.page-about {
  --about-index-w: 208px;
  --about-fog-ink: #22374A;
  --about-fog-muted: #55697C;
  --about-ring: rgba(255, 107, 44, 0.16);
}

/* 顶部上下文 */
.page-about .about-top {
  padding-top: clamp(18px, 3vw, 32px);
}

/* 首屏 */
.page-about .about-hero {
  padding-bottom: clamp(10px, 2vw, 20px);
}

.page-about .about-hero__title {
  max-width: 20ch;
  margin-top: 12px;
}

.page-about .about-hero__lead {
  max-width: 64ch;
  margin-top: 18px;
}

.page-about .about-score {
  margin-top: clamp(28px, 4vw, 46px);
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-score__cell {
  background: var(--panel);
  padding: clamp(16px, 2.4vw, 26px);
  display: flex;
  flex-direction: column;
  gap: 6px;
  min-height: 118px;
  justify-content: flex-end;
}

.page-about .about-score__num {
  font-size: clamp(2rem, 5vw, 3.2rem);
  line-height: 1;
}

.page-about .about-score__key {
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--muted);
}

/* 档案夹外壳 */
.page-about .about-shell {
  display: grid;
  gap: clamp(28px, 4vw, 48px);
  align-items: start;
  padding-top: clamp(30px, 4.5vw, 60px);
  padding-bottom: clamp(40px, 6vw, 80px);
}

.page-about .about-index {
  border: 1px solid var(--line);
  background: linear-gradient(160deg, var(--panel) 0%, var(--ink) 100%);
  padding: 18px 16px 20px;
}

.page-about .about-index__list {
  list-style: none;
  margin: 12px 0 0;
  padding: 0;
  display: grid;
  gap: 2px;
}

.page-about .about-index__link {
  display: flex;
  align-items: baseline;
  gap: 10px;
  padding: 8px 10px;
  font-size: 14px;
  color: var(--muted);
  text-decoration: none;
  border-left: 2px solid transparent;
  transition: color 160ms ease, border-color 160ms ease, background-color 160ms ease;
}

.page-about .about-index__link:hover,
.page-about .about-index__link:focus-visible {
  color: var(--white);
  border-left-color: var(--orange);
  background: var(--about-ring);
}

.page-about .about-index__no {
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--orange);
}

.page-about .about-index__note {
  margin: 16px 0 0;
  padding-top: 14px;
  border-top: 1px solid var(--line);
  font-size: 12px;
  line-height: 1.7;
  color: var(--muted);
}

/* 章节 */
.page-about .about-body {
  display: grid;
  gap: clamp(32px, 4.6vw, 58px);
  min-width: 0;
}

.page-about .about-chapter {
  position: relative;
  min-width: 0;
}

.page-about .chapter-plain {
  border-left: 3px solid var(--teal);
  padding-left: clamp(18px, 3vw, 34px);
}

.page-about .chapter-panel {
  background: var(--panel);
  border: 1px solid var(--line);
  padding: clamp(22px, 3.4vw, 42px);
}

.page-about .chapter-panel::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  width: 4px;
  height: 72px;
  background: var(--orange);
}

.page-about .chapter-fog {
  background: var(--fog);
  color: var(--about-fog-ink);
  padding: clamp(22px, 3.4vw, 42px);
  border-left: 3px solid var(--sand);
}

.page-about .chapter-fog .field-label,
.page-about .chapter-fog .muted {
  color: var(--about-fog-muted);
}

.page-about .about-chapter h2 {
  margin-top: 10px;
  max-width: 24ch;
}

.page-about .about-intro {
  margin-top: 16px;
  max-width: 60ch;
  font-size: 17px;
  line-height: 1.8;
  color: var(--muted);
}

.page-about .chapter-fog .about-intro {
  color: var(--about-fog-muted);
}

.page-about .about-prose {
  margin-top: 16px;
  max-width: 64ch;
}

.page-about .about-prose p {
  margin: 0 0 18px;
  font-size: 17px;
  line-height: 1.85;
}

.page-about .about-drop {
  border-left: 2px solid var(--line);
  padding-left: 18px;
}

.page-about .about-note {
  margin-top: 26px;
  display: flex;
  gap: 12px;
  align-items: flex-start;
  padding: 14px 16px;
  border: 1px dashed var(--line);
  font-size: 14px;
  line-height: 1.75;
  color: var(--muted);
  max-width: 68ch;
}

.page-about .about-note--dark {
  border-style: solid;
  background: rgba(46, 196, 182, 0.07);
  color: var(--white);
}

/* 三条业务线 */
.page-about .line-cards {
  margin-top: 28px;
  display: grid;
  gap: 14px;
}

.page-about .line-card {
  display: flex;
  flex-direction: column;
  gap: 10px;
  min-width: 0;
}

.page-about .line-card .card__title {
  margin: 0;
  font-size: 19px;
  line-height: 1.5;
}

.page-about .line-card .card__text {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--muted);
}

/* 图组 */
.page-about .about-figure {
  margin: clamp(26px, 3.6vw, 40px) 0 0;
  border: 1px solid var(--line);
  background: var(--ink);
  position: relative;
  overflow: hidden;
}

.page-about .about-figure::after {
  content: "";
  position: absolute;
  inset: 0;
  background-image: linear-gradient(rgba(126, 217, 209, 0.07) 1px, transparent 1px),
    linear-gradient(90deg, rgba(126, 217, 209, 0.07) 1px, transparent 1px);
  background-size: 42px 42px;
  pointer-events: none;
}

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

.page-about .about-figure figcaption {
  position: relative;
  z-index: 1;
  padding: 12px 16px;
  border-top: 1px solid var(--line);
  font-size: 13px;
  line-height: 1.7;
  color: var(--muted);
  background: var(--panel);
}

/* 团队 */
.page-about .team-layout {
  margin-top: 24px;
  display: grid;
  gap: clamp(22px, 3vw, 34px);
}

.page-about .team-layout__text p {
  margin: 0 0 20px;
  font-size: 17px;
  line-height: 1.85;
  max-width: 58ch;
}

.page-about .team-roles {
  margin: 0;
  display: grid;
  gap: 14px;
}

.page-about .team-role {
  border-top: 2px solid var(--line);
  padding-top: 12px;
}

.page-about .team-role dt {
  font-family: var(--font-mono);
  font-size: 14px;
  letter-spacing: 0.04em;
  color: var(--orange);
  margin-bottom: 6px;
}

.page-about .team-role dd {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--about-fog-muted);
  max-width: 56ch;
}

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

/* 发展历程时间轴 */
.page-about .tl {
  list-style: none;
  margin: 28px 0 0;
  padding: 0;
  display: grid;
  gap: 10px;
  counter-reset: tl;
}

.page-about .tl__item {
  display: grid;
  grid-template-columns: 54px minmax(0, 1fr);
  gap: 14px;
  padding: 16px 16px 16px 0;
  border-left: 2px solid var(--line);
  padding-left: 16px;
  background: transparent;
  transition: background-color 160ms ease, border-color 160ms ease, transform 160ms ease;
}

.page-about .tl__item:hover,
.page-about .tl__item:focus-visible,
.page-about .tl__item:focus-within {
  border-left-color: var(--orange);
  background: var(--panel);
  transform: translateX(3px);
  outline: none;
}

.page-about .tl__item:focus-visible {
  outline: 2px solid var(--orange);
  outline-offset: 2px;
}

.page-about .tl__ver {
  font-size: 15px;
  color: var(--sand);
  letter-spacing: 0.06em;
  padding-top: 3px;
}

.page-about .tl__title {
  margin: 0 0 6px;
  font-size: 17px;
  line-height: 1.5;
}

.page-about .tl__text {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--muted);
  max-width: 58ch;
}

.page-about .tl__note {
  margin: 0;
  max-height: 0;
  overflow: hidden;
  opacity: 0;
  font-size: 13px;
  line-height: 1.75;
  color: var(--teal-pale);
  transition: max-height 200ms ease, opacity 200ms ease, margin-top 200ms ease;
}

.page-about .tl__item:hover .tl__note,
.page-about .tl__item:focus-within .tl__note,
.page-about .tl__item:focus-visible .tl__note {
  max-height: 6em;
  opacity: 1;
  margin-top: 8px;
}

/* 合作网络 */
.page-about .site-grid {
  margin-top: 26px;
  display: grid;
  gap: 14px;
}

.page-about .site-grid__cell {
  border: 1px solid var(--line);
  border-top: 3px solid var(--teal);
  padding: 18px 16px 20px;
  display: flex;
  flex-direction: column;
  gap: 6px;
  min-width: 0;
}

.page-about .site-grid__cell:nth-child(2) {
  border-top-color: var(--sand);
}

.page-about .site-grid__cell:nth-child(3) {
  border-top-color: var(--orange);
}

.page-about .site-grid__cell:nth-child(4) {
  border-top-color: var(--teal-pale);
}

.page-about .site-grid__num {
  font-size: clamp(1.9rem, 4vw, 2.6rem);
  line-height: 1;
}

.page-about .site-grid__key {
  margin: 0;
  font-size: 14px;
  letter-spacing: 0.05em;
  color: var(--white);
}

.page-about .site-grid__text {
  margin: 4px 0 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--muted);
}

/* 后续入口 */
.page-about .about-next {
  border-top: 1px solid var(--line);
  padding-top: clamp(24px, 3.4vw, 38px);
}

.page-about .about-next__grid {
  margin-top: 20px;
  display: grid;
  gap: 10px;
}

.page-about .about-next__item {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 18px 16px;
  border: 1px solid var(--line);
  background: var(--panel);
  color: var(--white);
  text-decoration: none;
  transition: border-color 160ms ease, transform 160ms ease, background-color 160ms ease;
}

.page-about .about-next__item:hover,
.page-about .about-next__item:focus-visible {
  border-color: var(--orange);
  transform: translateY(-3px);
  background: var(--ink);
}

.page-about .about-next__title {
  font-size: 16px;
  line-height: 1.6;
}

.page-about .about-next__contact {
  margin: 22px 0 0;
  font-size: 13px;
  line-height: 1.8;
  color: var(--muted);
}

/* 响应式 */
@media (min-width: 640px) {
  .page-about .about-score {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

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

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

  .page-about .line-card:nth-child(2) {
    margin-top: 24px;
  }

  .page-about .line-card:nth-child(3) {
    margin-top: 48px;
  }

  .page-about .team-layout {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 1fr);
    align-items: start;
  }

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

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

@media (min-width: 1024px) {
  .page-about .about-shell {
    grid-template-columns: var(--about-index-w) minmax(0, 1fr);
    padding-left: 0;
    padding-right: 0;
  }

  .page-about .about-index {
    position: sticky;
    top: clamp(20px, 3vw, 36px);
  }
}

@media (max-width: 520px) {
  .page-about .tl__item {
    grid-template-columns: 44px minmax(0, 1fr);
    gap: 10px;
    padding-left: 12px;
  }

  .page-about .about-score__cell {
    min-height: 96px;
  }
}
<<<END>>>