.page-about {
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-body);
  overflow-x: hidden;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  color: var(--paper);
  padding: calc(var(--header-h) + 2.2rem) 0 clamp(2.8rem, 9vw, 5rem);
  background:
    radial-gradient(120% 90% at 84% 6%, rgba(43, 231, 200, .16), transparent 58%),
    linear-gradient(168deg, var(--deep) 0%, #08222f 60%, #0a2b3c 100%);
  border-bottom: 1px solid rgba(43, 231, 200, .2);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  top: -18%;
  right: -22%;
  width: min(78vw, 720px);
  aspect-ratio: 1 / 1;
  background: repeating-radial-gradient(circle at center, rgba(111, 143, 166, .38) 0 1px, transparent 1px 44px);
  opacity: .5;
  pointer-events: none;
}

.page-about .about-hero__grid {
  position: relative;
  z-index: 1;
  display: grid;
  gap: clamp(1.8rem, 5vw, 3rem);
}

.page-about .about-hero__crumb {
  font-size: .78rem;
  letter-spacing: .04em;
  color: rgba(245, 248, 247, .66);
}

.page-about .about-hero__crumb .breadcrumb__item {
  color: inherit;
}

.page-about .about-hero__crumb .breadcrumb__sep {
  margin: 0 .45rem;
  color: rgba(43, 231, 200, .7);
}

.page-about .about-hero__crumb a {
  color: rgba(245, 248, 247, .82);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color .2s ease, color .2s ease;
}

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

.page-about .about-hero__eyebrow {
  margin: 1.5rem 0 .9rem;
  font-family: var(--font-mono);
  font-size: .72rem;
  letter-spacing: .24em;
  color: var(--cyan);
}

.page-about .about-hero h1 {
  margin: 0 0 1.1rem;
  font-family: var(--font-title);
  font-weight: 900;
  font-size: clamp(2rem, 6.6vw, 3.7rem);
  line-height: 1.06;
  letter-spacing: -.02em;
}

.page-about .about-hero__lede {
  margin: 0 0 1.9rem;
  max-width: 46ch;
  font-size: clamp(.98rem, 2.4vw, 1.1rem);
  line-height: 1.82;
  color: rgba(245, 248, 247, .8);
}

.page-about .about-hero__facts {
  list-style: none;
  margin: 0 0 1.9rem;
  padding: 1.2rem 0 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1rem 1.2rem;
  border-top: 1px solid rgba(245, 248, 247, .16);
}

.page-about .about-hero__facts b {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(1.2rem, 3.2vw, 1.55rem);
  font-weight: 600;
  letter-spacing: -.01em;
  color: var(--cyan);
}

.page-about .about-hero__facts span {
  display: block;
  margin-top: .3rem;
  font-size: .8rem;
  line-height: 1.5;
  color: rgba(245, 248, 247, .62);
}

.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: .7rem;
}

.page-about .about-hero__figure {
  margin: 0;
  border: 1px solid rgba(245, 248, 247, .2);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: 0 18px 40px -28px rgba(0, 0, 0, .9);
}

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

.page-about .about-hero__figure .media-frame__caption {
  font-family: var(--font-mono);
  font-size: .68rem;
  letter-spacing: .1em;
  color: rgba(245, 248, 247, .78);
}

@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.08fr) minmax(0, .92fr);
    align-items: center;
  }

  .page-about .about-hero__figure {
    transform: translateY(1.4rem);
  }
}

/* ---------- 主体：章节导航 + 长卷 ---------- */
.page-about .about-body {
  display: grid;
  gap: clamp(1.4rem, 4vw, 2.4rem);
  padding-bottom: clamp(3rem, 8vw, 5.5rem);
}

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

.page-about .about-rail__title {
  margin: 0 0 .8rem;
  font-family: var(--font-mono);
  font-size: .68rem;
  letter-spacing: .2em;
  color: var(--mist);
}

.page-about .about-rail__link {
  display: flex;
  gap: .6rem;
  align-items: baseline;
  padding: .5rem 0 .5rem .8rem;
  border-left: 1px solid var(--hairline);
  color: var(--slate);
  font-size: .85rem;
  line-height: 1.4;
  text-decoration: none;
  transition: color .2s ease, border-color .2s ease;
}

.page-about .about-rail__link .mono {
  font-family: var(--font-mono);
  font-size: .7rem;
  color: var(--mist);
}

.page-about .about-rail__link:hover,
.page-about .about-rail__link:focus-visible {
  color: var(--ink);
  border-left-color: var(--mist);
}

.page-about .about-rail__link[aria-current="true"] {
  color: var(--ink);
  font-weight: 600;
  border-left-color: var(--cyan);
}

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

@media (min-width: 960px) {
  .page-about .about-body {
    grid-template-columns: 186px minmax(0, 1fr);
    gap: clamp(2rem, 4vw, 3.4rem);
    align-items: start;
  }

  .page-about .about-rail {
    display: block;
    position: sticky;
    top: calc(var(--header-h) + 1.6rem);
  }
}

/* ---------- 章节 ---------- */
.page-about .about-chapter {
  padding: clamp(2.2rem, 6vw, 3.6rem) 0;
  border-top: 1px solid var(--hairline);
  scroll-margin-top: calc(var(--header-h) + 1rem);
}

.page-about .about-chapter:first-child {
  border-top: 0;
  padding-top: clamp(1.6rem, 4vw, 2.4rem);
}

.page-about .about-chapter__num {
  display: flex;
  align-items: center;
  gap: .7rem;
  margin: 0 0 .8rem;
  font-family: var(--font-mono);
  font-size: .72rem;
  letter-spacing: .2em;
  color: var(--slate);
}

.page-about .about-chapter__num::after {
  content: "";
  width: 2.6rem;
  height: 1px;
  background: var(--sand);
}

.page-about .about-chapter__title {
  margin: 0 0 1rem;
  font-family: var(--font-title);
  font-weight: 800;
  font-size: clamp(1.4rem, 3.6vw, 2.1rem);
  line-height: 1.26;
  letter-spacing: -.01em;
  color: var(--ink);
}

.page-about .about-p {
  margin: 0 0 1rem;
  max-width: 64ch;
  font-size: clamp(.94rem, 2.2vw, 1.02rem);
  line-height: 1.85;
  color: var(--slate);
}

/* ---------- 01 起点 ---------- */
.page-about .about-split {
  display: grid;
  gap: clamp(1.4rem, 4vw, 2.4rem);
  margin-top: 1.2rem;
}

.page-about .about-split__side {
  display: grid;
  gap: .8rem;
  align-content: start;
}

.page-about .about-note {
  padding: .95rem 1rem;
  background: var(--fog);
  border-left: 3px solid var(--cyan);
  border-radius: 0 var(--radius) var(--radius) 0;
}

.page-about .about-note__label {
  margin: 0 0 .45rem;
  font-family: var(--font-mono);
  font-size: .7rem;
  letter-spacing: .16em;
  color: var(--slate);
}

.page-about .about-note__text {
  margin: 0;
  font-size: .88rem;
  line-height: 1.8;
  color: var(--slate);
}

@media (min-width: 820px) {
  .page-about .about-split {
    grid-template-columns: minmax(0, 1.12fr) minmax(0, .88fr);
    align-items: start;
  }
}

/* ---------- 02 演进时间轴 ---------- */
.page-about .about-timeline {
  list-style: none;
  margin: 1.8rem 0 0;
  padding: 0;
}

.page-about .about-timeline__item {
  position: relative;
  padding: 0 0 1.9rem 1.5rem;
  border-left: 1px solid var(--hairline);
  transition: border-color .25s ease;
}

.page-about .about-timeline__item:last-child {
  padding-bottom: 0;
  border-left-color: transparent;
}

.page-about .about-timeline__item::before {
  content: "";
  position: absolute;
  left: -4px;
  top: .55rem;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--mist);
  box-shadow: 0 0 0 3px rgba(111, 143, 166, .16);
  transition: background .25s ease, box-shadow .25s ease;
}

.page-about .about-timeline__item:hover {
  border-left-color: var(--cyan);
}

.page-about .about-timeline__item:hover::before {
  background: var(--cyan);
  box-shadow: 0 0 0 4px rgba(43, 231, 200, .22);
}

.page-about .about-timeline__year {
  display: inline-block;
  margin-bottom: .35rem;
  font-family: var(--font-mono);
  font-size: .92rem;
  font-weight: 600;
  letter-spacing: .08em;
  color: var(--sand);
  transition: color .25s ease;
}

.page-about .about-timeline__item:hover .about-timeline__year {
  color: var(--cyan);
}

.page-about .about-timeline__body h3 {
  margin: 0 0 .45rem;
  font-family: var(--font-title);
  font-size: 1.02rem;
  font-weight: 800;
  line-height: 1.5;
  color: var(--ink);
}

.page-about .about-timeline__body p {
  margin: 0;
  font-size: .92rem;
  line-height: 1.82;
  color: var(--slate);
}

@media (min-width: 700px) {
  .page-about .about-timeline__item {
    display: grid;
    grid-template-columns: 5.5rem minmax(0, 1fr);
    gap: .3rem 1.4rem;
    padding-left: 1.9rem;
  }

  .page-about .about-timeline__year {
    justify-self: end;
    text-align: right;
    margin-bottom: 0;
    padding-top: .18rem;
  }
}

/* ---------- 图片框 ---------- */
.page-about .about-figure {
  margin: 1.7rem 0 0;
  border: 1px solid var(--hairline);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: 0 14px 30px -26px rgba(6, 24, 38, .9);
}

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

.page-about .about-figure .media-frame__caption {
  font-family: var(--font-mono);
  font-size: .68rem;
  letter-spacing: .1em;
}

/* ---------- 03 适配状态条 ---------- */
.page-about .about-statusbar {
  display: grid;
  gap: .7rem;
  margin-top: 1.6rem;
}

.page-about .about-state {
  padding: .9rem .95rem;
  background: #fff;
  border: 1px solid var(--hairline);
  border-top: 3px solid var(--mist);
  border-radius: var(--radius);
  box-shadow: 0 8px 18px -18px rgba(6, 24, 38, .8);
}

.page-about .about-state summary {
  display: grid;
  gap: .45rem;
  cursor: pointer;
  list-style: none;
}

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

.page-about .about-state__title {
  font-family: var(--font-title);
  font-size: .93rem;
  font-weight: 800;
  color: var(--ink);
}

.page-about .about-state__hint {
  font-family: var(--font-mono);
  font-size: .66rem;
  letter-spacing: .16em;
  color: var(--mist);
  transition: color .2s ease;
}

.page-about .about-state[open] .about-state__hint {
  color: var(--cyan);
}

.page-about .about-state p {
  margin: .75rem 0 0;
  font-size: .87rem;
  line-height: 1.78;
  color: var(--slate);
}

.page-about .about-state--stable { border-top-color: var(--stable); }
.page-about .about-state--live { border-top-color: var(--cyan); }
.page-about .about-state--maint { border-top-color: var(--maint); }
.page-about .about-state--arch { border-top-color: var(--sand); }

@media (min-width: 760px) {
  .page-about .about-statusbar {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    align-items: start;
    gap: .8rem;
  }
}

/* ---------- 04 服务网络 ---------- */
.page-about .about-stats {
  list-style: none;
  margin: 1.6rem 0 0;
  padding: 1.2rem 0 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1rem;
  border-top: 1px solid var(--hairline);
}

.page-about .about-stats b {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(1.15rem, 3vw, 1.5rem);
  font-weight: 600;
  letter-spacing: -.01em;
  color: var(--ink);
}

.page-about .about-stats span {
  display: block;
  margin-top: .3rem;
  font-size: .78rem;
  line-height: 1.55;
  color: var(--slate);
}

.page-about .about-nodes {
  list-style: none;
  margin: 1.4rem 0 0;
  padding: 0;
  display: grid;
  gap: .8rem;
}

.page-about .about-nodes__item {
  position: relative;
  padding: 1rem 1.05rem 1rem 1.6rem;
  background: var(--fog);
  border: 1px solid var(--hairline);
  border-radius: var(--radius);
  transition: background .22s ease, border-color .22s ease, transform .22s ease;
}

.page-about .about-nodes__item::before {
  content: "";
  position: absolute;
  left: .65rem;
  top: 1.35rem;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--mist);
  transition: background .22s ease, box-shadow .22s ease;
}

.page-about .about-nodes__item:hover,
.page-about .about-nodes__item:focus-within {
  background: #fff;
  border-color: rgba(43, 231, 200, .45);
  transform: translateY(-2px);
}

.page-about .about-nodes__item:hover::before,
.page-about .about-nodes__item:focus-within::before {
  background: var(--sand);
  box-shadow: 0 0 0 4px rgba(216, 179, 106, .24);
}

.page-about .about-nodes__item h3 {
  margin: 0 0 .35rem;
  font-family: var(--font-title);
  font-size: .96rem;
  font-weight: 800;
  color: var(--ink);
}

.page-about .about-nodes__note {
  margin: 0;
  font-size: .87rem;
  line-height: 1.78;
  color: var(--slate);
}

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

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

/* ---------- 05 理由与收尾 ---------- */
.page-about .about-reasons {
  display: grid;
  gap: .9rem;
  margin-top: 1.5rem;
}

.page-about .about-reasons__item {
  padding: 1.1rem 1.15rem;
  background: #fff;
  border: 1px solid var(--hairline);
  border-radius: var(--radius);
  box-shadow: 0 2px 0 rgba(6, 24, 38, .05), 0 14px 26px -22px rgba(6, 24, 38, .8);
}

.page-about .about-reasons__num {
  margin: 0;
  font-family: var(--font-mono);
  font-size: .72rem;
  letter-spacing: .2em;
  color: var(--sand);
}

.page-about .about-reasons__item h3 {
  margin: .5rem 0 .45rem;
  font-family: var(--font-title);
  font-size: 1rem;
  font-weight: 800;
  color: var(--ink);
}

.page-about .about-reasons__item p:last-child {
  margin: 0;
  font-size: .89rem;
  line-height: 1.8;
  color: var(--slate);
}

@media (min-width: 820px) {
  .page-about .about-reasons {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

.page-about .about-cta {
  margin-top: clamp(1.8rem, 5vw, 2.8rem);
  padding: clamp(1.5rem, 4vw, 2.3rem);
  color: var(--paper);
  border: 1px solid rgba(43, 231, 200, .24);
  border-radius: var(--radius);
  background:
    radial-gradient(120% 120% at 88% 0%, rgba(43, 231, 200, .18), transparent 60%),
    linear-gradient(140deg, var(--deep), #0a2b3c 72%);
}

.page-about .about-cta h2 {
  margin: 0 0 .6rem;
  font-family: var(--font-title);
  font-size: clamp(1.25rem, 3.4vw, 1.8rem);
  font-weight: 800;
  line-height: 1.32;
}

.page-about .about-cta p {
  margin: 0 0 1.3rem;
  max-width: 52ch;
  font-size: .93rem;
  line-height: 1.82;
  color: rgba(245, 248, 247, .78);
}

.page-about .about-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: .65rem;
  margin-bottom: 1.15rem;
}

.page-about .about-cta .btn--ghost {
  color: var(--paper);
  border-color: rgba(245, 248, 247, .42);
}

.page-about .about-cta .btn--ghost:hover,
.page-about .about-cta .btn--ghost:focus-visible {
  border-color: var(--cyan);
  color: var(--cyan);
}

.page-about .about-cta .about-cta__contact {
  display: flex;
  flex-wrap: wrap;
  gap: .35rem 1.4rem;
  margin: 0;
  font-family: var(--font-mono);
  font-size: .78rem;
  letter-spacing: .04em;
  color: rgba(245, 248, 247, .7);
}
<<<END>>>