.page-about {
  --about-pad: clamp(64px, 9vw, 132px);
  --about-gap: clamp(24px, 4vw, 56px);
  background: var(--ink);
  color: var(--mist);
  padding-bottom: clamp(48px, 7vw, 110px);
}

.page-about .about-crumb {
  padding-inline: var(--gut);
  padding-block: clamp(18px, 3vw, 30px) 0;
  max-width: var(--wrap);
  margin-inline: auto;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  border-bottom: 1px solid var(--line);
  padding-block: clamp(36px, 5vw, 72px) clamp(56px, 8vw, 128px);
}

.page-about .about-hero__inner {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--about-gap);
}

.page-about .about-hero__rail {
  display: none;
}

.page-about .about-hero__body {
  display: grid;
  gap: 20px;
  max-width: 60ch;
}

.page-about .about-idx {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--steel);
  margin: 0;
}

.page-about .about-hero__title {
  font-family: var(--sans);
  font-weight: 800;
  font-size: clamp(30px, 6vw, 62px);
  line-height: 1.12;
  letter-spacing: -0.015em;
  color: var(--mist);
  margin: 0;
  max-width: 20ch;
}

.page-about .about-hero__lede {
  margin: 0;
  font-size: clamp(15px, 1.6vw, 17px);
  line-height: 1.8;
  color: var(--steel);
  max-width: 44ch;
}

.page-about .about-hero__facts {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 28px;
  margin: 6px 0 0;
  padding-top: 20px;
  border-top: 1px solid var(--line);
}

.page-about .about-fact {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  font-size: 13px;
  letter-spacing: 0.02em;
  color: var(--steel);
}

.page-about .about-fact .mx-num {
  font-family: var(--mono);
  font-size: 26px;
  font-weight: 700;
  line-height: 1;
  color: var(--cyan);
}

.page-about .about-hero__acts {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin: 6px 0 0;
}

/* ---------- 通用分区 ---------- */
.page-about .about-section {
  padding-block: var(--about-pad);
}

.page-about .about-head {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
  margin-bottom: clamp(32px, 5vw, 76px);
}

.page-about .about-head__main {
  display: grid;
  gap: 14px;
}

.page-about .about-h2 {
  font-family: var(--sans);
  font-weight: 700;
  font-size: clamp(24px, 3.6vw, 40px);
  line-height: 1.2;
  letter-spacing: -0.01em;
  color: var(--mist);
  margin: 0;
  max-width: 22ch;
}

.page-about .about-lede {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--steel);
  max-width: 44ch;
}

/* ---------- 演进时间线 ---------- */
.page-about .about-evo__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--about-gap);
}

.page-about .about-timeline {
  list-style: none;
  margin: 0;
  padding: 0 0 0 0;
  border-left: 1px solid var(--line-2);
}

.page-about .about-tl {
  position: relative;
  padding: 0 0 clamp(24px, 3vw, 38px) clamp(20px, 2.6vw, 32px);
  outline: none;
}

.page-about .about-tl:last-child {
  padding-bottom: 0;
}

.page-about .about-tl::before {
  content: "";
  position: absolute;
  left: -5px;
  top: 6px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  border: 1px solid var(--cyan);
  background: var(--ink);
  transition: background var(--dur) var(--ease), border-color var(--dur) var(--ease),
    box-shadow var(--dur) var(--ease);
}

.page-about .about-tl--now::before {
  border-color: var(--orange);
  background: var(--orange);
  box-shadow: 0 0 0 4px rgba(255, 122, 47, 0.16);
}

.page-about .about-tl__no {
  display: block;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.2em;
  color: var(--steel);
  margin-bottom: 6px;
}

.page-about .about-tl--now .about-tl__no {
  color: var(--orange);
}

.page-about .about-tl__name {
  margin: 0 0 6px;
  font-size: clamp(16px, 1.8vw, 19px);
  font-weight: 700;
  letter-spacing: 0.01em;
  color: var(--mist);
}

.page-about .about-tl__note {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--steel);
  max-width: 46ch;
}

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

/* ---------- 横向主题带 ---------- */
.page-about .about-band {
  max-width: var(--wrap);
  margin-inline: auto;
  padding-inline: var(--gut);
  border-block: 1px solid var(--line);
  padding-block: 16px;
}

.page-about .about-band .mx-band__item {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--steel);
  white-space: nowrap;
}

.page-about .about-band .mx-band__item--on {
  color: var(--cyan);
}

/* ---------- 四类入口 ---------- */
.page-about .about-quad {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-quad__cell {
  display: grid;
  align-content: start;
  gap: 10px;
  padding: clamp(22px, 3vw, 38px);
  background: linear-gradient(180deg, rgba(15, 42, 34, 0.78), rgba(16, 20, 19, 0.94));
  transition: background var(--dur) var(--ease);
}

.page-about .about-quad__cell:hover {
  background: var(--turf-2);
}

.page-about .about-quad__no {
  font-family: var(--mono);
  font-size: 13px;
  letter-spacing: 0.2em;
  color: var(--cyan);
}

.page-about .about-quad__name {
  margin: 0;
  font-size: clamp(17px, 2vw, 21px);
  font-weight: 700;
  color: var(--mist);
}

.page-about .about-quad__desc {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--steel);
}

.page-about .about-quad__link {
  justify-self: start;
  margin-top: 4px;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color var(--dur) var(--ease), color var(--dur) var(--ease);
}

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

/* ---------- 归档 ---------- */
.page-about .about-archive__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--about-gap);
}

.page-about .about-archive__text {
  display: grid;
  gap: 18px;
  align-content: start;
}

.page-about .about-archive__text p {
  margin: 0;
  font-size: 15px;
  line-height: 1.85;
  color: var(--steel);
  max-width: 46ch;
}

.page-about .about-archive__kpis {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  margin-top: 8px;
}

.page-about .about-archive__kpis .mx-kpi {
  background: var(--turf);
  padding: 18px 16px;
}

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

/* ---------- 更新节奏 ---------- */
.page-about .about-cadence__list {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--line);
}

.page-about .about-cadence__row {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 6px;
  padding-block: clamp(20px, 2.4vw, 28px);
  border-bottom: 1px solid var(--line);
}

.page-about .about-cadence__val {
  font-family: var(--mono);
  font-size: clamp(22px, 3vw, 30px);
  font-weight: 700;
  line-height: 1.1;
  color: var(--cyan);
}

.page-about .about-cadence__val--hot {
  color: var(--orange);
}

.page-about .about-cadence__key {
  font-size: 15px;
  font-weight: 700;
  color: var(--mist);
}

.page-about .about-cadence__desc {
  font-size: 14px;
  line-height: 1.75;
  color: var(--steel);
  max-width: 52ch;
}

/* ---------- 服务划分 ---------- */
.page-about .about-services__list {
  list-style: none;
  margin: 0 0 clamp(36px, 5vw, 72px);
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-serv {
  display: grid;
  align-content: start;
  gap: 8px;
  padding: clamp(20px, 2.6vw, 32px);
  background: var(--turf);
  outline: none;
  transition: background var(--dur) var(--ease);
}

.page-about .about-serv:hover,
.page-about .about-serv:focus-visible {
  background: var(--turf-2);
}

.page-about .about-serv__no {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.2em;
  color: var(--cyan);
}

.page-about .about-serv__name {
  margin: 0;
  font-size: clamp(16px, 1.8vw, 19px);
  font-weight: 700;
  color: var(--mist);
}

.page-about .about-serv__desc {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--steel);
  max-width: 42ch;
}

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

/* ---------- 下一步 ---------- */
.page-about .about-next {
  padding-block: var(--about-pad) clamp(40px, 6vw, 90px);
}

.page-about .about-next__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-next__card {
  display: grid;
  align-content: start;
  gap: 8px;
  padding: clamp(22px, 3vw, 34px);
  background: var(--ink);
  text-decoration: none;
  transition: background var(--dur) var(--ease);
}

.page-about .about-next__card:hover,
.page-about .about-next__card:focus-visible {
  background: var(--turf);
}

.page-about .about-next__no {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.2em;
  color: var(--steel);
}

.page-about .about-next__name {
  font-size: clamp(17px, 2vw, 21px);
  font-weight: 700;
  color: var(--mist);
}

.page-about .about-next__desc {
  font-size: 14px;
  line-height: 1.75;
  color: var(--steel);
  max-width: 40ch;
}

@media (min-width: 760px) {
  .page-about .about-quad {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

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

  .page-about .about-head {
    grid-template-columns: 158px minmax(0, 1fr);
    gap: 32px;
    align-items: start;
  }

  .page-about .about-cadence__row {
    grid-template-columns: 190px minmax(0, 0.9fr) minmax(0, 1.4fr);
    align-items: baseline;
    gap: 28px;
  }
}

@media (min-width: 1024px) {
  .page-about .about-hero__inner {
    grid-template-columns: 92px minmax(0, 1fr);
    align-items: start;
    gap: clamp(32px, 4vw, 64px);
  }

  .page-about .about-hero__rail {
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    min-height: 330px;
    padding-left: 18px;
    border-left: 1px solid var(--line-2);
  }

  .page-about .about-hero__railtick {
    font-family: var(--mono);
    font-size: 12px;
    letter-spacing: 0.18em;
    color: var(--steel);
  }

  .page-about .about-hero__railtick--now {
    color: var(--cyan);
  }

  .page-about .about-evo__grid {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
    align-items: start;
  }

  .page-about .about-evo__fig {
    position: sticky;
    top: calc(var(--head-h) + 28px);
  }

  .page-about .about-archive__grid {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
    align-items: start;
  }

  .page-about .about-tl__note {
    max-height: 0;
    opacity: 0;
    overflow: hidden;
    transition: max-height var(--dur-slow) var(--ease), opacity var(--dur-slow) var(--ease);
  }

  .page-about .about-tl:hover .about-tl__note,
  .page-about .about-tl:focus-within .about-tl__note,
  .page-about .about-tl:focus .about-tl__note {
    max-height: 120px;
    opacity: 1;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-tl__note {
    max-height: none;
    opacity: 1;
    transition: none;
  }

  .page-about * {
    transition-duration: 0.01ms !important;
  }
}
<<<END>>>