.page-about {
  --about-line: rgba(42, 59, 52, 0.9);
  --about-body: rgba(242, 239, 228, 0.84);
  --about-body-soft: rgba(242, 239, 228, 0.7);
  background: var(--ink);
  color: var(--bone);
  padding-block: clamp(18px, 3vw, 28px) clamp(48px, 7vw, 96px);
}

.page-about .breadcrumb {
  margin-bottom: clamp(14px, 2.2vw, 22px);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  display: grid;
  gap: 16px;
  padding-block: clamp(8px, 2vw, 18px) clamp(24px, 4vw, 40px);
  border-bottom: var(--stroke);
}

.page-about .about-hero__title {
  margin: 0;
  font-size: clamp(30px, 5.2vw, 60px);
  line-height: 1.14;
  font-weight: 900;
  letter-spacing: -0.01em;
  color: var(--bone);
}

.page-about .about-hero__aside p {
  margin: 0;
  max-width: 52ch;
  font-size: 15.5px;
  line-height: 1.85;
  color: var(--about-body-soft);
}

.page-about .about-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  margin: 8px 0 0;
  border-top: var(--stroke-soft);
}

.page-about .about-stats__item {
  padding: 12px 12px 12px 0;
  border-bottom: var(--stroke-soft);
}

.page-about .about-stats__item:nth-child(even) {
  padding-left: 14px;
  border-left: var(--stroke-soft);
}

.page-about .about-stats__num {
  display: block;
  font-size: clamp(19px, 2.6vw, 27px);
  font-weight: 600;
  line-height: 1.2;
  letter-spacing: -0.02em;
  color: var(--lime);
}

.page-about .about-stats__lbl {
  display: block;
  margin-top: 5px;
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--mist);
}

/* ---------- 主体网格 ---------- */
.page-about .about-body {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(24px, 4vw, 40px);
  margin-top: clamp(22px, 3.5vw, 36px);
}

/* ---------- 左侧沿革索引 ---------- */
.page-about .about-rail {
  padding-bottom: 6px;
}

.page-about .about-rail__title {
  margin: 0 0 10px;
  font-size: 11px;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--mist);
}

.page-about .about-rail__list {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-rail__link {
  display: inline-flex;
  align-items: baseline;
  gap: 7px;
  padding: 5px 9px;
  border: var(--stroke-soft);
  color: var(--mist);
  text-decoration: none;
  transition: color 0.22s var(--ease), background-color 0.22s var(--ease), border-color 0.22s var(--ease);
}

.page-about .about-rail__year {
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.06em;
  color: var(--sand);
}

.page-about .about-rail__txt {
  font-size: 12px;
  letter-spacing: 0.04em;
}

.page-about .about-rail__link:hover,
.page-about .about-rail__link:focus-visible {
  background: var(--lime);
  border-color: var(--lime);
  color: var(--ink);
}

.page-about .about-rail__link:hover .about-rail__year,
.page-about .about-rail__link:focus-visible .about-rail__year {
  color: var(--ink);
}

.page-about .about-rail__note {
  margin: 14px 0 0;
  padding-left: 12px;
  border-left: 2px solid var(--clay);
  font-size: 13px;
  line-height: 1.7;
  color: var(--mist);
}

.page-about .about-rail__note a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(79, 209, 224, 0.5);
}

.page-about .about-rail__note a:hover {
  border-bottom-color: var(--cyan);
}

/* ---------- 章节通用 ---------- */
.page-about .about-sec {
  scroll-margin-top: 88px;
  padding-block: clamp(22px, 3.4vw, 38px);
}

.page-about .about-flow > .about-sec:first-child {
  padding-top: 0;
}

.page-about .about-sec + .about-sec {
  border-top: var(--stroke-soft);
}

.page-about .about-sec__head {
  display: flex;
  align-items: baseline;
  gap: 12px;
  margin-bottom: 14px;
}

.page-about .about-sec__no {
  flex: none;
  padding: 2px 6px;
  border: 1px solid var(--lime);
  color: var(--lime);
  font-size: 11.5px;
  letter-spacing: 0.14em;
}

.page-about .about-h2 {
  margin: 0;
  font-size: clamp(21px, 3.2vw, 31px);
  line-height: 1.28;
  font-weight: 900;
  letter-spacing: 0.01em;
  color: var(--bone);
}

/* ---------- 正文与注释 ---------- */
.page-about .about-txt p {
  margin: 0 0 13px;
  font-size: 15.5px;
  line-height: 1.85;
  color: var(--about-body);
}

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

.page-about .about-txt strong {
  color: var(--bone);
  font-weight: 700;
}

.page-about .about-txt a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(79, 209, 224, 0.45);
}

.page-about .about-txt a:hover {
  border-bottom-color: var(--cyan);
}

.page-about .about-note {
  margin: 16px 0 0;
  padding: 10px 14px;
  border-left: 2px solid var(--cyan);
  background: rgba(79, 209, 224, 0.06);
  font-size: 13.5px;
  line-height: 1.75;
  color: var(--mist);
}

.page-about .about-note .mono {
  color: var(--cyan);
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.04em;
}

.page-about .about-note a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(79, 209, 224, 0.45);
}

/* ---------- 图片 ---------- */
.page-about .about-fig {
  margin: 0 0 18px;
  border: var(--stroke);
  background: var(--ink-2);
}

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

.page-about .about-fig__cap {
  padding: 9px 12px;
  border-top: var(--stroke-soft);
  font-size: 12.5px;
  line-height: 1.65;
  color: var(--mist);
}

.page-about .about-fig--tall {
  max-width: 280px;
  margin-bottom: 22px;
}

/* ---------- 标签体系 ---------- */
.page-about .tagmap {
  margin: 18px 0 0;
  padding: 0;
  list-style: none;
  border-top: var(--stroke-soft);
}

.page-about .tagmap__row {
  display: grid;
  grid-template-columns: minmax(84px, auto) minmax(0, 1fr);
  gap: 3px 14px;
  align-items: baseline;
  padding: 11px 8px 11px 0;
  border-bottom: var(--stroke-soft);
  transition: background-color 0.22s var(--ease);
}

.page-about .tagmap__row:hover {
  background: rgba(182, 240, 74, 0.055);
}

.page-about .tagmap__group {
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.06em;
  color: var(--bone);
}

.page-about .tagmap__items {
  font-size: 13px;
  line-height: 1.7;
  color: var(--mist);
  transition: color 0.22s var(--ease);
}

.page-about .tagmap__row:hover .tagmap__items {
  color: var(--cyan);
}

/* ---------- 流程 ---------- */
.page-about .flow {
  margin: 18px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .flow__step {
  display: grid;
  grid-template-columns: 30px minmax(0, 1fr);
  gap: 2px 14px;
  padding: 15px 0;
  border-top: var(--stroke-soft);
}

.page-about .flow__step:last-child {
  border-bottom: var(--stroke-soft);
}

.page-about .flow__no {
  padding-top: 3px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--clay);
}

.page-about .flow__title {
  margin: 0 0 5px;
  font-size: 16.5px;
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--bone);
}

.page-about .flow__desc {
  margin: 0 0 6px;
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--about-body);
}

.page-about .flow__meta {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.08em;
  color: var(--mist);
}

/* ---------- 时间轴 ---------- */
.page-about .tl {
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .tl__item {
  position: relative;
  scroll-margin-top: 88px;
  padding: 0 0 22px 18px;
  border-left: 1px solid var(--about-line);
}

.page-about .tl__item::before {
  content: "";
  position: absolute;
  left: -5px;
  top: 9px;
  width: 9px;
  height: 9px;
  background: var(--lime);
}

.page-about .tl__item:last-child {
  padding-bottom: 0;
  border-left-color: transparent;
}

.page-about .tl__year {
  display: inline-block;
  justify-self: start;
  padding: 2px 7px;
  background: var(--sand);
  color: var(--ink);
  font-family: var(--font-mono);
  font-size: 12.5px;
  font-weight: 600;
  letter-spacing: 0.1em;
}

.page-about .tl__title {
  margin: 8px 0 5px;
  font-size: 17px;
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--bone);
}

.page-about .tl__body p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--about-body);
}

.page-about .tl__more {
  margin-top: 8px;
}

.page-about .tl__more > summary {
  display: inline-block;
  cursor: pointer;
  list-style: none;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.1em;
  color: var(--cyan);
  border-bottom: 1px dashed rgba(79, 209, 224, 0.5);
}

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

.page-about .tl__more > summary::before {
  content: "+ ";
}

.page-about .tl__more[open] > summary::before {
  content: "− ";
}

.page-about .tl__more p {
  margin: 8px 0 0;
  padding: 10px 12px;
  border-left: 1px solid var(--about-line);
  background: rgba(14, 42, 33, 0.7);
  font-size: 13.5px;
  line-height: 1.75;
  color: var(--mist);
}

/* ---------- 双端对照 ---------- */
.page-about .duo {
  display: grid;
  gap: 0;
  margin-top: 18px;
  border-top: var(--stroke-soft);
}

.page-about .duo__col {
  padding: 15px 0;
  border-bottom: var(--stroke-soft);
}

.page-about .duo__title {
  margin: 0 0 10px;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.18em;
  color: var(--lime);
}

.page-about .duo__list {
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .duo__list li {
  position: relative;
  margin-bottom: 8px;
  padding-left: 14px;
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--about-body);
}

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

.page-about .duo__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.78em;
  width: 5px;
  height: 1px;
  background: var(--cyan);
}

/* ---------- 结尾引导 ---------- */
.page-about .about-cta {
  display: grid;
  gap: 16px;
  margin-top: clamp(30px, 5vw, 56px);
  padding: clamp(20px, 3vw, 32px);
  border: var(--stroke);
  background: linear-gradient(135deg, var(--ink-2) 0%, var(--veil) 100%);
}

.page-about .about-cta__title {
  margin: 0;
  font-size: clamp(20px, 3vw, 28px);
  line-height: 1.3;
  font-weight: 900;
  color: var(--bone);
}

.page-about .about-cta__text {
  margin: 10px 0 0;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--mist);
}

.page-about .about-cta__links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

/* ---------- 响应式 ---------- */
@media (min-width: 640px) {
  .page-about .about-stats__item {
    padding-right: 18px;
  }
}

@media (min-width: 760px) {
  .page-about .about-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .about-stats__item {
    border-bottom: 0;
    border-right: var(--stroke-soft);
    padding: 14px 18px 4px 0;
  }

  .page-about .about-stats__item:nth-child(even) {
    padding-left: 0;
    border-left: 0;
  }

  .page-about .about-stats__item:last-child {
    border-right: 0;
  }

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

  .page-about .duo__col {
    padding: 16px 22px 16px 0;
    border-bottom: var(--stroke-soft);
  }

  .page-about .duo__col + .duo__col {
    padding-left: 22px;
    padding-right: 0;
    border-left: var(--stroke-soft);
  }
}

@media (min-width: 900px) {
  .page-about .about-hero {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    align-items: end;
    column-gap: clamp(28px, 4vw, 56px);
  }

  .page-about .about-hero > .eyebrow {
    grid-column: 1 / -1;
  }

  .page-about .about-hero__title {
    grid-column: 1;
  }

  .page-about .about-hero__aside {
    grid-column: 2;
    padding-bottom: 6px;
  }

  .page-about .about-stats {
    grid-column: 1 / -1;
    margin-top: 14px;
  }

  .page-about .about-body {
    grid-template-columns: minmax(0, 3fr) minmax(0, 9fr);
    column-gap: clamp(28px, 4vw, 56px);
  }

  .page-about .about-rail {
    position: sticky;
    top: 96px;
    align-self: start;
  }

  .page-about .about-rail__list {
    flex-direction: column;
    flex-wrap: nowrap;
    gap: 0;
    border-top: var(--stroke-soft);
  }

  .page-about .about-rail__list li {
    border-bottom: var(--stroke-soft);
  }

  .page-about .about-rail__link {
    display: flex;
    width: 100%;
    padding: 9px 2px;
    border: 0;
    border-left: 2px solid transparent;
    padding-left: 10px;
  }

  .page-about .about-rail__link:hover,
  .page-about .about-rail__link:focus-visible {
    background: transparent;
    border-left-color: var(--lime);
    color: var(--bone);
  }

  .page-about .about-rail__link:hover .about-rail__year,
  .page-about .about-rail__link:focus-visible .about-rail__year {
    color: var(--lime);
  }

  .page-about .about-cta {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr);
    align-items: center;
    column-gap: clamp(24px, 3vw, 44px);
  }

  .page-about .about-cta__links {
    justify-content: flex-end;
  }

  .page-about .about-fig--tall {
    max-width: 320px;
  }
}

@media (min-width: 1100px) {
  .page-about .about-sec {
    padding-block: 40px;
  }

  .page-about .about-flow > .about-sec:first-child {
    padding-top: 0;
  }

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

@media (prefers-reduced-motion: reduce) {
  .page-about .tagmap__row,
  .page-about .tagmap__items,
  .page-about .about-rail__link {
    transition: none;
  }
}
<<<END>>>