.page-about {
  position: relative;
  background-color: var(--c-deep);
  background-image:
    repeating-linear-gradient(0deg, var(--grid-line) 0 1px, transparent 1px 64px),
    repeating-linear-gradient(90deg, var(--grid-line) 0 1px, transparent 1px 64px),
    radial-gradient(1100px 560px at 84% -6%, rgba(23, 224, 200, .11), transparent 62%),
    radial-gradient(900px 520px at 6% 106%, rgba(255, 122, 41, .09), transparent 62%);
  color: rgba(226, 236, 244, .82);
  padding-bottom: 64px;
}

.page-about .about-top {
  padding-top: 18px;
  padding-bottom: 4px;
}

.page-about .breadcrumb,
.page-about .breadcrumb a,
.page-about .breadcrumb li {
  color: var(--c-steel);
  font-size: var(--fs-12);
  letter-spacing: .04em;
}

.page-about .breadcrumb a {
  text-decoration: none;
  transition: color var(--dur) var(--ease);
}

.page-about .breadcrumb a:hover {
  color: var(--c-cyan);
}

.page-about .about-shell {
  display: block;
  padding-top: 8px;
}

/* ---------- 左侧年份刻度轨 ---------- */

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

.page-about .about-rail__eyebrow {
  color: var(--c-steel);
  margin: 0 0 18px;
}

.page-about .about-rail__list {
  list-style: none;
  margin: 0;
  padding: 0 0 0 20px;
  position: relative;
}

.page-about .about-rail__list::before {
  content: "";
  position: absolute;
  left: 3px;
  top: 6px;
  bottom: 6px;
  width: 2px;
  background: linear-gradient(180deg, var(--c-cyan) 0%, rgba(23, 224, 200, .22) 52%, rgba(23, 224, 200, .04) 100%);
}

.page-about .about-rail__list > li {
  position: relative;
}

.page-about .about-rail__list > li::before {
  content: "";
  position: absolute;
  left: -19px;
  top: 15px;
  width: 8px;
  height: 8px;
  background: var(--c-steel);
  opacity: .5;
  transform: rotate(45deg);
  transition: background var(--dur) var(--ease), opacity var(--dur) var(--ease);
}

.page-about .about-rail__link {
  display: flex;
  align-items: baseline;
  gap: 10px;
  padding: 9px 8px 9px 0;
  text-decoration: none;
  color: var(--c-steel);
  font-size: var(--fs-14);
  line-height: 1.4;
  transition: color var(--dur) var(--ease);
}

.page-about .about-rail__num {
  font-size: var(--fs-12);
  color: var(--c-steel);
  letter-spacing: .04em;
  transition: color var(--dur) var(--ease);
}

.page-about .about-rail__link:hover {
  color: var(--c-cyan);
}

.page-about .about-rail__link:hover .about-rail__num {
  color: var(--c-cyan);
}

.page-about .about-rail__link[aria-current="true"] {
  color: var(--c-white);
}

.page-about .about-rail__link[aria-current="true"] .about-rail__num {
  color: var(--c-cyan);
}

.page-about .about-rail__list > li:hover::before,
.page-about .about-rail__list > li:has([aria-current="true"])::before {
  background: var(--c-cyan);
  opacity: 1;
}

/* ---------- 首屏 ---------- */

.page-about .about-hero {
  padding: 24px 0 44px;
  border-bottom: 1px solid rgba(143, 166, 184, .22);
}

.page-about .about-hero__title {
  font-family: var(--font-sans);
  font-size: clamp(36px, 6.4vw, 84px);
  font-weight: 900;
  line-height: 1.04;
  letter-spacing: -.02em;
  color: var(--c-white);
  margin: 16px 0 0;
  max-width: 14em;
}

.page-about .about-hero__lede {
  margin: 24px 0 0;
  max-width: 44ch;
  font-size: var(--fs-16);
  line-height: 1.78;
  color: rgba(226, 236, 244, .76);
}

.page-about .about-hero__panel {
  margin-top: 38px;
  padding: 26px 24px;
  display: flex;
  flex-wrap: wrap;
  align-items: flex-end;
  gap: 26px 44px;
  background: linear-gradient(140deg, var(--c-navy) 0%, rgba(4, 28, 51, .9) 100%);
  border: 1px solid rgba(23, 224, 200, .26);
  clip-path: var(--cut-md);
}

.page-about .about-hero__status {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.page-about .about-hero__status .status-panel__label {
  font-size: var(--fs-12);
  letter-spacing: .16em;
  color: var(--c-steel);
}

.page-about .about-hero__year {
  font-size: clamp(52px, 9vw, 84px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -.03em;
  color: var(--c-cyan);
}

.page-about .about-hero__facts {
  list-style: none;
  margin: 0;
  padding: 0;
  flex: 1 1 240px;
  display: grid;
  gap: 10px;
}

.page-about .about-hero__facts li {
  display: flex;
  align-items: baseline;
  gap: 9px;
  padding: 7px 0 7px 12px;
  border-left: 2px solid var(--c-orange);
  font-size: var(--fs-14);
  line-height: 1.5;
  color: rgba(226, 236, 244, .78);
}

.page-about .about-hero__facts .u-mono {
  font-size: var(--fs-20);
  font-weight: 700;
  color: var(--c-orange-soft);
}

/* ---------- 区块通用 ---------- */

.page-about .about-sec {
  position: relative;
  padding: 52px 0;
}

.page-about .about-sec::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 52px;
  height: 3px;
  background: var(--c-cyan);
}

.page-about .about-sec--versions::before {
  background: var(--c-orange);
}

.page-about .about-sec__title {
  margin: 12px 0 0;
  font-family: var(--font-sans);
  font-size: clamp(25px, 3.6vw, 40px);
  font-weight: 900;
  line-height: 1.18;
  letter-spacing: -.01em;
  color: var(--c-white);
}

.page-about .about-sec__lede {
  margin: 18px 0 0;
  max-width: 52ch;
  font-size: var(--fs-16);
  line-height: 1.78;
  color: rgba(226, 236, 244, .76);
}

.page-about .about-sec__prose {
  margin-top: 20px;
}

.page-about .about-sec__prose p {
  margin: 0 0 16px;
  font-size: var(--fs-16);
  line-height: 1.78;
  color: rgba(226, 236, 244, .78);
}

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

.page-about .about-sec__aside {
  margin: 28px 0 0;
  padding: 14px 16px;
  background: rgba(23, 224, 200, .07);
  border-left: 3px solid var(--c-cyan);
  font-size: var(--fs-14);
  line-height: 1.74;
  color: rgba(226, 236, 244, .8);
}

.page-about .about-sec__aside a,
.page-about .about-sec__prose a {
  color: var(--c-cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(23, 224, 200, .38);
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .about-sec__aside a:hover,
.page-about .about-sec__prose a:hover {
  color: var(--c-orange-soft);
  border-bottom-color: var(--c-orange-soft);
}

/* ---------- 图片容器 ---------- */

.page-about .about-flow__figure {
  margin: 30px 0 0;
  border: 1px solid rgba(143, 166, 184, .2);
  clip-path: var(--cut-md);
  overflow: hidden;
  background: rgba(10, 46, 78, .5);
}

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

.page-about .about-flow__figure .media-frame__caption {
  padding: 10px 16px;
  font-size: var(--fs-12);
  letter-spacing: .04em;
  color: var(--c-steel);
  background: rgba(4, 28, 51, .72);
}

.page-about .about-flow__figure--wide {
  margin-top: 32px;
}

/* ---------- 四步流程 ---------- */

.page-about .about-steps {
  list-style: none;
  margin: 32px 0 0;
  padding: 0;
  display: grid;
  gap: 14px;
}

.page-about .about-step {
  padding: 22px 20px 18px;
  background: rgba(255, 255, 255, .035);
  border: 1px solid rgba(143, 166, 184, .22);
  clip-path: var(--cut-sm);
  transition: border-color var(--dur) var(--ease), background var(--dur) var(--ease);
}

.page-about .about-step:hover {
  border-color: var(--c-cyan);
  background: rgba(23, 224, 200, .06);
}

.page-about .about-step__num {
  display: block;
  font-size: var(--fs-28);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -.03em;
  color: var(--c-cyan);
}

.page-about .about-step__title {
  margin: 14px 0 0;
  font-size: var(--fs-20);
  font-weight: 700;
  line-height: 1.35;
  color: var(--c-white);
}

.page-about .about-step__desc {
  margin: 10px 0 0;
  font-size: var(--fs-14);
  line-height: 1.72;
  color: rgba(226, 236, 244, .72);
}

.page-about .about-step__meta {
  margin: 0;
  max-height: 0;
  overflow: hidden;
  opacity: 0;
  font-size: var(--fs-12);
  letter-spacing: .04em;
  color: var(--c-orange);
  transition: max-height var(--dur) var(--ease), opacity var(--dur) var(--ease), margin var(--dur) var(--ease);
}

.page-about .about-step:hover .about-step__meta {
  max-height: 60px;
  opacity: 1;
  margin-top: 12px;
}

.page-about .about-flow__note {
  margin-top: 30px;
}

.page-about .disclosure {
  border: 1px solid rgba(143, 166, 184, .22);
  background: rgba(10, 46, 78, .42);
}

.page-about .disclosure__summary {
  padding: 16px 18px;
  font-size: var(--fs-14);
  font-weight: 700;
  color: var(--c-white);
  cursor: pointer;
  list-style: none;
}

.page-about .disclosure__summary::-webkit-details-marker {
  display: none;
}

.page-about .disclosure__summary::before {
  content: "＋";
  display: inline-block;
  margin-right: 10px;
  color: var(--c-cyan);
  font-weight: 400;
}

.page-about .disclosure[open] .disclosure__summary::before {
  content: "－";
  color: var(--c-orange);
}

.page-about .disclosure__body {
  padding: 0 18px 18px;
  font-size: var(--fs-14);
  line-height: 1.78;
  color: rgba(226, 236, 244, .76);
}

.page-about .disclosure__body p {
  margin: 0 0 12px;
}

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

/* ---------- 团队 ---------- */

.page-about .about-roles {
  margin-top: 32px;
  display: grid;
  gap: 14px;
}

.page-about .about-role {
  padding: 24px 22px;
  background: rgba(255, 255, 255, .035);
  border: 1px solid rgba(143, 166, 184, .22);
  clip-path: var(--cut-md);
  transition: border-color var(--dur) var(--ease), background var(--dur) var(--ease);
}

.page-about .about-role:hover {
  border-color: var(--c-cyan);
  background: rgba(23, 224, 200, .06);
}

.page-about .about-role__num {
  display: inline-block;
  font-size: var(--fs-28);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -.02em;
  color: var(--c-white);
  padding-bottom: 8px;
  border-bottom: 3px solid var(--c-cyan);
}

.page-about .about-role__title {
  margin: 16px 0 0;
  font-size: var(--fs-20);
  font-weight: 700;
  color: var(--c-white);
}

.page-about .about-role p {
  margin: 10px 0 0;
  font-size: var(--fs-14);
  line-height: 1.72;
  color: rgba(226, 236, 244, .72);
}

.page-about .about-shifts {
  margin-top: 20px;
  display: grid;
  gap: 12px;
}

.page-about .about-shift {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 18px 20px;
  background: rgba(255, 255, 255, .03);
  border-left: 3px solid var(--c-orange);
}

.page-about .about-shift__k {
  font-size: var(--fs-12);
  letter-spacing: .16em;
  color: var(--c-orange-soft);
}

.page-about .about-shift p {
  margin: 0;
  font-size: var(--fs-14);
  line-height: 1.72;
  color: rgba(226, 236, 244, .74);
}

/* ---------- 版本时间线 ---------- */

.page-about .about-timeline {
  list-style: none;
  margin: 34px 0 0;
  padding: 0;
}

.page-about .about-node {
  position: relative;
  padding: 0 0 34px 32px;
}

.page-about .about-node::before {
  content: "";
  position: absolute;
  left: 0;
  top: 12px;
  bottom: 0;
  width: 2px;
  background: rgba(143, 166, 184, .32);
}

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

.page-about .about-node:last-child::before {
  height: 0;
  bottom: auto;
}

.page-about .about-node::after {
  content: "";
  position: absolute;
  left: -4px;
  top: 8px;
  width: 10px;
  height: 10px;
  background: var(--c-orange);
  transform: rotate(45deg);
  transition: background var(--dur) var(--ease);
}

.page-about .about-node:hover::after {
  background: var(--c-cyan);
}

.page-about .about-node__year {
  display: inline-block;
  font-size: var(--fs-14);
  font-weight: 700;
  letter-spacing: .08em;
  color: var(--c-cyan);
}

.page-about .about-node__body {
  margin-top: 8px;
}

.page-about .about-node__title {
  margin: 0;
  font-size: var(--fs-20);
  font-weight: 700;
  line-height: 1.35;
  color: var(--c-white);
}

.page-about .about-node__body p {
  margin: 10px 0 0;
  max-width: 56ch;
  font-size: var(--fs-16);
  line-height: 1.78;
  color: rgba(226, 236, 244, .76);
}

/* ---------- 地域 ---------- */

.page-about .about-region__banner {
  position: relative;
  margin: 0 0 30px;
  overflow: hidden;
  clip-path: var(--cut-md);
  border: 1px solid rgba(143, 166, 184, .2);
}

.page-about .about-region__banner img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  aspect-ratio: 7 / 4;
  object-fit: cover;
}

.page-about .about-region__banner::before {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, rgba(4, 28, 51, .12) 0%, rgba(4, 28, 51, .6) 100%);
  pointer-events: none;
}

.page-about .about-region__banner::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  top: 63%;
  height: 2px;
  background: linear-gradient(90deg, transparent 0%, var(--c-cyan) 42%, var(--c-orange) 68%, transparent 100%);
  pointer-events: none;
}

.page-about .about-region__stats {
  margin: 30px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: rgba(143, 166, 184, .24);
  border: 1px solid rgba(143, 166, 184, .24);
}

.page-about .about-region__stats > div {
  background: rgba(10, 46, 78, .55);
  padding: 18px 16px;
}

.page-about .about-region__stats dt {
  font-size: var(--fs-12);
  letter-spacing: .06em;
  color: var(--c-steel);
}

.page-about .about-region__stats dd {
  margin: 10px 0 0;
  font-size: var(--fs-28);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -.02em;
  color: var(--c-white);
}

/* ---------- 滚动显现 ---------- */

.js-ready .page-about [data-reveal] {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 520ms var(--ease), transform 520ms var(--ease);
}

.js-ready .page-about [data-reveal].is-in {
  opacity: 1;
  transform: translateY(0);
}

/* ---------- 响应式 ---------- */

@media (hover: none) {
  .page-about .about-step__meta {
    max-height: 60px;
    opacity: 1;
    margin-top: 12px;
  }
}

@media (min-width: 640px) {
  .page-about .about-steps {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

  .page-about .about-shift {
    flex-direction: row;
    align-items: baseline;
    gap: 14px;
  }

  .page-about .about-shift__k {
    flex: 0 0 auto;
    padding-top: 2px;
  }
}

@media (min-width: 860px) {
  .page-about .about-region__stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .about-node {
    display: grid;
    grid-template-columns: 92px minmax(0, 1fr);
    column-gap: 24px;
    align-items: start;
  }

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

@media (min-width: 1024px) {
  .page-about {
    padding-bottom: 96px;
  }

  .page-about .about-shell {
    display: grid;
    grid-template-columns: 210px minmax(0, 1fr);
    column-gap: 60px;
    align-items: start;
    padding-top: 16px;
  }

  .page-about .about-rail {
    display: block;
    position: sticky;
    top: 96px;
    align-self: start;
    padding-top: 10px;
  }

  .page-about .about-sec {
    padding: 60px 0;
  }

  .page-about .about-hero {
    padding-bottom: 56px;
  }
}

@media (min-width: 1240px) {
  .page-about .about-steps {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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