.page-about {
  background-color: var(--ink);
  color: var(--paper);
  font-family: var(--font-body);
  overflow-x: hidden;
  padding-bottom: 4px;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  padding: 42px 0 46px;
  border-bottom: 1px solid var(--line-soft);
}

.page-about .about-hero h1 {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(30px, 6.6vw, 64px);
  line-height: 1.1;
  letter-spacing: -0.025em;
  margin: 16px 0 22px;
  max-width: 18ch;
  color: var(--paper);
}

.page-about .about-hero-lead {
  max-width: 62ch;
  margin: 0;
  font-size: 16.5px;
  line-height: 1.9;
  color: var(--mist);
}

/* ---------- 章节骨架 ---------- */
.page-about .chapter {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
  padding: 46px 0;
  border-top: 1px solid var(--line-soft);
}

.page-about .chapter:first-of-type {
  border-top: 0;
  padding-top: 44px;
}

.page-about .chapter-rail {
  display: flex;
  align-items: baseline;
  gap: 12px;
}

.page-about .chapter-num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 24px;
  font-weight: 700;
  line-height: 1;
  letter-spacing: 0.02em;
  color: var(--gold);
}

.page-about .chapter-rail .vertical-label {
  display: none;
  writing-mode: vertical-rl;
  font-size: 11px;
  letter-spacing: 0.24em;
  color: var(--mist);
}

.page-about .chapter-body h2 {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(23px, 4.4vw, 36px);
  line-height: 1.28;
  letter-spacing: -0.015em;
  margin: 0 0 18px;
  max-width: 22ch;
  color: var(--paper);
}

.page-about .chapter-body p {
  margin: 0 0 16px;
  font-size: 16.5px;
  line-height: 1.9;
  color: var(--paper);
  max-width: 62ch;
}

.page-about .chapter-body .chapter-lead {
  color: var(--mist);
  font-size: 17px;
}

.page-about .chapter-prose p:last-child {
  margin-bottom: 0;
}

/* ---------- 图文分栏 ---------- */
.page-about .chapter-split {
  display: grid;
  gap: 26px;
  margin-top: 4px;
}

.page-about .media {
  margin: 0;
}

.page-about .media img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  border: 1px solid var(--line-soft);
}

.page-about .media-caption {
  margin-top: 10px;
  font-size: 13px;
  line-height: 1.7;
  color: var(--mist);
}

.page-about .base-photo {
  margin: 26px 0 4px;
}

/* ---------- 基地示意 ---------- */
.page-about .map-figure {
  display: none;
  margin: 26px 0 6px;
}

.page-about .route-map {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  overflow: visible;
}

.page-about .route-map .map-line {
  stroke: var(--line);
  stroke-width: 1;
}

.page-about .route-map .map-node {
  fill: var(--copper);
}

.page-about .route-map .map-city {
  fill: var(--paper);
  font-family: var(--font-display);
  font-size: 21px;
  font-weight: 800;
  letter-spacing: 0.04em;
}

.page-about .route-map .map-role {
  fill: var(--mist);
  font-family: var(--font-body);
  font-size: 14px;
}

/* ---------- 基地卡片 ---------- */
.page-about .base-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  margin-top: 24px;
  background-color: var(--line-soft);
  border: 1px solid var(--line-soft);
}

.page-about .base-card {
  background-color: var(--slate);
  padding: 24px 22px 26px;
  transition: background-color 0.2s ease, box-shadow 0.2s ease;
}

.page-about .base-card:hover {
  background-color: #202c36;
  box-shadow: inset 0 -2px 0 0 var(--gold);
}

.page-about .base-card .base-city {
  display: block;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.22em;
  color: var(--copper);
  margin-bottom: 10px;
}

.page-about .base-card h3 {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 19px;
  line-height: 1.35;
  margin: 0 0 10px;
  color: var(--paper);
}

.page-about .base-card p {
  margin: 0;
  font-size: 15px;
  line-height: 1.82;
  color: var(--mist);
}

/* ---------- 产品线 ---------- */
.page-about .line-list {
  list-style: none;
  margin: 26px 0 0;
  padding: 0;
  border-top: 1px solid var(--line-soft);
}

.page-about .line-list li {
  display: grid;
  grid-template-columns: 38px minmax(0, 1fr);
  gap: 14px;
  padding: 22px 0;
  border-bottom: 1px solid var(--line-soft);
}

.page-about .line-num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.06em;
  color: var(--gold);
  padding-top: 5px;
}

.page-about .line-list h3 {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 19px;
  margin: 0 0 8px;
  color: var(--paper);
}

.page-about .line-list p {
  margin: 0;
  font-size: 15.5px;
  line-height: 1.85;
  color: var(--mist);
  max-width: 60ch;
}

/* ---------- 数字组 ---------- */
.page-about .stat-row {
  display: grid;
  grid-template-columns: 1fr;
  gap: 26px;
  margin: 30px 0 26px;
  padding: 26px 0;
  border-top: 1px solid var(--line-soft);
  border-bottom: 1px solid var(--line-soft);
}

.page-about .stat-line {
  display: flex;
  align-items: baseline;
  gap: 8px;
  margin: 0 0 10px;
}

.page-about .stat-num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(44px, 9vw, 78px);
  font-weight: 900;
  line-height: 1;
  letter-spacing: -0.035em;
  color: var(--gold);
}

.page-about .stat-unit {
  font-size: 14px;
  letter-spacing: 0.1em;
  color: var(--amber);
}

.page-about .stat-desc {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--mist);
  max-width: 28ch;
}

/* ---------- 品控清单 ---------- */
.page-about .chapter-split--reverse {
  margin-top: 4px;
}

.page-about .check-list {
  list-style: none;
  margin: 22px 0 0;
  padding: 0;
}

.page-about .check-list li {
  position: relative;
  padding: 14px 0 14px 22px;
  border-bottom: 1px solid var(--line-soft);
  font-size: 15.5px;
  line-height: 1.85;
  color: var(--mist);
}

.page-about .check-list li:first-child {
  border-top: 1px solid var(--line-soft);
}

.page-about .check-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 21px;
  width: 8px;
  height: 8px;
  background-color: var(--copper);
}

.page-about .check-list strong {
  display: block;
  margin-bottom: 4px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 15px;
  color: var(--amber);
  letter-spacing: 0.02em;
}

/* ---------- 团队数字 ---------- */
.page-about .team-figures {
  display: grid;
  grid-template-columns: 1fr;
  gap: 24px;
  margin: 28px 0 24px;
  padding: 26px 0;
  border-top: 1px solid var(--line-soft);
  border-bottom: 1px solid var(--line-soft);
}

.page-about .team-figure .stat-num {
  display: block;
  color: var(--gold);
  transition: color 0.6s ease;
}

.page-about .figure-label {
  display: block;
  margin-top: 10px;
  font-size: 14px;
  line-height: 1.75;
  color: var(--mist);
  max-width: 24ch;
}

/* ---------- 里程碑 ---------- */
.page-about .milestones {
  list-style: none;
  position: relative;
  margin: 28px 0 0;
  padding: 0 0 0 28px;
}

.page-about .milestones::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 8px;
  bottom: 12px;
  width: 1px;
  background-color: var(--line-soft);
}

.page-about .milestone {
  position: relative;
  padding-bottom: 30px;
}

.page-about .milestone:last-child {
  padding-bottom: 0;
}

.page-about .ms-node {
  position: absolute;
  left: -28px;
  top: 4px;
  width: 15px;
  height: 15px;
  background-color: var(--ink);
  border: 1px solid var(--gold);
}

.page-about .ms-tag {
  margin: 0 0 6px;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 12.5px;
  letter-spacing: 0.18em;
  color: var(--copper);
}

.page-about .milestone h3 {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 18px;
  line-height: 1.4;
  margin: 0 0 8px;
  color: var(--paper);
}

.page-about .ms-desc {
  margin: 0;
  font-size: 15.5px;
  line-height: 1.85;
  color: var(--mist);
  max-width: 60ch;
}

/* ---------- 收尾 ---------- */
.page-about .about-cta {
  margin: 56px 0 72px;
  padding: 38px 24px 40px;
  border: 1px solid var(--line);
  background-image: linear-gradient(140deg, rgba(224, 138, 46, 0.16) 0%, rgba(16, 26, 43, 0.92) 62%);
  background-color: var(--night);
}

.page-about .about-cta h2 {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(22px, 4vw, 32px);
  line-height: 1.3;
  margin: 0 0 16px;
  max-width: 20ch;
  color: var(--paper);
}

.page-about .about-cta p {
  margin: 0 0 26px;
  font-size: 16px;
  line-height: 1.9;
  color: var(--mist);
  max-width: 58ch;
}

.page-about .cta-actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 14px 20px;
}

.page-about .cta-text-link {
  font-size: 14.5px;
  color: var(--teal);
  text-decoration: none;
  border-bottom: 1px solid rgba(78, 140, 160, 0.45);
  padding-bottom: 2px;
}

.page-about .cta-text-link:hover,
.page-about .cta-text-link:focus-visible {
  color: var(--amber);
  border-bottom-color: var(--amber);
}

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

/* ---------- 中等宽度 ---------- */
@media (min-width: 720px) {
  .page-about .about-hero {
    padding: 56px 0 54px;
  }

  .page-about .chapter {
    padding: 58px 0;
  }

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

  .page-about .map-figure {
    display: block;
  }

  .page-about .line-list li {
    grid-template-columns: 56px minmax(0, 1fr);
    gap: 24px;
    padding: 26px 0;
  }

  .page-about .stat-row {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 30px;
  }

  .page-about .team-figures {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 34px;
  }

  .page-about .about-cta {
    padding: 46px 44px 48px;
  }
}

/* ---------- 桌面 ---------- */
@media (min-width: 900px) {
  .page-about .chapter {
    grid-template-columns: 92px minmax(0, 1fr);
    gap: 38px;
    padding: 68px 0;
  }

  .page-about .chapter-rail {
    flex-direction: column;
    align-items: flex-start;
    gap: 16px;
    padding-left: 18px;
    border-left: 1px solid var(--line-soft);
  }

  .page-about .chapter-rail .vertical-label {
    display: block;
  }

  .page-about .chapter-num {
    font-size: 34px;
  }

  .page-about .chapter-split {
    grid-template-columns: minmax(0, 1.06fr) minmax(0, 0.94fr);
    gap: 46px;
    align-items: start;
  }

  .page-about .chapter-split--reverse .chapter-prose {
    order: 2;
  }

  .page-about .chapter-split--reverse .media {
    order: 1;
  }

  .page-about .base-photo {
    margin-top: 32px;
  }

  .page-about .about-cta {
    margin: 72px 0 88px;
  }
}

/* ---------- 桌面大号数字 ---------- */
@media (min-width: 1100px) {
  .page-about .chapter-body .chapter-lead {
    font-size: 17.5px;
  }

  .page-about .stat-num {
    font-size: 88px;
  }

  .page-about .team-figure .stat-num {
    font-size: 76px;
  }
}

/* ---------- 动效偏好 ---------- */
@media (prefers-reduced-motion: reduce) {
  .page-about .base-card,
  .page-about .team-figure .stat-num {
    transition: none;
  }
}