.page-about {
  --about-cut: 20px;
  --about-body: rgba(234, 244, 248, .8);
  --about-body-soft: rgba(234, 244, 248, .68);
  background: var(--ink);
  color: var(--paper);
  padding-bottom: clamp(48px, 7vw, 96px);
  overflow-x: hidden;
}

.page-about .crumbs {
  padding: 16px 0 0;
}

.page-about .crumbs-list {
  display: flex;
  flex-wrap: wrap;
  gap: 0;
  margin: 0;
  padding: 0;
  list-style: none;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--slate);
}

.page-about .crumbs-list li {
  display: flex;
  align-items: center;
  gap: 8px;
}

.page-about .crumbs-list li:not(:last-child)::after {
  content: "/";
  color: rgba(143, 169, 184, .45);
}

.page-about .crumbs-list a {
  color: var(--slate);
  text-decoration: none;
}

.page-about .crumbs-list a:hover {
  color: var(--cyan);
}

/* ---------- 封面 ---------- */

.page-about .about-cover {
  position: relative;
  padding-top: clamp(22px, 3.6vw, 44px);
}

.page-about .about-cover-inner {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(26px, 4.4vw, 48px);
  align-items: center;
}

.page-about .about-stamp {
  display: inline-block;
  margin: 0;
  padding-left: 10px;
  border-left: 2px solid var(--coral);
  font-size: 11px;
  letter-spacing: .2em;
  color: var(--cyan);
}

.page-about .about-title {
  margin: 16px 0 18px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(30px, 6.2vw, 54px);
  line-height: 1.06;
  letter-spacing: -.01em;
  color: var(--paper);
}

.page-about .about-lead {
  max-width: 44ch;
  margin: 0 0 26px;
  font-size: 16px;
  line-height: 1.78;
  color: var(--about-body);
}

.page-about .about-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.page-about .about-cover-visual {
  margin: 0;
  position: relative;
}

.page-about .about-cover-visual::before {
  content: "";
  position: absolute;
  top: -10px;
  right: -10px;
  width: 56px;
  height: 56px;
  border-top: 2px solid var(--cyan);
  border-right: 2px solid var(--cyan);
  opacity: .55;
  pointer-events: none;
}

.page-about .about-cover-visual img {
  display: block;
  width: 100%;
  height: auto;
  border: 1px solid var(--line-soft);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - var(--about-cut)), calc(100% - var(--about-cut)) 100%, 0 100%);
}

.page-about .about-metrics {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: clamp(32px, 5vw, 58px) 0 0;
  padding: 0;
  list-style: none;
  background: var(--line);
  border: 1px solid var(--line-soft);
}

.page-about .about-metric {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 18px 16px 20px;
  background: var(--ink-deep);
}

.page-about .about-metric-num {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(26px, 4vw, 36px);
  line-height: 1;
  color: var(--cyan);
}

.page-about .about-metric-num em {
  margin-left: 4px;
  font-style: normal;
  font-size: .48em;
  font-weight: 600;
  color: var(--slate);
}

.page-about .about-metric-label {
  font-size: 13px;
  line-height: 1.5;
  letter-spacing: .03em;
  color: var(--slate);
}

/* ---------- 通用区块 ---------- */

.page-about .about-block {
  margin-top: clamp(56px, 9vw, 108px);
}

.page-about .section-head {
  margin-bottom: clamp(22px, 3vw, 34px);
}

.page-about .section-head--plain {
  margin-bottom: 8px;
}

/* ---------- 发展节点 ---------- */

.page-about .stages-visual {
  margin: 0 0 clamp(22px, 3vw, 32px);
}

.page-about .stages-visual img {
  display: block;
  width: 100%;
  height: auto;
  border: 1px solid var(--line-soft);
  clip-path: polygon(var(--about-cut) 0, 100% 0, 100% 100%, 0 100%, 0 var(--about-cut));
}

.page-about .stage-rail {
  border-top: 1px solid var(--line-strong);
}

.page-about .stage {
  border-bottom: 1px solid var(--line-soft);
}

.page-about .stage-btn {
  display: grid;
  grid-template-columns: 66px minmax(0, 1fr) 20px;
  align-items: center;
  gap: 14px;
  width: 100%;
  margin: 0;
  padding: 20px 2px;
  background: transparent;
  border: 0;
  color: inherit;
  font-family: var(--font-body);
  text-align: left;
  cursor: pointer;
  transition: background .25s var(--ease);
}

.page-about .stage-btn:hover {
  background: rgba(69, 242, 223, .05);
}

.page-about .stage-btn:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 2px;
}

.page-about .stage-idx {
  font-size: 11px;
  letter-spacing: .1em;
  color: var(--coral);
}

.page-about .stage-name {
  display: block;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(18px, 2.6vw, 24px);
  line-height: 1.24;
  color: var(--paper);
}

.page-about .stage-tag {
  display: block;
  margin-top: 5px;
  font-size: 13px;
  line-height: 1.5;
  color: var(--slate);
}

.page-about .stage-mark {
  position: relative;
  width: 16px;
  height: 16px;
  justify-self: end;
}

.page-about .stage-mark::before,
.page-about .stage-mark::after {
  content: "";
  position: absolute;
  background: var(--cyan);
  transition: transform .3s var(--ease);
}

.page-about .stage-mark::before {
  left: 0;
  top: 7px;
  width: 16px;
  height: 2px;
}

.page-about .stage-mark::after {
  left: 7px;
  top: 0;
  width: 2px;
  height: 16px;
}

.page-about .stage-btn[aria-expanded="true"] .stage-mark::after {
  transform: scaleY(0);
}

.page-about .stage-panel {
  padding: 0 2px 24px;
}

.page-about .stage-body {
  max-width: 64ch;
  margin: 0 0 12px;
  font-size: 15.5px;
  line-height: 1.8;
  color: var(--about-body);
}

.page-about .stage-note {
  display: inline-block;
  margin: 0;
  padding: 5px 10px;
  border-left: 2px solid var(--coral);
  background: rgba(110, 31, 60, .3);
  font-size: 12px;
  letter-spacing: .05em;
  color: var(--paper);
}

/* ---------- 团队 ---------- */

.page-about .team-matrix {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 16px;
}

.page-about .team-card {
  position: relative;
  padding: 24px 20px 26px;
  background: linear-gradient(165deg, rgba(11, 47, 74, .95), rgba(4, 18, 31, .98));
  border: 1px solid var(--line-soft);
}

.page-about .team-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 48px;
  height: 3px;
  background: var(--cyan);
}

.page-about .team-card:nth-child(2)::before {
  background: var(--coral);
}

.page-about .team-card:nth-child(3)::before {
  background: var(--field);
  box-shadow: inset 24px 0 0 var(--cyan);
}

.page-about .team-count {
  display: block;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(32px, 4.6vw, 44px);
  line-height: 1;
  color: var(--cyan);
}

.page-about .team-count span {
  margin-left: 6px;
  font-family: var(--font-body);
  font-size: 13px;
  font-weight: 500;
  color: var(--slate);
}

.page-about .team-role {
  margin: 10px 0 10px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 20px;
  letter-spacing: .01em;
  color: var(--paper);
}

.page-about .team-desc {
  margin: 0;
  font-size: 15px;
  line-height: 1.76;
  color: var(--about-body-soft);
}

.page-about .team-visual {
  margin: clamp(24px, 3.4vw, 36px) 0 0;
}

.page-about .team-visual img {
  display: block;
  width: 100%;
  height: auto;
  border: 1px solid var(--line-soft);
  clip-path: polygon(0 0, calc(100% - var(--about-cut)) 0, 100% var(--about-cut), 100% 100%, 0 100%);
}

.page-about .team-foot {
  max-width: 70ch;
  margin: clamp(20px, 3vw, 28px) 0 0;
  padding-left: 14px;
  border-left: 2px solid var(--line-strong);
  font-size: 15px;
  line-height: 1.8;
  color: var(--about-body);
}

/* ---------- 内容生产方法 ---------- */

.page-about .about-flow {
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .flow-step {
  position: relative;
  padding: 0 0 30px 28px;
  border-left: 1px solid var(--line-soft);
}

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

.page-about .flow-step::before {
  content: "";
  position: absolute;
  left: -5px;
  top: 6px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--cyan);
  box-shadow: 0 0 0 4px rgba(69, 242, 223, .14);
}

.page-about .flow-step:nth-child(2)::before {
  background: var(--coral);
  box-shadow: 0 0 0 4px rgba(255, 107, 74, .16);
}

.page-about .flow-time {
  display: inline-block;
  margin-bottom: 8px;
  font-size: 11px;
  letter-spacing: .12em;
  color: var(--coral);
}

.page-about .flow-title {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 21px;
  line-height: 1.26;
  color: var(--paper);
}

.page-about .flow-text {
  max-width: 64ch;
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--about-body-soft);
}

/* ---------- 合作生态 ---------- */

.page-about .eco-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 16px;
}

.page-about .eco-card {
  padding: 22px 20px 24px;
  background: rgba(11, 47, 74, .66);
  border-left: 2px solid var(--cyan);
}

.page-about .eco-card:nth-child(2) {
  border-left-color: var(--coral);
}

.page-about .eco-card:nth-child(3) {
  border-left-color: var(--paper);
  background: rgba(43, 42, 110, .55);
}

.page-about .eco-kicker {
  margin: 0;
  font-size: 11px;
  letter-spacing: .14em;
  color: var(--slate);
}

.page-about .eco-title {
  margin: 9px 0 10px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 22px;
  line-height: 1.25;
  color: var(--paper);
}

.page-about .eco-text {
  margin: 0;
  font-size: 15px;
  line-height: 1.76;
  color: var(--about-body-soft);
}

.page-about .eco-list {
  display: grid;
  gap: 8px;
  margin: 16px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .eco-list li {
  position: relative;
  padding-left: 15px;
  font-size: 14px;
  line-height: 1.6;
  color: var(--about-body);
}

.page-about .eco-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 9px;
  width: 7px;
  height: 1px;
  background: var(--cyan);
}

/* ---------- 下一步 ---------- */

.page-about .about-next {
  margin: clamp(56px, 9vw, 104px) auto 0;
  padding: clamp(24px, 4.4vw, 48px);
  background: linear-gradient(135deg, rgba(43, 42, 110, .94), rgba(6, 26, 43, .96));
  border: 1px solid var(--line-strong);
  clip-path: polygon(0 0, calc(100% - 34px) 0, 100% 34px, 100% 100%, 34px 100%, 0 calc(100% - 34px));
}

.page-about .next-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
  margin-top: 20px;
}

.page-about .next-link {
  display: block;
  padding: 18px 18px 20px;
  border: 1px solid rgba(234, 244, 248, .22);
  color: var(--paper);
  text-decoration: none;
  transition: border-color .25s var(--ease), background .25s var(--ease), transform .25s var(--ease);
}

.page-about .next-link:hover,
.page-about .next-link:focus-visible {
  border-color: var(--cyan);
  background: rgba(69, 242, 223, .07);
  outline: none;
}

.page-about .next-kicker {
  display: block;
  font-size: 11px;
  letter-spacing: .14em;
  color: var(--cyan);
}

.page-about .next-title {
  display: block;
  margin: 8px 0 8px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 20px;
  line-height: 1.28;
  color: var(--paper);
}

.page-about .next-desc {
  display: block;
  font-size: 14px;
  line-height: 1.7;
  color: var(--about-body-soft);
}

.page-about .next-foot {
  margin: 24px 0 0;
  font-size: 12px;
  letter-spacing: .05em;
  line-height: 1.9;
  color: var(--slate);
  word-break: break-word;
}

/* ---------- 响应式 ---------- */

@media (min-width: 560px) {
  .page-about .stage-panel {
    padding-left: 80px;
  }
}

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

  .page-about .team-matrix,
  .page-about .eco-grid,
  .page-about .next-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (min-width: 900px) {
  .page-about .about-cover-inner {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
  }

  .page-about .about-cover-visual {
    transform: translateY(-6px);
  }

  .page-about .stage-btn {
    grid-template-columns: 84px minmax(0, 1fr) 22px;
    padding: 24px 4px;
  }

  .page-about .about-flow {
    max-width: 78ch;
  }
}
<<<END>>>