.page-about {
  --ab-rail: 104px;
  --ab-gap: clamp(24px, 3.6vw, 52px);
  --ab-stream: 820px;
  color: var(--graphite);
}

/* ---------- 面包屑 ---------- */

.page-about .about-crumb {
  background: var(--ivory);
  padding: clamp(14px, 2vw, 22px) 0 0;
}

/* ---------- 首屏 ---------- */

.page-about .about-hero {
  position: relative;
  background: var(--ink-800);
  color: var(--ivory);
  padding: clamp(40px, 6vw, 68px) 0 clamp(88px, 12vw, 148px);
  overflow: hidden;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  top: -70px;
  right: -110px;
  width: clamp(220px, 34vw, 400px);
  height: clamp(220px, 34vw, 400px);
  border: 1px solid var(--line-copper);
  transform: rotate(14deg);
  pointer-events: none;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: -1px;
  height: clamp(52px, 9vw, 130px);
  background: var(--ivory);
  clip-path: polygon(0 100%, 100% 0, 100% 100%);
  pointer-events: none;
}

.page-about .about-hero__inner {
  position: relative;
  z-index: 1;
}

.page-about .about-hero__kicker {
  margin: 0 0 18px;
  font-size: var(--fs-5);
  letter-spacing: 0.16em;
  color: var(--copper-soft);
}

.page-about .about-hero__title {
  margin: 0;
  max-width: 18ch;
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: var(--fs-1);
  line-height: 1.22;
  letter-spacing: 0.01em;
  color: var(--ivory);
}

.page-about .about-hero__lede {
  margin: 22px 0 0;
  max-width: 54ch;
  font-size: var(--fs-4);
  line-height: 1.95;
  color: rgba(246, 241, 228, 0.82);
}

.page-about .about-hero__stats {
  margin: 34px 0 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line-copper-soft);
  border: 1px solid var(--line-copper-soft);
}

.page-about .about-hero__stat {
  background: var(--ink-800);
  padding: 16px 18px;
}

.page-about .about-hero__stat dt {
  margin: 0 0 6px;
  font-size: var(--fs-5);
  letter-spacing: 0.1em;
  color: var(--silver);
}

.page-about .about-hero__stat dd {
  margin: 0;
  font-family: var(--font-mono);
  font-size: var(--fs-3);
  font-weight: 700;
  color: var(--copper-soft);
}

@media (min-width: 900px) {
  .page-about .about-hero__inner {
    display: grid;
    grid-template-columns: minmax(0, 1.45fr) minmax(0, 0.55fr);
    column-gap: clamp(36px, 5vw, 80px);
    align-items: start;
  }
  .page-about .about-hero__kicker,
  .page-about .about-hero__title,
  .page-about .about-hero__lede {
    grid-column: 1;
  }
  .page-about .about-hero__stats {
    grid-column: 2;
    grid-row: 1 / span 3;
    margin-top: 6px;
    grid-template-columns: minmax(0, 1fr);
  }
}

/* ---------- 开篇图版 ---------- */

.page-about .about-plate {
  margin: clamp(-72px, -7vw, -40px) 0 clamp(36px, 5vw, 64px);
  padding-left: clamp(0px, 6vw, 110px);
  position: relative;
  z-index: 2;
}

.page-about .about-plate img {
  display: block;
  width: 100%;
  max-width: 620px;
  height: auto;
  object-fit: cover;
  border: 1px solid var(--line-copper);
  box-shadow: var(--shadow-card);
  background: var(--paper);
}

.page-about .about-plate__cap {
  margin: 12px 0 0;
  max-width: 46ch;
  font-size: var(--fs-5);
  line-height: 1.9;
  color: var(--silver);
}

/* ---------- 编年史骨架 ---------- */

.page-about .chronicle {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  padding-bottom: clamp(40px, 6vw, 72px);
}

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

.page-about .chronicle__stream {
  min-width: 0;
  max-width: var(--ab-stream);
}

@media (min-width: 880px) {
  .page-about .chronicle {
    grid-template-columns: var(--ab-rail) minmax(0, 1fr);
    column-gap: var(--ab-gap);
  }
  .page-about .chronicle__rail {
    display: block;
    position: relative;
    padding-top: 6px;
  }
  .page-about .chronicle__rail::before {
    content: "";
    position: absolute;
    left: 6px;
    top: 40px;
    bottom: 0;
    width: 1px;
    background: linear-gradient(to bottom, var(--line-copper), var(--line-copper-soft) 78%, transparent);
  }
}

.page-about .chronicle__cap {
  display: block;
  margin-bottom: 16px;
  font-size: var(--fs-5);
  letter-spacing: 0.18em;
  color: var(--silver);
}

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

.page-about .chronicle__year-item {
  position: relative;
  margin-bottom: 26px;
}

.page-about .chronicle__year-item::before {
  content: "";
  position: absolute;
  left: 2px;
  top: 6px;
  width: 9px;
  height: 9px;
  border: 1px solid var(--copper);
  background: var(--paper);
  transform: rotate(45deg);
  transition: background var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .chronicle__year {
  display: block;
  padding-left: 28px;
  font-family: var(--font-mono);
  font-size: var(--fs-5);
  letter-spacing: 0.08em;
  color: var(--ink-600);
  text-decoration: none;
  transition: color var(--dur) var(--ease);
}

.page-about .chronicle__year:hover,
.page-about .chronicle__year:focus-visible {
  color: var(--copper);
}

.page-about .chronicle__year-item:hover::before {
  background: var(--copper);
  border-color: var(--copper);
}

/* ---------- 章节 ---------- */

.page-about .chapter {
  position: relative;
  padding: clamp(44px, 6vw, 76px) 0;
  border-top: 1px solid var(--line-copper-soft);
  scroll-margin-top: 110px;
}

.page-about .chapter:first-child {
  border-top: 0;
  padding-top: 4px;
}

.page-about .chapter--late {
  padding: clamp(36px, 4.6vw, 58px) 0;
}

.page-about .chapter__head {
  position: relative;
  padding-left: 0;
  margin-bottom: clamp(18px, 2.6vw, 28px);
}

.page-about .chapter__num {
  display: inline-block;
  font-size: var(--fs-5);
  letter-spacing: 0.14em;
  color: var(--copper);
}

.page-about .chapter__year {
  display: inline-block;
  margin-left: 14px;
  padding-left: 14px;
  border-left: 1px solid var(--line-copper);
  font-size: var(--fs-5);
  letter-spacing: 0.14em;
  color: var(--silver);
}

.page-about .chapter__title {
  margin: 10px 0 0;
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: var(--fs-2);
  line-height: 1.35;
  color: var(--ink-800);
}

.page-about .chapter__body > p {
  margin: 0 0 18px;
  font-size: var(--fs-4);
  line-height: 1.95;
  color: var(--body-text);
}

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

.page-about .chapter__mark {
  display: flex;
  align-items: baseline;
  gap: 16px;
  margin: 26px 0 26px;
  padding-left: 18px;
  border-left: 2px solid var(--copper);
}

.page-about .yearmark {
  font-size: clamp(40px, 8vw, 68px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--copper);
}

.page-about .chapter__marknote {
  font-size: var(--fs-5);
  line-height: 1.8;
  color: var(--silver);
  max-width: 14ch;
}

.page-about .chapter__foot {
  margin-top: 22px;
  padding-top: 16px;
  border-top: 1px dashed var(--line-paper);
  font-size: var(--fs-5);
  line-height: 2;
  color: var(--silver);
}

/* ---------- 四道工序 ---------- */

.page-about .steps {
  list-style: none;
  margin: 26px 0 0;
  padding: 0 0 0 22px;
  border-left: 1px solid var(--line-copper);
}

.page-about .steps__item {
  position: relative;
  padding: 0 0 26px;
}

.page-about .steps__item:last-child {
  padding-bottom: 4px;
}

.page-about .steps__item::before {
  content: "";
  position: absolute;
  left: -27px;
  top: 6px;
  width: 9px;
  height: 9px;
  background: var(--paper);
  border: 1px solid var(--copper);
  transform: rotate(45deg);
  transition: background var(--dur) var(--ease);
}

.page-about .steps__item:hover::before,
.page-about .steps__item:focus-within::before {
  background: var(--copper);
}

.page-about .steps__num {
  font-size: var(--fs-5);
  letter-spacing: 0.14em;
  color: var(--copper);
}

.page-about .steps__name {
  margin: 6px 0 0;
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: var(--fs-3);
  line-height: 1.4;
  color: var(--ink-800);
}

.page-about .steps__hint {
  margin: 8px 0 0;
  font-size: var(--fs-5);
  line-height: 1.9;
  color: var(--silver);
  max-height: 0;
  opacity: 0;
  overflow: hidden;
  transition: max-height var(--dur) var(--ease), opacity var(--dur) var(--ease), color var(--dur) var(--ease);
}

.page-about .steps__item:hover .steps__hint,
.page-about .steps__item:focus-within .steps__hint {
  max-height: 12em;
  opacity: 1;
  color: var(--body-text);
}

@media (hover: none) {
  .page-about .steps__hint {
    max-height: none;
    opacity: 1;
    color: var(--body-text);
  }
}

@media (min-width: 780px) {
  .page-about .steps {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    column-gap: 0;
    padding: 26px 0 0;
    border-left: 0;
    border-top: 1px solid var(--line-copper);
    margin-top: 30px;
  }
  .page-about .steps__item {
    padding: 6px 22px 8px 0;
  }
  .page-about .steps__item::before {
    left: 0;
    top: -31px;
  }
}

/* ---------- 团队分工 ---------- */

.page-about .chapter__split {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(22px, 3.4vw, 40px);
}

@media (min-width: 820px) {
  .page-about .chapter__split {
    grid-template-columns: minmax(0, 1.3fr) minmax(0, 0.7fr);
    align-items: start;
  }
}

.page-about .chapter__split-main > p {
  margin: 0 0 18px;
  font-size: var(--fs-4);
  line-height: 1.95;
  color: var(--body-text);
}

.page-about .chapter__split-side {
  margin: 0;
}

.page-about .chapter__split-side img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  border: 1px solid var(--line-copper);
  background: var(--paper);
  box-shadow: var(--shadow-card);
}

.page-about .chapter__split-cap {
  margin: 10px 0 0;
  font-size: var(--fs-5);
  line-height: 1.85;
  color: var(--silver);
}

.page-about .roster {
  list-style: none;
  margin: 24px 0 0;
  padding: 0;
  border-top: 1px solid var(--line-paper);
}

.page-about .roster__row {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: baseline;
  gap: 4px 14px;
  padding: 13px 0;
  border-bottom: 1px solid var(--line-paper);
}

.page-about .roster__label {
  font-size: var(--fs-4);
  color: var(--ink-800);
}

.page-about .roster__value {
  font-family: var(--font-mono);
  font-size: var(--fs-3);
  font-weight: 700;
  color: var(--copper);
}

.page-about .roster__note {
  grid-column: 1 / -1;
  font-size: var(--fs-5);
  line-height: 1.8;
  color: var(--silver);
}

/* ---------- 三次转折 ---------- */

.page-about .turns {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0;
}

.page-about .turns__item {
  padding: 20px 0;
  border-bottom: 1px solid var(--line-paper);
}

.page-about .turns__item:first-child {
  border-top: 1px solid var(--line-paper);
}

.page-about .turns__tag {
  display: inline-block;
  padding: 3px 10px;
  border: 1px solid var(--copper-soft);
  font-size: var(--fs-5);
  letter-spacing: 0.12em;
  color: var(--copper);
}

.page-about .turns__name {
  margin: 12px 0 0;
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: var(--fs-3);
  line-height: 1.4;
  color: var(--ink-800);
}

.page-about .turns__text {
  margin: 8px 0 0;
  font-size: var(--fs-4);
  line-height: 1.9;
  color: var(--body-text);
}

@media (min-width: 820px) {
  .page-about .turns {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 0 clamp(20px, 3vw, 34px);
  }
  .page-about .turns__item {
    border-bottom: 0;
    border-top: 1px solid var(--line-copper);
    padding: 20px 0 0;
  }
  .page-about .turns__item:first-child {
    border-top: 1px solid var(--line-copper);
  }
}

/* ---------- 市州盘点 ---------- */

.page-about .region {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(24px, 3.6vw, 44px);
  margin-top: 26px;
}

@media (min-width: 860px) {
  .page-about .region {
    grid-template-columns: minmax(0, 0.42fr) minmax(0, 0.58fr);
    align-items: start;
  }
}

.page-about .region__map {
  background: var(--paper);
  border: 1px solid var(--line-copper-soft);
  padding: 16px;
}

.page-about .region__svg {
  display: block;
  width: 100%;
  max-width: 300px;
  height: auto;
  margin: 0 auto;
}

.page-about .region__outline {
  fill: rgba(31, 90, 74, 0.1);
  stroke: var(--ink-600);
  stroke-width: 1.2;
  stroke-linejoin: round;
}

.page-about .region__pin circle {
  fill: var(--paper);
  stroke: var(--copper);
  stroke-width: 1.2;
}

.page-about .region__pin text {
  font-family: var(--font-mono);
  font-size: 9px;
  fill: var(--ink-800);
  text-anchor: middle;
}

.page-about .region__filter {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin-bottom: 18px;
}

.page-about .region__count {
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: var(--fs-5);
  letter-spacing: 0.08em;
  color: var(--silver);
}

.page-about .region__list {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--line-paper);
}

.page-about .region__item {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 2px 14px;
  padding: 14px 0;
  border-bottom: 1px solid var(--line-paper);
}

.page-about .region__code {
  grid-row: 1 / span 2;
  align-self: start;
  padding-top: 3px;
  font-size: var(--fs-5);
  letter-spacing: 0.1em;
  color: var(--copper);
}

.page-about .region__name {
  margin: 0;
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: var(--fs-4);
  line-height: 1.5;
  color: var(--ink-800);
}

.page-about .region__text {
  margin: 4px 0 0;
  font-size: var(--fs-5);
  line-height: 1.9;
  color: var(--body-text);
}

/* ---------- 收尾 ---------- */

.page-about .about-outro {
  background: var(--ink-900);
  color: var(--ivory);
  padding: clamp(52px, 8vw, 104px) 0 clamp(60px, 9vw, 120px);
  margin-top: clamp(24px, 4vw, 48px);
}

.page-about .about-outro__lead {
  margin: 0;
  max-width: 46ch;
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: var(--fs-3);
  line-height: 1.75;
  color: var(--ivory);
}

.page-about .about-outro__links {
  display: flex;
  flex-direction: column;
  gap: 14px;
  margin-top: clamp(28px, 4vw, 46px);
}

.page-about .about-outro__links .link {
  align-self: flex-start;
  font-size: var(--fs-4);
  color: var(--copper-soft);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color var(--dur) var(--ease), color var(--dur) var(--ease);
}

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

@media (min-width: 760px) {
  .page-about .about-outro__links {
    flex-direction: row;
    flex-wrap: wrap;
    gap: 14px 34px;
  }
}

/* ---------- 焦点与减动效 ---------- */

.page-about a:focus-visible,
.page-about button:focus-visible {
  outline: 2px solid var(--copper);
  outline-offset: 2px;
}

@media (prefers-reduced-motion: reduce) {
  .page-about .steps__hint,
  .page-about .steps__item::before,
  .page-about .chronicle__year,
  .page-about .about-outro__links .link {
    transition: none;
  }
}
<<<END>>>