.page-about {
  padding-block: 32px 72px;
  color: var(--paper);
  overflow-x: hidden;
}

@media (min-width: 768px) {
  .page-about {
    padding-block: 48px 96px;
  }
}

/* 面包屑 */
.page-about .breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 32px;
  font-size: 13px;
  color: var(--steel);
  flex-wrap: wrap;
}
.page-about .breadcrumb a {
  color: var(--muted);
  text-decoration: none;
  transition: color .2s var(--ease);
}
.page-about .breadcrumb a:hover,
.page-about .breadcrumb a:focus-visible {
  color: var(--cyan);
}
.page-about .breadcrumb__sep {
  color: var(--steel);
}
.page-about .breadcrumb__item[aria-current] {
  color: var(--paper);
}

/* 首屏 */
.page-about .about-hero {
  display: flex;
  flex-direction: column;
  gap: 28px;
}
.page-about .about-hero h1 {
  font-family: var(--font-sans);
  font-weight: 900;
  font-size: 32px;
  line-height: 1.15;
  letter-spacing: -0.02em;
  color: var(--paper);
  margin: 0;
  max-width: 24ch;
}
@media (min-width: 768px) {
  .page-about .about-hero h1 {
    font-size: 48px;
  }
}
@media (min-width: 1024px) {
  .page-about .about-hero h1 {
    font-size: 56px;
  }
}
.page-about .about-hero .lede {
  max-width: 62ch;
  font-size: 15px;
  color: var(--muted);
  line-height: 1.75;
  margin: 0;
}
@media (min-width: 768px) {
  .page-about .about-hero .lede {
    font-size: 18px;
  }
}

/* 阶段条带 */
.page-about .stage-strip {
  list-style: none;
  padding: 0;
  margin: 8px 0 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  background: var(--hair);
  border: 1px solid var(--hair);
  border-radius: 4px;
  overflow: hidden;
}
@media (min-width: 640px) {
  .page-about .stage-strip {
    grid-template-columns: repeat(2, 1fr);
  }
}
@media (min-width: 1024px) {
  .page-about .stage-strip {
    grid-template-columns: repeat(4, 1fr);
  }
}
.page-about .stage-strip__item {
  background: var(--ink-800);
  padding: 24px 20px;
  display: flex;
  flex-direction: column;
  gap: 10px;
  position: relative;
  transition: background .24s var(--ease);
}
.page-about .stage-strip__item:hover {
  background: var(--ink-700);
}
.page-about .stage-strip__item::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  height: 2px;
  width: 0;
  background: var(--cyan);
  transition: width .32s var(--ease);
}
.page-about .stage-strip__item:hover::before,
.page-about .stage-strip__item:focus-within::before {
  width: 100%;
}
.page-about .stage-strip__year {
  font-size: 28px;
  font-weight: 600;
  color: var(--cyan);
  letter-spacing: -0.02em;
  line-height: 1;
}
.page-about .stage-strip__title {
  font-size: 15px;
  font-weight: 700;
  color: var(--paper);
  margin: 0;
  line-height: 1.35;
}
.page-about .stage-strip__desc {
  font-size: 13px;
  color: var(--muted);
  line-height: 1.6;
  margin: 0;
}

.page-about .about-hero__figure {
  margin: 16px 0 0;
}

/* 时间轴布局 */
.page-about .timeline-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: 32px;
  margin-top: 32px;
}
@media (min-width: 900px) {
  .page-about .timeline-layout {
    grid-template-columns: 88px minmax(0, 1fr);
    gap: 48px;
  }
}

.page-about .timeline-rail {
  display: none;
}
@media (min-width: 900px) {
  .page-about .timeline-rail {
    display: flex;
    flex-direction: column;
    gap: 20px;
  }
}
.page-about .timeline-rail__label {
  font-family: var(--font-serif);
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--steel);
  writing-mode: vertical-rl;
  text-orientation: mixed;
  align-self: flex-start;
}
.page-about .timeline-rail__list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 56px;
  position: relative;
}
.page-about .timeline-rail__list::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 8px;
  bottom: 8px;
  width: 1px;
  background: var(--line);
}
.page-about .timeline-rail__node {
  display: flex;
  align-items: center;
  gap: 12px;
  position: relative;
  padding-left: 20px;
}
.page-about .timeline-rail__tick {
  width: 11px;
  height: 11px;
  border-radius: 50%;
  border: 1px solid var(--steel);
  background: var(--ink-900);
  position: absolute;
  left: 0;
  top: 50%;
  transform: translateY(-50%);
  transition: border-color .2s var(--ease), background .2s var(--ease);
}
.page-about .timeline-rail__node.is-active .timeline-rail__tick {
  border-color: var(--orange);
  background: var(--orange);
  box-shadow: 0 0 0 4px rgba(255, 122, 43, 0.18);
}
.page-about .timeline-rail__node span:not(.timeline-rail__tick) {
  font-size: 12px;
  color: var(--muted);
  letter-spacing: 0.04em;
}

/* 阶段卡片 */
.page-about .timeline-body {
  display: flex;
  flex-direction: column;
  gap: 24px;
}
.page-about .stage-card {
  background: var(--ink-800);
  border: 1px solid var(--line);
  border-left: 2px solid transparent;
  border-radius: 4px;
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 14px;
  transition: border-color .24s var(--ease), background .24s var(--ease);
}
@media (min-width: 768px) {
  .page-about .stage-card {
    padding: 32px;
  }
}
.page-about .stage-card:hover,
.page-about .stage-card:focus-within {
  border-left-color: var(--cyan);
  background: var(--ink-700);
}
.page-about .stage-card:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 2px;
}
.page-about .stage-card__head {
  display: flex;
  align-items: baseline;
  gap: 16px;
  flex-wrap: wrap;
}
.page-about .stage-card__year {
  font-size: 32px;
  color: var(--cyan);
  font-weight: 600;
  letter-spacing: -0.02em;
  line-height: 1;
}
.page-about .stage-card__title {
  font-size: 18px;
  font-weight: 700;
  color: var(--paper);
  margin: 0;
  line-height: 1.35;
}
@media (min-width: 768px) {
  .page-about .stage-card__title {
    font-size: 22px;
  }
}
.page-about .stage-card p {
  font-size: 15px;
  color: var(--muted);
  line-height: 1.75;
  margin: 0;
}
.page-about .stage-card__list {
  list-style: none;
  padding: 14px 0 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 8px;
  border-top: 1px solid var(--line);
}
.page-about .stage-card__list li {
  font-size: 13px;
  color: var(--muted);
  line-height: 1.6;
  padding-left: 16px;
  position: relative;
}
.page-about .stage-card__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 9px;
  width: 6px;
  height: 1px;
  background: var(--cyan);
}

/* 团队网格 */
.page-about .team-grid {
  gap: 16px;
  margin-top: 32px;
}
@media (min-width: 768px) {
  .page-about .team-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
  }
}
@media (min-width: 1024px) {
  .page-about .team-grid {
    grid-template-columns: repeat(4, 1fr);
  }
}
.page-about .team-card {
  background: var(--ink-700);
  border: 1px solid var(--line);
  border-top: 2px solid var(--cyan);
  border-radius: 4px;
  padding: 24px 20px;
  display: flex;
  flex-direction: column;
  gap: 10px;
  transition: transform .24s var(--ease), border-color .24s var(--ease);
}
.page-about .team-card:hover {
  transform: translateY(-2px);
  border-color: var(--cyan);
}
.page-about .team-card__title {
  font-family: var(--font-serif);
  font-weight: 500;
  font-size: 15px;
  color: var(--paper);
  margin: 0;
  letter-spacing: 0.02em;
}
.page-about .team-card__num {
  font-size: 44px;
  font-weight: 600;
  color: var(--cyan);
  line-height: 1;
  letter-spacing: -0.02em;
  margin: 0;
}
.page-about .team-card__desc {
  font-size: 14px;
  color: var(--muted);
  line-height: 1.7;
  margin: 0;
}
.page-about .team-card__meta {
  font-size: 12px;
  color: var(--steel);
  line-height: 1.55;
  margin: 0;
  padding-top: 12px;
  border-top: 1px solid var(--line);
}

/* 资质与荣誉 */
.page-about .cert-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: 32px;
  align-items: start;
  margin-top: 32px;
}
@media (min-width: 900px) {
  .page-about .cert-layout {
    grid-template-columns: minmax(0, 1.55fr) minmax(0, 1fr);
    gap: 40px;
  }
}
.page-about .cert-cards {
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
}
@media (min-width: 640px) {
  .page-about .cert-cards {
    grid-template-columns: repeat(2, 1fr);
  }
}
@media (min-width: 1024px) {
  .page-about .cert-cards {
    grid-template-columns: repeat(3, 1fr);
  }
}
.page-about .cert-card {
  background: var(--ink-800);
  border: 1px solid var(--line);
  border-radius: 4px;
  padding: 20px 18px;
  display: flex;
  flex-direction: column;
  gap: 8px;
  transition: border-color .24s var(--ease);
}
.page-about .cert-card:hover {
  border-color: var(--cyan);
}
.page-about .cert-card__num {
  font-size: 24px;
  font-weight: 600;
  color: var(--paper);
  line-height: 1;
  letter-spacing: -0.01em;
  margin: 0;
}
.page-about .cert-card__title {
  font-size: 14px;
  font-weight: 700;
  color: var(--paper);
  margin: 0;
  font-family: var(--font-sans);
}
.page-about .cert-card p {
  font-size: 13px;
  color: var(--muted);
  line-height: 1.65;
  margin: 0;
}
.page-about .cert-figure {
  margin: 0;
  border-left: 2px solid var(--orange);
}

/* 服务地区 */
.page-about .region-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: 32px;
  align-items: start;
  margin-top: 32px;
}
@media (min-width: 900px) {
  .page-about .region-layout {
    grid-template-columns: minmax(0, 1.2fr) minmax(0, 1fr);
    gap: 48px;
  }
}
.page-about .region-content h2 {
  font-size: 24px;
  font-weight: 800;
  color: var(--paper);
  margin: 8px 0 12px;
  letter-spacing: -0.02em;
  line-height: 1.2;
}
@media (min-width: 768px) {
  .page-about .region-content h2 {
    font-size: 32px;
  }
}
.page-about .region-content .lede {
  color: var(--muted);
  font-size: 15px;
  line-height: 1.75;
  margin: 0 0 24px;
  max-width: 54ch;
}
.page-about .region-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 14px;
}
.page-about .region-list li {
  font-size: 14px;
  color: var(--muted);
  line-height: 1.7;
  padding-left: 20px;
  position: relative;
}
.page-about .region-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 11px;
  width: 8px;
  height: 1px;
  background: var(--orange);
}
.page-about .region-list .mono {
  color: var(--paper);
  font-weight: 600;
}
.page-about .region-note {
  font-size: 13px;
  color: var(--steel);
  margin: 24px 0 0;
  line-height: 1.75;
}
.page-about .region-note a,
.page-about .conversion-note a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(44, 224, 206, 0.35);
  transition: border-color .2s var(--ease);
}
.page-about .region-note a:hover,
.page-about .conversion-note a:hover,
.page-about .region-note a:focus-visible,
.page-about .conversion-note a:focus-visible {
  border-bottom-color: var(--cyan);
}
.page-about .region-figure {
  margin: 0;
  aspect-ratio: 3 / 2;
}

/* 合作周期换算表 */
.page-about .conversion-wrap {
  margin-top: 32px;
}
.page-about .conversion-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 14px;
}
.page-about .conversion-table thead th {
  font-family: var(--font-serif);
  font-weight: 500;
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--steel);
  text-align: left;
  padding: 12px 16px;
  border-bottom: 1px solid var(--hair);
  background: var(--ink-800);
  position: sticky;
  top: 0;
}
.page-about .conversion-table tbody th,
.page-about .conversion-table tbody td {
  padding: 16px;
  border-bottom: 1px solid var(--line);
  font-weight: 400;
  color: var(--muted);
  vertical-align: top;
  text-align: left;
  line-height: 1.6;
}
.page-about .conversion-table tbody th {
  width: 96px;
}
.page-about .conversion-table tbody tr:hover {
  background: rgba(44, 224, 206, 0.04);
}
.page-about .conversion-table .is-num {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--paper);
  text-align: right;
}
.page-about .conversion-note {
  font-size: 13px;
  color: var(--steel);
  line-height: 1.75;
  margin: 16px 0 0;
}

@media (max-width: 640px) {
  .page-about .conversion-table thead {
    display: none;
  }
  .page-about .conversion-table,
  .page-about .conversion-table tbody,
  .page-about .conversion-table tr,
  .page-about .conversion-table th,
  .page-about .conversion-table td {
    display: block;
    width: 100%;
  }
  .page-about .conversion-table tr {
    border: 1px solid var(--line);
    border-radius: 4px;
    margin-bottom: 12px;
    background: var(--ink-800);
    padding: 4px 0;
  }
  .page-about .conversion-table tbody th,
  .page-about .conversion-table tbody td {
    padding: 8px 16px;
    border: none;
  }
  .page-about .conversion-table tbody th {
    padding-top: 14px;
    width: auto;
  }
  .page-about .conversion-table .is-num {
    text-align: left;
    padding-bottom: 14px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .stage-strip__item,
  .page-about .stage-strip__item::before,
  .page-about .stage-card,
  .page-about .team-card,
  .page-about .cert-card {
    transition: none;
  }
  .page-about .team-card:hover {
    transform: none;
  }
  .page-about .stage-strip__item:hover::before {
    width: 100%;
  }
}