.page-about {
  --about-rule: rgba(138, 168, 175, .26);
  --about-pad: clamp(28px, 5vw, 64px);
  background: var(--ink);
  color: var(--paper);
  overflow-x: hidden;
}

.page-about .breadcrumb {
  padding-block: 18px 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--muted);
}

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

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

.page-about .breadcrumb span[aria-current="page"] {
  color: var(--paper);
}

/* ---------- 首屏：海报式声明 ---------- */
.page-about .about-masthead {
  padding-block: clamp(28px, 5vw, 56px) clamp(30px, 4vw, 52px);
  border-bottom: 2px solid var(--steel);
}

.page-about .about-masthead .eyebrow {
  color: var(--cyan);
  margin: 0 0 18px;
}

.page-about .about-masthead h1 {
  font-family: var(--font-display);
  font-weight: 300;
  font-size: clamp(2.1rem, 8.4vw, 5.2rem);
  line-height: 1.02;
  letter-spacing: -.01em;
  margin: 0;
  max-width: 18ch;
  text-wrap: balance;
}

.page-about .about-lede {
  margin: clamp(20px, 3vw, 32px) 0 0;
  max-width: 60ch;
  font-size: clamp(15px, 1.6vw, 17px);
  line-height: 1.75;
  color: rgba(242, 251, 248, .82);
}

.page-about .masthead-stats {
  list-style: none;
  margin: clamp(28px, 4vw, 44px) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  border-top: 1px solid var(--about-rule);
  border-left: 1px solid var(--about-rule);
}

.page-about .masthead-stats li {
  padding: 16px 14px 18px;
  border-right: 1px solid var(--about-rule);
  border-bottom: 1px solid var(--about-rule);
}

.page-about .stat-num {
  display: block;
  font-size: clamp(1.5rem, 5.4vw, 2.3rem);
  font-weight: 700;
  color: var(--lime);
  letter-spacing: -.02em;
  line-height: 1.1;
}

.page-about .stat-label {
  display: block;
  margin-top: 6px;
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--muted);
}

/* ---------- 主体布局 ---------- */
.page-about .about-layout {
  display: block;
  padding-bottom: clamp(48px, 8vw, 96px);
}

.page-about .about-index {
  padding-block: 24px 8px;
  border-bottom: 1px solid var(--about-rule);
  margin-bottom: 8px;
}

.page-about .index-label {
  margin: 0 0 12px;
  font-size: 11px;
  letter-spacing: .18em;
  color: var(--cyan);
}

.page-about .index-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 8px 18px;
}

.page-about .index-list a {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 4px 0;
  font-size: 13px;
  color: var(--muted);
  text-decoration: none;
  border-bottom: 1px solid transparent;
}

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

.page-about .index-tick {
  width: 14px;
  height: 2px;
  background: var(--steel);
  flex: none;
}

.page-about .index-list a:hover .index-tick {
  background: var(--cyan);
}

/* ---------- 章节 ---------- */
.page-about .about-sec {
  padding-block: clamp(36px, 6vw, 68px);
  border-bottom: 1px solid var(--about-rule);
}

.page-about .about-sec--last {
  border-bottom: 0;
}

.page-about .sec-index {
  margin: 0 0 10px;
  font-size: 12px;
  letter-spacing: .2em;
  color: var(--orange);
}

.page-about .sec-title {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: clamp(1.5rem, 5vw, 2.6rem);
  line-height: 1.14;
  letter-spacing: -.005em;
  margin: 0 0 20px;
  max-width: 22ch;
}

.page-about .sec-lead {
  margin: 0 0 26px;
  max-width: 62ch;
  line-height: 1.75;
  color: rgba(242, 251, 248, .8);
}

.page-about .sec-body p {
  margin: 0 0 16px;
  max-width: 68ch;
  line-height: 1.78;
  color: rgba(242, 251, 248, .84);
}

.page-about .about-figure {
  margin: 28px 0 0;
  border: 2px solid var(--steel);
  box-shadow: var(--shadow-hard);
  background: var(--ink-2);
}

.page-about .about-figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 16 / 9;
  object-fit: cover;
}

.page-about .about-figure .media__caption {
  padding: 12px 14px;
  font-size: 12px;
  letter-spacing: .04em;
  color: var(--muted);
  border-top: 1px solid var(--steel);
}

/* ---------- 团队 ---------- */
.page-about .crew-strip {
  display: grid;
  gap: 2px;
  background: var(--steel);
  border: 2px solid var(--steel);
  margin-bottom: 26px;
}

.page-about .crew-cell {
  background: var(--ink-2);
  padding: 18px 16px 20px;
}

.page-about .crew-num {
  display: block;
  font-size: clamp(2rem, 8vw, 3rem);
  font-weight: 700;
  line-height: 1;
  color: var(--cyan);
}

.page-about .crew-role {
  margin: 10px 0 4px;
  font-family: var(--font-display);
  font-size: 1.05rem;
  font-weight: 600;
  letter-spacing: .02em;
}

.page-about .crew-note {
  margin: 0;
  font-size: 13px;
  line-height: 1.6;
  color: var(--muted);
}

.page-about .crew-details,
.page-about .pipe-list {
  display: grid;
  gap: 10px;
}

.page-about .fold {
  border: 1px solid var(--steel);
  background: var(--ink-2);
}

.page-about .fold > summary {
  list-style: none;
  cursor: pointer;
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding: 14px 16px;
  font-family: var(--font-display);
  font-size: clamp(14px, 3.6vw, 1.02rem);
  font-weight: 600;
  line-height: 1.4;
  color: var(--paper);
}

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

.page-about .fold > summary:hover,
.page-about .fold > summary:focus-visible {
  background: var(--panel);
}

.page-about .fold[open] > summary {
  color: var(--cyan);
  border-bottom: 1px solid var(--steel);
}

.page-about .fold-num {
  flex: none;
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--orange);
}

.page-about .fold-body {
  padding: 14px 16px 16px;
}

.page-about .fold-body p {
  margin: 0 0 12px;
  max-width: 66ch;
  line-height: 1.75;
  font-size: 14.5px;
  color: rgba(242, 251, 248, .82);
}

.page-about .fold-output {
  margin: 0;
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--lime);
  border-top: 1px dashed var(--steel);
  padding-top: 10px;
}

/* ---------- 流程 ---------- */
.page-about .flow {
  border: 2px solid var(--steel);
  background: linear-gradient(180deg, var(--ink-2), var(--ink));
  padding: 18px 12px 10px;
  margin-bottom: 22px;
  overflow: hidden;
}

.page-about .flow-svg {
  display: block;
  width: 100%;
  height: auto;
}

.page-about .flow-line {
  stroke: var(--steel);
  stroke-width: 3;
  stroke-dasharray: 8 8;
}

.page-about .flow-node circle {
  fill: var(--ink);
  stroke: var(--cyan);
  stroke-width: 3;
}

.page-about .flow-node--hot circle {
  fill: var(--cyan);
  stroke: var(--cyan);
}

.page-about .flow-node text {
  font-family: var(--font-mono);
  font-size: 15px;
  letter-spacing: .04em;
  fill: var(--muted);
}

.page-about .flow-node--hot text {
  fill: var(--paper);
}

/* ---------- 协作网络 ---------- */
.page-about .net-block {
  display: grid;
  gap: 24px;
}

.page-about .net-copy p {
  margin: 0 0 14px;
  max-width: 62ch;
  line-height: 1.78;
  color: rgba(242, 251, 248, .84);
}

.page-about .net-facts {
  list-style: none;
  margin: 18px 0 0;
  padding: 0;
  display: grid;
  gap: 8px;
}

.page-about .net-facts li {
  display: flex;
  align-items: baseline;
  gap: 10px;
  padding-left: 12px;
  border-left: 3px solid var(--lime);
  font-size: 14px;
  color: rgba(242, 251, 248, .78);
}

.page-about .net-facts .mono {
  color: var(--lime);
  font-weight: 700;
  font-size: 1.1rem;
}

.page-about .net-map {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 8px;
  padding: 14px;
  border: 1px solid var(--steel);
  background:
    repeating-linear-gradient(0deg, transparent 0 22px, rgba(50, 75, 84, .38) 22px 23px),
    repeating-linear-gradient(90deg, transparent 0 22px, rgba(50, 75, 84, .38) 22px 23px),
    var(--ink-2);
}

.page-about .net-node {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 52px;
  padding: 6px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .06em;
  text-align: center;
  color: var(--muted);
  background: var(--ink);
  border: 1px solid var(--steel);
  transition: color .2s var(--ease), background .2s var(--ease), border-color .2s var(--ease);
}

.page-about .net-node:hover,
.page-about .net-node:focus-visible {
  color: var(--ink);
  background: var(--cyan);
  border-color: var(--cyan);
}

.page-about .net-node--link {
  color: var(--paper);
  border-color: rgba(17, 240, 208, .5);
}

.page-about .net-node--hub {
  grid-column: span 3;
  color: var(--ink);
  background: var(--lime);
  border-color: var(--lime);
  font-weight: 700;
  letter-spacing: .2em;
}

.page-about .net-node--hub:hover,
.page-about .net-node--hub:focus-visible {
  background: var(--orange);
  border-color: var(--orange);
}

/* ---------- 版本演进 ---------- */
.page-about .version-wrap {
  position: relative;
  margin-top: 24px;
  padding: 20px 0 0;
}

.page-about .version-bg {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 4 / 3;
  object-fit: cover;
  opacity: .22;
  border: 1px solid var(--steel);
  filter: saturate(.6);
}

.page-about .version-list {
  list-style: none;
  margin: -60px 0 0;
  padding: 0 12px 0 0;
  position: relative;
  display: grid;
  gap: 2px;
}

.page-about .version-item {
  background: rgba(6, 26, 36, .92);
  border-left: 3px solid var(--steel);
  padding: 14px 14px 16px;
}

.page-about .version-item.is-current {
  border-left-color: var(--orange);
  background: var(--panel);
}

.page-about .version-tag {
  margin: 0 0 6px;
  font-size: 11px;
  letter-spacing: .16em;
  color: var(--cyan);
}

.page-about .version-item.is-current .version-tag {
  color: var(--orange);
}

.page-about .version-item h3 {
  font-family: var(--font-display);
  font-size: 1.15rem;
  font-weight: 600;
  margin: 0 0 8px;
  line-height: 1.3;
}

.page-about .version-item p {
  margin: 0;
  font-size: 14px;
  line-height: 1.72;
  color: rgba(242, 251, 248, .8);
}

/* ---------- 服务对象 ---------- */
.page-about .who-grid {
  display: grid;
  gap: 2px;
  background: var(--steel);
  border: 2px solid var(--steel);
}

.page-about .who-card {
  background: var(--ink-2);
  padding: 18px 16px 20px;
}

.page-about .who-tag {
  margin: 0 0 8px;
  font-size: 11px;
  letter-spacing: .16em;
  color: var(--violet);
}

.page-about .who-card h3 {
  font-family: var(--font-display);
  font-size: 1.12rem;
  font-weight: 600;
  margin: 0 0 8px;
  line-height: 1.3;
  color: var(--paper);
}

.page-about .who-card p {
  margin: 0;
  font-size: 14px;
  line-height: 1.72;
  color: rgba(242, 251, 248, .78);
}

/* ---------- 合作 ---------- */
.page-about .coop-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 2px;
  background: var(--steel);
  border-top: 2px solid var(--steel);
  border-bottom: 2px solid var(--steel);
}

.page-about .coop-list li {
  display: flex;
  gap: 14px;
  background: var(--ink);
  padding: 18px 14px 20px;
}

.page-about .coop-num {
  flex: none;
  font-size: 13px;
  font-weight: 700;
  color: var(--orange);
  padding-top: 3px;
}

.page-about .coop-list h3 {
  font-family: var(--font-display);
  font-size: 1.1rem;
  font-weight: 600;
  margin: 0 0 6px;
  line-height: 1.3;
}

.page-about .coop-list p {
  margin: 0;
  font-size: 14px;
  line-height: 1.72;
  color: rgba(242, 251, 248, .78);
}

.page-about .coop-list a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(17, 240, 208, .45);
}

.page-about .coop-list a:hover,
.page-about .coop-list a:focus-visible {
  color: var(--lime);
  border-bottom-color: var(--lime);
}

.page-about .coop-cta {
  margin-top: 26px;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 16px 24px;
  padding: 18px 16px;
  border: 2px solid var(--steel);
  border-left: 6px solid var(--orange);
  background: var(--ink-2);
}

.page-about .coop-cta p {
  margin: 0;
  flex: 1 1 240px;
  font-size: 14.5px;
  line-height: 1.7;
  color: rgba(242, 251, 248, .84);
}

/* ---------- 响应式 ---------- */
@media (min-width: 640px) {
  .page-about .crew-strip {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

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

  .page-about .net-map {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .net-node--hub {
    grid-column: span 4;
  }
}

@media (min-width: 960px) {
  .page-about .about-layout {
    display: grid;
    grid-template-columns: 196px minmax(0, 1fr);
    gap: clamp(28px, 4vw, 64px);
    align-items: start;
    padding-top: 8px;
  }

  .page-about .about-index {
    position: sticky;
    top: calc(96px + 12px);
    padding-block: 32px 0;
    border-bottom: 0;
    margin-bottom: 0;
    border-right: 1px solid var(--about-rule);
    padding-right: 18px;
  }

  .page-about .index-list {
    display: grid;
    gap: 2px;
  }

  .page-about .index-list a {
    padding: 6px 0;
  }

  .page-about .masthead-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .net-block {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 1fr);
    gap: clamp(24px, 3vw, 44px);
    align-items: start;
  }

  .page-about .version-bg {
    aspect-ratio: 16 / 9;
  }

  .page-about .version-list {
    margin-top: -96px;
    padding: 0 clamp(24px, 5vw, 64px) 0 0;
    gap: 2px;
  }

  .page-about .version-item {
    padding: 18px 20px 20px;
  }

  .page-about .coop-list li {
    padding: 22px 20px 24px;
  }
}

@media (min-width: 1180px) {
  .page-about .about-masthead h1 {
    max-width: 16ch;
  }

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

@media (prefers-reduced-motion: reduce) {
  .page-about .net-node {
    transition: none;
  }
}
<<<END>>>