.page-about {
  --about-radius: var(--r-md);
  display: block;
  color: var(--ink);
  font-family: var(--font-body);
}

.page-about img {
  max-width: 100%;
  height: auto;
}

.page-about .mono {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  letter-spacing: 0;
}

.page-about .about-crumb {
  padding-top: 20px;
  padding-bottom: 16px;
}

.page-about .about-crumb .breadcrumb-list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  list-style: none;
  margin: 0;
  padding: 0;
  font-size: 13px;
}

.page-about .about-crumb .breadcrumb-item + .breadcrumb-item::before {
  content: "/";
  margin-right: 8px;
  color: var(--line-strong);
}

.page-about .about-crumb .breadcrumb-link {
  color: var(--muted);
  text-decoration: none;
}

.page-about .about-crumb .breadcrumb-link:hover {
  color: var(--frost);
  text-decoration: underline;
}

.page-about .about-crumb .breadcrumb-current {
  color: var(--frost-deep);
  font-weight: 700;
}

/* 首屏 */
.page-about .about-hero {
  position: relative;
  padding: 12px 0 40px;
  background-image:
    repeating-linear-gradient(0deg, transparent 0 55px, rgba(31, 95, 139, 0.055) 55px 56px),
    repeating-linear-gradient(90deg, transparent 0 55px, rgba(31, 95, 139, 0.055) 55px 56px),
    linear-gradient(180deg, var(--frost-pale) 0%, var(--snow) 82%);
}

.page-about .about-hero-grid {
  display: grid;
  gap: 32px;
  align-items: start;
}

.page-about .about-hero-copy .eyebrow {
  margin: 0 0 12px;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--orange);
}

.page-about .about-hero h1 {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(30px, 4.4vw, 52px);
  font-weight: 800;
  line-height: 1.15;
  letter-spacing: -0.02em;
  color: var(--frost-deep);
  max-width: 18em;
}

.page-about .about-hero .lede {
  margin: 20px 0 0;
  max-width: 34em;
  font-size: clamp(16px, 1.9vw, 18px);
  line-height: 1.8;
  color: var(--muted);
}

.page-about .about-hero .btn-row {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 26px;
}

.page-about .about-hero-note {
  margin: 22px 0 0;
  padding-left: 14px;
  border-left: 3px solid var(--orange);
  font-size: 14px;
  line-height: 1.7;
  color: var(--muted);
  max-width: 30em;
}

.page-about .about-figures {
  padding: 24px 22px;
  border-radius: var(--r-lg);
  background: var(--frost-deep);
  box-shadow: 0 18px 44px -30px rgba(14, 58, 87, 0.85);
}

.page-about .about-figures-title {
  margin: 0 0 14px;
  font-size: 13px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: rgba(255, 255, 255, 0.6);
}

.page-about .about-figure-list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .about-figure {
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding: 14px 0;
  border-top: 1px solid rgba(255, 255, 255, 0.14);
}

.page-about .about-figure:first-child {
  border-top: 0;
  padding-top: 4px;
}

.page-about .about-figure-num {
  flex: 0 0 auto;
  min-width: 3ch;
  font-size: clamp(30px, 4.6vw, 40px);
  font-weight: 700;
  line-height: 1;
  color: var(--orange);
}

.page-about .about-figure-label {
  font-size: 14.5px;
  line-height: 1.6;
  color: rgba(255, 255, 255, 0.86);
}

/* 主体两栏：内容 + 目录 */
.page-about .about-layout {
  display: grid;
  gap: 36px;
  padding-bottom: 56px;
}

.page-about .about-main {
  min-width: 0;
}

.page-about .about-chapter {
  padding-top: 40px;
  margin-top: 40px;
  border-top: 1px solid var(--line);
}

.page-about .about-chapter:first-child {
  margin-top: 0;
  padding-top: 24px;
  border-top: 0;
}

.page-about .chapter-index {
  margin: 0 0 10px;
  font-size: 14px;
  font-weight: 700;
  color: var(--orange);
  letter-spacing: 0.08em;
}

.page-about .about-chapter h2 {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(24px, 3.4vw, 36px);
  font-weight: 800;
  line-height: 1.2;
  letter-spacing: -0.02em;
  color: var(--frost-deep);
}

.page-about .about-prose {
  margin-top: 18px;
}

.page-about .about-prose p {
  max-width: 34em;
  margin: 0 0 14px;
  font-size: 17px;
  line-height: 1.78;
  color: var(--ink);
}

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

/* 目录 */
.page-about .about-toc {
  min-width: 0;
}

.page-about .about-toc-title {
  margin: 0 0 8px;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--muted);
}

.page-about .about-toc-list {
  display: flex;
  gap: 0;
  list-style: none;
  margin: 0;
  padding: 0;
  overflow-x: auto;
  border-top: 1px solid var(--line);
  -webkit-overflow-scrolling: touch;
}

.page-about .about-toc-item {
  flex: 0 0 auto;
}

.page-about .about-toc-link {
  display: block;
  padding: 12px 14px;
  white-space: nowrap;
  font-size: 14px;
  line-height: 1.4;
  color: var(--muted);
  text-decoration: none;
  border-bottom: 2px solid transparent;
  transition: color 160ms var(--ease), border-color 160ms var(--ease);
}

.page-about .about-toc-link:hover {
  color: var(--frost);
}

.page-about .about-toc-link.is-active {
  color: var(--frost-deep);
  font-weight: 700;
  border-bottom-color: var(--orange);
}

/* 团队图与四段带状 */
.page-about .about-media {
  margin: 26px 0 0;
  border-radius: var(--about-radius);
  overflow: hidden;
  background: var(--frost-pale);
}

.page-about .about-media img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 16 / 9;
  object-fit: cover;
}

.page-about .about-media--tall img {
  aspect-ratio: 11 / 8;
}

.page-about .about-caption {
  margin: 0;
  padding: 10px 4px 0;
  font-size: 13px;
  line-height: 1.6;
  color: var(--muted);
}

.page-about .team-band {
  display: grid;
  gap: 1px;
  margin: 26px 0 0;
  padding: 0;
  list-style: none;
  background: var(--line);
  border-radius: var(--about-radius);
  overflow: hidden;
}

.page-about .team-item {
  background: var(--snow);
  padding: 20px 18px 22px;
  min-width: 0;
  transition: transform 180ms var(--ease), background 180ms var(--ease);
}

.page-about .team-item:hover {
  transform: translateY(-2px);
  background: var(--frost-pale);
}

.page-about .team-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--jade-pale);
  color: var(--jade);
}

.page-about .team-name {
  margin: 14px 0 4px;
  font-family: var(--font-display);
  font-size: 19px;
  font-weight: 800;
  color: var(--frost-deep);
}

.page-about .team-count {
  margin: 0 0 10px;
  font-size: 15px;
  font-weight: 700;
  color: var(--orange);
}

.page-about .team-desc {
  margin: 0;
  font-size: 15px;
  line-height: 1.72;
  color: var(--muted);
}

/* 准入流程 */
.page-about .about-split {
  display: grid;
  gap: 28px;
  margin-top: 26px;
}

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

.page-about .flow-steps {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .flow-step {
  position: relative;
  padding-left: 42px;
  padding-bottom: 10px;
}

.page-about .flow-step::before {
  content: "";
  position: absolute;
  left: 14px;
  top: 22px;
  bottom: -8px;
  width: 2px;
  background: var(--jade-pale);
}

.page-about .flow-step:last-child::before {
  display: none;
}

.page-about .flow-step::after {
  content: "";
  position: absolute;
  left: 8px;
  top: 16px;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--jade);
  box-shadow: 0 0 0 4px var(--snow);
}

.page-about .flow-details {
  background: var(--frost-pale);
  border-radius: var(--about-radius);
  overflow: hidden;
}

.page-about .flow-summary {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 14px 16px;
  cursor: pointer;
  list-style: none;
}

.page-about .flow-summary::-webkit-details-marker {
  display: none;
}

.page-about .flow-num {
  font-size: 13px;
  font-weight: 700;
  color: var(--orange);
}

.page-about .flow-name {
  font-family: var(--font-display);
  font-size: 17px;
  font-weight: 800;
  color: var(--frost-deep);
}

.page-about .flow-plus {
  position: relative;
  flex: 0 0 auto;
  width: 14px;
  height: 14px;
  margin-left: auto;
}

.page-about .flow-plus::before,
.page-about .flow-plus::after {
  content: "";
  position: absolute;
  background: var(--frost);
  border-radius: 2px;
  transition: transform 200ms var(--ease);
}

.page-about .flow-plus::before {
  left: 0;
  top: 6px;
  width: 14px;
  height: 2px;
}

.page-about .flow-plus::after {
  left: 6px;
  top: 0;
  width: 2px;
  height: 14px;
}

.page-about .flow-details[open] .flow-plus::after {
  transform: scaleY(0);
}

.page-about .flow-details[open] {
  background: var(--snow);
  box-shadow: inset 0 0 0 1px var(--line-strong);
}

.page-about .flow-body {
  padding: 0 16px 16px;
}

.page-about .flow-body p {
  margin: 0;
  font-size: 15px;
  line-height: 1.75;
  color: var(--muted);
}

/* 区域覆盖 */
.page-about .region-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 22px 0 0;
  padding: 0;
  list-style: none;
  background: var(--line);
  border-radius: var(--about-radius);
  overflow: hidden;
}

.page-about .region-stat {
  background: var(--jade-pale);
  padding: 18px 16px;
}

.page-about .region-num {
  display: block;
  font-size: clamp(26px, 4vw, 34px);
  font-weight: 700;
  line-height: 1.05;
  color: var(--frost-deep);
}

.page-about .region-label {
  display: block;
  margin-top: 6px;
  font-size: 13.5px;
  line-height: 1.55;
  color: var(--muted);
}

/* 版本演进 */
.page-about .version-log {
  list-style: none;
  margin: 26px 0 0;
  padding: 0;
}

.page-about .version-item {
  display: grid;
  gap: 10px;
  padding: 22px 0;
  border-top: 1px solid var(--line);
}

.page-about .version-item:first-child {
  border-top: 0;
  padding-top: 8px;
}

.page-about .version-tag {
  margin: 0;
  font-size: clamp(24px, 3.6vw, 32px);
  font-weight: 700;
  line-height: 1;
  color: var(--line-strong);
}

.page-about .version-item--now .version-tag {
  color: var(--orange);
}

.page-about .version-title {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-size: 18px;
  font-weight: 800;
  line-height: 1.45;
  color: var(--frost-deep);
}

.page-about .version-desc {
  margin: 0;
  max-width: 34em;
  font-size: 15.5px;
  line-height: 1.78;
  color: var(--muted);
}

/* 原则 */
.page-about .principle-list {
  display: grid;
  gap: 1px;
  margin: 26px 0 0;
  padding: 0;
  list-style: none;
  background: var(--line);
  border-radius: var(--about-radius);
  overflow: hidden;
}

.page-about .principle-item {
  position: relative;
  background: var(--snow);
  padding: 18px 18px 18px 40px;
}

.page-about .principle-item::before {
  content: "";
  position: absolute;
  left: 18px;
  top: 23px;
  width: 10px;
  height: 6px;
  border-left: 2px solid var(--jade);
  border-bottom: 2px solid var(--jade);
  transform: rotate(-45deg);
}

.page-about .principle-title {
  margin: 0 0 6px;
  font-family: var(--font-display);
  font-size: 17px;
  font-weight: 800;
  color: var(--frost-deep);
}

.page-about .principle-desc {
  margin: 0;
  font-size: 15px;
  line-height: 1.72;
  color: var(--muted);
}

/* 收尾行动块 */
.page-about .about-cta {
  margin-top: 32px;
  padding: 26px 22px 28px;
  border-radius: var(--r-lg);
  background: linear-gradient(135deg, var(--frost-deep) 0%, var(--frost) 100%);
  color: #fff;
}

.page-about .about-cta-title {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(20px, 2.8vw, 26px);
  font-weight: 800;
  line-height: 1.3;
  color: #fff;
}

.page-about .about-cta-text {
  margin: 10px 0 0;
  max-width: 32em;
  font-size: 15.5px;
  line-height: 1.75;
  color: rgba(255, 255, 255, 0.82);
}

.page-about .about-cta .btn-row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 20px;
}

.page-about .about-cta .btn--ghost {
  color: #fff;
  border-color: rgba(255, 255, 255, 0.5);
}

.page-about .about-cta .btn--ghost:hover {
  border-color: #fff;
  color: #fff;
}

/* 响应式 */
@media (min-width: 640px) {
  .page-about .region-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .team-band {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .principle-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 900px) {
  .page-about .about-hero {
    padding: 24px 0 56px;
  }

  .page-about .about-hero-grid {
    grid-template-columns: minmax(0, 1.12fr) minmax(0, 0.88fr);
    gap: 48px;
  }

  .page-about .about-figures {
    padding: 28px 26px;
  }

  .page-about .about-chapter {
    padding-top: 56px;
    margin-top: 56px;
  }
}

@media (min-width: 960px) {
  .page-about .about-layout {
    grid-template-columns: minmax(0, 1fr) 216px;
    gap: 56px;
    align-items: start;
  }

  .page-about .about-toc {
    position: sticky;
    top: 32px;
    align-self: start;
  }

  .page-about .about-toc-title {
    margin-bottom: 10px;
  }

  .page-about .about-toc-list {
    display: block;
    overflow: visible;
    border-top: 0;
    border-left: 1px solid var(--line);
  }

  .page-about .about-toc-link {
    padding: 9px 0 9px 16px;
    margin-left: -1px;
    white-space: normal;
    border-bottom: 0;
    border-left: 2px solid transparent;
  }

  .page-about .about-toc-link.is-active {
    border-bottom-color: transparent;
    border-left-color: var(--orange);
  }
}

@media (min-width: 1180px) {
  .page-about .team-band {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .about-split {
    grid-template-columns: minmax(0, 1.35fr) minmax(0, 0.85fr);
    gap: 36px;
  }

  .page-about .version-item {
    grid-template-columns: 128px minmax(0, 1fr);
    gap: 28px;
    align-items: start;
  }

  .page-about .version-tag {
    font-size: 34px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .team-item,
  .page-about .about-toc-link,
  .page-about .flow-plus::before,
  .page-about .flow-plus::after {
    transition: none;
  }
}