.page-about {
  background: var(--paper);
  color: var(--ink);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  background:
    radial-gradient(130% 100% at 8% 0%, #125263 0%, var(--lake) 44%, var(--night) 100%);
  color: var(--paper);
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: repeating-linear-gradient(
    118deg,
    transparent 0 26px,
    rgba(143, 179, 184, 0.08) 26px 27px
  );
}

.page-about .about-hero__inner {
  position: relative;
  z-index: 1;
  max-width: var(--wrap);
  margin-inline: auto;
  padding: clamp(1.4rem, 3.6vw, 2.2rem) var(--gutter) clamp(2.4rem, 5vw, 3.8rem);
}

.page-about .about-hero__crumbs {
  margin-bottom: clamp(1.4rem, 3.4vw, 2.2rem);
  font-size: 0.82rem;
  color: var(--mist);
}

.page-about .about-hero__crumbs .breadcrumbs__item {
  color: var(--mist);
}

.page-about .about-hero__crumbs a.breadcrumbs__item {
  color: var(--paper);
  text-decoration: none;
  border-bottom: 1px solid rgba(247, 241, 230, 0.35);
}

.page-about .about-hero__grid {
  display: grid;
  gap: clamp(1.6rem, 3.4vw, 2.4rem);
  align-items: center;
}

.page-about .about-kicker {
  display: inline-flex;
  align-items: center;
  gap: 0.55rem;
  margin: 0 0 0.9rem;
  font-size: 0.78rem;
  letter-spacing: 0.16em;
  font-weight: 700;
  color: var(--flare);
}

.page-about .about-kicker::before {
  content: "";
  width: 26px;
  height: 2px;
  background: var(--ember);
}

.page-about .about-hero__title {
  margin: 0;
  font-size: clamp(1.95rem, 6.2vw, 3.3rem);
  line-height: 1.12;
  letter-spacing: -0.01em;
  font-weight: 800;
  color: var(--paper);
}

.page-about .about-hero__title-em {
  display: block;
  color: var(--flare);
}

.page-about .about-hero__lead {
  margin: clamp(1rem, 2.4vw, 1.4rem) 0 0;
  max-width: 40em;
  font-size: clamp(0.98rem, 2.1vw, 1.06rem);
  line-height: 1.8;
  color: #DCE6E5;
}

.page-about .about-facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1rem 1.1rem;
  margin: clamp(1.4rem, 3vw, 2rem) 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-facts li {
  border-left: 2px solid var(--ember);
  padding-left: 0.7rem;
}

.page-about .about-facts b {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(1.4rem, 4.4vw, 2rem);
  line-height: 1.05;
  color: var(--flare);
}

.page-about .about-facts span {
  display: block;
  margin-top: 0.32rem;
  font-size: 0.78rem;
  line-height: 1.5;
  color: var(--mist);
}

.page-about .about-hero__svg {
  width: 100%;
  height: auto;
  display: block;
  max-width: 560px;
  margin-inline: auto;
}

/* ---------- 章节通用骨架 ---------- */
.page-about .about-chapter {
  max-width: var(--wrap);
  margin-inline: auto;
  padding: clamp(2.2rem, 5.6vw, 3.8rem) var(--gutter);
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(1.1rem, 2.8vw, 1.8rem);
  border-bottom: 1px solid var(--cold);
}

.page-about .about-chapter:last-of-type {
  border-bottom: 0;
}

.page-about .about-chapter__rail {
  display: flex;
  align-items: baseline;
  gap: 0.7rem;
  border-left: 4px solid var(--ember);
  padding-left: 0.75rem;
}

.page-about .about-chapter__num {
  font-family: var(--font-mono);
  font-size: clamp(1.7rem, 5vw, 2.4rem);
  font-weight: 700;
  line-height: 1;
  color: var(--ember);
}

.page-about .about-chapter__tag {
  font-size: 0.74rem;
  letter-spacing: 0.18em;
  font-weight: 700;
  color: var(--mist);
}

.page-about .about-chapter__title {
  margin: 0 0 0.9rem;
  font-size: clamp(1.35rem, 4vw, 2rem);
  line-height: 1.28;
  letter-spacing: -0.005em;
  font-weight: 800;
  color: var(--lake);
}

.page-about .about-chapter__body > p {
  margin: 0 0 0.95rem;
  font-size: 1rem;
  line-height: 1.8;
}

.page-about .about-chapter__lead {
  font-size: clamp(1rem, 2.3vw, 1.08rem);
  line-height: 1.85;
  color: var(--ink);
  max-width: 44em;
}

.page-about .about-chapter__note {
  margin: 1.4rem 0 0;
  padding: 0.9rem 1rem 0.9rem 1.1rem;
  border-left: 3px solid var(--meadow);
  background: var(--paper-deep);
  font-size: 0.9rem;
  line-height: 1.75;
  color: var(--ink);
}

/* ---------- 图文错位 ---------- */
.page-about .about-split {
  display: grid;
  gap: clamp(1.2rem, 3vw, 1.8rem);
  align-items: start;
}

.page-about .about-split__text > p {
  margin: 0 0 0.95rem;
  font-size: 1rem;
  line-height: 1.8;
}

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

.page-about .about-figure .media-frame {
  overflow: hidden;
  background: var(--cold);
}

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

.page-about .about-figure__cap {
  margin-top: 0.6rem;
  font-size: 0.78rem;
  line-height: 1.65;
  color: var(--mist);
  border-left: 2px solid var(--cold);
  padding-left: 0.6rem;
}

/* ---------- 团队分工折叠 ---------- */
.page-about .about-roles {
  display: grid;
  gap: 0.65rem;
}

.page-about .about-role {
  background: var(--paper-light);
  border: 1px solid var(--cold);
  clip-path: polygon(0 0, calc(100% - var(--cut)) 0, 100% var(--cut), 100% 100%, 0 100%);
  transition: border-color var(--dur) var(--ease), box-shadow var(--dur) var(--ease);
}

.page-about .about-role[open] {
  border-color: var(--lake);
  box-shadow: inset 4px 0 0 var(--lake);
}

.page-about .about-role summary {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  padding: 0.9rem 1.05rem;
  font-size: 0.98rem;
  font-weight: 700;
  color: var(--lake);
  cursor: pointer;
  list-style: none;
}

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

.page-about .about-role summary::after {
  content: "+";
  margin-left: auto;
  font-family: var(--font-mono);
  color: var(--ember);
  font-size: 1.1rem;
  line-height: 1;
}

.page-about .about-role[open] summary::after {
  content: "–";
}

.page-about .about-role__idx {
  display: inline-grid;
  place-items: center;
  width: 22px;
  height: 22px;
  font-size: 0.72rem;
  background: var(--lake);
  color: var(--paper);
}

.page-about .about-role__count {
  font-size: 0.72rem;
  font-weight: 400;
  color: var(--ember);
  margin-left: auto;
  padding-right: 0.3rem;
}

.page-about .about-role__body {
  padding: 0 1.05rem 1rem;
  font-size: 0.92rem;
  line-height: 1.8;
  color: var(--ink);
  opacity: 0.85;
}

/* ---------- 三级流程阶梯 ---------- */
.page-about .about-flow {
  display: grid;
  gap: 0.9rem;
  margin: 1.5rem 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-step {
  position: relative;
  padding: 1.3rem 1.2rem 1.45rem;
  background: var(--night);
  color: var(--paper);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - var(--cut)), calc(100% - var(--cut)) 100%, 0 100%);
}

.page-about .about-step__n {
  display: block;
  font-family: var(--font-mono);
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--flare);
  line-height: 1;
}

.page-about .about-step__title {
  margin: 0.55rem 0 0.5rem;
  font-size: 1.06rem;
  font-weight: 800;
  letter-spacing: 0.02em;
  color: var(--paper);
}

.page-about .about-step__text {
  margin: 0;
  font-size: 0.9rem;
  line-height: 1.8;
  color: #D3E0DE;
}

/* ---------- 里程碑刻度 ---------- */
.page-about .about-miles {
  position: relative;
  margin: 1.6rem 0 0;
  padding: 0 0 0 1.6rem;
  border-left: 1px solid var(--cold);
  list-style: none;
  display: grid;
  gap: 1.3rem;
}

.page-about .about-mile {
  position: relative;
  outline: none;
}

.page-about .about-mile::before {
  content: "";
  position: absolute;
  left: -1.6rem;
  top: 0.45rem;
  width: 9px;
  height: 9px;
  background: var(--ember);
  border-radius: 50%;
  transform: translateX(-50%);
  transition: transform var(--dur) var(--ease), background var(--dur) var(--ease);
}

.page-about .about-mile:hover::before,
.page-about .about-mile:focus-visible::before {
  background: var(--flare);
  transform: translateX(-50%) scale(1.35);
}

.page-about .about-mile__year {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.82rem;
  font-weight: 700;
  padding: 0.24rem 0.75rem 0.24rem 0.5rem;
  background: var(--lake);
  color: var(--paper);
  clip-path: polygon(0 0, calc(100% - 10px) 0, 100% 100%, 0 100%);
}

.page-about .about-mile__title {
  margin: 0.5rem 0 0.35rem;
  font-size: 1rem;
  font-weight: 800;
  color: var(--lake);
}

.page-about .about-mile__note {
  margin: 0;
  font-size: 0.86rem;
  line-height: 1.75;
  color: var(--ink);
  opacity: 0.78;
  transition: opacity var(--dur) var(--ease), transform var(--dur) var(--ease);
}

.page-about .about-mile:hover .about-mile__note,
.page-about .about-mile:focus-visible .about-mile__note {
  opacity: 1;
  transform: translateY(-2px);
}

/* ---------- 合作数据 ---------- */
.page-about .about-partner-stats {
  margin: 1.2rem 0 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 0.5rem;
}

.page-about .about-partner-stats li {
  display: flex;
  align-items: baseline;
  gap: 0.55rem;
  font-size: 0.9rem;
  line-height: 1.65;
  padding-bottom: 0.5rem;
  border-bottom: 1px dashed var(--cold);
  color: var(--ink);
}

.page-about .about-partner-stats .mono {
  font-family: var(--font-mono);
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--ember);
  line-height: 1;
}

/* ---------- 阅读体验示范 ---------- */
.page-about .about-type {
  display: grid;
  gap: 1.1rem;
  margin-top: 1.4rem;
}

.page-about .about-type__sample {
  padding: 1.2rem 1.15rem 1.3rem;
  background: var(--paper-light);
  border: 1px solid var(--cold);
  clip-path: polygon(0 0, calc(100% - var(--cut)) 0, 100% var(--cut), 100% 100%, 0 100%);
}

.page-about .about-type__num {
  margin: 0;
  font-family: var(--font-mono);
  font-size: clamp(1.9rem, 6vw, 2.6rem);
  font-weight: 700;
  line-height: 1;
  color: var(--ember);
}

.page-about .about-type__h {
  margin: 0.4rem 0 0.5rem;
  font-size: 0.95rem;
  font-weight: 800;
  letter-spacing: 0.04em;
  color: var(--lake);
}

.page-about .about-type__p {
  margin: 0;
  font-size: 0.9rem;
  line-height: 1.75;
  color: var(--ink);
  opacity: 0.86;
}

.page-about .about-type__list {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 0.85rem;
}

.page-about .about-type__list li {
  display: flex;
  gap: 0.75rem;
  align-items: flex-start;
  font-size: 0.88rem;
  line-height: 1.7;
}

.page-about .about-type__list strong {
  display: block;
  font-size: 0.92rem;
  color: var(--lake);
}

.page-about .about-type__list p {
  margin: 0.15rem 0 0;
  color: var(--ink);
  opacity: 0.8;
}

.page-about .about-chip {
  flex: 0 0 auto;
  width: 18px;
  height: 18px;
  margin-top: 0.25rem;
  border-radius: 50%;
}

.page-about .about-chip--lake {
  background: var(--lake);
}

.page-about .about-chip--flare {
  background: var(--flare);
  box-shadow: 0 0 0 3px var(--night) inset;
}

.page-about .about-chip--meadow {
  background: var(--meadow);
}

/* ---------- 下一步入口 ---------- */
.page-about .about-next {
  background: linear-gradient(150deg, var(--lake) 0%, var(--night) 100%);
  color: var(--paper);
  position: relative;
  overflow: hidden;
}

.page-about .about-next::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 6px;
  background: linear-gradient(90deg, var(--ember) 0%, var(--flare) 32%, var(--meadow) 62%, var(--mist) 100%);
}

.page-about .about-next__inner {
  max-width: var(--wrap);
  margin-inline: auto;
  padding: clamp(2.2rem, 5.4vw, 3.4rem) var(--gutter);
}

.page-about .about-next__title {
  margin: 0 0 1.4rem;
  font-size: clamp(1.3rem, 3.8vw, 1.85rem);
  font-weight: 800;
  letter-spacing: -0.005em;
  color: var(--paper);
}

.page-about .about-next__links {
  display: grid;
  gap: 0.8rem;
}

.page-about .about-next__link {
  display: grid;
  gap: 0.25rem;
  padding: 1rem 1.1rem 1.05rem;
  text-decoration: none;
  color: var(--paper);
  background: rgba(247, 241, 230, 0.06);
  border: 1px solid rgba(247, 241, 230, 0.22);
  clip-path: polygon(0 0, calc(100% - var(--cut)) 0, 100% var(--cut), 100% 100%, 0 100%);
  transition: background var(--dur) var(--ease), border-color var(--dur) var(--ease), transform var(--dur) var(--ease);
}

.page-about .about-next__link:hover,
.page-about .about-next__link:focus-visible {
  background: rgba(216, 91, 42, 0.22);
  border-color: var(--flare);
  transform: translateY(-2px);
}

.page-about .about-next__link-k {
  font-family: var(--font-mono);
  font-size: 0.74rem;
  color: var(--flare);
  letter-spacing: 0.12em;
}

.page-about .about-next__link-t {
  font-size: 1.02rem;
  font-weight: 800;
}

.page-about .about-next__link-d {
  font-size: 0.82rem;
  line-height: 1.6;
  color: var(--mist);
}

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

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

@media (min-width: 860px) {
  .page-about .about-chapter {
    grid-template-columns: 96px minmax(0, 1fr);
    gap: clamp(1.6rem, 3.4vw, 3rem);
  }

  .page-about .about-chapter__rail {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.5rem;
    position: sticky;
    top: 132px;
    align-self: start;
    padding-left: 0.85rem;
  }

  .page-about .about-split {
    grid-template-columns: minmax(0, 1.08fr) minmax(0, 0.92fr);
    gap: clamp(1.6rem, 3.4vw, 2.6rem);
  }

  .page-about .about-split--flip {
    grid-template-columns: minmax(0, 1.12fr) minmax(0, 0.88fr);
  }

  .page-about .about-flow {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 1.1rem;
    align-items: start;
  }

  .page-about .about-step:nth-child(2) {
    margin-top: 1.6rem;
  }

  .page-about .about-step:nth-child(3) {
    margin-top: 3.2rem;
  }

  .page-about .about-miles {
    padding: 2.6rem 0 0;
    border-left: 0;
    border-top: 0;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 1.1rem;
  }

  .page-about .about-miles::before {
    content: "";
    position: absolute;
    left: 0;
    right: 0;
    top: 1.2rem;
    height: 1px;
    background: linear-gradient(90deg, var(--ember) 0%, var(--mist) 55%, var(--cold) 100%);
  }

  .page-about .about-mile::before {
    left: 0;
    top: -1.4rem;
  }

  .page-about .about-mile:hover::before,
  .page-about .about-mile:focus-visible::before {
    transform: scale(1.35);
  }

  .page-about .about-type {
    grid-template-columns: minmax(0, 0.85fr) minmax(0, 1.15fr);
    gap: 1.6rem;
    align-items: start;
  }

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

@media (min-width: 940px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.1fr) minmax(0, 0.9fr);
  }

  .page-about .about-hero__svg {
    margin-inline: 0 0;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about * {
    transition: none !important;
    animation: none !important;
  }

  .page-about .about-mile:hover .about-mile__note,
  .page-about .about-mile:focus-visible .about-mile__note,
  .page-about .about-next__link:hover,
  .page-about .about-next__link:focus-visible {
    transform: none;
  }
}
<<<END>>>