.page-about {
  background: var(--paper);
  color: var(--ink);
}

/* ---------- 面包屑 ---------- */
.page-about .breadcrumb {
  padding-block: 18px 4px;
}

/* ---------- 首屏：左竖排索引 + 右正文 ---------- */
.page-about .story-hero {
  padding-block: 24px 56px;
}

@media (min-width: 900px) {
  .page-about .story-hero {
    display: grid;
    grid-template-columns: 200px minmax(0, 1fr);
    gap: 52px;
    padding-block: 52px 96px;
  }
}

.page-about .story-rail {
  margin-bottom: 30px;
  padding-bottom: 18px;
  border-bottom: 1px solid var(--rule);
}

@media (min-width: 900px) {
  .page-about .story-rail {
    position: sticky;
    top: 104px;
    align-self: start;
    margin-bottom: 0;
    padding-bottom: 0;
    padding-right: 22px;
    border-bottom: 0;
    border-right: 1px solid var(--rule);
  }
}

.page-about .story-rail__label {
  display: inline-block;
  font-family: var(--font-read);
  font-size: 13px;
  letter-spacing: 0.24em;
  color: var(--gray-ink);
  margin-bottom: 10px;
}

@media (min-width: 900px) {
  .page-about .story-rail__label {
    writing-mode: vertical-rl;
    height: 104px;
    margin-bottom: 16px;
    letter-spacing: 0.3em;
  }
}

.page-about .story-rail__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 6px 14px;
}

@media (min-width: 900px) {
  .page-about .story-rail__list {
    flex-direction: column;
    flex-wrap: nowrap;
    gap: 2px;
  }
}

.page-about .story-rail__link {
  display: block;
  padding: 9px 12px;
  min-height: 44px;
  font-family: var(--font-display);
  font-size: 14px;
  font-weight: 500;
  color: var(--ink-mid);
  text-decoration: none;
  border-left: 2px solid transparent;
  transition: border-color 160ms ease, color 160ms ease, background-color 160ms ease;
}

.page-about .story-rail__link:hover,
.page-about .story-rail__link:focus-visible {
  border-left-color: var(--seal);
  color: var(--ink);
  background: var(--paper-light);
  outline: none;
}

@media (min-width: 900px) {
  .page-about .story-rail__link {
    padding: 7px 0 7px 14px;
    min-height: 0;
    background: transparent;
  }
  .page-about .story-rail__link:hover,
  .page-about .story-rail__link:focus-visible {
    background: transparent;
  }
}

.page-about .story-hero__body h1 {
  font-family: var(--font-display);
  font-weight: 900;
  letter-spacing: -0.02em;
  line-height: 1.14;
  font-size: clamp(30px, 6.4vw, 58px);
  color: var(--ink);
  margin: 20px 0 24px;
  max-width: 15em;
}

.page-about .story-hero__body .lede {
  max-width: 34em;
  font-family: var(--font-read);
  font-size: 19px;
  line-height: 1.8;
  color: var(--ink-mid);
  margin: 0 0 22px;
}

.page-about .story-hero__note {
  max-width: 34em;
  font-family: var(--font-read);
  font-size: 15px;
  line-height: 1.85;
  color: var(--gray-ink);
  margin: 0;
  padding-top: 18px;
  border-top: 1px solid var(--rule);
}

/* ---------- 通用章节 ---------- */
.page-about .story-section {
  padding-block: 64px;
}

@media (min-width: 900px) {
  .page-about .story-section {
    padding-block: 96px;
  }
}

.page-about .story-section h2 {
  font-family: var(--font-display);
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.24;
  font-size: clamp(24px, 3.6vw, 34px);
  color: var(--ink);
  margin: 16px 0 22px;
  max-width: 20em;
}

.page-about .story-section h3 {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 17px;
  letter-spacing: -0.01em;
  color: var(--ink);
  margin: 0 0 8px;
}

.page-about .story-column {
  max-width: 68ch;
}

.page-about .story-column p {
  font-family: var(--font-read);
  font-size: 16px;
  line-height: 1.85;
  color: var(--ink-mid);
  margin: 0 0 20px;
}

.page-about .story-section .prose {
  max-width: 68ch;
  font-family: var(--font-read);
  font-size: 16px;
  line-height: 1.85;
  color: var(--ink-mid);
}

.page-about .story-section > .container > .prose {
  margin-bottom: 0;
}

/* ---------- 引言 ---------- */
.page-about .pull-quote {
  margin: 32px 0;
  padding: 6px 0 6px 22px;
  border-left: 3px solid var(--seal);
}

.page-about .pull-quote p {
  font-family: var(--font-read);
  font-size: clamp(19px, 2.4vw, 24px);
  line-height: 1.7;
  color: var(--ink);
  margin: 0;
}

/* ---------- 编号示例带 ---------- */
.page-about .code-band {
  margin-top: 40px;
  background: var(--paper-light);
  border-top: 2px solid var(--ink);
  border-bottom: 1px solid var(--ink);
  overflow-x: auto;
}

.page-about .code-band__inner {
  padding-block: 0;
}

.page-about .code-band__strip {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  min-width: 720px;
}

.page-about .code-band__seg {
  position: relative;
  flex: 1 1 0;
  min-width: 168px;
  padding: 26px 22px 20px;
  border-left: 1px solid var(--rule);
  cursor: default;
  outline: none;
}

.page-about .code-band__seg:first-child {
  border-left: 0;
}

.page-about .code-band__seg::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--seal);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform 160ms ease;
}

.page-about .code-band__seg:hover::before,
.page-about .code-band__seg:focus-visible::before {
  transform: scaleX(1);
}

.page-about .code-band__text {
  display: block;
  font-family: var(--font-mono);
  font-size: 27px;
  font-weight: 600;
  letter-spacing: 0.02em;
  color: var(--ink);
  line-height: 1.2;
}

.page-about .code-band__label {
  display: block;
  margin-top: 8px;
  font-family: var(--font-read);
  font-size: 13px;
  line-height: 1.6;
  color: var(--gray-ink);
}

.page-about .code-band__hint {
  display: block;
  max-height: 0;
  overflow: hidden;
  opacity: 0;
  margin-top: 0;
  font-family: var(--font-read);
  font-size: 13px;
  line-height: 1.75;
  color: var(--ink-mid);
  transition: max-height 160ms ease, opacity 160ms ease, margin-top 160ms ease;
}

.page-about .code-band__seg:hover .code-band__hint,
.page-about .code-band__seg:focus-visible .code-band__hint,
.page-about .code-band__seg:focus .code-band__hint {
  max-height: 10em;
  opacity: 1;
  margin-top: 12px;
}

.page-about .code-band__footnote {
  margin-top: 18px;
}

.page-about .code-band__footnote .annotation {
  font-family: var(--font-read);
  font-size: 13px;
  line-height: 1.8;
  color: var(--gray-ink);
}

/* ---------- 四类索引 ---------- */
.page-about .index-grid {
  margin-top: 56px;
}

@media (min-width: 900px) {
  .page-about .index-grid {
    display: grid;
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    gap: 52px;
  }
}

.page-about .index-grid__main p {
  font-family: var(--font-read);
  font-size: 16px;
  line-height: 1.85;
  color: var(--ink-mid);
  margin: 0;
}

.page-about .index-grid__main h3 {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 19px;
  color: var(--ink);
  margin: 0 0 12px;
}

.page-about .index-grid__list {
  list-style: none;
  margin: 28px 0 0;
  padding: 0;
}

@media (min-width: 900px) {
  .page-about .index-grid__list {
    margin-top: 0;
  }
}

.page-about .index-item {
  padding: 20px 0;
  border-top: 1px solid var(--rule);
}

.page-about .index-item:last-child {
  border-bottom: 1px solid var(--rule);
}

.page-about .index-item p {
  margin: 10px 0 0;
  font-family: var(--font-read);
  font-size: 15px;
  line-height: 1.8;
  color: var(--gray-ink);
  max-width: 44ch;
}

/* ---------- 更新节奏 ---------- */
.page-about .cadence {
  display: grid;
  gap: 36px;
}

@media (min-width: 900px) {
  .page-about .cadence {
    grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
    gap: 56px;
    align-items: start;
  }
}

.page-about .cadence-list {
  list-style: none;
  margin: 30px 0 0;
  padding: 0;
}

.page-about .cadence-item {
  padding: 24px 0;
  border-top: 1px solid var(--rule);
}

.page-about .cadence-item:last-child {
  border-bottom: 1px solid var(--rule);
}

.page-about .cadence-item__head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 10px 14px;
  margin-bottom: 10px;
}

.page-about .cadence-item__head h3 {
  margin: 0;
}

.page-about .cadence-item p {
  font-family: var(--font-read);
  font-size: 15px;
  line-height: 1.85;
  color: var(--ink-mid);
  margin: 0;
}

.page-about .cadence__side {
  padding-top: 24px;
  border-top: 2px solid var(--ink);
}

@media (min-width: 900px) {
  .page-about .cadence__side {
    position: sticky;
    top: 112px;
  }
}

.page-about .cadence__side p {
  font-family: var(--font-read);
  font-size: 15px;
  line-height: 1.85;
  color: var(--ink-mid);
  margin: 14px 0 0;
}

.page-about .cadence__side-note {
  color: var(--gray-ink) !important;
  font-size: 13px !important;
  padding-top: 12px;
  border-top: 1px solid var(--rule);
}

.page-about .annotation-v {
  display: inline-block;
  font-family: var(--font-read);
  font-size: 13px;
  letter-spacing: 0.22em;
  color: var(--gray-ink);
}

@media (min-width: 900px) {
  .page-about .annotation-v {
    writing-mode: vertical-rl;
    height: 84px;
  }
}

/* ---------- 折叠说明 ---------- */
.page-about .story-disclosure {
  margin-top: 26px;
}

/* ---------- 影像 ---------- */
.page-about .story-figure {
  margin: 0;
}

.page-about .story-figure--wide {
  padding-block: 8px;
}

.page-about .story-figure .figure__media {
  overflow: hidden;
  background: var(--paper-light);
  border-top: 2px solid var(--ink);
  border-bottom: 1px solid var(--rule);
}

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

.page-about .story-figure--wide .figure__media img {
  aspect-ratio: 7 / 4;
}

.page-about .story-figure .figure__caption {
  margin-top: 12px;
  font-family: var(--font-read);
  font-size: 13px;
  line-height: 1.8;
  color: var(--gray-ink);
  max-width: 60ch;
}

.page-about .story-section--media {
  padding-block: 56px;
}

@media (min-width: 900px) {
  .page-about .story-section--media {
    padding-block: 72px;
  }
}

.page-about .story-figure--boxed .figure__media {
  max-width: 720px;
}

.page-about .story-figure--boxed .figure__media img {
  aspect-ratio: 4 / 3;
}

/* ---------- 维护分工 ---------- */
.page-about .division__intro {
  max-width: 62ch;
  margin-bottom: 36px;
}

.page-about .division-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--rule);
  border-top: 2px solid var(--ink);
  border-bottom: 1px solid var(--ink);
}

@media (min-width: 900px) {
  .page-about .division-list {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

.page-about .division-item {
  background: var(--paper);
  padding: 24px 20px 28px;
}

.page-about .division-item__num {
  display: block;
  font-family: var(--font-mono);
  font-size: 40px;
  font-weight: 600;
  line-height: 1;
  letter-spacing: 0.02em;
  color: var(--bronze);
  margin-bottom: 14px;
}

.page-about .division-item h3 {
  font-size: 16px;
  margin-bottom: 8px;
}

.page-about .division-item p {
  font-family: var(--font-read);
  font-size: 14px;
  line-height: 1.8;
  color: var(--gray-ink);
  margin: 0;
}

/* ---------- 服务范围（深底反白） ---------- */
.page-about .story-scope {
  background: var(--ink);
  color: var(--paper);
}

.page-about .story-scope h2 {
  color: var(--paper);
}

.page-about .scope-grid {
  display: grid;
  gap: 32px;
  margin-top: 22px;
}

@media (min-width: 900px) {
  .page-about .scope-grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: 56px;
    align-items: start;
  }
}

.page-about .scope-grid__main p {
  font-family: var(--font-read);
  font-size: 16px;
  line-height: 1.85;
  color: rgba(244, 239, 230, 0.82);
  margin: 0 0 18px;
}

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

.page-about .scope-grid__facts {
  margin: 0;
  border-top: 1px solid rgba(244, 239, 230, 0.28);
}

.page-about .scope-fact {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 16px;
  padding: 14px 0;
  border-bottom: 1px solid rgba(244, 239, 230, 0.18);
}

.page-about .scope-fact dt {
  font-family: var(--font-read);
  font-size: 13px;
  color: rgba(244, 239, 230, 0.62);
  flex: 0 0 auto;
}

.page-about .scope-fact dd {
  margin: 0;
  font-family: var(--font-display);
  font-size: 15px;
  font-weight: 600;
  color: var(--paper);
  text-align: right;
}

.page-about .scope-grid__footnote {
  margin: 32px 0 0;
  padding-top: 18px;
  border-top: 1px solid rgba(244, 239, 230, 0.28);
  font-family: var(--font-read);
  font-size: 13px;
  line-height: 1.8;
  color: rgba(244, 239, 230, 0.62);
}

/* ---------- 三条查询路径 ---------- */
.page-about .path-grid {
  display: grid;
  margin-top: 36px;
  border-top: 2px solid var(--ink);
  border-bottom: 1px solid var(--ink);
}

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

.page-about .path-item {
  display: block;
  position: relative;
  padding: 26px 0 28px;
  text-decoration: none;
  color: inherit;
  border-bottom: 1px solid var(--rule);
  transition: background-color 160ms ease;
}

.page-about .path-item:last-child {
  border-bottom: 0;
}

@media (min-width: 900px) {
  .page-about .path-item {
    padding: 32px 26px 34px;
    border-bottom: 0;
    border-right: 1px solid var(--rule);
  }
  .page-about .path-item:last-child {
    border-right: 0;
  }
}

.page-about .path-item::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--seal);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform 160ms ease;
}

.page-about .path-item:hover::before,
.page-about .path-item:focus-visible::before {
  transform: scaleX(1);
}

.page-about .path-item:hover,
.page-about .path-item:focus-visible {
  background: var(--paper-light);
  outline: none;
}

.page-about .path-item__code {
  display: block;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.08em;
  color: var(--seal);
  margin-bottom: 14px;
}

.page-about .path-item h3 {
  font-size: 19px;
  margin: 0 0 12px;
}

.page-about .path-item p {
  font-family: var(--font-read);
  font-size: 15px;
  line-height: 1.85;
  color: var(--gray-ink);
  margin: 0 0 18px;
}

.page-about .path-item__go {
  display: inline-block;
  font-family: var(--font-display);
  font-size: 14px;
  font-weight: 600;
  color: var(--ink);
  padding-bottom: 3px;
  border-bottom: 1px solid var(--ink-mid);
  transition: border-color 160ms ease, color 160ms ease;
}

.page-about .path-item:hover .path-item__go,
.page-about .path-item:focus-visible .path-item__go {
  color: var(--seal);
  border-bottom-color: var(--seal);
}

.page-about .path-secondary {
  margin-top: 32px;
  padding-top: 20px;
  border-top: 1px solid var(--rule);
}

.page-about .path-secondary p {
  font-family: var(--font-read);
  font-size: 15px;
  line-height: 1.85;
  color: var(--gray-ink);
  margin: 0;
  max-width: 66ch;
}

@media (prefers-reduced-motion: reduce) {
  .page-about .code-band__seg::before,
  .page-about .code-band__hint,
  .page-about .path-item::before,
  .page-about .story-rail__link,
  .page-about .path-item__go,
  .page-about .path-item {
    transition: none;
  }
}
<<<END>>>