.page-about {
  padding-bottom: 72px;
}

/* ---------- 面包屑 ---------- */
.page-about .breadcrumbs {
  padding: 20px 0 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--muted);
  line-height: 1.6;
}

.page-about .breadcrumbs a {
  color: var(--cyan-dark);
  text-decoration: none;
}

.page-about .breadcrumbs a:hover,
.page-about .breadcrumbs a:focus-visible {
  text-decoration: underline;
}

.page-about .breadcrumbs span {
  margin: 0 6px;
}

.page-about .breadcrumbs span:last-child {
  color: var(--stone);
  margin-right: 0;
}

/* ---------- 页首 ---------- */
.page-about .about-head {
  padding: 22px 0 40px;
  border-bottom: 1px solid var(--line);
}

.page-about .about-kicker {
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--red);
}

.page-about h1 {
  margin: 0 0 18px;
  max-width: 18em;
  font-size: clamp(30px, 6.4vw, 58px);
  font-weight: 500;
  line-height: 1.14;
  letter-spacing: -0.01em;
  color: var(--stone);
}

.page-about .about-lede {
  margin: 0 0 24px;
  max-width: 36em;
  font-size: 16px;
  line-height: 1.85;
  color: var(--stone);
}

.page-about .about-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 22px;
  margin: 0;
  padding: 0;
  list-style: none;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--stone);
}

.page-about .about-meta li {
  display: flex;
  align-items: baseline;
  gap: 7px;
}

.page-about .about-meta b {
  font-family: var(--font-num);
  font-size: 24px;
  font-weight: 700;
  line-height: 1;
  letter-spacing: 0;
  color: var(--navy);
}

/* ---------- 竖向主轴 ---------- */
.page-about .about-track {
  position: relative;
  padding-top: 48px;
}

.page-about .about-track::before {
  content: "";
  position: absolute;
  left: 9px;
  top: 56px;
  bottom: 24px;
  width: 1px;
  background: var(--line);
}

.page-about .about-chapter {
  position: relative;
  padding-left: 32px;
  padding-bottom: 56px;
}

.page-about .about-chapter::before {
  content: "";
  position: absolute;
  left: 4px;
  top: 6px;
  width: 11px;
  height: 11px;
  background: var(--white);
  border: 1px solid var(--red);
  box-sizing: border-box;
}

.page-about .about-chapter:last-child {
  padding-bottom: 40px;
}

.page-about .chapter-tag {
  margin: 0 0 12px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--muted);
}

.page-about .chapter-tag::before {
  content: "";
  display: inline-block;
  width: 18px;
  height: 2px;
  margin-right: 9px;
  vertical-align: 4px;
  background: var(--red);
}

.page-about .about-chapter > h2 {
  margin: 0 0 18px;
  max-width: 24em;
  font-size: clamp(22px, 4vw, 34px);
  font-weight: 500;
  line-height: 1.28;
  letter-spacing: -0.01em;
  color: var(--navy);
}

.page-about .about-chapter > p {
  margin: 0 0 14px;
  max-width: 36em;
  font-size: 16px;
  line-height: 1.85;
  color: var(--stone);
}

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

/* ---------- 图形容器 ---------- */
.page-about .about-flow,
.page-about .about-versions {
  margin: 26px 0 0;
  padding: 0;
  overflow: hidden;
  background: var(--paper-dark);
  border: 1px solid var(--line);
}

.page-about .about-flow {
  aspect-ratio: 1600 / 600;
}

.page-about .about-versions {
  aspect-ratio: 1400 / 500;
}

.page-about .about-shift {
  margin: 26px 0 14px;
  padding: 0;
  overflow: hidden;
  background: var(--paper-dark);
  border: 1px solid var(--line);
  aspect-ratio: 1200 / 800;
}

.page-about .about-flow img,
.page-about .about-shift img,
.page-about .about-versions img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
  max-width: 100%;
}

/* ---------- 团队卡片 ---------- */
.page-about .team-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
  margin-top: 26px;
}

.page-about .team-card {
  position: relative;
  padding: 20px 18px 22px;
  background: var(--white);
  border: 1px solid var(--line);
  transition: background-color 0.22s var(--ease), border-color 0.22s var(--ease);
}

.page-about .team-card::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  opacity: 0.06;
  background-image: repeating-conic-gradient(var(--line) 0% 25%, transparent 0% 50%);
  background-size: 24px 24px;
  transition: opacity 0.22s var(--ease);
}

.page-about .team-card:hover::after,
.page-about .team-card:focus-within::after {
  opacity: 0.1;
}

.page-about .team-card:hover,
.page-about .team-card:focus-within {
  background: var(--navy);
  border-color: var(--navy);
}

.page-about .team-card .idx {
  position: relative;
  z-index: 1;
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--muted);
  transition: color 0.22s var(--ease);
}

.page-about .team-card__num {
  position: relative;
  z-index: 1;
  margin: 12px 0 4px;
  font-family: var(--font-num);
  font-size: 46px;
  font-weight: 700;
  line-height: 0.9;
  letter-spacing: 0;
  color: var(--red);
  transition: color 0.22s var(--ease);
}

.page-about .team-card__name {
  position: relative;
  z-index: 1;
  margin: 0 0 8px;
  font-size: 18px;
  font-weight: 500;
  line-height: 1.4;
  color: var(--navy);
  transition: color 0.22s var(--ease);
}

.page-about .team-card__desc {
  position: relative;
  z-index: 1;
  margin: 0;
  font-size: 14px;
  line-height: 1.78;
  color: var(--stone);
  transition: color 0.22s var(--ease);
}

.page-about .team-card__list {
  position: relative;
  z-index: 1;
  margin: 14px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .team-card__list li {
  position: relative;
  padding-left: 16px;
  margin-bottom: 7px;
  font-size: 14px;
  line-height: 1.7;
  color: var(--stone);
  transition: color 0.22s var(--ease);
}

.page-about .team-card__list li:last-child {
  margin-bottom: 0;
}

.page-about .team-card__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 9px;
  width: 5px;
  height: 5px;
  background: var(--red);
  transition: background-color 0.22s var(--ease);
}

.page-about .team-card:hover .team-card__num,
.page-about .team-card:focus-within .team-card__num,
.page-about .team-card:hover .team-card__name,
.page-about .team-card:focus-within .team-card__name,
.page-about .team-card:hover .team-card__desc,
.page-about .team-card:focus-within .team-card__desc,
.page-about .team-card:hover .team-card__list li,
.page-about .team-card:focus-within .team-card__list li {
  color: var(--white);
}

.page-about .team-card:hover .idx,
.page-about .team-card:focus-within .idx {
  color: var(--cyan);
}

.page-about .team-card:hover .team-card__list li::before,
.page-about .team-card:focus-within .team-card__list li::before {
  background: var(--cyan);
}

.page-about .source-line {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--muted);
}

/* ---------- 三步流程 ---------- */
.page-about .flow-jump {
  display: flex;
  gap: 10px;
  margin: 24px 0 0;
}

.page-about .flow-jump a {
  padding: 4px 11px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--stone);
  text-decoration: none;
  border: 1px solid var(--line);
  transition: background-color 0.2s var(--ease), border-color 0.2s var(--ease), color 0.2s var(--ease);
}

.page-about .flow-jump a:hover,
.page-about .flow-jump a:focus-visible {
  background: var(--red);
  border-color: var(--red);
  color: var(--white);
}

.page-about .flow-list {
  margin: 20px 0 0;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--line);
}

.page-about .flow-step {
  display: grid;
  grid-template-columns: 54px 1fr;
  padding: 22px 0;
  border-bottom: 1px solid var(--line);
  transition: background-color 0.22s var(--ease);
}

.page-about .flow-step:target {
  background: var(--paper-dark);
}

.page-about .flow-num {
  padding-right: 14px;
  font-family: var(--font-num);
  font-size: 36px;
  font-weight: 700;
  line-height: 1;
  letter-spacing: 0.01em;
  color: var(--line);
  text-align: right;
  border-right: 1px solid var(--line);
  transition: color 0.22s var(--ease);
}

.page-about .flow-step:hover .flow-num,
.page-about .flow-step:target .flow-num {
  color: var(--red);
}

.page-about .flow-body {
  padding-left: 18px;
}

.page-about .flow-body h3 {
  margin: 0 0 8px;
  font-size: 17px;
  font-weight: 500;
  line-height: 1.45;
  letter-spacing: -0.005em;
  color: var(--navy);
}

.page-about .flow-body p {
  margin: 0 0 10px;
  max-width: 36em;
  font-size: 15px;
  line-height: 1.82;
  color: var(--stone);
}

.page-about .flow-meta {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--muted);
}

/* ---------- 版本时间线 ---------- */
.page-about .version-list {
  position: relative;
  margin: 24px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .version-list::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 10px;
  bottom: 10px;
  width: 1px;
  background: var(--line);
}

.page-about .version-item {
  position: relative;
  padding-left: 38px;
  padding-bottom: 26px;
}

.page-about .version-item:last-child {
  padding-bottom: 8px;
}

.page-about .version-item:focus {
  outline: none;
}

.page-about .version-item:focus-visible {
  outline: 1px solid var(--cyan-dark);
  outline-offset: 4px;
}

.page-about .version-node {
  position: absolute;
  left: 2px;
  top: 5px;
  width: 11px;
  height: 11px;
  background: var(--red);
  transition: background-color 0.22s var(--ease), box-shadow 0.22s var(--ease);
}

.page-about .version-item--current .version-node {
  background: var(--clay);
  box-shadow: 0 0 0 4px var(--paper), 0 0 0 5px var(--clay);
}

.page-about .version-item:hover .version-node,
.page-about .version-item:focus-within .version-node {
  background: var(--navy);
}

.page-about .version-tag {
  margin: 0 0 6px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--red);
}

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

.page-about .version-title {
  margin: 0 0 6px;
  font-size: 17px;
  font-weight: 500;
  line-height: 1.45;
  color: var(--navy);
}

.page-about .version-sum {
  margin: 0;
  max-width: 36em;
  font-size: 15px;
  line-height: 1.8;
  color: var(--stone);
}

.page-about .version-detail {
  display: grid;
  grid-template-rows: 0fr;
  transition: grid-template-rows 0.3s var(--ease);
}

.page-about .version-detail > div {
  min-height: 0;
  overflow: hidden;
}

.page-about .version-detail p {
  margin: 10px 0 0;
  padding-left: 12px;
  border-left: 2px solid var(--line);
  font-family: var(--font-mono);
  font-size: 12px;
  line-height: 1.85;
  letter-spacing: 0.04em;
  color: var(--muted);
}

.page-about .version-item:hover .version-detail,
.page-about .version-item:focus-within .version-detail {
  grid-template-rows: 1fr;
}

/* ---------- 边界对照 ---------- */
.page-about .boundary {
  display: grid;
  grid-template-columns: 1fr;
  margin-top: 24px;
  border: 1px solid var(--line);
}

.page-about .boundary-col {
  padding: 22px 18px 24px;
  background: var(--white);
}

.page-about .boundary-col:first-child {
  border-bottom: 1px solid var(--line);
}

.page-about .boundary-col:last-child {
  background: var(--paper-dark);
}

.page-about .boundary-col h3 {
  display: flex;
  align-items: center;
  gap: 9px;
  margin: 0 0 14px;
  font-size: 16px;
  font-weight: 500;
  color: var(--navy);
}

.page-about .boundary-dot {
  flex: none;
  width: 9px;
  height: 9px;
  background: var(--moss);
}

.page-about .boundary-col--no .boundary-dot {
  background: var(--stone);
}

.page-about .boundary-col ul {
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .boundary-col li {
  position: relative;
  padding-left: 20px;
  margin-bottom: 10px;
  font-size: 15px;
  line-height: 1.75;
  color: var(--stone);
}

.page-about .boundary-col li:last-child {
  margin-bottom: 0;
}

.page-about .boundary-col li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 11px;
  width: 10px;
  height: 1px;
  background: var(--line);
}

/* ---------- 尾部延伸 ---------- */
.page-about .about-next {
  margin-top: 8px;
  padding: 26px 20px 28px;
  background: var(--navy);
}

.page-about .about-next .idx {
  margin: 0 0 12px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--cyan);
}

.page-about .about-next h2 {
  margin: 0 0 16px;
  font-size: 20px;
  font-weight: 500;
  line-height: 1.4;
  color: var(--white);
}

.page-about .about-next__list {
  display: grid;
  gap: 1px;
  margin: 0;
  padding: 0;
  list-style: none;
  background: rgba(255, 255, 255, 0.16);
}

.page-about .about-next__list li {
  background: var(--navy);
}

.page-about .about-next__list a {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
  padding: 14px 2px;
  font-size: 15px;
  color: var(--white);
  text-decoration: none;
  transition: color 0.2s var(--ease), padding-left 0.2s var(--ease);
}

.page-about .about-next__list a::after {
  content: "→";
  flex: none;
  font-family: var(--font-mono);
  color: var(--cyan);
}

.page-about .about-next__list a:hover,
.page-about .about-next__list a:focus-visible {
  color: var(--cyan);
  padding-left: 6px;
}

/* ---------- 中屏 ---------- */
@media (min-width: 700px) {
  .page-about .about-lede,
  .page-about .about-chapter > p {
    font-size: 17px;
  }

  .page-about .about-chapter {
    padding-left: 44px;
    padding-bottom: 64px;
  }

  .page-about .about-track::before {
    left: 11px;
  }

  .page-about .about-chapter::before {
    left: 6px;
    top: 7px;
  }

  .page-about .flow-step {
    grid-template-columns: 76px 1fr;
    padding: 26px 0;
  }

  .page-about .flow-num {
    font-size: 46px;
    padding-right: 20px;
  }

  .page-about .flow-body {
    padding-left: 26px;
  }

  .page-about .flow-body h3 {
    font-size: 19px;
  }

  .page-about .flow-body p {
    font-size: 16px;
  }

  .page-about .about-next {
    padding: 34px 32px 36px;
  }

  .page-about .about-next__list a {
    padding: 16px 4px;
  }
}

/* ---------- 桌面栅格 ---------- */
@media (min-width: 880px) {
  .page-about .team-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 18px;
  }

  .page-about .team-card {
    align-self: start;
    padding: 22px 20px 24px;
  }

  .page-about .team-card:nth-child(2) {
    margin-top: 30px;
  }

  .page-about .team-card:nth-child(3) {
    margin-top: 60px;
  }

  .page-about .boundary {
    grid-template-columns: 1fr 1fr;
  }

  .page-about .boundary-col {
    padding: 26px 26px 28px;
  }

  .page-about .boundary-col:first-child {
    border-bottom: 0;
    border-right: 1px solid var(--line);
  }

  .page-about .about-lede {
    font-size: 18px;
  }
}

@media (min-width: 1100px) {
  .page-about .about-chapter {
    padding-left: 56px;
  }

  .page-about .about-track::before {
    left: 13px;
  }

  .page-about .about-chapter::before {
    left: 8px;
    width: 12px;
    height: 12px;
    top: 7px;
  }

  .page-about .version-item {
    padding-left: 44px;
  }

  .page-about .version-list::before {
    left: 9px;
  }

  .page-about .version-node {
    left: 4px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .team-card,
  .page-about .team-card::after,
  .page-about .team-card__num,
  .page-about .team-card__name,
  .page-about .team-card__desc,
  .page-about .team-card__list li,
  .page-about .team-card__list li::before,
  .page-about .version-detail,
  .page-about .version-node,
  .page-about .flow-num,
  .page-about .about-next__list a,
  .page-about .flow-jump a {
    transition: none;
  }
}
<<<END>>>