.page-about {
  --about-rail-w: 11rem;
  --about-gap: clamp(1.5rem, 4vw, 3rem);
  display: block;
  background: var(--bg);
  color: var(--fg);
  padding: clamp(1rem, 3vw, 2rem) 0 clamp(2.5rem, 6vw, 5rem);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  margin-top: clamp(1rem, 3vw, 1.75rem);
  padding: clamp(1.5rem, 4vw, 3rem);
  background: var(--paper);
  color: var(--brown);
  border: 2px solid var(--brown);
  box-shadow: 10px 10px 0 var(--teal-deep);
}

.page-about .about-hero__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(1.25rem, 3vw, 2.5rem);
}

.page-about .about-hero__kicker {
  margin: 0 0 .75rem;
  font-size: .75rem;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--teal-deep);
}

.page-about .about-hero__title {
  margin: 0;
  font-family: var(--font-serif);
  font-weight: 600;
  font-size: clamp(1.75rem, 6vw, 3.4rem);
  line-height: 1.22;
  letter-spacing: -.01em;
  color: var(--brown);
}

.page-about .about-hero__intro p {
  margin: 0 0 .85rem;
  font-size: clamp(.95rem, 1.6vw, 1.0625rem);
  line-height: 1.8;
  color: var(--brown);
}

.page-about .about-hero__intro p:last-child {
  margin-bottom: 0;
  color: rgba(22, 17, 12, .76);
}

.page-about .about-hero__stats {
  display: flex;
  flex-wrap: wrap;
  gap: .75rem 2.25rem;
  margin: clamp(1.5rem, 3vw, 2.25rem) 0 0;
  padding: clamp(1rem, 2.5vw, 1.25rem) 0 0;
  list-style: none;
  border-top: 2px solid rgba(22, 17, 12, .18);
}

.page-about .about-hero__stat {
  display: flex;
  align-items: baseline;
  gap: .5rem;
}

.page-about .about-hero__num {
  font-family: var(--font-num);
  font-size: clamp(1.75rem, 5vw, 2.75rem);
  line-height: 1;
  color: var(--teal-deep);
}

.page-about .about-hero__cap {
  font-size: .8125rem;
  letter-spacing: .08em;
  color: rgba(22, 17, 12, .72);
}

/* ---------- 主体两栏 ---------- */
.page-about .about-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--about-gap);
  padding-top: clamp(2rem, 5vw, 3.5rem);
}

.page-about .about-rail {
  display: none;
}

.page-about .about-flow {
  min-width: 0;
  display: flex;
  flex-direction: column;
  gap: clamp(2.5rem, 6vw, 4.5rem);
}

/* ---------- 章节通用 ---------- */
.page-about .about-sec {
  min-width: 0;
  scroll-margin-top: 8rem;
}

.page-about .about-sec__kicker {
  display: flex;
  align-items: center;
  gap: .7rem;
  margin: 0 0 .9rem;
  font-size: .8125rem;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--teal);
}

.page-about .about-sec__no {
  font-family: var(--font-num);
  font-size: 1.6rem;
  line-height: 1;
  letter-spacing: .04em;
  color: var(--amber);
}

.page-about .about-sec__title {
  margin: 0 0 1rem;
  font-family: var(--font-serif);
  font-weight: 600;
  font-size: clamp(1.4rem, 3.6vw, 2.2rem);
  line-height: 1.3;
  color: var(--ivory);
}

.page-about .about-lead {
  margin: 0 0 1.5rem;
  max-width: 62ch;
  font-size: clamp(1rem, 1.7vw, 1.125rem);
  line-height: 1.85;
  color: var(--ivory);
}

.page-about .about-sec__text {
  margin: 1.25rem 0 0;
  max-width: 62ch;
  font-size: .9375rem;
  line-height: 1.85;
  color: var(--mist);
}

.page-about .about-sub {
  margin: clamp(1.75rem, 4vw, 2.5rem) 0 1rem;
  font-family: var(--font-serif);
  font-weight: 600;
  font-size: clamp(1.05rem, 2.2vw, 1.3rem);
  line-height: 1.4;
  color: var(--ivory);
  padding-left: .75rem;
  border-left: 4px solid var(--teal);
}

.page-about .about-link {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(91, 240, 224, .5);
  transition: color .25s ease, border-color .25s ease;
}

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

/* ---------- 错位图文 ---------- */
.page-about .about-split {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(1.25rem, 3vw, 2rem);
  align-items: start;
}

.page-about .about-split__text {
  min-width: 0;
}

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

.page-about .about-figure img,
.page-about .about-figure svg {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  border: 2px solid var(--brown);
}

.page-about .about-figure img {
  object-fit: cover;
  background: var(--ink-900);
}

.page-about .about-figure--slant {
  clip-path: polygon(0 2.5%, 100% 0, 100% 97.5%, 0 100%);
}

.page-about .about-figure--wide {
  margin-bottom: clamp(1.5rem, 4vw, 2.5rem);
}

.page-about .about-radar-figure {
  padding: clamp(.75rem, 2vw, 1.25rem);
  background: var(--ink-900);
  border: 2px solid var(--brown);
}

.page-about .about-radar {
  border: 0 !important;
}

.page-about .about-figure__caption {
  margin: .75rem 0 0;
  font-size: .8125rem;
  line-height: 1.7;
  color: var(--mist);
}

/* ---------- 引用块 ---------- */
.page-about .about-quote {
  position: relative;
  margin: clamp(1.75rem, 4vw, 2.5rem) 0 0;
  padding: clamp(1.25rem, 3vw, 2rem) clamp(1.25rem, 3vw, 2.25rem);
  max-width: 68ch;
  background: var(--paper);
  color: var(--brown);
  border: 2px solid var(--brown);
  box-shadow: var(--shadow-hard);
  transition: transform .3s cubic-bezier(.22, .9, .3, 1), box-shadow .3s ease;
}

.page-about .about-quote::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 6px;
  height: 100%;
  background: var(--orange);
}

.page-about .about-quote p {
  margin: 0;
  font-family: var(--font-serif);
  font-size: clamp(1rem, 2.1vw, 1.2rem);
  line-height: 1.75;
}

.page-about .about-quote:hover,
.page-about .about-quote:focus-within {
  transform: translate(-3px, -3px);
  box-shadow: 9px 9px 0 var(--brown);
}

/* ---------- 分工矩阵 ---------- */
.page-about .about-roles {
  display: flex;
  flex-direction: column;
  gap: .5rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-roles__item {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  grid-template-rows: auto auto;
  gap: .2rem .875rem;
  padding: .8rem .9rem;
  background: var(--ink-900);
  border-left: 3px solid var(--teal);
  transition: border-color .28s ease, background-color .28s ease, transform .28s cubic-bezier(.22, .9, .3, 1);
}

.page-about .about-roles__item:hover,
.page-about .about-roles__item:focus-within {
  background: var(--ink-700);
  border-left-color: var(--amber);
  transform: translateX(4px);
}

.page-about .about-roles__num {
  grid-column: 1;
  grid-row: 1 / span 2;
  align-self: center;
  font-family: var(--font-num);
  font-size: clamp(1.6rem, 4vw, 2.1rem);
  line-height: 1;
  color: var(--amber);
}

.page-about .about-roles__name {
  grid-column: 2;
  grid-row: 1;
  font-size: 1rem;
  font-weight: 600;
  letter-spacing: .04em;
  color: var(--ivory);
}

.page-about .about-roles__desc {
  grid-column: 2;
  grid-row: 2;
  font-size: .875rem;
  line-height: 1.72;
  color: var(--mist);
}

/* ---------- 五维列表 ---------- */
.page-about .about-dims {
  display: grid;
  gap: .625rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-dims__item {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  grid-template-rows: auto auto;
  gap: .15rem .8rem;
  padding: .7rem .9rem;
  background: linear-gradient(90deg, rgba(23, 179, 163, .14), rgba(23, 179, 163, 0) 72%);
  border-left: 3px solid var(--teal-deep);
}

.page-about .about-dims__max {
  grid-column: 1;
  grid-row: 1 / span 2;
  align-self: center;
  font-family: var(--font-num);
  font-size: 1.35rem;
  line-height: 1;
  color: var(--amber);
}

.page-about .about-dims__name {
  grid-column: 2;
  grid-row: 1;
  font-size: .9375rem;
  font-weight: 600;
  color: var(--ivory);
}

.page-about .about-dims__desc {
  grid-column: 2;
  grid-row: 2;
  font-size: .8125rem;
  line-height: 1.7;
  color: var(--mist);
}

/* ---------- 三轮流程 ---------- */
.page-about .about-checks {
  display: grid;
  grid-template-columns: 1fr;
  gap: .75rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-checks__item {
  display: flex;
  flex-direction: column;
  gap: .3rem;
  padding: 1rem;
  background: var(--ink-900);
  border-top: 3px solid var(--teal);
  border-bottom: 1px solid var(--hair);
}

.page-about .about-checks__step {
  font-family: var(--font-num);
  font-size: .8125rem;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--amber);
}

.page-about .about-checks__name {
  font-family: var(--font-serif);
  font-size: 1.0625rem;
  color: var(--ivory);
}

.page-about .about-checks__desc {
  font-size: .8125rem;
  line-height: 1.7;
  color: var(--mist);
}

/* ---------- 年份时间轴 ---------- */
.page-about .about-years {
  display: flex;
  flex-direction: column;
  margin: 0;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--hair);
}

.page-about .about-years__item {
  display: grid;
  grid-template-columns: 4.5rem minmax(0, 1fr);
  gap: .35rem 1rem;
  padding: 1.1rem 0;
  border-bottom: 1px solid var(--hair);
}

.page-about .about-years__year {
  position: relative;
  font-family: var(--font-num);
  font-size: clamp(1.5rem, 4.5vw, 2.1rem);
  line-height: 1;
  letter-spacing: .02em;
  color: var(--amber);
  padding-left: .55rem;
}

.page-about .about-years__year::before {
  content: "";
  position: absolute;
  left: 0;
  top: .1em;
  width: 3px;
  height: .95em;
  background: var(--teal);
}

.page-about .about-years__body {
  min-width: 0;
}

.page-about .about-years__name {
  display: block;
  margin-bottom: .3rem;
  font-size: .9375rem;
  font-weight: 600;
  letter-spacing: .04em;
  color: var(--ivory);
}

.page-about .about-years__body p {
  margin: 0;
  font-size: .875rem;
  line-height: 1.8;
  color: var(--mist);
}

/* ---------- 数字栅格 ---------- */
.page-about .about-figures {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(9rem, 1fr));
  gap: 1px;
  margin: clamp(1.25rem, 3vw, 1.75rem) 0 0;
  padding: 0;
  list-style: none;
  background: var(--hair);
  border: 1px solid var(--hair);
}

.page-about .about-figures__cell {
  padding: 1rem .9rem;
  background: var(--ink-900);
}

.page-about .about-figures__num {
  display: block;
  font-family: var(--font-num);
  font-size: clamp(1.5rem, 4vw, 2.15rem);
  line-height: 1;
  color: var(--amber);
}

.page-about .about-figures__label {
  display: block;
  margin-top: .4rem;
  font-size: .8125rem;
  letter-spacing: .07em;
  color: var(--mist);
}

.page-about .about-figures--usage {
  margin-top: 1rem;
}

/* ---------- 城市标签 ---------- */
.page-about .about-cities {
  display: flex;
  flex-wrap: wrap;
  gap: .5rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-cities li {
  padding: .35rem .75rem;
  font-size: .8125rem;
  letter-spacing: .07em;
  color: var(--ivory);
  background: var(--ink-900);
  border: 1px solid var(--hair);
  transition: border-color .25s ease, color .25s ease;
}

.page-about .about-cities li:hover {
  border-color: var(--cyan);
  color: var(--cyan);
}

/* ---------- 响应节奏 ---------- */
.page-about .about-response {
  display: grid;
  gap: 0;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-response li {
  display: grid;
  grid-template-columns: 1fr;
  gap: .2rem;
  padding: .75rem 0;
  border-bottom: 1px solid var(--hair);
}

.page-about .about-response__key {
  font-size: .8125rem;
  letter-spacing: .1em;
  color: var(--teal);
}

.page-about .about-response__val {
  font-size: .875rem;
  line-height: 1.75;
  color: var(--mist);
}

/* ---------- 异常监测与无障碍 ---------- */
.page-about .about-watch {
  display: flex;
  flex-direction: column;
  gap: .5rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-watch__item {
  display: flex;
  flex-direction: column;
  gap: .2rem;
  padding: .7rem .9rem;
  background: var(--ink-900);
  border-left: 3px solid var(--orange);
}

.page-about .about-watch__name {
  font-size: .9375rem;
  font-weight: 600;
  color: var(--ivory);
}

.page-about .about-watch__desc {
  font-size: .8125rem;
  line-height: 1.7;
  color: var(--mist);
}

.page-about .about-a11y {
  display: grid;
  gap: .5rem;
  margin: 1.25rem 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-a11y li {
  font-size: .8125rem;
  line-height: 1.7;
  color: var(--mist);
  padding-left: 1rem;
  border-left: 2px solid var(--teal);
}

.page-about .about-a11y strong {
  font-family: var(--font-num);
  font-size: 1.15rem;
  letter-spacing: .03em;
  color: var(--cyan);
  margin-right: .35rem;
}

/* ---------- 收尾 ---------- */
.page-about .about-cta {
  margin-top: clamp(1rem, 3vw, 2rem);
  padding: clamp(1.5rem, 4vw, 2.75rem);
  background: linear-gradient(135deg, rgba(12, 110, 102, .55), rgba(11, 27, 43, .25));
  border: 2px solid var(--teal);
  border-left-width: 8px;
}

.page-about .about-cta__title {
  margin: 0 0 .75rem;
  font-family: var(--font-serif);
  font-weight: 600;
  font-size: clamp(1.25rem, 3.2vw, 1.9rem);
  line-height: 1.35;
  color: var(--ivory);
}

.page-about .about-cta__text {
  margin: 0 0 1.5rem;
  max-width: 58ch;
  font-size: .9375rem;
  line-height: 1.8;
  color: var(--mist);
}

.page-about .about-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: .75rem;
}

/* ---------- 平板与桌面 ---------- */
@media (min-width: 700px) {
  .page-about .about-checks {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .about-response li {
    grid-template-columns: 8.5rem minmax(0, 1fr);
    gap: 1rem;
    align-items: baseline;
  }
}

@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.1fr) minmax(0, .9fr);
    align-items: end;
  }

  .page-about .about-split--text-first {
    grid-template-columns: minmax(0, 1.1fr) minmax(0, .9fr);
  }

  .page-about .about-split--media-first {
    grid-template-columns: minmax(0, .85fr) minmax(0, 1.15fr);
  }

  .page-about .about-years__item {
    grid-template-columns: 6.5rem minmax(0, 1fr);
    gap: 1rem 1.5rem;
  }
}

@media (min-width: 1024px) {
  .page-about .about-layout {
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
    align-items: start;
  }

  .page-about .about-rail {
    display: block;
    position: sticky;
    top: 7.5rem;
    align-self: start;
  }

  .page-about .about-rail__head {
    margin: 0 0 .75rem;
    font-size: .6875rem;
    letter-spacing: .22em;
    text-transform: uppercase;
    color: var(--mist);
  }

  .page-about .about-rail__list {
    display: flex;
    flex-direction: column;
    gap: 2px;
    margin: 0;
    padding: 0;
    list-style: none;
    border-left: 2px solid var(--hair);
  }

  .page-about .about-rail__link {
    display: flex;
    align-items: baseline;
    gap: .5rem;
    margin-left: -2px;
    padding: .5rem .7rem;
    text-decoration: none;
    color: var(--mist);
    border-left: 3px solid transparent;
    transition: color .25s ease, border-color .25s ease, background-color .25s ease;
  }

  .page-about .about-rail__num {
    font-family: var(--font-num);
    font-size: 1rem;
    letter-spacing: .05em;
    color: var(--teal);
  }

  .page-about .about-rail__label {
    font-size: .8125rem;
    letter-spacing: .06em;
  }

  .page-about .about-rail__link:hover,
  .page-about .about-rail__link:focus-visible {
    color: var(--ivory);
    border-left-color: var(--teal);
    background: rgba(23, 179, 163, .08);
  }

  .page-about:has(#sec-team:target) .about-rail__link[href="#sec-team"],
  .page-about:has(#sec-method:target) .about-rail__link[href="#sec-method"],
  .page-about:has(#sec-history:target) .about-rail__link[href="#sec-history"],
  .page-about:has(#sec-source:target) .about-rail__link[href="#sec-source"],
  .page-about:has(#sec-service:target) .about-rail__link[href="#sec-service"],
  .page-about:has(#sec-quality:target) .about-rail__link[href="#sec-quality"] {
    color: var(--ivory);
    border-left-color: var(--amber);
    background: rgba(229, 168, 59, .1);
  }
}

@media (min-width: 1280px) {
  .page-about {
    --about-rail-w: 12.5rem;
  }

  .page-about .about-quote {
    margin-left: clamp(0rem, 3vw, 2.5rem);
  }
}

/* ---------- 减弱动效 ---------- */
@media (prefers-reduced-motion: reduce) {
  .page-about .about-roles__item,
  .page-about .about-quote,
  .page-about .about-link,
  .page-about .about-cities li,
  .page-about .about-rail__link {
    transition: none;
  }

  .page-about .about-roles__item:hover,
  .page-about .about-roles__item:focus-within,
  .page-about .about-quote:hover,
  .page-about .about-quote:focus-within {
    transform: none;
  }
}
<<<END>>>