hover .about-team__card:not(:hover) {
    opacity: .58;
  }

  .page-about .about-team__card:hover {
    transform: translateY(-4px);
    border-color: rgba(31, 227, 188, .5);
    background: #164034;
  }
}

.page-about .about-handoff {
  margin-top: 20px;
  padding: 22px;
  border-radius: var(--r-md);
  border: 1px solid var(--line);
  background: linear-gradient(150deg, rgba(18, 51, 43, .7), rgba(5, 18, 14, .5));
}

.page-about .about-handoff__t {
  margin: 0 0 14px;
  font-size: .95rem;
  letter-spacing: .1em;
  color: var(--cyan);
}

.page-about .about-handoff__list {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 12px;
}

.page-about .about-handoff__list li {
  display: grid;
  grid-template-columns: 24px 1fr;
  gap: 10px;
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--ice);
  opacity: .88;
}

.page-about .about-handoff__list .bsx-num {
  color: var(--amber);
  font-size: 12px;
  padding-top: 4px;
}

/* ---------- 合作 ---------- */

.page-about .about-partner {
  display: grid;
  grid-template-columns: 1fr;
  gap: 26px;
  margin-top: 4px;
}

.page-about .about-partner__points {
  margin: 22px 0 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 12px;
}

.page-about .about-partner__points li {
  display: grid;
  grid-template-columns: 14px 1fr;
  gap: 10px;
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--ice);
  opacity: .86;
}

.page-about .about-partner__dot {
  width: 7px;
  height: 7px;
  margin-top: 9px;
  border-radius: 50%;
  background: var(--pulse);
  box-shadow: 0 0 0 3px rgba(255, 83, 38, .16);
}

.page-about .about-partner__fig {
  margin: 0;
}

.page-about .about-partner__fig .bsx-figure {
  margin: 12px 0 0;
  font-size: 12.5px;
  line-height: 1.7;
  color: var(--mist);
}

/* ---------- 承诺 ---------- */

.page-about .about-sec--promise {
  background:
    radial-gradient(60% 50% at 20% 0%, rgba(31, 227, 188, .12), transparent 70%),
    radial-gradient(48% 46% at 100% 100%, rgba(255, 178, 51, .1), transparent 72%),
    var(--ink);
  border-top: 1px solid rgba(31, 227, 188, .1);
}

.page-about .about-sec__rail--end::after {
  content: "";
}

.page-about .about-promise {
  margin-top: 26px;
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
}

.page-about .about-promise__item {
  padding: 22px 20px;
  border-radius: var(--r-md);
  border: 1px solid rgba(255, 178, 51, .22);
  background: linear-gradient(160deg, rgba(255, 178, 51, .08), rgba(11, 31, 25, .8) 62%);
}

.page-about .about-promise__num {
  margin: 0;
  font-size: clamp(2.2rem, 8vw, 3rem);
  font-weight: 700;
  line-height: 1;
  color: var(--amber);
  letter-spacing: -.03em;
  display: flex;
  align-items: baseline;
  gap: 4px;
}

.page-about .about-promise__unit {
  font-size: .95rem;
  letter-spacing: .04em;
  color: var(--ice);
  opacity: .78;
}

.page-about .about-promise__t {
  margin: 12px 0 8px;
  font-size: 1rem;
  font-weight: 700;
  color: var(--mint);
}

.page-about .about-promise__item p:last-child {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--ice);
  opacity: .84;
}

.page-about .about-verify {
  margin-top: 22px;
  padding: 24px 20px;
  border-radius: var(--r-lg);
  border: 1px solid var(--line);
  background: rgba(11, 31, 25, .82);
}

.page-about .about-verify__t {
  margin: 0 0 12px;
  font-size: 1rem;
  letter-spacing: .06em;
  color: var(--cyan);
}

.page-about .about-verify p {
  margin: 0;
  max-width: 62ch;
  font-size: 14.5px;
  line-height: 1.82;
  color: var(--ice);
  opacity: .88;
}

.page-about .about-verify__btn {
  display: inline-block;
  margin-top: 18px;
  text-decoration: none;
}

/* ---------- 断点 ---------- */

@media (min-width: 700px) {
  .page-about .about-hero__facts {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

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

  .page-about .about-promise {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .about-steps__item--shift {
    margin-left: 32px;
  }

  .page-about .about-handoff__list li {
    grid-template-columns: 28px 1fr;
  }
}

@media (min-width: 900px) {
  .page-about {
    --about-pad: 72px;
  }

  .page-about .about-hero {
    padding: 48px 0 80px;
  }

  .page-about .about-hero__in {
    grid-template-columns: minmax(0, 1.4fr) minmax(280px, .6fr);
    gap: 56px;
    align-items: start;
  }

  .page-about .about-hero__lead {
    max-width: 42ch;
    font-size: 17.5px;
  }

  .page-about .about-sec__grid {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: 44px;
  }

  .page-about .about-sec__rail {
    display: block;
  }

  .page-about .about-sec__rail::after {
    content: "";
    position: absolute;
    left: 6px;
    top: 44px;
    bottom: calc(var(--about-pad) * -1);
    width: 1px;
    background: linear-gradient(180deg, rgba(31, 227, 188, .55), rgba(31, 227, 188, .06));
  }

  .page-about .about-sec__rail::before {
    content: "";
    position: absolute;
    left: 1px;
    top: 22px;
    width: 11px;
    height: 11px;
    border-radius: 50%;
    background: var(--ink);
    border: 2px solid var(--cyan);
    box-shadow: 0 0 0 4px rgba(31, 227, 188, .12);
    z-index: 1;
  }

  .page-about .about-sec--deck .about-sec__rail::before {
    background: var(--deck);
  }

  .page-about .about-sec__rail--end::after {
    background: linear-gradient(180deg, rgba(31, 227, 188, .45), transparent 60%);
    bottom: 0;
  }

  .page-about .about-sec__body--narrow {
    max-width: 60ch;
  }

  .page-about .about-sec__body--push {
    margin-left: 6%;
  }

  .page-about .about-steps {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 18px;
  }

  .page-about .about-steps__item--shift {
    margin-left: 0;
    margin-top: 26px;
  }

  .page-about .about-steps__item:nth-child(even) {
    margin-top: 26px;
  }

  .page-about .about-team {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 12px;
  }

  .page-about .about-team__card:nth-child(even) {
    margin-top: 22px;
  }

  .page-about .about-partner {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, .95fr);
    gap: 40px;
    align-items: start;
  }

  .page-about .about-partner__text {
    max-width: 58ch;
  }

  .page-about .about-verify {
    padding: 28px 32px;
  }

  .page-about .about-vers__item {
    padding-left: 46px;
  }
}

@media (min-width: 1120px) {
  .page-about .about-promise {
    gap: 18px;
  }

  .page-about .about-promise__item:nth-child(2) {
    transform: translateY(-14px);
  }

  .page-about .about-sec__body--push {
    margin-left: 9%;
  }
}
<<<END>>>