.page-about {
  --c-terra: #FF9F1C;
  --space-section: 72px;
  position: relative;
  color: var(--c-cream);
}

/* 面包屑 */
.page-about .breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-1);
  max-width: var(--content-max);
  margin-inline: auto;
  padding: var(--space-3) var(--space-3) 0;
  font-size: 14px;
  color: var(--c-stone);
}
.page-about .breadcrumb a {
  color: var(--c-stone);
  text-decoration: none;
  transition: color 0.2s ease;
}
.page-about .breadcrumb a:hover,
.page-about .breadcrumb a:focus-visible {
  color: var(--c-neon);
}
.page-about .breadcrumb__sep {
  color: var(--c-line);
  font-family: var(--font-mono);
}
.page-about .breadcrumb [aria-current="page"] {
  color: var(--c-cream);
}

/* 首屏 Hero */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding: var(--space-4) var(--space-3) var(--space-5);
  border-bottom: 1px solid var(--c-line);
}
.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 1;
  background-image:
    linear-gradient(rgba(42, 53, 86, 0.22) 1px, transparent 1px),
    linear-gradient(90deg, rgba(42, 53, 86, 0.22) 1px, transparent 1px);
  background-size: 44px 44px;
  pointer-events: none;
}
.page-about .about-hero__media {
  position: absolute;
  inset: 0;
  z-index: 0;
  overflow: hidden;
}
.page-about .about-hero__media::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, rgba(10, 16, 32, 0.76) 0%, rgba(10, 16, 32, 0.92) 100%);
}
.page-about .about-hero__img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}
.page-about .about-hero__inner {
  position: relative;
  z-index: 2;
  max-width: var(--content-max);
  margin-inline: auto;
}
.page-about .about-hero__inner .index-tag {
  display: inline-flex;
  margin-bottom: var(--space-3);
}
.page-about .about-hero__title {
  margin: 0 0 var(--space-2);
  font-family: var(--font-head);
  font-size: clamp(28px, 6vw, 56px);
  line-height: 1.15;
  letter-spacing: 0.01em;
  font-weight: 700;
  max-width: 880px;
}
.page-about .about-hero__lead {
  font-size: clamp(17px, 2.4vw, 24px);
  color: var(--c-neon);
  margin: 0 0 var(--space-2);
  font-weight: 600;
}
.page-about .about-hero__abstract {
  max-width: 640px;
  color: var(--c-stone);
  font-size: 16px;
  line-height: 1.8;
  margin: 0 0 var(--space-4);
}
.page-about .about-hero__stats {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-3);
  margin: 0;
  padding-top: var(--space-3);
  border-top: 1px solid var(--c-line);
}
.page-about .about-hero__stat {
  display: flex;
  flex-direction: column;
  gap: 4px;
  min-width: 92px;
  padding-left: var(--space-2);
  border-left: 2px solid var(--c-terra);
}
.page-about .about-hero__stat-num {
  font-family: var(--font-mono);
  font-size: 26px;
  font-weight: 700;
  line-height: 1.1;
  color: var(--c-cream);
  margin: 0;
}
.page-about .about-hero__stat-label {
  font-size: 13px;
  color: var(--c-stone);
  margin: 0;
}
.page-about .vertical-note {
  display: none;
}

/* 通用章节骨架 */
.page-about .about-section {
  max-width: var(--content-max);
  margin-inline: auto;
  padding: var(--space-section) var(--space-3);
}
.page-about .about-section__head {
  display: flex;
  align-items: baseline;
  gap: var(--space-3);
  margin-bottom: var(--space-4);
  border-bottom: 1px solid var(--c-line);
  padding-bottom: var(--space-2);
}
.page-about .about-section__index {
  font-family: var(--font-mono);
  font-size: 14px;
  color: var(--c-terra);
  letter-spacing: 0.1em;
  font-weight: 700;
}
.page-about .about-section__title {
  font-family: var(--font-head);
  font-size: clamp(24px, 4vw, 40px);
  font-weight: 700;
  margin: 0;
  line-height: 1.2;
}

/* 我们的故事 */
.page-about .about-story__grid {
  display: grid;
  gap: var(--space-4);
}
.page-about .about-story__visual {
  position: relative;
  background: var(--c-night);
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
  padding: var(--space-3);
}
.page-about .about-story__skyline {
  width: 100%;
  height: auto;
  display: block;
  border-radius: var(--radius);
}
.page-about .about-story__caption {
  margin: var(--space-2) 0 0;
  font-size: 13px;
  color: var(--c-stone);
  line-height: 1.6;
  font-family: var(--font-mono);
  letter-spacing: 0.02em;
}
.page-about .about-story__content p {
  font-size: 16px;
  line-height: 1.85;
  color: var(--c-cream);
  margin: 0 0 var(--space-3);
}

/* 使命与愿景 */
.page-about .about-mission__board {
  display: grid;
  gap: var(--space-3);
}
.page-about .mission-card {
  position: relative;
  background: var(--c-night);
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
  padding: var(--space-4);
  transition: border-color 0.25s ease, transform 0.25s ease;
}
.page-about .mission-card::after {
  content: "";
  position: absolute;
  right: var(--space-3);
  top: var(--space-3);
  width: 12px;
  height: 12px;
  border-top: 1px solid var(--c-terra);
  border-right: 1px solid var(--c-terra);
  opacity: 0.6;
}
.page-about .mission-card:hover {
  border-color: var(--c-hover);
  transform: translateY(-4px);
}
.page-about .mission-card__no {
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
  color: var(--c-neon);
  letter-spacing: 0.12em;
}
.page-about .mission-card h3 {
  font-family: var(--font-head);
  font-size: 20px;
  font-weight: 700;
  margin: var(--space-2) 0 var(--space-1);
  color: var(--c-cream);
}
.page-about .mission-card p {
  font-size: 15px;
  line-height: 1.75;
  color: var(--c-stone);
  margin: 0;
}
.page-about .mission-card__list {
  list-style: none;
  padding: 0;
  margin: var(--space-2) 0 0;
}
.page-about .mission-card__list li {
  position: relative;
  padding-left: 18px;
  font-size: 15px;
  line-height: 1.7;
  color: var(--c-stone);
  margin-bottom: 8px;
}
.page-about .mission-card__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.6em;
  width: 8px;
  height: 8px;
  background: var(--c-terra);
  border-radius: 1px;
}
.page-about .mission-card__list li:last-child {
  margin-bottom: 0;
}

/* 数据速览条 */
.page-about .about-factstrip {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1px;
  max-width: var(--content-max);
  margin-inline: auto;
  margin-block: var(--space-1) var(--space-2);
  background: var(--c-line);
  border-top: 1px solid var(--c-line);
  border-bottom: 1px solid var(--c-line);
}
.page-about .about-factstrip__item {
  background: var(--c-midnight);
  padding: var(--space-3);
  display: flex;
  flex-direction: column;
  gap: 4px;
}
.page-about .about-factstrip__num {
  font-family: var(--font-mono);
  font-size: 26px;
  font-weight: 700;
  color: var(--c-neon);
  letter-spacing: -0.02em;
  line-height: 1.1;
}
.page-about .about-factstrip__label {
  font-size: 13px;
  color: var(--c-stone);
}

/* 关键里程碑 */
.page-about .about-milestones__layout {
  display: grid;
  gap: var(--space-4);
}
.page-about .milestone-list {
  list-style: none;
  margin: 0;
  padding: 0;
  position: relative;
}
.page-about .milestone-list::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 8px;
  bottom: 8px;
  width: 1px;
  background: var(--c-line);
}
.page-about .milestone-item {
  position: relative;
  padding: 0 0 var(--space-4) var(--space-4);
}
.page-about .milestone-item__dot {
  position: absolute;
  left: 3px;
  top: 6px;
  width: 9px;
  height: 9px;
  border: 2px solid var(--c-neon);
  background: var(--c-midnight);
  border-radius: 50%;
}
.page-about .milestone-item__year {
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
  color: var(--c-terra);
  letter-spacing: 0.08em;
}
.page-about .milestone-item__card {
  margin-top: 6px;
  background: var(--c-night);
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
  padding: var(--space-3);
  transition: border-color 0.2s ease, background 0.2s ease;
}
.page-about .milestone-item__card:hover {
  border-color: var(--c-hover);
  background: var(--c-hover);
}
.page-about .milestone-item__card h3 {
  font-family: var(--font-head);
  font-size: 18px;
  font-weight: 700;
  margin: 0 0 6px;
  color: var(--c-cream);
}
.page-about .milestone-item__card p {
  font-size: 15px;
  line-height: 1.7;
  color: var(--c-stone);
  margin: 0;
}
.page-about .about-milestones__aside img {
  width: 100%;
  height: auto;
  display: block;
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
  margin-bottom: var(--space-3);
}
.page-about .milestone-chart {
  width: 100%;
  height: auto;
  display: block;
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
  margin-bottom: var(--space-3);
}
.page-about .milestone-chart text {
  font-family: var(--font-mono);
}
.page-about .about-milestones__note {
  font-size: 14px;
  line-height: 1.7;
  color: var(--c-stone);
  margin: 0;
  border-left: 2px solid var(--c-terra);
  padding-left: var(--space-2);
}

/* 技术团队 */
.page-about .about-team__layout {
  display: grid;
  gap: var(--space-4);
}
.page-about .about-team__media img {
  width: 100%;
  height: auto;
  display: block;
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
}
.page-about .about-team__caption {
  font-size: 13px;
  color: var(--c-stone);
  margin-top: var(--space-2);
  line-height: 1.6;
  font-family: var(--font-mono);
}
.page-about .about-team__content > p {
  font-size: 16px;
  line-height: 1.85;
  color: var(--c-cream);
  margin: 0 0 var(--space-3);
}
.page-about .team-detail {
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
  background: var(--c-night);
  margin-bottom: var(--space-2);
  transition: border-color 0.2s ease, background 0.2s ease;
}
.page-about .team-detail[open] {
  border-color: var(--c-hover);
  background: var(--c-hover);
}
.page-about .team-detail summary {
  cursor: pointer;
  padding: var(--space-3);
  font-family: var(--font-head);
  font-size: 16px;
  font-weight: 600;
  color: var(--c-cream);
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: var(--space-2);
}
.page-about .team-detail summary::-webkit-details-marker {
  display: none;
}
.page-about .team-detail summary::after {
  content: "+";
  font-family: var(--font-mono);
  color: var(--c-neon);
  font-size: 20px;
  line-height: 1;
  transition: transform 0.2s ease;
}
.page-about .team-detail[open] summary::after {
  transform: rotate(45deg);
}
.page-about .team-detail__body {
  padding: 0 var(--space-3) var(--space-3);
  margin: 0;
  font-size: 15px;
  line-height: 1.75;
  color: var(--c-stone);
}

/* 服务范围 */
.page-about .about-services__grid {
  display: grid;
  gap: var(--space-3);
}
.page-about .about-service-card {
  display: block;
  background: var(--c-night);
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
  padding: var(--space-4);
  text-decoration: none;
  color: var(--c-cream);
  position: relative;
  overflow: hidden;
  transition: border-color 0.25s ease, transform 0.25s ease, background 0.25s ease;
}
.page-about .about-service-card::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 3px;
  background: var(--c-terra);
  transform: scaleY(0);
  transform-origin: top;
  transition: transform 0.3s ease;
}
.page-about .about-service-card:hover,
.page-about .about-service-card:focus-visible {
  border-color: var(--c-terra);
  background: var(--c-hover);
  transform: translateY(-3px);
}
.page-about .about-service-card:hover::before,
.page-about .about-service-card:focus-visible::before {
  transform: scaleY(1);
}
.page-about .about-service-card__code {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--c-neon);
  letter-spacing: 0.1em;
}
.page-about .about-service-card h3 {
  font-family: var(--font-head);
  font-size: 20px;
  font-weight: 700;
  margin: var(--space-2) 0 var(--space-1);
  color: var(--c-cream);
}
.page-about .about-service-card p {
  font-size: 15px;
  line-height: 1.75;
  color: var(--c-stone);
  margin: 0 0 var(--space-3);
}
.page-about .about-service-card__link {
  font-size: 14px;
  font-weight: 600;
  color: var(--c-cream);
  border-bottom: 1px solid var(--c-neon);
  padding-bottom: 2px;
}
.page-about .about-service-card:hover .about-service-card__link,
.page-about .about-service-card:focus-visible .about-service-card__link {
  color: var(--c-neon);
}

/* 信任与保障 */
.page-about .about-trust {
  display: grid;
  gap: var(--space-4);
  border: 1px solid var(--c-line);
  border-radius: var(--radius);
  background: linear-gradient(135deg, var(--c-night) 0%, var(--c-midnight) 100%);
  padding: var(--space-4);
  margin-top: var(--space-2);
}
.page-about .about-trust__seal svg {
  width: 110px;
  height: 110px;
  display: block;
}
.page-about .about-trust__seal text {
  font-family: var(--font-head);
}
.page-about .about-trust__content h2 {
  font-family: var(--font-head);
  font-size: 24px;
  font-weight: 700;
  margin: 0 0 var(--space-2);
  color: var(--c-cream);
}
.page-about .about-trust__content p {
  font-size: 15px;
  line-height: 1.8;
  color: var(--c-stone);
  margin: 0 0 var(--space-3);
}
.page-about .about-trust__list {
  list-style: none;
  padding: 0;
  margin: 0 0 var(--space-3);
}
.page-about .about-trust__list li {
  position: relative;
  padding-left: 20px;
  font-size: 15px;
  line-height: 1.7;
  color: var(--c-cream);
  margin-bottom: var(--space-1);
}
.page-about .about-trust__list li::before {
  content: "✓";
  position: absolute;
  left: 0;
  color: var(--c-neon);
  font-weight: 700;
}
.page-about .about-trust__links {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
}
.page-about .about-trust__links a {
  color: var(--c-neon);
  text-decoration: none;
  font-size: 14px;
  font-weight: 600;
  border: 1px solid var(--c-neon);
  border-radius: var(--radius);
  padding: 8px 16px;
  transition: background 0.2s ease, color 0.2s ease;
}
.page-about .about-trust__links a:hover,
.page-about .about-trust__links a:focus-visible {
  background: var(--c-neon);
  color: var(--c-midnight);
}

/* 桌面端布局 */
@media (min-width: 900px) {
  .page-about .about-hero {
    padding-top: var(--space-6);
    padding-bottom: var(--space-6);
  }
  .page-about .about-hero__title {
    font-size: 56px;
    max-width: 900px;
  }
  .page-about .about-hero__abstract {
    max-width: 620px;
  }
  .page-about .vertical-note {
    display: block;
    position: absolute;
    right: 16px;
    bottom: var(--space-6);
    writing-mode: vertical-rl;
    font-size: 12px;
    letter-spacing: 0.35em;
    color: var(--c-line);
    z-index: 2;
    pointer-events: none;
  }
  .page-about .about-section {
    padding: var(--space-6) var(--space-3);
  }

  /* 故事：左右错位 */
  .page-about .about-story__grid {
    grid-template-columns: 48% 52%;
    gap: var(--space-5);
    align-items: center;
  }
  .page-about .about-story__visual {
    margin-top: var(--space-5);
    margin-left: -var(--space-2);
  }
  .page-about .about-story__content {
    margin-bottom: var(--space-4);
  }

  /* 使命三卡 */
  .page-about .about-mission__board {
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-4);
  }

  /* 数据速览条四列 */
  .page-about .about-factstrip {
    grid-template-columns: repeat(4, 1fr);
  }
  .page-about .about-factstrip__item {
    padding: var(--space-4);
    align-items: center;
    text-align: center;
  }

  /* 里程碑：时间线 + 旁栏 */
  .page-about .about-milestones__layout {
    grid-template-columns: 62% 38%;
    gap: var(--space-5);
    align-items: start;
  }
  .page-about .about-milestones__aside {
    position: sticky;
    top: calc(var(--header-h) + var(--space-3));
  }
  .page-about .milestone-item {
    padding-bottom: var(--space-5);
  }

  /* 团队：图片粘性 + 文字详情 */
  .page-about .about-team__layout {
    grid-template-columns: 40% 60%;
    gap: var(--space-5);
    align-items: start;
  }
  .page-about .about-team__media {
    position: sticky;
    top: calc(var(--header-h) + var(--space-3));
  }

  /* 服务三卡 */
  .page-about .about-services__grid {
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-4);
  }

  /* 信任横向排布 */
  .page-about .about-trust {
    grid-template-columns: auto 1fr;
    gap: var(--space-5);
    align-items: center;
    padding: var(--space-5);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-service-card,
  .page-about .mission-card,
  .page-about .milestone-item__card,
  .page-about .team-detail {
    transition: none;
  }
}