.page-about {
  --about-line-soft: rgba(124, 151, 171, 0.18);
  --about-txt-dim: rgba(244, 241, 233, 0.72);
  background: var(--ink);
  color: var(--paper);
  overflow-x: clip;
}

/* ---------- 首屏 ---------- */
.page-about .brand-intro {
  position: relative;
  padding: clamp(20px, 3vw, 32px) 0 clamp(44px, 6vw, 84px);
  border-bottom: 1px solid var(--about-line-soft);
  background:
    radial-gradient(110% 82% at 88% -20%, rgba(31, 209, 178, 0.15), transparent 62%),
    linear-gradient(180deg, var(--ink) 0%, var(--navy) 100%);
}

.page-about .brand-intro::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  background-image:
    linear-gradient(rgba(124, 151, 171, 0.07) 1px, transparent 1px),
    linear-gradient(90deg, rgba(124, 151, 171, 0.07) 1px, transparent 1px);
  background-size: 72px 72px;
}

.page-about .brand-intro > .container {
  position: relative;
  z-index: 1;
}

.page-about .intro-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(24px, 4vw, 40px);
  margin-top: clamp(22px, 4vw, 46px);
}

.page-about .intro-title {
  margin: 12px 0 0;
  max-width: 14em;
  font-size: clamp(30px, 6.2vw, 74px);
  line-height: 1.08;
  letter-spacing: -0.03em;
  font-weight: 800;
  color: var(--paper);
}

.page-about .intro-lead .lead {
  margin-top: clamp(16px, 2vw, 24px);
  max-width: 36em;
  font-size: clamp(15px, 1.5vw, 17px);
  line-height: 1.8;
  color: var(--about-txt-dim);
}

.page-about .intro-note {
  border-left: 2px solid var(--teal);
  padding-left: clamp(14px, 2vw, 22px);
}

.page-about .intro-note-text {
  margin: 0 0 18px;
  font-size: 14.5px;
  line-height: 1.7;
  color: var(--slate);
}

.page-about .intro-facts {
  margin: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--about-line-soft);
}

.page-about .intro-facts .fact {
  background: rgba(4, 18, 30, 0.74);
  padding: 12px 14px;
}

.page-about .intro-facts dt {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--slate);
}

.page-about .intro-facts dd {
  margin: 6px 0 0;
  font-size: clamp(19px, 2.3vw, 25px);
  font-weight: 800;
  letter-spacing: -0.01em;
  color: var(--teal-hi);
}

/* ---------- 两栏正文 ---------- */
.page-about .about-body {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(24px, 4vw, 40px);
  padding: clamp(28px, 5vw, 56px) 0 clamp(48px, 7vw, 96px);
}

.page-about .about-rail,
.page-about .about-main {
  min-width: 0;
}

.page-about .rail-label {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--slate);
}

.page-about .index-rail {
  display: flex;
  flex-wrap: wrap;
  gap: 4px 18px;
}

.page-about .index-link {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  padding: 5px 0;
  font-size: 14px;
  color: var(--slate);
  text-decoration: none;
  transition: color 180ms var(--ease), border-color 180ms var(--ease);
}

.page-about .index-link:hover {
  color: var(--paper);
}

.page-about .rail-num {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.06em;
  color: var(--teal);
}

.page-about .index-link[aria-current="true"] {
  color: var(--lemon);
}

.page-about .index-link[aria-current="true"] .rail-num {
  color: var(--lemon);
}

@media (min-width: 960px) {
  .page-about .about-body {
    grid-template-columns: minmax(0, 3fr) minmax(0, 9fr);
    gap: clamp(32px, 4vw, 64px);
  }

  .page-about .about-rail {
    position: sticky;
    top: calc(var(--hdr-h) + 28px);
    align-self: start;
  }

  .page-about .index-rail {
    flex-direction: column;
    flex-wrap: nowrap;
    gap: 0;
  }

  .page-about .index-link {
    display: flex;
    padding: 9px 0 9px 14px;
    border-left: 1px solid var(--about-line-soft);
    font-size: 15px;
  }

  .page-about .index-link[aria-current="true"] {
    border-left-color: var(--lemon);
  }
}

/* ---------- 章节骨架 ---------- */
.page-about .about-section {
  padding: clamp(34px, 5vw, 70px) 0;
  border-top: 1px solid var(--about-line-soft);
}

.page-about .about-section:first-child {
  padding-top: 0;
  border-top: 0;
}

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

.page-about .section-head {
  margin-bottom: clamp(20px, 3vw, 32px);
}

.page-about .sec-index {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(36px, 7vw, 74px);
  line-height: 0.85;
  font-weight: 700;
  letter-spacing: 0.02em;
  color: rgba(140, 242, 224, 0.26);
}

.page-about .sec-title {
  margin: 10px 0 0;
  max-width: 22em;
  font-size: clamp(23px, 3.2vw, 40px);
  line-height: 1.18;
  letter-spacing: -0.02em;
  font-weight: 800;
  color: var(--paper);
}

.page-about .prose {
  max-width: 40em;
}

.page-about .prose p {
  margin: 0 0 1.05em;
  font-size: 16px;
  line-height: 1.8;
  color: var(--about-txt-dim);
}

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

.page-about .text-link {
  color: var(--teal);
  text-decoration: none;
  border-bottom: 1px solid rgba(31, 209, 178, 0.42);
  transition: color 160ms var(--ease), border-color 160ms var(--ease);
}

.page-about .text-link:hover {
  color: var(--lemon);
  border-bottom-color: var(--lemon);
}

.page-about .inline-link-line {
  margin: clamp(20px, 3vw, 28px) 0 0;
  font-size: 15px;
  line-height: 1.7;
  color: var(--slate);
}

/* ---------- 图片框 ---------- */
.page-about .media-frame {
  margin: 0 0 clamp(22px, 3vw, 34px);
  background: var(--navy);
  overflow: hidden;
}

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

.page-about .mile-frame {
  margin: clamp(28px, 4vw, 44px) 0 0;
}

/* ---------- 栏目分组 ---------- */
.page-about .columns-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(22px, 3vw, 32px);
  margin-bottom: clamp(24px, 4vw, 40px);
}

.page-about .columns-visual {
  background: linear-gradient(150deg, var(--navy), var(--ink));
  clip-path: var(--cut);
  overflow: hidden;
}

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

@media (min-width: 860px) {
  .page-about .columns-grid {
    grid-template-columns: minmax(0, 1.3fr) minmax(0, 1fr);
    align-items: start;
  }
}

.page-about .column-groups {
  border-top: 1px solid var(--about-line-soft);
}

.page-about .group {
  border-bottom: 1px solid var(--about-line-soft);
  transition: background-color 220ms var(--ease);
}

.page-about .group[open] {
  background: rgba(14, 46, 74, 0.34);
}

.page-about .group-summary {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: clamp(14px, 2vw, 20px) clamp(12px, 2vw, 20px);
  list-style: none;
  cursor: pointer;
}

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

.page-about .group-summary::before {
  content: "";
  flex: 0 0 auto;
  width: 9px;
  height: 9px;
  background: var(--teal);
  clip-path: polygon(0 0, 100% 50%, 0 100%);
  transition: transform 200ms var(--ease), background-color 200ms var(--ease);
}

.page-about .group[open] > .group-summary::before {
  transform: rotate(90deg);
  background: var(--lemon);
}

.page-about .group-num {
  flex: 0 0 auto;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--teal);
}

.page-about .group-title {
  flex: 1 1 auto;
  min-width: 0;
  font-size: clamp(16px, 2vw, 19px);
  font-weight: 700;
  color: var(--paper);
}

.page-about .group-count {
  flex: 0 0 auto;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--slate);
}

.page-about .group-body {
  padding: 0 clamp(12px, 2vw, 20px) clamp(18px, 3vw, 26px)
    calc(clamp(12px, 2vw, 20px) + 23px);
}

.page-about .group-lead {
  margin: 0 0 14px;
  font-size: 15px;
  line-height: 1.7;
  color: var(--slate);
}

.page-about .zone-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .zone-list li {
  padding: 14px 16px;
  background: rgba(4, 18, 30, 0.68);
  border-left: 2px solid var(--teal);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 12px), calc(100% - 12px) 100%, 0 100%);
}

.page-about .zone-code {
  display: block;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--teal);
}

.page-about .zone-name {
  display: block;
  margin: 5px 0 6px;
  font-size: 15px;
  font-weight: 700;
  color: var(--paper);
}

.page-about .zone-desc {
  display: block;
  font-size: 13.5px;
  line-height: 1.7;
  color: var(--about-txt-dim);
}

@media (min-width: 720px) {
  .page-about .zone-list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

/* ---------- 团队数据 ---------- */
.page-about .team-stats {
  margin: clamp(24px, 3vw, 32px) 0 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--about-line-soft);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 18px), calc(100% - 18px) 100%, 0 100%);
}

.page-about .stat-cell {
  background: var(--navy);
  padding: clamp(16px, 2.4vw, 24px);
}

.page-about .stat-cell dt {
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.09em;
  color: var(--slate);
}

.page-about .stat-cell dd {
  margin: 10px 0 0;
  display: flex;
  align-items: baseline;
  gap: 5px;
}

.page-about .stat-num {
  font-size: clamp(28px, 4vw, 42px);
  font-weight: 800;
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--teal-hi);
}

.page-about .stat-unit {
  font-size: 14px;
  color: var(--slate);
}

@media (min-width: 640px) {
  .page-about .team-stats {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

.page-about .paper-slab {
  margin-top: clamp(24px, 3vw, 36px);
  padding: clamp(22px, 3.6vw, 40px);
  background: var(--paper);
  color: var(--black);
  clip-path: polygon(0 0, calc(100% - 22px) 0, 100% 22px, 100% 100%, 22px 100%, 0 calc(100% - 22px));
}

.page-about .slab-title {
  margin: 0 0 14px;
  font-size: clamp(18px, 2.2vw, 23px);
  line-height: 1.4;
  letter-spacing: -0.01em;
  font-weight: 800;
  color: var(--black);
}

.page-about .slab-text {
  margin: 0;
  max-width: 40em;
  font-size: 15.5px;
  line-height: 1.8;
  color: rgba(16, 24, 32, 0.78);
}

/* ---------- 里程碑 ---------- */
.page-about .mile-list {
  list-style: none;
  margin: clamp(24px, 3.5vw, 36px) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(14px, 2vw, 20px);
}

.page-about .mile-item {
  padding: clamp(18px, 2.4vw, 24px);
  background: linear-gradient(160deg, rgba(14, 46, 74, 0.95), rgba(4, 18, 30, 0.58));
  border-left: 3px solid var(--coral);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 16px), calc(100% - 16px) 100%, 0 100%);
}

.page-about .mile-when {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--coral);
}

.page-about .mile-title {
  margin: 8px 0;
  font-size: clamp(17px, 2vw, 20px);
  font-weight: 800;
  color: var(--paper);
}

.page-about .mile-body {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.72;
  color: var(--about-txt-dim);
}

@media (min-width: 860px) {
  .page-about .mile-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .mile-item:nth-child(even) {
    margin-top: clamp(18px, 3vw, 36px);
  }
}

/* ---------- 合作对接 ---------- */
.page-about .coop-steps {
  list-style: none;
  margin: clamp(24px, 3vw, 32px) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
}

.page-about .coop-step {
  padding: clamp(16px, 2.2vw, 22px);
  background: rgba(14, 46, 74, 0.6);
  clip-path: var(--cut);
}

.page-about .step-num {
  display: block;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--lemon);
}

.page-about .step-title {
  margin: 8px 0;
  font-size: 16px;
  font-weight: 700;
  color: var(--paper);
}

.page-about .step-body {
  margin: 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--about-txt-dim);
}

@media (min-width: 800px) {
  .page-about .coop-steps {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

.page-about .coop-cta {
  margin-top: clamp(24px, 3vw, 32px);
  padding: clamp(20px, 3vw, 30px);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 16px 24px;
  background: linear-gradient(120deg, rgba(31, 209, 178, 0.16), rgba(14, 46, 74, 0.52));
  clip-path: polygon(0 0, calc(100% - 20px) 0, 100% 20px, 100% 100%, 0 100%);
}

.page-about .coop-cta p {
  margin: 0;
  flex: 1 1 260px;
  font-size: 15px;
  line-height: 1.7;
  color: var(--about-txt-dim);
}

@media (min-width: 900px) {
  .page-about .intro-grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
    align-items: end;
    gap: clamp(32px, 5vw, 80px);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .index-link,
  .page-about .text-link,
  .page-about .group,
  .page-about .group-summary::before {
    transition: none;
  }
}
<<<END>>>