.page-about {
  --about-rail: 216px;
  --about-gap: 64px;
  display: block;
}

/* ---------- 首屏框景 ---------- */
.page-about .about-hero {
  padding: 26px 0 56px;
  border-bottom: 1px solid var(--line);
  background: linear-gradient(180deg, rgba(236, 228, 214, 0.72) 0%, rgba(245, 240, 230, 0) 78%);
}

.page-about .about-hero .crumbs {
  margin-bottom: 22px;
  font-size: 13px;
  color: var(--ash);
}

.page-about .about-hero__frame {
  position: relative;
  padding: 30px 20px 28px;
  border: 1px solid var(--line);
  background-color: var(--paper);
  background-image: repeating-linear-gradient(90deg, var(--line-soft) 0 1px, transparent 1px 104px);
}

.page-about .about-hero__frame::before,
.page-about .about-hero__frame::after {
  content: "";
  position: absolute;
  width: 16px;
  height: 16px;
}

.page-about .about-hero__frame::before {
  top: -1px;
  left: -1px;
  border-top: 2px solid var(--sand);
  border-left: 2px solid var(--sand);
}

.page-about .about-hero__frame::after {
  right: -1px;
  bottom: -1px;
  border-right: 2px solid var(--sand);
  border-bottom: 2px solid var(--sand);
}

.page-about .about-hero__tag {
  margin: 0 0 16px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--sand);
}

.page-about .about-hero__title {
  margin: 0 0 20px;
  max-width: 860px;
  font-size: 30px;
  line-height: 1.3;
  font-weight: 900;
  letter-spacing: -0.01em;
  color: var(--ink);
}

.page-about .about-hero__lede {
  max-width: 660px;
  margin: 0;
  color: var(--ash);
}

.page-about .about-hero__facts {
  display: grid;
  gap: 18px;
  margin: 30px 0 0;
  padding: 24px 0 0;
  border-top: 1px solid var(--line);
}

.page-about .about-hero__fact dt {
  margin: 0 0 6px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--ash);
}

.page-about .about-hero__fact dd {
  margin: 0;
  font-size: 16px;
  color: var(--ink);
}

.page-about .about-hero__num {
  font-family: var(--font-mono);
  font-size: 24px;
  letter-spacing: 0.02em;
  color: var(--dusk);
}

/* ---------- 两栏骨架 ---------- */
.page-about .about-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 40px;
  padding: 44px 0 96px;
}

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

/* ---------- 左侧章号索引 ---------- */
.page-about .about-rail__title {
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--ash);
}

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

.page-about .about-rail__link {
  position: relative;
  display: grid;
  grid-template-columns: 32px minmax(0, 1fr);
  gap: 8px;
  align-items: baseline;
  padding: 9px 8px 9px 16px;
  font-size: 14px;
  line-height: 1.5;
  color: var(--ash);
  text-decoration: none;
  transition: color 140ms var(--ease), background-color 140ms var(--ease);
}

.page-about .about-rail__link::before {
  content: "";
  position: absolute;
  left: -1px;
  top: 50%;
  width: 10px;
  height: 1px;
  background: var(--line-dusk);
  transform: translateY(-50%);
  transition: width 140ms var(--ease), background-color 140ms var(--ease);
}

.page-about .about-rail__link:hover,
.page-about .about-rail__link:focus-visible {
  color: var(--ink);
  background: rgba(230, 211, 164, 0.28);
}

.page-about .about-rail__link:hover::before,
.page-about .about-rail__link:focus-visible::before {
  width: 24px;
  background: var(--sand);
}

.page-about .about-rail__no {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--dusk);
}

/* ---------- 章节 ---------- */
.page-about .about-chapter {
  padding: 0 0 60px;
}

.page-about .about-chapter + .about-chapter,
.page-about .about-cta {
  padding-top: 56px;
  border-top: 1px solid var(--line);
}

.page-about .about-chapter + .about-chapter {
  padding-bottom: 60px;
}

.page-about .about-chapter__no {
  display: flex;
  align-items: center;
  gap: 12px;
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.14em;
  color: var(--sand);
}

.page-about .about-chapter__no::after {
  content: "";
  width: 46px;
  height: 1px;
  background: var(--sand);
}

/* ---------- 图片来源 ---------- */
.page-about .about-sources {
  margin: 28px 0 0;
  border-top: 1px solid var(--line);
}

.page-about .about-sources__row {
  display: grid;
  gap: 8px;
  padding: 20px 0;
  border-bottom: 1px solid var(--line-soft);
}

.page-about .about-sources__term {
  font-size: 17px;
  font-weight: 700;
  color: var(--ink);
}

.page-about .about-sources__desc {
  margin: 0;
  max-width: 660px;
  font-size: 16px;
  line-height: 1.8;
  color: var(--ash);
}

/* ---------- 图片 ---------- */
.page-about .about-figure {
  margin: 32px 0 0;
}

.page-about .about-figure .figure__inner {
  overflow: hidden;
  border: 1px solid var(--line);
  background: var(--paper-2);
  aspect-ratio: 11 / 6;
}

.page-about .about-figure--team .figure__inner {
  aspect-ratio: 10 / 7;
}

.page-about .about-figure--band {
  margin: 0 0 56px;
}

.page-about .about-figure--band .figure__inner {
  aspect-ratio: 16 / 5;
}

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

/* ---------- 归档刻度条 ---------- */
.page-about .about-scale {
  margin: 28px 0 0;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--line);
}

.page-about .about-scale__row {
  display: grid;
  grid-template-columns: 86px minmax(0, 1fr) 46px;
  align-items: center;
  gap: 12px;
  padding: 14px 0;
  border-bottom: 1px solid var(--line-soft);
  outline-offset: 3px;
}

.page-about .about-scale__name {
  font-size: 15px;
  color: var(--ink);
}

.page-about .about-scale__track {
  display: block;
  height: 6px;
  background: var(--paper-2);
}

.page-about .about-scale__bar {
  display: block;
  height: 100%;
}

.page-about .about-scale__bar--a {
  width: 40%;
  background: var(--dusk);
}

.page-about .about-scale__bar--b {
  width: 27%;
  background: var(--dusk-soft);
}

.page-about .about-scale__bar--c {
  width: 20%;
  background: var(--sand);
}

.page-about .about-scale__bar--d {
  width: 13%;
  background: var(--brick-soft);
}

.page-about .about-scale__num {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.06em;
  text-align: right;
  color: var(--dusk);
}

.page-about .about-scale__note {
  grid-column: 2 / -1;
  margin: 0;
  max-height: 0;
  overflow: hidden;
  opacity: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  line-height: 1.6;
  color: var(--ash);
  transition: max-height 180ms var(--ease), opacity 180ms var(--ease);
}

.page-about .about-scale__row:hover .about-scale__note,
.page-about .about-scale__row:focus-within .about-scale__note {
  max-height: 48px;
  opacity: 1;
}

/* ---------- 更新节奏 ---------- */
.page-about .about-cadence {
  margin: 28px 0 0;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--line);
}

.page-about .about-cadence__item {
  padding: 20px 0 20px 18px;
  border-bottom: 1px solid var(--line-soft);
  border-left: 2px solid var(--sand-soft);
}

.page-about .about-cadence__label {
  margin: 0 0 8px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.1em;
  color: var(--brick);
}

.page-about .about-cadence__text {
  margin: 0;
  max-width: 660px;
  font-size: 16px;
  line-height: 1.8;
  color: var(--ink);
}

/* ---------- 团队 ---------- */
.page-about .about-team {
  display: grid;
  gap: 32px;
  margin-top: 28px;
}

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

.page-about .about-roles__item {
  display: grid;
  grid-template-columns: 10px minmax(0, 1fr);
  gap: 18px;
  padding: 18px 0;
  border-bottom: 1px solid var(--line-soft);
}

.page-about .about-roles__gauge {
  position: relative;
  display: block;
  width: 6px;
  height: 68px;
  background: var(--line-soft);
}

.page-about .about-roles__gauge::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: 100%;
  height: var(--h, 50%);
  background: var(--dusk);
}

.page-about .about-roles__item--edit {
  --h: 100%;
}

.page-about .about-roles__item--review {
  --h: 75%;
}

.page-about .about-roles__item--tech {
  --h: 50%;
}

.page-about .about-roles__role {
  margin: 0 0 8px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--dusk);
}

.page-about .about-roles__desc {
  margin: 0;
  font-size: 16px;
  line-height: 1.8;
  color: var(--ash);
}

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

/* ---------- 发展节点 ---------- */
.page-about .about-phases {
  margin: 32px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-phases__item {
  position: relative;
  padding: 24px 20px 20px 0;
}

.page-about .about-phases__item::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 1px;
  background: var(--line-dusk);
}

.page-about .about-phases__item::after {
  content: "";
  position: absolute;
  top: -5px;
  left: 0;
  width: 1px;
  height: 11px;
  background: var(--sand);
}

.page-about .about-phases__no {
  margin: 0 0 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--sand);
}

.page-about .about-phases__title {
  margin: 0 0 8px;
  font-size: 20px;
  font-weight: 800;
  letter-spacing: -0.01em;
  color: var(--ink);
}

.page-about .about-phases__text {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--ash);
}

/* ---------- 收尾入口 ---------- */
.page-about .about-cta {
  padding-bottom: 8px;
}

.page-about .about-cta__grid {
  display: grid;
  gap: 0;
  margin-top: 26px;
  border-top: 1px solid var(--line);
}

.page-about .about-cta__card {
  display: block;
  padding: 22px 4px 22px 0;
  border-bottom: 1px solid var(--line-soft);
  text-decoration: none;
  color: inherit;
  transition: background-color 140ms var(--ease), padding-left 140ms var(--ease);
}

.page-about .about-cta__card:hover,
.page-about .about-cta__card:focus-visible {
  background: rgba(230, 211, 164, 0.3);
  padding-left: 12px;
}

.page-about .about-cta__no {
  display: block;
  margin-bottom: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--sand);
}

.page-about .about-cta__label {
  display: block;
  margin-bottom: 8px;
  font-size: 18px;
  font-weight: 700;
  color: var(--ink);
}

.page-about .about-cta__text {
  display: block;
  max-width: 420px;
  font-size: 15px;
  line-height: 1.8;
  color: var(--ash);
}

/* ---------- 断点 ---------- */
@media (min-width: 560px) {
  .page-about .about-hero__frame {
    padding: 40px 32px 36px;
  }

  .page-about .about-hero__title {
    font-size: 40px;
  }

  .page-about .about-hero__facts {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 0;
  }

  .page-about .about-hero__fact + .about-hero__fact {
    padding-left: 24px;
    border-left: 1px solid var(--line);
  }

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

  .page-about .about-cta__grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .about-cta__card {
    padding: 24px;
    border-right: 1px solid var(--line-soft);
  }

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

@media (min-width: 720px) {
  .page-about .about-team {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    align-items: start;
    gap: 40px;
  }

  .page-about .about-sources__row {
    grid-template-columns: 200px minmax(0, 1fr);
    gap: 24px;
    align-items: baseline;
  }
}

@media (min-width: 860px) {
  .page-about .about-phases {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .about-phases__item {
    padding: 26px 26px 8px 0;
  }
}

@media (min-width: 1000px) {
  .page-about .about-grid {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: var(--about-gap);
    padding: 64px 0 120px;
  }

  .page-about .about-rail {
    position: sticky;
    top: calc(var(--header-h) + 32px);
    align-self: start;
    max-height: calc(100vh - var(--header-h) - 64px);
    overflow: auto;
  }

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

  .page-about .about-hero {
    padding: 34px 0 64px;
  }

  .page-about .about-hero__title {
    font-size: 48px;
  }

  .page-about .about-chapter {
    padding-bottom: 72px;
  }

  .page-about .about-chapter + .about-chapter {
    padding-top: 72px;
    padding-bottom: 72px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-rail__link,
  .page-about .about-rail__link::before,
  .page-about .about-scale__note,
  .page-about .about-cta__card {
    transition: none;
  }
}
</>

已在上方输出。

已在上方输出。

已在上方输出。