.page-about {
  --about-rail: 11rem;
  --about-gap: clamp(1.5rem, 4vw, 3.5rem);
}

/* ---------- Hero ---------- */
.page-about .about-hero {
  padding-block: clamp(2.5rem, 7vw, 5rem) clamp(2.5rem, 6vw, 4.5rem);
  border-bottom: 1px solid var(--moss-line);
}

.page-about .about-hero__title {
  margin: 1.25rem 0 0;
  color: var(--paper);
}

.page-about .about-hero__brand {
  display: inline-block;
  margin-top: 0.75rem;
  font-size: 0.36em;
  letter-spacing: 0.04em;
  line-height: 1.25;
  color: var(--cyan);
}

.page-about .about-hero__lede {
  margin-top: 1.5rem;
  color: var(--paper);
  max-width: 36em;
}

.page-about .about-hero__facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1.25rem 1.5rem;
  margin: 2.75rem 0 0;
  padding-top: 1.75rem;
  border-top: 1px solid var(--moss-line);
}

.page-about .about-hero__fact dt {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.16em;
  color: var(--stone);
  margin-bottom: 0.45rem;
}

.page-about .about-hero__fact dd {
  margin: 0;
  font-size: 1.5rem;
  color: var(--cyan);
  line-height: 1.1;
}

.page-about .about-hero__unit {
  font-family: var(--font-sans);
  font-size: 0.8125rem;
  letter-spacing: 0;
  color: var(--stone);
  margin-left: 0.35rem;
}

/* ---------- 画册式跨栏 ---------- */
.page-about .about-chapter {
  padding-block: clamp(3rem, 7vw, 5.5rem);
}

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

.page-about .about-spread__rail {
  display: flex;
  align-items: baseline;
  gap: 1rem;
  padding-bottom: 0.75rem;
  border-bottom: 1px solid var(--moss-line);
}

.page-about .about-year {
  margin: 0;
  display: flex;
  align-items: baseline;
  gap: 0.75rem;
}

.page-about .about-year__num {
  font-family: var(--font-mono);
  font-size: 1.375rem;
  letter-spacing: 0.08em;
  line-height: 1.1;
  color: var(--cyan);
}

.page-about .about-year__label {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.16em;
  color: var(--stone);
}

.page-about .about-chapter__title {
  margin: 0 0 1.25rem;
  font-size: clamp(1.5rem, 3.6vw, 2.25rem);
  font-weight: 700;
  line-height: 1.25;
  letter-spacing: -0.01em;
}

.page-about .about-chapter__lede {
  margin: 0 0 1.75rem;
  max-width: 34em;
}

/* 分区配色 */
.page-about .section--paper .about-chapter__title,
.page-about .section--paper .prose,
.page-about .section--paper .about-chapter__lede {
  color: var(--ink);
}

.page-about .section--paper .about-year__num {
  color: var(--clay);
}

.page-about .section--paper .about-spread__rail {
  border-bottom-color: rgba(7, 26, 22, 0.18);
}

.page-about .section--ink .about-chapter__title,
.page-about .section--moss .about-chapter__title {
  color: var(--paper);
}

.page-about .section--ink .prose,
.page-about .section--moss .prose,
.page-about .section--ink .about-chapter__lede,
.page-about .section--moss .about-chapter__lede {
  color: var(--stone);
}

.page-about .section--ink .about-spread__rail,
.page-about .section--moss .about-spread__rail {
  border-bottom-color: var(--moss-line);
}

.page-about .section--ink .about-year__label,
.page-about .section--moss .about-year__label {
  color: var(--stone);
}

/* ---------- 图片 ---------- */
.page-about .about-figure {
  margin: 2rem 0 0;
}

.page-about .about-figure--team {
  margin-top: 2.25rem;
}

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

/* ---------- 折线示意 ---------- */
.page-about .about-trend {
  display: block;
  width: 100%;
  height: auto;
  margin: 0.5rem 0 2rem;
}

/* ---------- 六个层级 ---------- */
.page-about .about-levels {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--moss-line);
  border: 1px solid var(--moss-line);
}

.page-about .about-level {
  display: grid;
  grid-template-columns: 1.75rem minmax(0, 1fr);
  gap: 0.3rem 0.9rem;
  padding: 1.15rem 1.15rem 1.25rem;
  background: var(--ink-2);
}

.page-about .about-level__no {
  grid-column: 1;
  grid-row: 1 / span 2;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.16em;
  color: var(--cyan);
  padding-top: 0.3rem;
}

.page-about .about-level__name {
  grid-column: 2;
  margin: 0;
  font-size: 1.0625rem;
  font-weight: 500;
  color: var(--paper);
  line-height: 1.5;
}

.page-about .about-level__text {
  grid-column: 2;
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.7;
  color: var(--stone);
}

/* ---------- 团队分段 ---------- */
.page-about .about-team {
  margin-top: 0.5rem;
}

.page-about .about-team .tabs__list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.25rem 1.5rem;
  border-bottom: 1px solid rgba(7, 26, 22, 0.18);
  padding-bottom: 0;
}

.page-about .about-team .tabs__tab {
  appearance: none;
  background: transparent;
  border: 0;
  border-bottom: 2px solid transparent;
  margin-bottom: -1px;
  padding: 0.55rem 0.15rem 0.7rem;
  font: inherit;
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  letter-spacing: 0.16em;
  color: var(--ink);
  opacity: 0.5;
  cursor: pointer;
  transition: opacity 180ms ease, border-color 180ms ease;
}

.page-about .about-team .tabs__tab:hover {
  opacity: 0.82;
}

.page-about .about-team .tabs__tab[aria-selected="true"] {
  opacity: 1;
  border-bottom-color: var(--moss);
}

.page-about .about-team .tabs__tab:focus-visible {
  outline: 2px solid var(--moss);
  outline-offset: 3px;
}

.page-about .about-team__panel {
  padding-top: 1.5rem;
}

.page-about .about-team__panel + .about-team__panel {
  margin-top: 1.75rem;
  padding-top: 1.5rem;
  border-top: 1px dashed rgba(7, 26, 22, 0.18);
}

.page-about .about-team__title {
  margin: 0 0 0.75rem;
  font-size: 1.125rem;
  font-weight: 500;
  color: var(--ink);
}

.page-about .about-team__panel p {
  margin: 0 0 1rem;
  max-width: 34em;
  line-height: 1.75;
  color: var(--ink);
}

.page-about .about-role__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0.55rem;
}

.page-about .about-role__list li {
  position: relative;
  padding-left: 1.25rem;
  font-size: 0.9375rem;
  line-height: 1.7;
  color: var(--ink);
  opacity: 0.82;
}

.page-about .about-role__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.7em;
  width: 0.5rem;
  height: 1px;
  background: var(--moss);
}

/* ---------- 四条准则 ---------- */
.page-about .about-rules {
  margin-top: 0.5rem;
  border-top: 1px solid var(--moss-line);
}

.page-about .about-rule {
  border-bottom: 1px solid var(--moss-line);
}

.page-about .about-rule__heading {
  margin: 0;
  font-size: inherit;
  font-weight: inherit;
}

.page-about .about-rule__head {
  appearance: none;
  display: grid;
  grid-template-columns: 2.25rem minmax(0, 1fr) 1.25rem;
  align-items: center;
  gap: 0.9rem;
  width: 100%;
  background: transparent;
  border: 0;
  padding: 1.25rem 0;
  font: inherit;
  text-align: left;
  color: var(--paper);
  cursor: pointer;
}

.page-about .about-rule__head:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 3px;
}

.page-about .about-rule__no {
  font-family: var(--font-mono);
  font-size: 0.875rem;
  letter-spacing: 0.16em;
  color: var(--cyan);
}

.page-about .about-rule__title {
  font-size: 1.0625rem;
  font-weight: 500;
  line-height: 1.5;
}

.page-about .about-rule__mark {
  position: relative;
  width: 1.25rem;
  height: 1.25rem;
}

.page-about .about-rule__mark::before,
.page-about .about-rule__mark::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  top: 50%;
  height: 1px;
  background: var(--cyan);
}

.page-about .about-rule__mark::after {
  transform: rotate(90deg);
  transition: transform 180ms ease;
}

.page-about .about-rule__head[aria-expanded="false"] .about-rule__mark::after {
  transform: rotate(0deg);
}

.page-about .about-rule__body {
  padding: 0 0 1.5rem 0;
}

.page-about .about-rule__body p {
  margin: 0;
  max-width: 34em;
  font-size: 0.9375rem;
  line-height: 1.8;
  color: var(--stone);
}

/* ---------- 规模 ---------- */
.page-about .about-scale__grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: rgba(7, 26, 22, 0.16);
  border: 1px solid rgba(7, 26, 22, 0.16);
  margin-top: 1.5rem;
}

.page-about .about-stat {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
  padding: 1.25rem 1.15rem 1.4rem;
  background: var(--ink-2);
}

.page-about .about-stat__num {
  font-size: clamp(1.5rem, 3vw, 2.125rem);
  line-height: 1.05;
  color: var(--cyan);
}

.page-about .about-stat__unit {
  font-family: var(--font-sans);
  font-size: 0.8125rem;
  color: var(--stone);
  margin-left: 0.3rem;
  letter-spacing: 0;
}

.page-about .about-stat__key {
  font-size: 0.9375rem;
  font-weight: 500;
  color: var(--paper);
}

.page-about .about-stat__note {
  font-size: 0.8125rem;
  line-height: 1.65;
  color: var(--stone);
}

.page-about .about-partner {
  margin-top: 2.5rem;
  padding-top: 1.75rem;
  border-top: 1px solid rgba(7, 26, 22, 0.16);
}

.page-about .about-partner__title {
  margin: 0 0 0.75rem;
  font-size: 1.125rem;
  font-weight: 500;
  color: var(--ink);
}

.page-about .about-partner p {
  margin: 0 0 1rem;
  max-width: 34em;
  line-height: 1.75;
  color: var(--ink);
}

.page-about .about-partner__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 1.75rem;
}

/* ---------- 里程碑 ---------- */
.page-about .about-track {
  list-style: none;
  margin: 1.75rem 0 0;
  padding: 0 0 0 1.4rem;
  border-left: 2px solid var(--moss-line);
  display: grid;
  gap: 1.5rem;
}

.page-about .about-track__item {
  position: relative;
}

.page-about .about-track__item::before {
  content: "";
  position: absolute;
  left: calc(-1.4rem - 6px);
  top: 0.42rem;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--stone);
}

.page-about .about-track__item--now::before {
  background: var(--cyan);
}

.page-about .about-track__stage {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.16em;
  color: var(--cyan);
  margin-bottom: 0.4rem;
}

.page-about .about-track__text {
  margin: 0;
  max-width: 34em;
  font-size: 0.9375rem;
  line-height: 1.75;
  color: var(--stone);
}

/* ---------- 结尾指引 ---------- */
.page-about .about-cta {
  margin-top: 3rem;
  padding-top: 2rem;
  border-top: 1px solid var(--moss-line);
}

.page-about .about-cta__text {
  margin: 0 0 1.5rem;
  max-width: 34em;
  font-size: 1.0625rem;
  line-height: 1.75;
  color: var(--paper);
}

.page-about .about-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem 1rem;
  margin: 0;
}

/* ---------- 中屏起进入画册跨栏 ---------- */
@media (min-width: 40rem) {
  .page-about .about-level {
    grid-template-columns: 2.25rem minmax(0, 1fr);
    padding: 1.35rem 1.5rem 1.45rem;
  }

  .page-about .about-level__no {
    font-size: 0.8125rem;
  }

  .page-about .about-rule__body {
    padding-left: 3.15rem;
  }
}

@media (min-width: 56rem) {
  .page-about .about-spread {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: var(--about-gap);
  }

  .page-about .about-spread__rail {
    display: block;
    position: sticky;
    top: calc(var(--rail-h) + 2.5rem);
    align-self: start;
    padding-bottom: 1rem;
    border-bottom: 0;
    border-left: 1px solid var(--moss-line);
    padding-left: 1.25rem;
  }

  .page-about .section--paper .about-spread__rail {
    border-left-color: rgba(7, 26, 22, 0.18);
    border-bottom-color: transparent;
  }

  .page-about .about-year {
    display: block;
    margin-top: 0.75rem;
  }

  .page-about .about-year__num {
    display: block;
    font-size: 2.25rem;
    line-height: 1;
    margin-bottom: 0.6rem;
  }

  .page-about .about-year__label {
    display: block;
    line-height: 1.6;
  }

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

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

@media (min-width: 72rem) {
  .page-about .about-hero__fact dd {
    font-size: 1.75rem;
  }

  .page-about .about-year__num {
    font-size: 2.75rem;
  }
}
<<<END>>>