.page-about {
  counter-reset: about-chapter;
  --about-edge: rgba(201, 210, 217, 0.18);
  --about-panel: rgba(58, 70, 84, 0.26);
  --about-glow: rgba(127, 209, 224, 0.14);
  color: var(--c-paper);
  padding-bottom: clamp(2.5rem, 7vw, 5rem);
  overflow-x: clip;
}

.page-about img {
  display: block;
  max-width: 100%;
  height: auto;
}

.page-about .breadcrumbs {
  padding: 1.1rem 0 0.4rem;
}

/* ---------- 封面 ---------- */
.page-about .about-cover {
  position: relative;
  padding-bottom: clamp(1.5rem, 4vw, 2.5rem);
  background:
    radial-gradient(110% 85% at 88% 0%, var(--about-glow), transparent 62%),
    linear-gradient(180deg, rgba(10, 46, 92, 0.55), rgba(6, 24, 47, 0) 72%);
}

.page-about .about-cover__grid {
  display: grid;
  gap: 1.75rem;
  padding-top: clamp(1rem, 3vw, 2rem);
}

.page-about .about-cover__title {
  margin: 0.6rem 0 0;
  font-family: var(--font-sans);
  font-weight: 800;
  font-size: clamp(2.05rem, 6.4vw, 4.05rem);
  line-height: 1.07;
  letter-spacing: -0.03em;
  color: var(--c-paper);
  max-width: 18ch;
}

.page-about .about-cover__lead {
  margin: 1.1rem 0 0;
  max-width: 62ch;
  color: var(--c-mist);
  font-size: clamp(0.95rem, 1.6vw, 1.05rem);
  line-height: 1.75;
}

.page-about .about-cover__facts {
  list-style: none;
  margin: 1.75rem 0 0;
  padding: 1.25rem 0 0;
  border-top: 1px solid var(--about-edge);
  display: grid;
  gap: 1rem;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
}

.page-about .about-cover__facts li {
  display: flex;
  flex-direction: column;
  gap: 0.2rem;
}

.page-about .about-cover__num {
  font-family: var(--font-mono);
  font-size: clamp(1.6rem, 4vw, 2.1rem);
  font-weight: 700;
  line-height: 1;
  color: var(--c-amber);
  letter-spacing: -0.02em;
}

.page-about .about-cover__fact {
  font-size: 0.8rem;
  line-height: 1.5;
  color: var(--c-mist);
}

.page-about .about-cover__figure {
  margin: 0;
  position: relative;
  border: 1px solid var(--line-strong);
  background: var(--c-night);
  box-shadow: var(--shadow);
}

.page-about .about-cover__img {
  width: 100%;
  aspect-ratio: 14 / 10;
  object-fit: cover;
  filter: saturate(0.85) contrast(1.06);
}

.page-about .about-cover__caption {
  padding: 0.7rem 0.9rem;
  font-size: 0.74rem;
  line-height: 1.55;
  color: var(--c-mist);
  border-top: 1px solid var(--about-edge);
}

/* ---------- 章节索引 ---------- */
.page-about .about-index {
  margin-top: clamp(1.75rem, 4vw, 2.75rem);
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  border-top: 1px solid var(--line-strong);
}

.page-about .about-index__item {
  display: flex;
  align-items: baseline;
  gap: 0.55rem;
  min-width: 0;
  padding: 0.85rem 0.6rem 0.85rem 0;
  border-bottom: 1px solid var(--about-edge);
  text-decoration: none;
  color: var(--c-paper);
  transition: color 220ms var(--ease), border-color 220ms var(--ease);
}

.page-about .about-index__no {
  font-family: var(--font-mono);
  font-size: 0.74rem;
  color: var(--c-clay);
  flex: none;
}

.page-about .about-index__label {
  font-size: 0.9rem;
  letter-spacing: 0.04em;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.page-about .about-index__item:hover,
.page-about .about-index__item:focus-visible {
  color: var(--c-amber);
  border-color: var(--c-amber);
}

/* ---------- 章节骨架 ---------- */
.page-about .about-chapter {
  counter-increment: about-chapter;
  border-top: 1px solid var(--about-edge);
  padding: clamp(2.25rem, 6vw, 4.5rem) 0;
}

.page-about .about-chapter:first-of-type {
  border-top: 0;
}

.page-about .about-chapter__grid {
  display: grid;
  gap: 1rem;
}

.page-about .about-chapter__aside {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.page-about .about-chapter__no {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(2rem, 7vw, 3rem);
  line-height: 1;
  letter-spacing: -0.04em;
  color: var(--c-cyan);
  opacity: 0.5;
}

.page-about .about-chapter__no::before {
  content: counter(about-chapter, decimal-leading-zero);
}

.page-about .about-chapter__aside .note-vertical {
  display: none;
  margin: 0;
  writing-mode: vertical-rl;
  text-orientation: mixed;
  letter-spacing: 0.3em;
  font-size: 0.68rem;
  color: var(--c-mist);
  opacity: 0.75;
}

.page-about .about-chapter__body > .section__title {
  margin: 0.35rem 0 0;
  font-size: clamp(1.45rem, 3.4vw, 2.3rem);
  line-height: 1.24;
  letter-spacing: -0.02em;
  max-width: 24ch;
}

.page-about .about-chapter__body > .section__lead {
  margin: 0.85rem 0 0;
  max-width: 66ch;
  font-size: 0.95rem;
  line-height: 1.8;
  color: var(--c-mist);
}

/* ---------- 发展轨道 ---------- */
.page-about .about-track {
  list-style: none;
  margin: clamp(1.5rem, 4vw, 2.25rem) 0 0;
  padding: 0 0 0 1.6rem;
  position: relative;
  display: grid;
  gap: 1rem;
}

.page-about .about-track::before {
  content: "";
  position: absolute;
  left: 4px;
  top: 0.9rem;
  bottom: 0.9rem;
  width: 1px;
  background: linear-gradient(180deg, var(--c-cyan), rgba(245, 166, 35, 0.55), var(--c-moss));
  opacity: 0.55;
}

.page-about .about-track__item {
  position: relative;
  padding: 1rem 1.1rem;
  background: var(--about-panel);
  border: 1px solid var(--about-edge);
  transition: transform 260ms var(--ease), border-color 260ms var(--ease), background 260ms var(--ease);
}

.page-about .about-track__item::before {
  content: "";
  position: absolute;
  left: -1.6rem;
  top: 1.35rem;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--c-night);
  border: 1px solid var(--c-cyan);
  box-shadow: 0 0 0 4px rgba(127, 209, 224, 0.1);
  transition: background 240ms var(--ease), border-color 240ms var(--ease), box-shadow 240ms var(--ease);
}

.page-about .about-track__item--current {
  border-color: rgba(245, 166, 35, 0.42);
  background: linear-gradient(160deg, rgba(245, 166, 35, 0.1), rgba(58, 70, 84, 0.22) 60%);
}

.page-about .about-track__item--current::before {
  background: var(--c-amber);
  border-color: var(--c-amber);
  box-shadow: 0 0 0 5px rgba(245, 166, 35, 0.16);
}

.page-about .about-track__ver {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.14em;
  color: var(--c-cyan);
}

.page-about .about-track__item--current .about-track__ver {
  color: var(--c-amber);
}

.page-about .about-track__title {
  margin: 0.3rem 0 0;
  font-size: 1.02rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--c-paper);
}

.page-about .about-track__text {
  margin: 0.45rem 0 0;
  font-size: 0.88rem;
  line-height: 1.75;
  color: var(--c-mist);
}

.page-about .about-track__figure {
  margin: clamp(1.25rem, 3vw, 1.75rem) 0 0;
  border: 1px solid var(--about-edge);
  background: var(--c-night);
  position: relative;
}

.page-about .about-track__figure::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(90deg, rgba(6, 24, 47, 0.55), transparent 55%);
  pointer-events: none;
}

.page-about .about-track__img {
  width: 100%;
  aspect-ratio: 2 / 1;
  object-fit: cover;
  filter: saturate(0.78) contrast(1.08);
}

.page-about .about-track__caption {
  padding: 0.7rem 0.9rem;
  font-size: 0.74rem;
  line-height: 1.55;
  color: var(--c-mist);
  border-top: 1px solid var(--about-edge);
}

/* ---------- 内容体系 ---------- */
.page-about .about-lanes {
  margin-top: clamp(1.5rem, 4vw, 2.25rem);
  display: grid;
  gap: 0.85rem;
}

.page-about .about-lane {
  padding: 1.15rem 1.1rem 1.25rem;
  border: 1px solid var(--about-edge);
  border-top: 2px solid var(--c-cyan);
  background: linear-gradient(180deg, rgba(58, 70, 84, 0.32), rgba(6, 24, 47, 0.34));
  display: flex;
  flex-direction: column;
}

.page-about .about-lane--clay {
  border-top-color: var(--c-clay);
}

.page-about .about-lane--moss {
  border-top-color: var(--c-moss);
}

.page-about .about-lane__kicker {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.2em;
  color: var(--c-mist);
}

.page-about .about-lane__title {
  margin: 0.45rem 0 0;
  font-size: 1.02rem;
  font-weight: 700;
  line-height: 1.4;
  color: var(--c-paper);
}

.page-about .about-lane__text {
  margin: 0.6rem 0 0;
  font-size: 0.86rem;
  line-height: 1.75;
  color: var(--c-mist);
}

.page-about .about-lane__meta {
  margin: 0.9rem 0 0;
  padding-top: 0.7rem;
  border-top: 1px solid var(--about-edge);
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.06em;
  color: var(--c-cyan);
}

.page-about .about-lane--clay .about-lane__meta {
  color: var(--c-clay);
}

.page-about .about-lane--moss .about-lane__meta {
  color: var(--c-moss);
}

/* ---------- 合作与认证 ---------- */
.page-about .about-trust {
  margin-top: clamp(1.5rem, 4vw, 2.25rem);
  display: grid;
  gap: 1.5rem;
}

.page-about .about-trust__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1rem;
}

.page-about .about-trust__list li {
  padding-left: 1rem;
  border-left: 1px solid var(--c-silver);
  font-size: 0.88rem;
  line-height: 1.75;
  color: var(--c-mist);
}

.page-about .about-trust__list strong {
  display: block;
  margin-bottom: 0.2rem;
  font-size: 0.94rem;
  color: var(--c-paper);
}

.page-about .about-trust__actions {
  margin-top: 1.4rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
}

.page-about .about-trust__figure {
  margin: 0;
  border: 1px solid var(--about-edge);
  background: var(--c-night);
}

.page-about .about-trust__img {
  width: 100%;
  aspect-ratio: 3 / 2;
  object-fit: cover;
  filter: saturate(0.8) contrast(1.05);
}

.page-about .about-trust__caption {
  padding: 0.7rem 0.9rem;
  font-size: 0.74rem;
  line-height: 1.55;
  color: var(--c-mist);
  border-top: 1px solid var(--about-edge);
}

/* ---------- 服务网络 ---------- */
.page-about .about-network {
  margin-top: clamp(1.5rem, 4vw, 2.25rem);
  display: grid;
  gap: 1px;
  background: var(--about-edge);
  border: 1px solid var(--about-edge);
}

.page-about .about-network__stat {
  background: rgba(6, 24, 47, 0.72);
  padding: 1.1rem 1rem 1.25rem;
  display: flex;
  flex-direction: column;
  gap: 0.15rem;
}

.page-about .about-network__num {
  font-family: var(--font-mono);
  font-size: clamp(1.6rem, 4.6vw, 2.2rem);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.03em;
  color: var(--c-amber);
}

.page-about .about-network__unit {
  font-size: 0.78rem;
  letter-spacing: 0.08em;
  color: var(--c-cyan);
}

.page-about .about-network__desc {
  margin: 0.55rem 0 0;
  font-size: 0.82rem;
  line-height: 1.7;
  color: var(--c-mist);
}

.page-about .about-network__note {
  margin-top: 1.25rem;
  padding: 1.1rem 1.1rem 1.25rem;
  border: 1px solid var(--about-edge);
  border-left: 2px solid var(--c-moss);
  background: rgba(110, 127, 92, 0.1);
}

.page-about .about-network__note-text {
  margin: 0;
  font-size: 0.88rem;
  line-height: 1.8;
  color: var(--c-mist);
}

.page-about .about-network__links {
  margin-top: 0.9rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem 1.4rem;
}

.page-about .about-network__link {
  font-size: 0.84rem;
  color: var(--c-cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(127, 209, 224, 0.35);
  padding-bottom: 0.1rem;
  transition: color 200ms var(--ease), border-color 200ms var(--ease);
}

.page-about .about-network__link:hover,
.page-about .about-network__link:focus-visible {
  color: var(--c-amber);
  border-color: var(--c-amber);
}

/* ---------- 收尾 ---------- */
.page-about .about-outro {
  padding-top: clamp(1.5rem, 4vw, 2.5rem);
}

.page-about .about-outro__inner {
  border-top: 1px solid var(--line-strong);
  padding-top: clamp(1.5rem, 4vw, 2.25rem);
}

.page-about .about-outro__title {
  margin: 0.45rem 0 0;
  font-size: clamp(1.4rem, 3.4vw, 2rem);
  line-height: 1.26;
  letter-spacing: -0.02em;
  color: var(--c-paper);
}

.page-about .about-outro__text {
  margin: 0.75rem 0 0;
  max-width: 62ch;
  font-size: 0.9rem;
  line-height: 1.8;
  color: var(--c-mist);
}

.page-about .about-outro__actions {
  margin-top: 1.3rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
}

/* ---------- 交互增强 ---------- */
@media (hover: hover) {
  .page-about .about-track__item:hover {
    transform: translateY(-2px);
    border-color: var(--line-strong);
    background: rgba(58, 70, 84, 0.34);
  }

  .page-about .about-track__item:hover::before {
    background: var(--c-amber);
    border-color: var(--c-amber);
    box-shadow: 0 0 0 5px rgba(245, 166, 35, 0.14);
  }
}

/* ---------- 平板 ---------- */
@media (min-width: 700px) {
  .page-about .about-cover__grid {
    grid-template-columns: minmax(0, 1.1fr) minmax(0, 0.9fr);
    align-items: end;
    gap: 2rem;
  }

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

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

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

  .page-about .about-track {
    gap: 0.9rem;
  }
}

/* ---------- 桌面 ---------- */
@media (min-width: 960px) {
  .page-about .about-chapter__grid {
    grid-template-columns: 104px minmax(0, 1fr);
    gap: 2.75rem;
  }

  .page-about .about-chapter__aside {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.9rem;
    padding-top: 0.35rem;
  }

  .page-about .about-chapter__aside .note-vertical {
    display: block;
    margin-left: 0.35rem;
  }

  .page-about .about-trust {
    grid-template-columns: minmax(0, 1fr) minmax(0, 0.85fr);
    align-items: start;
    gap: 2.5rem;
  }

  .page-about .about-trust__figure {
    margin-top: -1.5rem;
  }

  .page-about .about-track {
    padding-left: 1.9rem;
  }

  .page-about .about-track__item::before {
    left: -1.9rem;
  }

  .page-about .about-chapter__body > .section__title {
    max-width: 30ch;
  }
}

@media (min-width: 1200px) {
  .page-about .about-cover__grid {
    gap: 3.5rem;
  }

  .page-about .about-cover__figure {
    margin-right: -1.5rem;
  }

  .page-about .about-track__figure {
    margin-left: -3rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-track__item,
  .page-about .about-track__item::before,
  .page-about .about-index__item,
  .page-about .about-network__link {
    transition: none;
  }

  .page-about .about-track__item:hover {
    transform: none;
  }
}
<<<END>>>