.page-about {
  --rail-w: 200px;
  background: var(--night);
  color: var(--snow);
  font-family: var(--font-body);
  overflow-wrap: break-word;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  margin-top: calc(var(--header-h) * -1);
  padding: calc(var(--header-h) + 28px) 0 36px;
  background:
    radial-gradient(130% 90% at 84% -10%, rgba(59, 130, 246, 0.26), transparent 62%),
    linear-gradient(180deg, var(--ink) 0%, var(--night) 72%);
  border-bottom: 1px solid var(--line-soft);
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: -1px;
  height: 3px;
  background: linear-gradient(
    90deg,
    var(--flag-blue) 0 20%,
    var(--snow) 20% 40%,
    var(--signal-red) 40% 60%,
    var(--teal) 60% 80%,
    var(--amber) 80% 100%
  );
  opacity: 0.9;
}

.page-about .hero-grid {
  display: grid;
  gap: 28px;
  margin-top: 26px;
}

.page-about .about-h1 {
  margin: 10px 0 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(30px, 7vw, 60px);
  line-height: 1.12;
  letter-spacing: -0.02em;
  color: var(--snow);
}

.page-about .about-h1 .hl {
  color: var(--cold);
  position: relative;
}

.page-about .about-h1 .hl::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0.04em;
  height: 3px;
  background: var(--amber);
  opacity: 0.85;
}

.page-about .hero-lede {
  margin: 18px 0 0;
  max-width: 46ch;
  color: var(--mist);
  font-size: 15px;
  line-height: 1.9;
}

.page-about .hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 24px;
}

/* ---------- 首屏统计纸卡 ---------- */
.page-about .hero-side {
  min-width: 0;
}

.page-about .stat-stack {
  position: relative;
  background: var(--paper);
  color: var(--ink);
  padding: 22px 18px 18px 26px;
  border: 1px solid rgba(5, 11, 20, 0.2);
  box-shadow: 8px 8px 0 rgba(237, 230, 214, 0.22), 16px 16px 0 rgba(237, 230, 214, 0.09);
  transform: skewY(-0.8deg);
}

.page-about .stat-stack > * {
  transform: skewY(0.8deg);
}

.page-about .stat-stack::after {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 4px;
  background: linear-gradient(
    180deg,
    var(--flag-blue) 0 20%,
    var(--snow) 20% 40%,
    var(--signal-red) 40% 60%,
    var(--teal) 60% 80%,
    var(--amber) 80% 100%
  );
}

.page-about .stat-stack__label {
  margin: 0 0 16px;
  font-size: 11px;
  letter-spacing: 0.2em;
  color: rgba(5, 11, 20, 0.55);
}

.page-about .stat-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px 12px;
}

.page-about .stat-item {
  display: flex;
  flex-direction: column;
  gap: 2px;
  min-width: 0;
}

.page-about .stat-num {
  font-size: clamp(24px, 5vw, 32px);
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: -0.02em;
  color: var(--night);
}

.page-about .stat-cap {
  font-size: 12px;
  letter-spacing: 0.04em;
  color: rgba(5, 11, 20, 0.6);
}

.page-about .stat-foot {
  margin: 18px 0 0;
  padding-top: 14px;
  border-top: 1px solid rgba(5, 11, 20, 0.16);
  font-size: 12.5px;
  line-height: 1.75;
  color: rgba(5, 11, 20, 0.68);
}

.page-about .hero-trust {
  margin: 26px 0 0;
  padding-left: 14px;
  border-left: 2px solid var(--teal);
  font-size: 12.5px;
  line-height: 1.8;
  color: var(--mist);
  max-width: 76ch;
}

/* ---------- 主体骨架 ---------- */
.page-about .about-body {
  padding: 34px 0 56px;
}

.page-about .about-shell {
  display: grid;
  gap: 28px;
}

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

/* ---------- 章节索引 ---------- */
.page-about .rail-title {
  margin: 0 0 10px;
  font-size: 11px;
  letter-spacing: 0.2em;
  color: var(--mist);
}

.page-about .rail-list {
  list-style: none;
  margin: 0;
  padding: 0 0 6px;
  display: flex;
  gap: 8px;
  overflow-x: auto;
  scrollbar-width: thin;
}

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

.page-about .rail-link {
  display: flex;
  align-items: baseline;
  gap: 8px;
  padding: 8px 12px;
  font-size: 13px;
  line-height: 1.4;
  white-space: nowrap;
  text-decoration: none;
  color: var(--mist);
  background: rgba(247, 250, 253, 0.04);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius);
  transition: color 180ms var(--ease), border-color 180ms var(--ease), background 180ms var(--ease);
}

.page-about .rail-link:hover,
.page-about .rail-link:focus-visible {
  color: var(--snow);
  border-color: var(--line-strong);
  background: rgba(59, 130, 246, 0.14);
}

.page-about .rail-num {
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--flag-blue);
}

/* ---------- 章节通用 ---------- */
.page-about .about-sec {
  margin-top: 44px;
  scroll-margin-top: calc(var(--header-h) + 24px);
}

.page-about .about-sec:first-child {
  margin-top: 0;
}

.page-about .sec-head {
  padding-left: 14px;
  border-left: 3px solid var(--flag-blue);
}

.page-about .sec-head--teal {
  border-left-color: var(--teal);
}

.page-about .sec-head--amber {
  border-left-color: var(--amber);
}

.page-about .sec-num {
  display: block;
  font-size: 11px;
  letter-spacing: 0.18em;
  color: var(--mist);
}

.page-about .sec-head h2 {
  margin: 6px 0 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(22px, 4.4vw, 34px);
  line-height: 1.3;
  letter-spacing: -0.01em;
  color: var(--snow);
}

.page-about .about-p {
  margin: 16px 0 0;
  max-width: 62ch;
  font-size: 15px;
  line-height: 1.9;
  color: var(--mist);
}

.page-about .inline-link {
  color: var(--cold);
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-color: rgba(221, 243, 255, 0.45);
}

.page-about .inline-link:hover {
  color: var(--flag-blue);
}

/* ---------- 图片 ---------- */
.page-about .media-frame {
  margin: 22px 0 0;
  border: 1px solid var(--line-mid);
  background: var(--ink);
  padding: 6px;
}

.page-about .media-frame img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
}

.page-about .media-frame__caption {
  margin: 8px 2px 2px;
  font-size: 12px;
  line-height: 1.7;
  color: var(--mist);
}

.page-about .photo-origin {
  margin-top: 22px;
}

/* ---------- 起点：图文分栏 ---------- */
.page-about .split-photo {
  display: grid;
  gap: 4px;
}

/* ---------- 编辑台 / 数据台 ---------- */
.page-about .desks {
  display: grid;
  gap: 14px;
  margin-top: 22px;
}

.page-about .desk {
  position: relative;
  padding: 20px 18px;
  background: rgba(5, 11, 20, 0.55);
  border: 1px solid var(--line-mid);
}

.page-about .desk::before {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  top: 0;
  height: 3px;
}

.page-about .desk--edit::before {
  background: var(--flag-blue);
}

.page-about .desk--data::before {
  background: var(--teal);
}

.page-about .desk-title {
  margin: 6px 0 12px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 19px;
  letter-spacing: 0.02em;
  color: var(--snow);
}

.page-about .desk-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .desk-list li {
  position: relative;
  padding-left: 14px;
  font-size: 14px;
  line-height: 1.8;
  color: var(--mist);
}

.page-about .desk-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.72em;
  width: 5px;
  height: 5px;
  background: var(--line-strong);
  transform: rotate(45deg);
}

.page-about .desk--edit .desk-list li::before {
  background: var(--flag-blue);
}

.page-about .desk--data .desk-list li::before {
  background: var(--teal);
}

.page-about .desk-bridge {
  display: none;
}

.page-about .flow-steps {
  list-style: none;
  margin: 18px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 8px;
}

.page-about .flow-step {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 10px 12px;
  font-size: 13px;
  color: var(--snow);
  border: 1px solid var(--line-soft);
  background: rgba(59, 130, 246, 0.08);
}

.page-about .flow-step .mono {
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--flag-blue);
}

.page-about .photo-desk {
  margin-top: 24px;
}

/* ---------- 时间轴 ---------- */
.page-about .timeline {
  list-style: none;
  margin: 26px 0 0;
  padding: 0 0 0 18px;
  border-left: 1px solid var(--line-mid);
}

.page-about .tl-item {
  position: relative;
  padding: 0 0 22px 18px;
}

.page-about .tl-item:last-child {
  padding-bottom: 0;
}

.page-about .tl-item::before {
  content: "";
  position: absolute;
  left: -5px;
  top: 8px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--night);
  border: 2px solid var(--flag-blue);
  transition: transform 200ms var(--ease), border-color 200ms var(--ease);
}

.page-about .tl-item--key::before {
  background: var(--amber);
  border-color: var(--amber);
}

.page-about .tl-item:hover::before {
  transform: scale(1.35);
  border-color: var(--cold);
}

.page-about .tl-year {
  display: inline-block;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.12em;
  color: var(--cold);
}

.page-about .tl-item--key .tl-year {
  color: var(--amber);
}

.page-about .tl-body {
  margin-top: 8px;
  padding: 14px 16px;
  background: rgba(247, 250, 253, 0.04);
  border: 1px solid var(--line-soft);
  transition: border-color 200ms var(--ease), background 200ms var(--ease);
}

.page-about .tl-item:hover .tl-body {
  border-color: var(--line-strong);
  background: rgba(59, 130, 246, 0.09);
}

.page-about .tl-title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 16px;
  line-height: 1.5;
  color: var(--snow);
}

.page-about .tl-text {
  margin: 6px 0 0;
  font-size: 13.5px;
  line-height: 1.8;
  color: var(--mist);
}

/* ---------- 多端 ---------- */
.page-about .devices {
  display: grid;
  gap: 22px;
  margin-top: 22px;
}

.page-about .device-label {
  margin: 20px 0 10px;
  font-size: 11px;
  letter-spacing: 0.18em;
  color: var(--mist);
}

.page-about .device-side .device-label:first-child {
  margin-top: 0;
}

.page-about .field-chips {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 7px;
}

.page-about .chip {
  padding: 5px 11px;
  font-size: 12.5px;
  line-height: 1.5;
  color: var(--cold);
  border: 1px solid var(--line-mid);
  background: rgba(221, 243, 255, 0.06);
}

.page-about .share-bars {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .share-bar {
  display: grid;
  grid-template-columns: 56px minmax(0, 1fr) 42px;
  align-items: center;
  gap: 10px;
}

.page-about .share-bar__name {
  font-size: 12.5px;
  color: var(--mist);
}

.page-about .share-bar__track {
  display: block;
  height: 8px;
  background: rgba(247, 250, 253, 0.1);
  overflow: hidden;
}

.page-about .share-bar__fill {
  display: block;
  height: 100%;
}

.page-about .share-bar__fill--blue {
  background: var(--flag-blue);
}

.page-about .share-bar__fill--teal {
  background: var(--teal);
}

.page-about .share-bar__fill--amber {
  background: var(--amber);
}

.page-about .share-bar__val {
  font-size: 12px;
  font-weight: 700;
  text-align: right;
  color: var(--snow);
}

.page-about .device-note {
  margin: 12px 0 0;
  font-size: 12.5px;
  line-height: 1.7;
  color: var(--mist);
}

/* ---------- 团队（米白纸带） ---------- */
.page-about .paper-card {
  position: relative;
  background: var(--paper);
  color: var(--night);
  padding: 24px 18px 26px;
  border: 1px solid rgba(5, 11, 20, 0.18);
  box-shadow: 10px 10px 0 rgba(237, 230, 214, 0.14);
}

.page-about .paper-card::before {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  top: 0;
  height: 3px;
  background: linear-gradient(
    90deg,
    var(--flag-blue) 0 20%,
    var(--snow) 20% 40%,
    var(--signal-red) 40% 60%,
    var(--teal) 60% 80%,
    var(--amber) 80% 100%
  );
}

.page-about .sec-head--paper {
  border-left-color: var(--signal-red);
  padding-top: 6px;
}

.page-about .sec-head--paper .sec-num {
  color: rgba(5, 11, 20, 0.55);
}

.page-about .sec-head--paper h2 {
  color: var(--night);
}

.page-about .paper-card .about-p {
  color: rgba(5, 11, 20, 0.74);
}

.page-about .paper-card .inline-link {
  color: #1d4ed8;
  text-decoration-color: rgba(29, 78, 216, 0.4);
}

.page-about .paper-card .inline-link:hover {
  color: var(--teal);
}

.page-about .team-grid {
  list-style: none;
  margin: 22px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: rgba(5, 11, 20, 0.14);
  border: 1px solid rgba(5, 11, 20, 0.14);
}

.page-about .team-stat {
  display: flex;
  flex-direction: column;
  gap: 2px;
  padding: 16px 14px;
  background: var(--paper);
}

.page-about .team-num {
  font-size: clamp(26px, 5.4vw, 34px);
  font-weight: 800;
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--night);
}

.page-about .team-cap {
  font-size: 12px;
  letter-spacing: 0.04em;
  color: rgba(5, 11, 20, 0.6);
}

.page-about .team-label {
  color: rgba(5, 11, 20, 0.55);
}

.page-about .partner-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .partner-item {
  display: flex;
  gap: 12px;
  align-items: flex-start;
  padding: 12px 14px;
  background: rgba(247, 250, 253, 0.55);
  border-left: 3px solid var(--flag-blue);
}

.page-about .partner-item:nth-child(2) {
  border-left-color: var(--teal);
}

.page-about .partner-item:nth-child(3) {
  border-left-color: var(--amber);
}

.page-about .partner-num {
  flex: 0 0 auto;
  font-size: 18px;
  font-weight: 800;
  line-height: 1.2;
  letter-spacing: 0.02em;
  color: var(--night);
}

.page-about .partner-text {
  font-size: 13.5px;
  line-height: 1.75;
  color: rgba(5, 11, 20, 0.76);
}

/* ---------- 质量 ---------- */
.page-about .quality-grid {
  list-style: none;
  margin: 22px 0 0;
  padding: 0;
  display: grid;
  gap: 12px;
}

.page-about .q-card {
  position: relative;
  padding: 18px 16px 18px 20px;
  border: 1px solid var(--line-soft);
  background: rgba(247, 250, 253, 0.035);
}

.page-about .q-card::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 3px;
}

.page-about .q-card--teal::before {
  background: var(--teal);
}

.page-about .q-card--blue::before {
  background: var(--flag-blue);
}

.page-about .q-card--amber::before {
  background: var(--amber);
}

.page-about .q-title {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 16px;
  color: var(--snow);
}

.page-about .q-text {
  margin: 0;
  font-size: 13.5px;
  line-height: 1.8;
  color: var(--mist);
}

/* ---------- 原则清单 ---------- */
.page-about .principles {
  margin-top: 22px;
  border-top: 1px solid var(--line-mid);
}

.page-about .pr {
  border-bottom: 1px solid var(--line-mid);
}

.page-about .pr summary {
  list-style: none;
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 15px 4px;
  cursor: pointer;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 15.5px;
  line-height: 1.6;
  color: var(--snow);
  transition: color 180ms var(--ease);
}

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

.page-about .pr summary:hover {
  color: var(--cold);
}

.page-about .pr summary::after {
  content: "+";
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 18px;
  line-height: 1;
  color: var(--flag-blue);
}

.page-about .pr[open] summary::after {
  content: "-";
  color: var(--teal);
}

.page-about .pr-code {
  flex: 0 0 auto;
  font-size: 11px;
  letter-spacing: 0.12em;
  padding: 3px 7px;
  border: 1px solid var(--line-mid);
  color: var(--mist);
}

.page-about .pr-text {
  margin: 0;
  padding: 0 4px 18px 4px;
  max-width: 62ch;
  font-size: 13.5px;
  line-height: 1.85;
  color: var(--mist);
}

/* ---------- 收束 ---------- */
.page-about .about-cta {
  position: relative;
  margin-top: 48px;
  padding: 28px 20px;
  background: var(--ink);
  border: 1px solid var(--line-mid);
  overflow: hidden;
}

.page-about .about-cta::before {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  top: 0;
  height: 3px;
  background: linear-gradient(
    90deg,
    var(--flag-blue) 0 20%,
    var(--snow) 20% 40%,
    var(--signal-red) 40% 60%,
    var(--teal) 60% 80%,
    var(--amber) 80% 100%
  );
}

.page-about .about-cta h2 {
  margin: 8px 0 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(21px, 4.2vw, 30px);
  line-height: 1.35;
  color: var(--snow);
}

.page-about .cta-text {
  margin: 12px 0 0;
  max-width: 58ch;
  font-size: 14px;
  line-height: 1.85;
  color: var(--mist);
}

.page-about .cta-links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 22px;
}

/* ---------- 媒体查询 ---------- */
@media (min-width: 620px) {
  .page-about .flow-steps {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .team-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

@media (min-width: 768px) {
  .page-about .about-hero {
    padding: calc(var(--header-h) + 40px) 0 52px;
  }

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

  .page-about .about-p {
    font-size: 15.5px;
  }

  .page-about .about-cta {
    padding: 34px 30px;
  }

  .page-about .paper-card {
    padding: 28px 26px 30px;
  }
}

@media (min-width: 860px) {
  .page-about .hero-grid {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    gap: 40px;
    align-items: end;
  }

  .page-about .split-photo {
    grid-template-columns: minmax(0, 1fr) minmax(0, 0.92fr);
    gap: 26px;
    align-items: start;
  }

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

  .page-about .desks {
    grid-template-columns: minmax(0, 1fr) auto minmax(0, 1fr);
    gap: 0;
    align-items: stretch;
  }

  .page-about .desk-bridge {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 32px;
  }

  .page-about .desk-bridge span {
    display: block;
    width: 1px;
    height: 100%;
    min-height: 120px;
    background: linear-gradient(180deg, transparent, var(--line-strong), transparent);
  }

  .page-about .devices {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 1fr);
    gap: 26px;
    align-items: start;
  }

  .page-about .photo-device {
    margin-top: 0;
  }
}

@media (min-width: 1024px) {
  .page-about .about-shell {
    grid-template-columns: var(--rail-w) minmax(0, 1fr);
    gap: 48px;
    align-items: start;
  }

  .page-about .about-rail {
    position: sticky;
    top: calc(var(--header-h) + 28px);
  }

  .page-about .rail-list {
    display: block;
    overflow: visible;
    padding-bottom: 0;
  }

  .page-about .rail-item + .rail-item {
    margin-top: 2px;
  }

  .page-about .rail-link {
    white-space: normal;
    padding: 9px 12px;
    border: 0;
    border-left: 2px solid transparent;
    background: transparent;
  }

  .page-about .rail-link:hover,
  .page-about .rail-link:focus-visible {
    border-left-color: var(--flag-blue);
    background: rgba(59, 130, 246, 0.1);
  }

  .page-about .about-sec {
    margin-top: 60px;
  }

  .page-about .about-body {
    padding: 44px 0 72px;
  }
}
<<<END>>>