.page-about {
  --about-hover-bg: #FFF7EA;
  background-color: var(--paper);
  color: var(--ink);
  font-family: var(--font-body);
  line-height: 1.75;
  padding-bottom: clamp(2.5rem, 7vw, 5rem);
  overflow-x: clip;
}

/* ---------- 面包屑 ---------- */
.page-about .breadcrumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.45rem;
  padding-top: clamp(1rem, 3vw, 1.5rem);
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  letter-spacing: 0.02em;
  color: var(--slate);
}

.page-about .breadcrumbs__link {
  color: var(--slate);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .breadcrumbs__link:hover {
  color: var(--signal);
  border-bottom-color: var(--signal);
}

.page-about .breadcrumbs__sep {
  color: var(--rule);
}

.page-about .breadcrumbs__item {
  color: var(--archive);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(1.75rem, 5vw, 2.75rem);
  padding: clamp(1.5rem, 5vw, 2.5rem) 0 clamp(2rem, 6vw, 3.25rem);
  border-bottom: 1px solid var(--rule);
}

.page-about .about-hero__kicker {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.18em;
  color: var(--signal);
}

.page-about .about-hero__title {
  margin: 0.65rem 0 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(1.95rem, 5.4vw, 3.25rem);
  line-height: 1.14;
  letter-spacing: -0.01em;
  color: var(--ink);
}

.page-about .about-hero__lede {
  margin: 1.1rem 0 0;
  max-width: 48ch;
  font-size: clamp(1rem, 1.5vw, 1.0625rem);
  color: var(--ink-soft);
}

.page-about .about-stats {
  list-style: none;
  margin: 1.75rem 0 0;
  padding: 1.25rem 0 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1rem 1.25rem;
  border-top: 1px solid var(--rule);
}

.page-about .about-stats__num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(1.15rem, 2.4vw, 1.5rem);
  font-weight: 600;
  line-height: 1.2;
  color: var(--archive);
}

.page-about .about-stats__label {
  display: block;
  margin-top: 0.2rem;
  font-size: 0.8125rem;
  color: var(--slate);
}

.page-about .about-hero__panel {
  background-color: var(--ink);
  border-radius: var(--radius-lg);
  padding: 1rem 1rem 1.35rem;
  color: var(--on-ink-strong);
}

.page-about .about-hero__panel .media__caption {
  color: var(--on-ink-soft);
}

.page-about .spec-list {
  list-style: none;
  margin: 1.1rem 0 0;
  padding: 0;
  display: grid;
  gap: 0.55rem;
}

.page-about .spec-list__row {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
  padding-bottom: 0.45rem;
  border-bottom: 1px dashed var(--hairline);
  font-family: var(--font-mono);
  font-size: 0.8125rem;
}

.page-about .spec-list__row:last-child {
  border-bottom: 0;
  padding-bottom: 0;
}

.page-about .spec-list__key {
  color: var(--on-ink-faint);
}

.page-about .spec-list__val {
  color: var(--on-ink-strong);
  text-align: right;
}

/* ---------- 章节通用 ---------- */
.page-about .about-section {
  padding-top: clamp(2.5rem, 7vw, 4rem);
}

.page-about .year-rail,
.page-about .steps,
.page-about .cadence {
  margin-top: 1.75rem;
}

/* ---------- 年度轴 ---------- */
.page-about .year-rail {
  list-style: none;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1rem;
}

.page-about .year-rail__item {
  position: relative;
  padding: 1.35rem 1.25rem 1.3rem 1.5rem;
  background-color: var(--paper-card);
  border: 1px solid var(--rule);
  border-radius: var(--radius-md);
  transition: transform var(--dur) var(--ease),
              border-color var(--dur) var(--ease),
              background-color var(--dur) var(--ease),
              box-shadow var(--dur) var(--ease);
}

.page-about .year-rail__item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 1.35rem;
  bottom: 1.3rem;
  width: 3px;
  border-radius: 0 3px 3px 0;
  background-color: var(--archive);
  transition: background-color var(--dur) var(--ease);
}

.page-about .year-rail__item:hover,
.page-about .year-rail__item:focus-within {
  transform: translateY(-3px);
  border-color: var(--signal);
  background-color: var(--about-hover-bg);
  box-shadow: 0 10px 24px -18px rgba(15, 27, 45, 0.55);
}

.page-about .year-rail__item:hover::before,
.page-about .year-rail__item:focus-within::before {
  background-color: var(--signal);
}

.page-about .year-rail__item.is-current {
  border-color: var(--amber);
  background-color: #FFFBF3;
}

.page-about .year-rail__item.is-current::before {
  background-color: var(--signal);
}

.page-about .year-rail__meta {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin: 0;
}

.page-about .year-rail__year {
  font-family: var(--font-mono);
  font-size: 1.0625rem;
  font-weight: 600;
  letter-spacing: 0.03em;
  color: var(--ink);
}

.page-about .year-rail__ver {
  display: inline-block;
  padding: 0.1rem 0.5rem;
  border-radius: var(--radius-pill);
  background-color: var(--paper-deep);
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  color: var(--archive);
}

.page-about .year-rail__item.is-current .year-rail__ver {
  background-color: var(--signal);
  color: #FFFFFF;
}

.page-about .year-rail__title {
  margin: 0.55rem 0 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.0625rem;
  line-height: 1.4;
  color: var(--ink);
}

.page-about .year-rail__text {
  margin: 0.4rem 0 0;
  font-size: 0.9375rem;
  line-height: 1.7;
  color: var(--ink-soft);
}

/* ---------- 视觉沿革 ---------- */
.page-about .visual-split {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1.75rem;
  margin-top: 1.75rem;
}

.page-about .feature-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0.875rem;
}

.page-about .feature-list__item {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 0.9rem;
  padding: 1rem 1.125rem;
  background-color: var(--paper-card);
  border: 1px solid var(--rule);
  border-left: 3px solid var(--archive);
  border-radius: var(--radius-md);
  transition: border-color var(--dur) var(--ease),
              transform var(--dur) var(--ease),
              background-color var(--dur) var(--ease);
}

.page-about .feature-list__item:hover {
  border-left-color: var(--signal);
  background-color: var(--about-hover-bg);
  transform: translateX(3px);
}

.page-about .feature-list__code {
  padding-top: 0.25rem;
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.12em;
  color: var(--slate);
}

.page-about .feature-list__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1rem;
  line-height: 1.45;
  color: var(--ink);
}

.page-about .feature-list__text {
  margin: 0.2rem 0 0;
  font-size: 0.9375rem;
  line-height: 1.7;
  color: var(--ink-soft);
}

/* ---------- 三步定位 ---------- */
.page-about .steps {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1rem;
}

.page-about .step-card {
  position: relative;
  padding: 1.35rem 1.25rem 1.3rem;
  background-color: var(--paper-card);
  border: 1px solid var(--rule);
  border-radius: var(--radius-md);
  transition: transform var(--dur) var(--ease),
              border-color var(--dur) var(--ease),
              background-color var(--dur) var(--ease);
}

.page-about .step-card:hover {
  transform: translateY(-3px);
  border-color: var(--signal);
  background-color: var(--about-hover-bg);
}

.page-about .step-card__num {
  display: block;
  font-family: var(--font-mono);
  font-size: 2.1rem;
  font-weight: 600;
  line-height: 1;
  color: var(--signal);
  opacity: 0.9;
}

.page-about .step-card__title {
  margin: 0.7rem 0 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.0625rem;
  line-height: 1.45;
  color: var(--ink);
}

.page-about .step-card__text {
  margin: 0.4rem 0 0;
  font-size: 0.9375rem;
  line-height: 1.7;
  color: var(--ink-soft);
}

/* ---------- 维护节奏 ---------- */
.page-about .cadence {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  background-color: var(--paper-card);
  border: 1px solid var(--rule);
  border-radius: var(--radius-lg);
  overflow: hidden;
}

.page-about .cadence__item {
  padding: 1.5rem 1.35rem;
  border-bottom: 1px solid var(--rule);
  transition: background-color var(--dur) var(--ease);
}

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

.page-about .cadence__item:hover {
  background-color: var(--about-hover-bg);
}

.page-about .cadence__freq {
  display: inline-block;
  margin: 0;
  padding: 0.18rem 0.65rem;
  border-radius: var(--radius-pill);
  background-color: var(--ink);
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  color: var(--on-ink-strong);
}

.page-about .cadence__title {
  margin: 0.75rem 0 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.125rem;
  line-height: 1.4;
  color: var(--ink);
}

.page-about .cadence__text {
  margin: 0.45rem 0 0;
  font-size: 0.9375rem;
  line-height: 1.72;
  color: var(--ink-soft);
}

/* ---------- 团队 ---------- */
.page-about .team-split {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1.75rem;
  margin-top: 1.75rem;
}

.page-about .team-body .prose {
  margin: 0;
  font-size: 1rem;
  line-height: 1.78;
  color: var(--ink-soft);
}

.page-about .team-list {
  list-style: none;
  margin: 1.35rem 0 0;
  padding: 0;
  display: grid;
  gap: 0;
}

.page-about .team-list__item {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0.15rem;
  padding: 0.85rem 0;
  border-bottom: 1px solid var(--rule);
}

.page-about .team-list__item:first-child {
  border-top: 1px solid var(--rule);
}

.page-about .team-list__role {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  letter-spacing: 0.05em;
  color: var(--archive);
}

.page-about .team-list__desc {
  font-size: 0.9375rem;
  line-height: 1.7;
  color: var(--ink-soft);
}

/* ---------- 结尾行动区 ---------- */
.page-about .about-cta {
  margin-top: clamp(2.75rem, 8vw, 4.5rem);
  padding: clamp(1.6rem, 5vw, 2.75rem);
  background-color: var(--ink);
  border-radius: var(--radius-lg);
  color: var(--on-ink-strong);
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1.35rem;
}

.page-about .about-cta__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(1.4rem, 3.4vw, 2rem);
  line-height: 1.25;
  color: var(--on-ink-strong);
}

.page-about .about-cta__text {
  margin: 0.7rem 0 0;
  max-width: 52ch;
  font-size: 0.9375rem;
  line-height: 1.75;
  color: var(--on-ink-soft);
}

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

.page-about .about-cta .btn--ghost {
  color: var(--on-ink-strong);
  border-color: var(--hairline);
}

.page-about .about-cta__more {
  margin: 0;
  font-size: 0.875rem;
  line-height: 1.7;
  color: var(--on-ink-faint);
}

.page-about .about-cta__link {
  color: var(--amber);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color var(--dur) var(--ease);
}

.page-about .about-cta__link:hover {
  border-bottom-color: var(--amber);
}

/* ---------- 焦点可见性 ---------- */
.page-about a:focus-visible,
.page-about .year-rail__item:focus-within {
  outline: 2px solid var(--focus);
  outline-offset: 3px;
  border-radius: var(--radius-md);
}

/* ---------- 显现 ---------- */
.page-about [data-reveal] {
  opacity: 1;
}

.has-js .page-about [data-reveal] {
  opacity: 0.6;
  transform: translateY(10px);
  transition: opacity 200ms var(--ease), transform 200ms var(--ease);
}

.has-js .page-about [data-reveal].is-visible {
  opacity: 1;
  transform: none;
}

/* ---------- 响应式 ---------- */
@media (min-width: 640px) {
  .page-about .about-hero__title {
    max-width: 22ch;
  }
}

@media (min-width: 780px) {
  .page-about .steps {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 1.25rem;
  }

  .page-about .about-cta {
    grid-template-columns: minmax(0, 1.4fr) minmax(0, 1fr);
    align-items: center;
  }

  .page-about .about-cta__body {
    grid-column: 1;
    grid-row: 1;
  }

  .page-about .about-cta__actions {
    grid-column: 2;
    grid-row: 1;
    justify-content: flex-end;
  }

  .page-about .about-cta__more {
    grid-column: 1 / -1;
    grid-row: 2;
  }
}

@media (min-width: 860px) {
  .page-about .cadence {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .cadence__item {
    border-bottom: 0;
    border-right: 1px solid var(--rule);
  }

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

@media (min-width: 900px) {
  .page-about .about-hero {
    grid-template-columns: minmax(0, 1.18fr) minmax(0, 0.82fr);
    align-items: start;
  }

  .page-about .about-hero__panel {
    padding: 1.15rem 1.15rem 1.5rem;
  }

  .page-about .visual-split {
    grid-template-columns: minmax(0, 1.08fr) minmax(0, 0.92fr);
    gap: 2.5rem;
    align-items: start;
  }

  .page-about .team-split {
    grid-template-columns: minmax(0, 0.95fr) minmax(0, 1.05fr);
    gap: 2.5rem;
    align-items: center;
  }
}

@media (min-width: 1060px) {
  .page-about .year-rail {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 1.15rem;
  }

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

@media (prefers-reduced-motion: reduce) {
  .page-about [data-reveal],
  .has-js .page-about [data-reveal] {
    opacity: 1;
    transform: none;
    transition: none;
  }

  .page-about .year-rail__item,
  .page-about .feature-list__item,
  .page-about .step-card {
    transition: none;
  }

  .page-about .year-rail__item:hover,
  .page-about .feature-list__item:hover,
  .page-about .step-card:hover {
    transform: none;
  }
}
<<<END>>>