.page-about {
  --ab-rail: 232px;
  --ab-pad: 18px;
  position: relative;
  display: block;
  background:
    radial-gradient(120% 70% at 8% -12%, rgba(31, 111, 92, 0.22), transparent 58%),
    radial-gradient(80% 55% at 100% 4%, rgba(200, 162, 74, 0.09), transparent 62%),
    var(--ink);
  color: var(--white);
  font-family: var(--f-body);
  font-size: 16px;
  line-height: 1.75;
  overflow-x: hidden;
  padding: 0 0 96px;
}

.page-about::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(to right, var(--line) 1px, transparent 1px),
    linear-gradient(to bottom, var(--line) 1px, transparent 1px);
  background-size: 88px 88px;
  opacity: 0.32;
  pointer-events: none;
  -webkit-mask-image: linear-gradient(to bottom, rgba(0,0,0,0.85), rgba(0,0,0,0.15) 60%, transparent 92%);
          mask-image: linear-gradient(to bottom, rgba(0,0,0,0.85), rgba(0,0,0,0.15) 60%, transparent 92%);
}

.page-about .about-wrap {
  position: relative;
  z-index: 1;
  max-width: var(--wrap);
  margin: 0 auto;
  padding: 28px 18px 0;
}

/* 面包屑 */
.page-about .breadcrumb {
  font-family: var(--f-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--mute);
  margin: 0 0 32px;
}
.page-about .breadcrumb ol {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  list-style: none;
  margin: 0;
  padding: 0;
}
.page-about .breadcrumb li {
  display: inline-flex;
  align-items: center;
}
.page-about .breadcrumb li + li::before {
  content: "/";
  color: var(--line);
  padding: 0 10px;
}
.page-about .breadcrumb a {
  color: var(--jade);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 0.2s var(--ease), border-color 0.2s var(--ease);
}
.page-about .breadcrumb a:hover {
  color: var(--gold-lite);
  border-bottom-color: var(--gold-lite);
}
.page-about .breadcrumb [aria-current="page"] {
  color: var(--white);
}

/* 小标签 */
.page-about .about-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--f-mono);
  font-size: 11px;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--bronze);
  margin: 0 0 16px;
}
.page-about .about-eyebrow::before {
  content: "";
  display: inline-block;
  width: 24px;
  height: 1px;
  background: var(--bronze);
}

/* 首屏 */
.page-about .about-hero {
  display: grid;
  gap: 28px;
  padding-bottom: 44px;
  margin-bottom: 48px;
  border-bottom: 1px solid var(--line);
}
.page-about .about-hero-copy h1 {
  font-family: var(--f-head);
  font-weight: 900;
  font-size: 34px;
  line-height: 1.15;
  letter-spacing: -0.03em;
  margin: 0 0 20px;
  color: var(--white);
  max-width: 20ch;
}
.page-about .about-hero-lede {
  margin: 0;
  font-size: 16px;
  line-height: 1.85;
  color: var(--mute);
  max-width: 58ch;
}
.page-about .about-hero-stats {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
  margin: 28px 0 0;
  padding: 22px 0 0;
  border-top: 1px solid var(--line);
}
.page-about .about-stat dt {
  font-family: var(--f-mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--mute);
  margin: 0 0 6px;
}
.page-about .about-stat dd {
  margin: 0;
  display: flex;
  align-items: baseline;
  gap: 4px;
}
.page-about .about-stat .mono {
  font-family: var(--f-mono);
  font-size: 26px;
  font-weight: 600;
  letter-spacing: -0.02em;
  line-height: 1;
  color: var(--gold);
}
.page-about .about-stat em {
  font-style: normal;
  font-size: 12px;
  color: var(--mute);
}
.page-about .about-hero-figure {
  margin: 0;
  position: relative;
}
.page-about .about-hero-figure::after {
  content: "";
  position: absolute;
  right: -8px;
  bottom: -8px;
  width: 64px;
  height: 4px;
  background: var(--cinnabar);
  transform: rotate(-3deg);
}

/* 布局：章节轨道 + 正文流 */
.page-about .about-grid {
  display: block;
}

.page-about .about-rail {
  margin: 0 0 36px;
}
.page-about .about-rail .toc-title {
  font-family: var(--f-mono);
  font-size: 11px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--mute);
  margin: 0 0 12px;
}
.page-about .about-toc-list {
  list-style: none;
  margin: 0;
  padding: 0 0 6px;
  display: flex;
  gap: 8px;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: none;
}
.page-about .about-toc-list::-webkit-scrollbar {
  display: none;
}
.page-about .about-toc-list a {
  display: inline-block;
  white-space: nowrap;
  padding: 8px 14px;
  font-family: var(--f-mono);
  font-size: 12px;
  letter-spacing: 0.05em;
  color: var(--mute);
  text-decoration: none;
  background: var(--rock);
  border: 1px solid var(--line);
  transition: color 0.2s var(--ease), border-color 0.2s var(--ease);
}
.page-about .about-toc-list a:hover {
  color: var(--white);
  border-color: var(--bronze);
}
.page-about .about-toc-list a.is-active {
  color: var(--jade);
  border-color: var(--jade);
}

/* 章节 */
.page-about .about-stream > .about-section + .about-section {
  margin-top: 52px;
  padding-top: 52px;
  border-top: 1px solid var(--line);
}
.page-about .about-section h2 {
  font-family: var(--f-head);
  font-weight: 900;
  font-size: 26px;
  line-height: 1.28;
  letter-spacing: -0.02em;
  margin: 0 0 18px;
  color: var(--white);
  max-width: 24ch;
}
.page-about .about-section > p {
  margin: 0 0 16px;
  color: var(--white);
  max-width: 76ch;
}
.page-about .about-section > p:last-child {
  margin-bottom: 0;
}

/* 列表 */
.page-about .about-points {
  list-style: none;
  margin: 22px 0 0;
  padding: 0;
  display: grid;
  gap: 10px;
}
.page-about .about-points li {
  position: relative;
  padding: 14px 16px 14px 34px;
  font-size: 15px;
  line-height: 1.7;
  color: var(--white);
  background: var(--rock);
  border: 1px solid var(--line);
  border-left: 3px solid var(--bronze);
}
.page-about .about-points li::before {
  content: "";
  position: absolute;
  left: 15px;
  top: 23px;
  width: 8px;
  height: 8px;
  background: var(--jade);
  transform: rotate(45deg);
}
.page-about .about-points strong {
  color: var(--gold-lite);
  font-weight: 600;
}

/* 里程碑时间轴 */
.page-about .about-milestones {
  list-style: none;
  margin: 30px 0 0;
  padding: 0;
  position: relative;
}
.page-about .about-milestones::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 10px;
  bottom: 10px;
  width: 1px;
  background: linear-gradient(to bottom, var(--bronze), var(--line) 90%);
}
.page-about .about-milestones > li {
  position: relative;
  padding: 0 0 30px 34px;
}
.page-about .about-milestones > li:last-child {
  padding-bottom: 0;
}
.page-about .about-milestones > li::before {
  content: "";
  position: absolute;
  left: 2px;
  top: 6px;
  width: 11px;
  height: 11px;
  background: var(--jade);
  border: 1px solid var(--gold);
  transform: rotate(45deg);
  box-shadow: 0 0 0 3px var(--ink);
}
.page-about .about-ver {
  display: inline-block;
  font-family: var(--f-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--gold);
  background: rgba(200, 162, 74, 0.09);
  border: 1px solid rgba(200, 162, 74, 0.34);
  padding: 3px 9px;
  margin-bottom: 10px;
}
.page-about .about-milestones h3 {
  font-family: var(--f-head);
  font-weight: 700;
  font-size: 19px;
  letter-spacing: -0.01em;
  margin: 0 0 8px;
  color: var(--white);
}
.page-about .about-milestones p {
  margin: 0;
  font-size: 15px;
  color: var(--mute);
  max-width: 60ch;
}

/* 团队与复核 */
.page-about .about-team-figure {
  margin: 26px 0 0;
}
.page-about .about-stages {
  display: grid;
  gap: 14px;
  margin-top: 26px;
}
.page-about .about-stage {
  position: relative;
  padding: 22px 20px 20px;
  background: var(--rock);
  border: 1px solid var(--line);
  border-top: 2px solid var(--bronze);
  transition: transform 0.25s var(--ease), border-color 0.25s var(--ease);
}
.page-about .about-stage:nth-child(2) {
  border-top-color: var(--gold);
}
.page-about .about-stage:nth-child(3) {
  border-top-color: var(--cinnabar);
}
.page-about .about-stage-num {
  display: block;
  font-family: var(--f-mono);
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--mute);
}
.page-about .about-stage h3 {
  font-family: var(--f-head);
  font-weight: 700;
  font-size: 20px;
  letter-spacing: -0.01em;
  margin: 10px 0 10px;
  color: var(--white);
}
.page-about .about-stage p {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--mute);
}
@media (hover: hover) {
  .page-about .about-stage:hover {
    transform: translateY(-3px);
    border-color: var(--bronze);
  }
}

/* 设备端切换 */
.page-about .about-tabs {
  margin-top: 28px;
  border: 1px solid var(--line);
  background: var(--rock);
}
.page-about .about-tablist {
  display: flex;
  border-bottom: 1px solid var(--line);
  background: rgba(31, 111, 92, 0.07);
}
.page-about .about-tab {
  flex: 1;
  padding: 15px 14px;
  font-family: var(--f-head);
  font-weight: 700;
  font-size: 15px;
  letter-spacing: 0.02em;
  color: var(--mute);
  background: transparent;
  border: 0;
  border-bottom: 2px solid transparent;
  cursor: pointer;
  transition: color 0.2s var(--ease), background 0.2s var(--ease), border-color 0.2s var(--ease);
}
.page-about .about-tab:hover {
  color: var(--white);
}
.page-about .about-tab[aria-selected="true"] {
  color: var(--jade);
  border-bottom-color: var(--jade);
  background: rgba(63, 182, 140, 0.09);
}
.page-about .about-panel {
  padding: 24px 20px 26px;
}
.page-about .about-panel[hidden] {
  display: none;
}
.page-about .about-panel h3 {
  font-family: var(--f-head);
  font-weight: 700;
  font-size: 18px;
  letter-spacing: -0.01em;
  margin: 0 0 14px;
  color: var(--gold-lite);
}
.page-about .about-panel .about-points {
  margin-top: 0;
}

/* 地区与服务 */
.page-about .about-region {
  display: grid;
  gap: 22px;
  margin-top: 26px;
}
.page-about .about-region-copy {
  padding: 22px 20px 20px;
  background: linear-gradient(135deg, rgba(200, 162, 74, 0.09), transparent 62%), var(--rock);
  border: 1px solid var(--line);
  border-left: 3px solid var(--gold);
}
.page-about .about-region-code {
  font-family: var(--f-mono);
  font-size: 14px;
  letter-spacing: 0.08em;
  color: var(--gold-lite);
  margin: 0 0 12px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--line);
}
.page-about .about-region-copy p {
  margin: 0;
  font-size: 15px;
  color: var(--mute);
}
.page-about .about-region-figure {
  margin: 0;
}

/* 结果表 */
.page-about .about-outcome-table {
  width: 100%;
  margin-top: 26px;
}
.page-about .about-outcome-table caption {
  text-align: left;
  padding: 0 0 12px;
  font-family: var(--f-mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--mute);
}
.page-about .about-outcome-table th,
.page-about .about-outcome-table td {
  padding: 14px 14px;
}
.page-about .about-outcome-table td.mono {
  font-family: var(--f-mono);
  font-size: 16px;
  color: var(--gold);
  white-space: nowrap;
}

/* 承接下一站 */
.page-about .about-next {
  margin: 30px 0 0;
  padding: 18px 20px;
  font-size: 15px;
  line-height: 1.8;
  color: var(--white);
  background: rgba(63, 182, 140, 0.06);
  border-left: 3px solid var(--jade);
}
.page-about .about-next a {
  color: var(--gold);
  text-decoration: none;
  border-bottom: 1px solid rgba(200, 162, 74, 0.45);
  padding-bottom: 1px;
  transition: color 0.2s var(--ease), border-color 0.2s var(--ease);
}
.page-about .about-next a:hover {
  color: var(--gold-lite);
  border-bottom-color: var(--gold-lite);
}

/* 平板及以上 */
@media (min-width: 720px) {
  .page-about .about-wrap {
    padding: 40px 32px 0;
  }
  .page-about .about-hero-copy h1 {
    font-size: 46px;
  }
  .page-about .about-hero-lede {
    font-size: 17px;
  }
  .page-about .about-section h2 {
    font-size: 32px;
  }
  .page-about .about-stages {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 16px;
  }
  .page-about .about-region {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    align-items: center;
    gap: 32px;
  }
}

/* 桌面：侧边轨道与正文形成横向层级 */
@media (min-width: 1024px) {
  .page-about {
    padding-bottom: 128px;
  }
  .page-about .about-wrap {
    padding: 52px 48px 0;
  }
  .page-about .about-hero {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: 52px;
    align-items: end;
    padding-bottom: 60px;
    margin-bottom: 64px;
  }
  .page-about .about-hero-copy h1 {
    font-size: 56px;
  }
  .page-about .about-grid {
    display: grid;
    grid-template-columns: var(--ab-rail) minmax(0, 1fr);
    gap: 60px;
    align-items: start;
  }
  .page-about .about-rail {
    margin-bottom: 0;
    position: sticky;
    top: 32px;
    align-self: start;
    border-left: 1px solid var(--line);
    padding-left: 20px;
  }
  .page-about .about-toc-list {
    display: flex;
    flex-direction: column;
    gap: 0;
    padding-bottom: 0;
    overflow: visible;
  }
  .page-about .about-toc-list a {
    display: block;
    white-space: normal;
    padding: 11px 12px 11px 16px;
    background: transparent;
    border: 0;
    border-left: 2px solid transparent;
    font-size: 12px;
  }
  .page-about .about-toc-list a:hover {
    color: var(--white);
    border-left-color: var(--bronze);
    background: linear-gradient(90deg, rgba(31, 111, 92, 0.14), transparent 72%);
  }
  .page-about .about-toc-list a.is-active {
    color: var(--jade);
    border-left-color: var(--jade);
    background: linear-gradient(90deg, rgba(63, 182, 140, 0.16), transparent 72%);
  }
  .page-about .about-section h2 {
    font-size: 34px;
  }
  .page-about .about-milestones > li {
    padding-left: 40px;
  }
}

@media (min-width: 1280px) {
  .page-about .about-hero-copy h1 {
    font-size: 62px;
  }
  .page-about .about-grid {
    gap: 72px;
  }
}

/* 尊重用户的减少动效偏好 */
@media (prefers-reduced-motion: reduce) {
  .page-about * {
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
  }
  .page-about .about-stage:hover {
    transform: none;
  }
}
</main>