.page-about {
  --about-rail: 12px;
  --about-gutter: 40px;
  padding-bottom: clamp(56px, 7vw, 96px);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  padding-top: clamp(24px, 4vw, 48px);
  padding-bottom: clamp(40px, 6vw, 76px);
}

.page-about .about-hero__grid {
  align-items: end;
  row-gap: clamp(28px, 4vw, 40px);
}

.page-about .about-hero__title {
  margin: 14px 0 0;
  font-family: var(--font-heading);
  font-size: clamp(2.1rem, 5.6vw, 3.9rem);
  font-weight: 800;
  line-height: 1.08;
  letter-spacing: -0.025em;
  color: var(--porcelain);
}

.page-about .about-hero__title-line,
.page-about .about-hero__title-em {
  display: block;
}

.page-about .about-hero__title-em {
  color: var(--gold-soft);
}

.page-about .about-hero__lead {
  margin-top: 20px;
  max-width: 46ch;
  color: var(--mist);
}

.page-about .about-hero__pills {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 24px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 28px;
}

.page-about .hero-ruler {
  border-left: 1px solid var(--line);
  padding-left: 18px;
  display: grid;
  gap: 16px;
}

.page-about .hero-ruler__row {
  display: grid;
  grid-template-columns: auto 1fr;
  align-items: baseline;
  gap: 12px;
  padding-bottom: 12px;
  border-bottom: 1px dashed rgba(28, 68, 54, 0.8);
}

.page-about .hero-ruler__row:last-of-type {
  border-bottom: 0;
}

.page-about .hero-ruler__num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(1.5rem, 3.4vw, 2.1rem);
  font-weight: 700;
  line-height: 1;
  color: var(--cyan);
}

.page-about .hero-ruler__label {
  font-size: 0.9375rem;
  color: var(--mist);
}

.page-about .hero-ruler__foot {
  margin: 0;
  font-size: 0.875rem;
  color: var(--jade-500);
}

/* ---------- 竖向时间脊 ---------- */
.page-about .about-shell {
  display: block;
}

.page-about .about-chapter {
  position: relative;
  padding-left: var(--about-gutter);
  padding-block: clamp(38px, 5.5vw, 68px);
}

.page-about .about-chapter:first-child {
  padding-top: clamp(28px, 4vw, 48px);
}

.page-about .about-chapter::before {
  content: "";
  position: absolute;
  left: var(--about-rail);
  top: 0;
  bottom: 0;
  width: 1px;
  background: var(--line);
}

.page-about .about-chapter__head {
  position: relative;
  max-width: 62ch;
}

.page-about .about-chapter__head::after {
  content: "";
  position: absolute;
  left: calc(-1 * var(--about-gutter) + var(--about-rail) - 6px);
  top: 10px;
  width: 13px;
  height: 13px;
  border-radius: 4px;
  background: var(--ink-900);
  border: 1px solid var(--jade-500);
  transition: background-color 0.26s var(--ease), border-color 0.26s var(--ease), box-shadow 0.26s var(--ease);
}

.page-about .about-chapter.is-current .about-chapter__head::after {
  background: var(--gold);
  border-color: var(--gold);
  box-shadow: 0 0 0 5px rgba(201, 162, 74, 0.14);
}

.page-about .chapter__index {
  display: block;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(2.4rem, 6.4vw, 4rem);
  font-weight: 700;
  line-height: 0.85;
  letter-spacing: -0.05em;
  color: rgba(201, 162, 74, 0.9);
}

.page-about .chapter__title {
  margin: 10px 0 0;
  font-family: var(--font-heading);
  font-size: clamp(1.5rem, 3.2vw, 2.2rem);
  font-weight: 800;
  line-height: 1.2;
  letter-spacing: -0.02em;
  color: var(--mist);
  transition: color 0.24s var(--ease);
}

.page-about .about-chapter.is-current .chapter__title {
  color: var(--porcelain);
}

.page-about .chapter__lead {
  margin: 14px 0 0;
  color: var(--mist);
}

.page-about .about-chapter__body {
  margin-top: clamp(28px, 4vw, 44px);
  transition: transform 0.45s var(--ease);
}

.page-about .about-chapter__body .grid {
  row-gap: clamp(24px, 3.5vw, 36px);
}

.page-about .about-chapter__body > .prose {
  max-width: 66ch;
  color: var(--mist);
}

/* ---------- 岗位名册 ---------- */
.page-about .duty-roster {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
  margin: 28px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .duty-roster__item {
  position: relative;
  padding: 18px 20px 18px 22px;
  background: var(--ink-800);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.page-about .duty-roster__item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 2px;
  background: var(--gold);
}

.page-about .duty-roster__num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 1.75rem;
  font-weight: 700;
  line-height: 1;
  color: var(--cyan);
}

.page-about .duty-roster__unit {
  margin-left: 4px;
  font-size: 0.8125rem;
  color: var(--mist);
}

.page-about .duty-roster__role {
  margin: 8px 0 0;
  font-family: var(--font-heading);
  font-size: 1.0625rem;
  font-weight: 700;
  color: var(--porcelain);
}

.page-about .duty-roster__desc {
  margin: 6px 0 0;
  font-size: 0.9375rem;
  line-height: 1.65;
  color: var(--mist);
}

/* ---------- 班次时间带 ---------- */
.page-about .chapter-media {
  max-width: 760px;
  margin: 0 0 clamp(28px, 4vw, 44px);
}

.page-about .shift-band {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
  margin-top: 4px;
}

.page-about .shift-band__seg {
  position: relative;
  padding: 20px 22px;
  background: linear-gradient(160deg, var(--ink-700), var(--ink-800));
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  outline: none;
  transition: border-color 0.24s var(--ease), background-color 0.24s var(--ease), transform 0.24s var(--ease);
}

.page-about .shift-band__seg:hover,
.page-about .shift-band__seg:focus-visible {
  border-color: var(--gold);
  transform: translateY(-3px);
}

.page-about .shift-band__seg:focus-visible {
  box-shadow: 0 0 0 2px var(--gold-soft);
}

.page-about .shift-band__time {
  margin: 0;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 1.125rem;
  font-weight: 700;
  letter-spacing: 0.01em;
  color: var(--cyan);
}

.page-about .shift-band__name {
  margin: 8px 0 0;
  font-family: var(--font-heading);
  font-size: 1.25rem;
  font-weight: 800;
  color: var(--porcelain);
}

.page-about .shift-band__note {
  margin: 8px 0 0;
  font-size: 0.9375rem;
  line-height: 1.7;
  color: var(--mist);
}

.page-about .shift-band__handover {
  margin: 24px 0 0;
  padding-left: 16px;
  border-left: 2px solid var(--cyan);
  font-size: 0.9375rem;
  line-height: 1.75;
  color: var(--mist);
}

/* ---------- 培训关卡 ---------- */
.page-about .drill-list {
  display: grid;
  gap: 0;
  margin: 0;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--line);
}

.page-about .drill-list__item {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 16px;
  padding: 22px 0;
  border-bottom: 1px solid var(--line);
}

.page-about .drill-list__marker {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 0.875rem;
  font-weight: 700;
  line-height: 1.6;
  color: var(--gold);
}

.page-about .drill-list__title {
  margin: 0;
  font-family: var(--font-heading);
  font-size: 1.0625rem;
  font-weight: 700;
  color: var(--porcelain);
}

.page-about .drill-list__body p {
  margin: 8px 0 0;
  font-size: 0.9375rem;
  line-height: 1.75;
  color: var(--mist);
}

/* ---------- 值班室指标 ---------- */
.page-about .duty-metrics {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
  margin: 26px 0 26px;
  padding: 0;
  list-style: none;
}

.page-about .duty-metrics__item {
  padding: 16px 18px;
  background: var(--ink-800);
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
}

.page-about .duty-metrics__item--cyan {
  border-color: rgba(69, 217, 198, 0.45);
}

.page-about .duty-metrics__num {
  display: block;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(1.15rem, 2.6vw, 1.5rem);
  font-weight: 700;
  line-height: 1.15;
  color: var(--porcelain);
}

.page-about .duty-metrics__item--cyan .duty-metrics__num {
  color: var(--cyan);
}

.page-about .duty-metrics__num em {
  font-style: normal;
  font-size: 0.72em;
  margin-left: 2px;
  color: var(--mist);
}

.page-about .duty-metrics__label {
  display: block;
  margin-top: 8px;
  font-size: 0.8125rem;
  line-height: 1.5;
  color: var(--mist);
}

/* ---------- 阶段节点轴 ---------- */
.page-about .stage-axis {
  position: relative;
  display: grid;
  gap: 26px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .stage-axis__node {
  position: relative;
  padding-top: 30px;
}

.page-about .stage-axis__dot {
  position: absolute;
  top: 0;
  left: 0;
  width: 15px;
  height: 15px;
  border-radius: 50%;
  background: var(--ink-900);
  border: 1px solid var(--gold);
}

.page-about .stage-axis__phase {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.16em;
  color: var(--gold);
}

.page-about .stage-axis__title {
  margin: 8px 0 0;
  font-family: var(--font-heading);
  font-size: 1.25rem;
  font-weight: 800;
  color: var(--porcelain);
}

.page-about .stage-axis__note {
  margin: 10px 0 0;
  font-size: 0.9375rem;
  line-height: 1.75;
  color: var(--mist);
}

/* ---------- 凭证 ---------- */
.page-about .proof-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .proof-grid__item {
  padding: 22px 22px 24px;
  background: var(--ink-800);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
}

.page-about .proof-grid__num {
  display: block;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(1.6rem, 3.6vw, 2.2rem);
  font-weight: 700;
  line-height: 1;
  color: var(--gold-soft);
}

.page-about .proof-grid__title {
  margin: 12px 0 0;
  font-family: var(--font-heading);
  font-size: 1rem;
  font-weight: 700;
  line-height: 1.5;
  color: var(--porcelain);
}

.page-about .proof-grid__note {
  margin: 8px 0 0;
  font-size: 0.875rem;
  line-height: 1.7;
  color: var(--mist);
}

/* ---------- 收尾行动区 ---------- */
.page-about .about-cta {
  margin-top: 34px;
  padding: 26px 24px;
  background: linear-gradient(150deg, var(--ink-700), var(--ink-900));
  border: 1px solid var(--line-soft);
  border-radius: var(--radius-lg);
}

.page-about .about-cta__text {
  margin: 0;
  max-width: 52ch;
  font-size: 1rem;
  line-height: 1.7;
  color: var(--porcelain);
}

.page-about .about-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 20px;
}

/* ---------- 断点 ---------- */
@media (min-width: 700px) {
  .page-about .duty-roster {
    grid-template-columns: 1fr 1fr;
  }

  .page-about .proof-grid {
    grid-template-columns: 1fr 1fr;
  }

  .page-about .duty-metrics {
    grid-template-columns: 1fr 1fr;
  }
}

@media (min-width: 1024px) {
  .page-about {
    --about-rail: 22px;
    --about-gutter: 72px;
  }

  .page-about .about-hero {
    padding-top: clamp(36px, 4vw, 64px);
  }

  .page-about .about-chapter__body {
    margin-top: 40px;
  }

  .page-about .about-chapter.is-current .about-chapter__body {
    transform: translateX(8px);
  }

  .page-about .shift-band {
    position: relative;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
    padding-top: 26px;
  }

  .page-about .shift-band::before {
    content: "";
    position: absolute;
    top: 6px;
    left: 0;
    right: 0;
    height: 1px;
    background: var(--line);
  }

  .page-about .shift-band__seg {
    padding: 24px 24px 26px;
  }

  .page-about .shift-band__seg::after {
    content: "";
    position: absolute;
    top: -26px;
    left: 0;
    width: 13px;
    height: 13px;
    border-radius: 4px;
    background: var(--ink-900);
    border: 1px solid var(--jade-500);
    transition: background-color 0.24s var(--ease), border-color 0.24s var(--ease);
  }

  .page-about .shift-band__seg:hover::after,
  .page-about .shift-band__seg:focus-visible::after {
    background: var(--cyan);
    border-color: var(--cyan);
  }

  .page-about .stage-axis {
    grid-template-columns: repeat(3, 1fr);
    gap: 34px;
  }

  .page-about .stage-axis::before {
    content: "";
    position: absolute;
    top: 7px;
    left: 0;
    right: 0;
    height: 1px;
    background: var(--line);
  }

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

  .page-about .drill-list__item {
    grid-template-columns: 64px 1fr;
    gap: 24px;
    padding: 26px 0;
  }

  .page-about .about-cta {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 28px;
    padding: 30px 32px;
  }

  .page-about .about-cta__actions {
    margin-top: 0;
    flex-shrink: 0;
  }
}

@media (max-width: 480px) {
  .page-about .duty-metrics {
    grid-template-columns: 1fr;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-chapter__body,
  .page-about .shift-band__seg,
  .page-about .chapter__title {
    transition: none;
  }

  .page-about .about-chapter.is-current .about-chapter__body {
    transform: none;
  }

  .page-about .shift-band__seg:hover {
    transform: none;
  }
}