.page-about {
  --about-rhythm: clamp(56px, 8vw, 112px);
  --about-measure: 42rem;
  padding-bottom: var(--about-rhythm);
}

/* ---------- 面包屑 ---------- */
.page-about .breadcrumb {
  padding-top: clamp(14px, 2.6vw, 26px);
}

/* ---------- 首屏 ---------- */
.page-about .about-mast {
  padding: clamp(30px, 5.5vw, 68px) 0 clamp(26px, 4vw, 48px);
}

.page-about .about-mast .eyebrow {
  color: var(--turf);
  letter-spacing: 0.18em;
}

.page-about .about-mast__title {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(34px, 7.4vw, 76px);
  line-height: 1.02;
  letter-spacing: -0.02em;
  color: var(--cream);
  margin: 14px 0 0;
  max-width: 15ch;
}

.page-about .about-mast__lede {
  margin: clamp(18px, 3vw, 30px) 0 0;
  max-width: 40rem;
  color: var(--silver);
  font-size: clamp(16px, 1.15vw, 17.5px);
  line-height: 1.78;
}

.page-about .about-mast__facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: clamp(26px, 4vw, 44px) 0 0;
  padding: 0;
  list-style: none;
  background: var(--line-soft);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius-lg);
  overflow: hidden;
}

.page-about .about-mast__facts li {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: clamp(14px, 2.2vw, 22px);
  background: var(--ink);
}

.page-about .about-mast__num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-weight: 700;
  font-size: clamp(24px, 3.2vw, 34px);
  line-height: 1;
  color: var(--turf);
}

.page-about .about-mast__cap {
  font-size: 12px;
  line-height: 1.5;
  color: var(--stone);
  letter-spacing: 0.03em;
}

@media (min-width: 720px) {
  .page-about .about-mast__facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

/* ---------- 图片容器间距 ---------- */
.page-about .about-hero {
  margin-bottom: var(--about-rhythm);
}

.page-about .about-hero .figure {
  margin: 0;
}

.page-about .about-flow-figure {
  margin: clamp(32px, 5vw, 64px) 0 0;
}

/* ---------- 通用区块 ---------- */
.page-about .about-band {
  padding: var(--about-rhythm) 0 0;
}

.page-about .about-h2 {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(26px, 3.8vw, 42px);
  line-height: 1.14;
  letter-spacing: -0.015em;
  color: var(--cream);
  margin: 12px 0 0;
  max-width: 22ch;
}

.page-about .about-intro {
  max-width: 44rem;
  margin: clamp(14px, 2vw, 22px) 0 0;
  color: var(--stone);
  font-size: 15px;
  line-height: 1.8;
}

/* ---------- 正文 + 旁注 ---------- */
.page-about .prose-block {
  display: grid;
  gap: clamp(24px, 4vw, 44px);
}

.page-about .prose p {
  margin: 0 0 1.15em;
  color: var(--silver);
  font-size: clamp(16px, 1.1vw, 17px);
  line-height: 1.78;
}

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

.page-about .prose .eyebrow {
  color: var(--amber);
  letter-spacing: 0.18em;
}

.page-about .prose .about-h2 {
  margin-bottom: clamp(16px, 2.4vw, 26px);
}

.page-about .rail {
  display: grid;
  gap: 14px;
  align-content: start;
}

.page-about .rail__note {
  margin: 0;
  padding-left: 14px;
  border-left: 1px solid var(--line-turf);
  font-family: var(--font-mono);
  font-size: 12px;
  line-height: 1.75;
  color: var(--stone);
}

.page-about .rail__fold {
  border: 1px solid var(--line-soft);
  border-radius: var(--radius-md);
  background: rgba(18, 51, 40, 0.55);
  padding: 12px 14px;
}

.page-about .rail__fold > summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  list-style: none;
  cursor: pointer;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--turf);
}

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

.page-about .rail__fold > summary::after {
  content: "＋";
  color: var(--stone);
  font-size: 13px;
  line-height: 1;
}

.page-about .rail__fold[open] > summary::after {
  content: "－";
  color: var(--turf);
}

.page-about .rail__fold-body {
  margin: 10px 0 0;
  font-size: 13px;
  line-height: 1.75;
  color: var(--steel);
}

@media (min-width: 960px) {
  .page-about .prose-block {
    grid-template-columns: minmax(0, var(--about-measure)) minmax(0, 1fr);
    gap: clamp(40px, 6vw, 88px);
    align-items: start;
  }
}

/* ---------- 阶段时间线 ---------- */
.page-about .timeline {
  margin-top: clamp(30px, 4.5vw, 56px);
}

.page-about .timeline__nodes {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .timeline__node {
  min-width: 0;
}

.page-about .tstage {
  position: relative;
  border-top: 1px solid var(--line);
  padding: clamp(20px, 2.6vw, 28px) 0 clamp(20px, 2.6vw, 28px);
}

.page-about .tstage::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 9px;
  height: 9px;
  margin-top: -5px;
  border-radius: 50%;
  background: var(--turf);
  box-shadow: 0 0 0 5px rgba(124, 228, 155, 0.15);
  transition: box-shadow 120ms var(--ease);
}

.page-about .tstage[open]::before {
  box-shadow: 0 0 0 8px rgba(124, 228, 155, 0.22);
}

.page-about .tstage__summary {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 12px;
  list-style: none;
  cursor: pointer;
  padding-top: 6px;
}

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

.page-about .tstage__summary::after {
  content: "展开";
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--stone);
}

.page-about .tstage[open] .tstage__summary::after {
  content: "收起";
  color: var(--turf);
}

.page-about .tstage__year {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-weight: 700;
  font-size: clamp(19px, 2.5vw, 27px);
  letter-spacing: -0.01em;
  color: var(--turf);
}

.page-about .tstage__label {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(16px, 1.9vw, 20px);
  color: var(--cream);
}

.page-about .tstage__body {
  margin-top: 14px;
  max-width: 34rem;
  font-size: 15px;
  line-height: 1.78;
  color: var(--silver);
}

.page-about .tstage__body p {
  margin: 0 0 0.9em;
}

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

@media (min-width: 860px) {
  .page-about .timeline__nodes {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .tstage {
    padding-right: clamp(18px, 2.4vw, 32px);
  }
}

/* ---------- 团队 ---------- */
.page-about .crew-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  margin-top: clamp(28px, 4vw, 46px);
  background: var(--line-soft);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius-lg);
  overflow: hidden;
}

.page-about .crew {
  background: var(--ink);
  padding: clamp(20px, 3vw, 32px);
}

.page-about .crew__idx {
  display: block;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--clay);
}

.page-about .crew--lead .crew__idx {
  color: var(--amber);
}

.page-about .crew__title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(18px, 2.2vw, 23px);
  letter-spacing: -0.01em;
  color: var(--cream);
  margin: 10px 0 0;
}

.page-about .crew__text {
  margin: 10px 0 0;
  font-size: 15px;
  line-height: 1.78;
  color: var(--silver);
  max-width: 46rem;
}

.page-about .crew--lead .crew__text {
  color: var(--steel);
}

@media (min-width: 900px) {
  .page-about .crew-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .crew--lead {
    grid-column: span 3;
    border-left: 2px solid var(--line-turf);
  }
}

/* ---------- 流程技能树 ---------- */
.page-about .flow {
  position: relative;
  display: grid;
  gap: clamp(20px, 3vw, 30px);
  margin: clamp(28px, 4vw, 46px) 0 0;
  padding: 0 0 0 34px;
  list-style: none;
}

.page-about .flow::before {
  content: "";
  position: absolute;
  left: 9px;
  top: 8px;
  bottom: 8px;
  width: 1px;
  background: linear-gradient(180deg, var(--turf) 0%, var(--line-turf) 55%, var(--line-soft) 100%);
}

.page-about .flow__step {
  position: relative;
  min-width: 0;
  border-radius: var(--radius-md);
  transition: background-color 140ms var(--ease);
}

.page-about .flow__step::before {
  content: "";
  position: absolute;
  left: -29px;
  top: 7px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--ink);
  border: 1px solid var(--turf);
  transition: background-color 140ms var(--ease), box-shadow 140ms var(--ease);
}

.page-about .flow__step::after {
  content: "";
  position: absolute;
  left: -20px;
  top: 11px;
  width: 20px;
  height: 1px;
  background: var(--line-turf);
}

.page-about .flow__step:hover::before,
.page-about .flow__step:focus-within::before {
  background: var(--turf);
  box-shadow: 0 0 0 5px rgba(124, 228, 155, 0.18);
}

.page-about .flow__step:hover .flow__title,
.page-about .flow__step:focus-within .flow__title {
  color: var(--turf);
}

.page-about .flow__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(17px, 2vw, 21px);
  letter-spacing: -0.01em;
  color: var(--cream);
  transition: color 140ms var(--ease);
}

.page-about .flow__text {
  margin: 8px 0 0;
  font-size: 15px;
  line-height: 1.78;
  color: var(--silver);
  max-width: 34rem;
}

/* ---------- 长期维护双栏 ---------- */
.page-about .maintain-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(24px, 4vw, 44px);
  margin-top: clamp(24px, 3.5vw, 42px);
}

.page-about .maintain__col {
  display: grid;
  gap: 1em;
  align-content: start;
  padding-top: clamp(16px, 2vw, 24px);
  border-top: 1px solid var(--line-soft);
}

.page-about .maintain__text {
  margin: 0;
  font-size: clamp(15px, 1.05vw, 16.5px);
  line-height: 1.8;
  color: var(--silver);
  max-width: 40rem;
}

@media (min-width: 880px) {
  .page-about .maintain-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: clamp(36px, 6vw, 88px);
  }
}

/* ---------- 收尾跳转 ---------- */
.page-about .about-cta {
  margin-top: var(--about-rhythm);
}

.page-about .about-cta__inner {
  border: 1px solid var(--line-soft);
  border-radius: var(--radius-xl);
  background: linear-gradient(150deg, var(--deep) 0%, var(--ink) 62%);
  padding: clamp(26px, 4.5vw, 56px);
  display: grid;
  gap: clamp(22px, 3vw, 36px);
}

.page-about .about-cta__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(23px, 3.2vw, 36px);
  line-height: 1.14;
  letter-spacing: -0.015em;
  color: var(--cream);
  max-width: 20ch;
}

.page-about .about-cta__text {
  margin: 14px 0 0;
  max-width: 42rem;
  font-size: 15px;
  line-height: 1.8;
  color: var(--silver);
}

.page-about .about-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  align-items: center;
}

@media (min-width: 900px) {
  .page-about .about-cta__inner {
    grid-template-columns: minmax(0, 1.25fr) minmax(0, 1fr);
    align-items: end;
  }

  .page-about .about-cta__actions {
    justify-content: flex-end;
  }
}

/* ---------- 减少动效 ---------- */
@media (prefers-reduced-motion: reduce) {
  .page-about .tstage::before,
  .page-about .flow__step::before,
  .page-about .flow__title {
    transition: none;
  }
}
<<<END>>>