.page-about {
  --about-rail: 56px;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-serif);
  overflow-x: hidden;
}

.page-about h1,
.page-about h2,
.page-about h3 {
  font-family: var(--font-sans);
  font-weight: 700;
  color: var(--ink);
  margin: 0;
}

.page-about .eyebrow {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--amber-deep);
  margin: 0 0 12px;
}

.page-about a {
  color: var(--blue-700);
}

/* ---------- 面包屑 ---------- */
.page-about .breadcrumb ol {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px;
  list-style: none;
  margin: 0 0 26px;
  padding: 0;
  font-family: var(--font-sans);
  font-size: 12px;
  color: var(--ink-dim);
}

.page-about .breadcrumb li + li::before {
  content: "/";
  margin-right: 6px;
  color: var(--grey-200);
}

.page-about .breadcrumb a {
  color: var(--ink-dim);
  text-decoration: none;
}

.page-about .breadcrumb a:hover,
.page-about .breadcrumb a:focus-visible {
  color: var(--blue-700);
  text-decoration: underline;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  padding: 26px 0 44px;
  background: linear-gradient(180deg, var(--grey-100) 0%, var(--paper) 92%);
  border-bottom: 1px solid var(--line);
}

.page-about .hero-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 32px;
  align-items: start;
}

.page-about .hero-copy h1 {
  font-size: 28px;
  line-height: 1.28;
  letter-spacing: -0.01em;
  margin-bottom: 18px;
}

.page-about .hero-lead {
  font-size: 15px;
  line-height: 1.8;
  color: var(--ink-dim);
  margin: 0 0 26px;
  max-width: 34em;
}

.page-about .hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.page-about .hero-figure {
  margin: 0;
}

.page-about .hero-figure img {
  display: block;
  width: 100%;
  height: auto;
  border: 1px solid var(--line);
  border-radius: 4px;
  box-shadow: var(--shadow-md);
}

.page-about .hero-figure figcaption {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.04em;
  color: var(--ink-dim);
  margin-top: 12px;
  padding-left: 2px;
}

/* ---------- 章节索引 ---------- */
.page-about .chapter-index {
  border-bottom: 1px solid var(--line);
  background: var(--paper);
}

.page-about .chapter-index ol {
  display: flex;
  gap: 8px;
  list-style: none;
  margin: 0;
  padding: 14px 0;
  overflow-x: auto;
  scrollbar-width: thin;
}

.page-about .chapter-index a {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  padding: 6px 13px;
  border: 1px solid var(--line);
  border-radius: var(--radius-pill);
  font-family: var(--font-sans);
  font-size: 12px;
  color: var(--ink-dim);
  text-decoration: none;
  white-space: nowrap;
  transition: border-color 0.18s ease, color 0.18s ease, background 0.18s ease;
}

.page-about .chapter-index a:hover,
.page-about .chapter-index a:focus-visible {
  border-color: var(--blue-500);
  background: var(--grey-100);
  color: var(--blue-900);
}

.page-about .idx-no {
  font-family: var(--font-mono);
  font-size: 10px;
  font-weight: 600;
  color: var(--amber-deep);
}

/* ---------- 章节骨架 ---------- */
.page-about .chapter {
  padding: 44px 0;
  border-bottom: 1px solid var(--line);
}

.page-about .chapter--tint {
  background: var(--grey-100);
}

.page-about .chapter-inner {
  display: grid;
  grid-template-columns: 1fr;
  gap: 18px;
}

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

.page-about .chapter-no {
  font-family: var(--font-mono);
  font-size: 20px;
  font-weight: 600;
  color: var(--amber-deep);
  letter-spacing: 0.02em;
}

.page-about .chapter-line {
  flex: 1;
  height: 1px;
  background: var(--line);
}

.page-about .section-head h2 {
  font-size: 22px;
  line-height: 1.32;
  letter-spacing: -0.005em;
  max-width: 20em;
}

.page-about .prose p {
  font-size: 15px;
  line-height: 1.85;
  color: var(--ink-dim);
  margin: 0 0 16px;
}

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

.page-about .chapter-link {
  margin: 26px 0 0;
  font-family: var(--font-sans);
  font-size: 13px;
}

.page-about .chapter-link a {
  display: inline-block;
  border-bottom: 1px solid var(--celadon);
  padding-bottom: 2px;
  text-decoration: none;
  color: var(--blue-700);
}

.page-about .chapter-link a:hover {
  color: var(--blue-900);
}

/* ---------- 01 服务对象 ---------- */
.page-about .audience-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
  margin-top: 26px;
}

.page-about .audience-card {
  background: var(--paper);
  border: 1px solid var(--line);
  border-top-width: 3px;
  border-radius: var(--radius-card);
  padding: 20px;
  box-shadow: var(--shadow-sm);
}

.page-about .audience-card--member {
  border-top-color: var(--blue-500);
}

.page-about .audience-card--org {
  border-top-color: var(--amber);
}

.page-about .audience-card--self {
  border-top-color: var(--celadon);
}

.page-about .audience-card h3 {
  font-size: 16px;
  font-weight: 700;
  margin-bottom: 8px;
}

.page-about .audience-card p {
  font-size: 14px;
  line-height: 1.8;
  color: var(--ink-dim);
  margin: 0;
}

.page-about .audience-card a {
  color: var(--blue-700);
  text-underline-offset: 3px;
}

/* ---------- 02 内容体系 ---------- */
.page-about .layer-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 26px;
  margin-top: 22px;
  align-items: start;
}

.page-about .layer-figure {
  margin: 0;
}

.page-about .layer-figure img {
  display: block;
  width: 100%;
  height: auto;
  border: 1px solid var(--grey-200);
  border-radius: 6px;
  background: var(--paper);
}

.page-about .layer-figure figcaption {
  font-family: var(--font-sans);
  font-size: 12px;
  color: var(--ink-dim);
  margin-top: 10px;
}

.page-about .doc-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  list-style: none;
  margin: 26px 0 0;
  padding: 0;
}

.page-about .doc-chip {
  font-family: var(--font-sans);
  font-size: 12px;
  font-weight: 500;
  padding: 5px 13px;
  border: 1px solid var(--grey-200);
  border-radius: var(--radius-pill);
  background: var(--paper);
  color: var(--ink-dim);
}

.page-about .doc-chip--key {
  background: var(--celadon-pale);
  border-color: var(--celadon);
  color: var(--blue-900);
}

.page-about .layer-stat {
  margin: 22px 0 0;
  padding-left: 14px;
  border-left: 3px solid var(--celadon);
  font-family: var(--font-sans);
  font-size: 13px;
  color: var(--ink-dim);
}

.page-about .stat-num {
  font-family: var(--font-mono);
  font-size: 22px;
  font-weight: 600;
  color: var(--blue-900);
  margin-right: 6px;
}

/* ---------- 03 版本演进 ---------- */
.page-about .version-strip {
  display: flex;
  margin: 30px 0 22px;
}

.page-about .vs-step {
  position: relative;
  flex: 1 1 0;
  padding: 18px 10px 0 0;
  border-top: 2px solid var(--grey-200);
}

.page-about .vs-step--two {
  border-top-color: var(--blue-500);
}

.page-about .vs-step--three {
  border-top-color: var(--amber);
}

.page-about .vs-dot {
  position: absolute;
  top: -8px;
  left: 0;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--paper);
  border: 2px solid var(--blue-500);
}

.page-about .vs-step--three .vs-dot {
  background: var(--amber);
  border-color: var(--amber);
}

.page-about .vs-code {
  display: block;
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 600;
  color: var(--blue-900);
}

.page-about .vs-label {
  display: block;
  font-family: var(--font-sans);
  font-size: 11px;
  line-height: 1.5;
  color: var(--ink-dim);
  margin-top: 4px;
}

.page-about .version-tabs .tab-list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--line);
}

.page-about .version-tabs .tab {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.02em;
  padding: 8px 15px;
  border: 1px solid var(--line);
  border-radius: var(--radius-pill);
  background: var(--paper);
  color: var(--ink-dim);
  cursor: pointer;
  transition: background 0.18s ease, color 0.18s ease, border-color 0.18s ease;
}

.page-about .version-tabs .tab:hover,
.page-about .version-tabs .tab:focus-visible {
  border-color: var(--blue-500);
  color: var(--blue-900);
}

.page-about .version-tabs .tab[aria-selected="true"] {
  background: var(--blue-900);
  border-color: var(--blue-900);
  color: var(--on-dark);
}

.page-about .tab-panel {
  padding: 22px 0 4px;
  outline-offset: 4px;
}

.page-about .version-body h3 {
  font-size: 17px;
  line-height: 1.5;
  margin-bottom: 12px;
}

.page-about .version-tag {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--amber-deep);
  margin: 0 0 8px;
}

.page-about .version-body p {
  font-size: 15px;
  line-height: 1.85;
  color: var(--ink-dim);
  margin: 0 0 16px;
  max-width: 40em;
}

.page-about .version-points {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 8px;
}

.page-about .version-points li {
  position: relative;
  padding-left: 20px;
  font-family: var(--font-sans);
  font-size: 13px;
  line-height: 1.7;
  color: var(--ink-dim);
}

.page-about .version-points li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 9px;
  width: 8px;
  height: 8px;
  border-radius: 2px;
  background: var(--celadon);
}

.page-about .version-figure {
  margin: 28px 0 0;
}

.page-about .version-figure img {
  display: block;
  width: 100%;
  height: auto;
  border: 1px solid var(--line);
  border-radius: 6px;
}

.page-about .version-figure figcaption {
  font-family: var(--font-sans);
  font-size: 12px;
  color: var(--ink-dim);
  margin-top: 10px;
}

/* ---------- 04 团队 ---------- */
.page-about .team-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
  margin-top: 26px;
}

.page-about .team-card {
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: var(--radius-card);
  padding: 20px;
  transition: transform 0.2s ease, border-color 0.2s ease, box-shadow 0.2s ease;
}

.page-about .team-card:hover,
.page-about .team-card:focus-within {
  border-color: var(--celadon);
  box-shadow: var(--shadow-sm);
  transform: translateY(-3px);
}

.page-about .team-figure {
  margin: 0 0 12px;
  display: flex;
  align-items: baseline;
  gap: 4px;
}

.page-about .team-num {
  font-family: var(--font-mono);
  font-size: 30px;
  font-weight: 600;
  line-height: 1;
  color: var(--blue-900);
  letter-spacing: -0.02em;
}

.page-about .team-unit {
  font-family: var(--font-sans);
  font-size: 12px;
  color: var(--ink-dim);
}

.page-about .team-card h3 {
  font-size: 15px;
  font-weight: 700;
  margin-bottom: 8px;
}

.page-about .team-note {
  font-size: 13px;
  line-height: 1.75;
  color: var(--ink-dim);
  margin: 0;
}

/* ---------- 05 资质与保障 ---------- */
.page-about .assurance-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 26px;
  margin-top: 22px;
  align-items: start;
}

.page-about .assurance-item {
  padding: 16px 0;
  border-top: 1px solid var(--line);
}

.page-about .assurance-item:last-child {
  border-bottom: 1px solid var(--line);
}

.page-about .assurance-item h3 {
  font-size: 15px;
  font-weight: 700;
  margin-bottom: 7px;
}

.page-about .assurance-item p {
  font-size: 14px;
  line-height: 1.8;
  color: var(--ink-dim);
  margin: 0;
}

.page-about .assurance-card {
  background: var(--blue-900);
  color: var(--on-dark);
  border-radius: var(--radius-card);
  padding: 24px 22px;
  box-shadow: var(--shadow-md);
}

.page-about .assurance-card-title {
  font-family: var(--font-sans);
  font-size: 15px;
  font-weight: 700;
  color: var(--on-dark);
  margin: 0 0 18px;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--line-dark);
}

.page-about .contact-row {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 4px 10px;
  padding: 9px 0;
}

.page-about .contact-key {
  font-family: var(--font-sans);
  font-size: 12px;
  color: var(--on-dark-dim);
  min-width: 60px;
}

.page-about .contact-val {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--on-dark);
  word-break: break-all;
}

.page-about .copy-btn {
  font-family: var(--font-sans);
  font-size: 11px;
  padding: 4px 10px;
  border: 1px solid rgba(251, 250, 247, 0.32);
  border-radius: var(--radius-pill);
  background: transparent;
  color: var(--on-dark);
  cursor: pointer;
  transition: background 0.18s ease, border-color 0.18s ease;
}

.page-about .copy-btn:hover,
.page-about .copy-btn:focus-visible {
  background: rgba(251, 250, 247, 0.14);
  border-color: var(--amber);
}

.page-about .assurance-note {
  font-size: 12px;
  line-height: 1.8;
  color: var(--on-dark-dim);
  margin: 16px 0 0;
  padding-top: 14px;
  border-top: 1px solid var(--line-dark);
}

/* ---------- 收尾入口 ---------- */
.page-about .about-next {
  padding: 46px 0 58px;
  background: linear-gradient(180deg, var(--paper) 0%, var(--grey-100) 100%);
}

.page-about .next-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
  margin-top: 24px;
}

.page-about .next-card {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 20px;
  border: 1px solid var(--line);
  border-radius: var(--radius-card);
  background: var(--paper);
  text-decoration: none;
  color: var(--ink);
  transition: border-color 0.2s ease, box-shadow 0.2s ease, transform 0.2s ease;
}

.page-about .next-card:hover,
.page-about .next-card:focus-visible {
  border-color: var(--blue-500);
  box-shadow: var(--shadow-sm);
  transform: translateY(-2px);
}

.page-about .next-no {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 600;
  color: var(--amber-deep);
}

.page-about .next-card h3 {
  font-size: 16px;
  font-weight: 700;
  color: var(--blue-900);
}

.page-about .next-card p {
  font-size: 13px;
  line-height: 1.75;
  color: var(--ink-dim);
  margin: 0;
}

.page-about .next-go {
  font-family: var(--font-sans);
  font-size: 12px;
  font-weight: 500;
  color: var(--blue-700);
  margin-top: 4px;
}

.page-about .next-foot {
  font-size: 13px;
  line-height: 1.8;
  color: var(--ink-dim);
  margin: 22px 0 0;
}

.page-about .next-foot a {
  color: var(--blue-700);
  text-underline-offset: 3px;
}

/* ---------- 响应式 ---------- */
@media (min-width: 720px) {
  .page-about .hero-copy h1 {
    font-size: 32px;
  }

  .page-about .hero-lead {
    font-size: 16px;
  }

  .page-about .section-head h2 {
    font-size: 25px;
  }

  .page-about .audience-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 18px;
  }

  .page-about .audience-card:nth-child(2) {
    margin-top: 18px;
  }

  .page-about .audience-card:nth-child(3) {
    margin-top: 36px;
  }

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

  .page-about .next-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 14px;
  }
}

@media (min-width: 900px) {
  .page-about {
    --about-rail: 68px;
  }

  .page-about .about-hero {
    padding: 32px 0 62px;
  }

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

  .page-about .hero-copy h1 {
    font-size: 38px;
    line-height: 1.22;
  }

  .page-about .hero-figure img {
    transform: rotate(-1.2deg);
    transform-origin: center;
  }

  .page-about .chapter {
    padding: 72px 0;
  }

  .page-about .chapter-inner {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: 36px;
  }

  .page-about .chapter-rail {
    flex-direction: column;
    align-items: flex-start;
    gap: 14px;
  }

  .page-about .chapter-no {
    font-size: 24px;
  }

  .page-about .chapter-line {
    width: 1px;
    height: auto;
    flex: 1 1 auto;
    min-height: 120px;
    background: linear-gradient(180deg, var(--celadon) 0%, var(--line) 42%, transparent 100%);
  }

  .page-about .section-head h2 {
    font-size: 30px;
  }

  .page-about .layer-grid {
    grid-template-columns: minmax(0, 0.95fr) minmax(0, 1.05fr);
    gap: 40px;
  }

  .page-about .assurance-grid {
    grid-template-columns: minmax(0, 1.1fr) minmax(0, 0.9fr);
    gap: 40px;
  }

  .page-about .assurance-card {
    position: sticky;
    top: 96px;
    padding: 26px 24px;
  }
}

@media (min-width: 1040px) {
  .page-about .team-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 16px;
  }

  .page-about .team-card:nth-child(3n + 2) {
    margin-top: 22px;
  }

  .page-about .team-card:nth-child(3n + 3) {
    margin-top: 44px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .team-card,
  .page-about .next-card,
  .page-about .chapter-index a,
  .page-about .copy-btn,
  .page-about .version-tabs .tab {
    transition: none;
  }

  .page-about .team-card:hover,
  .page-about .next-card:hover,
  .page-about .hero-figure img {
    transform: none;
  }
}
<<<END>>>