.page-about {
  --about-rail-w: 172px;
  --about-rail-top: 92px;
  --about-tl-pad: clamp(28px, 5vw, 44px);
  color: var(--chalk);
}

.page-about .about-shell {
  max-width: var(--shell-max);
  margin: 0 auto;
  padding: 0 var(--gutter);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding: clamp(16px, 3vw, 28px) 0 clamp(36px, 6vw, 76px);
  overflow: hidden;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  top: -14%;
  left: -26%;
  right: -12%;
  height: min(720px, 112vw);
  background: repeating-radial-gradient(circle at 26% 42%, transparent 0 92px, rgba(55, 232, 208, 0.085) 92px 94px);
  pointer-events: none;
  z-index: 0;
}

.page-about .breadcrumb {
  position: relative;
  z-index: 1;
  margin-bottom: clamp(18px, 3vw, 32px);
  font-size: 13px;
}

.page-about .hero-grid {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(24px, 4vw, 48px);
}

.page-about .hero-copy .eyebrow {
  margin: 0 0 12px;
}

.page-about .hero-copy .h1 {
  margin: 0 0 clamp(14px, 2vw, 20px);
  max-width: 15em;
}

.page-about .hero-copy .lede {
  margin: 0;
  max-width: 34em;
}

.page-about .hero-index {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  margin-top: clamp(22px, 3.4vw, 34px);
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  overflow: hidden;
}

.page-about .hero-index a {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding: 13px 16px;
  background: var(--surface);
  color: var(--text-soft);
  text-decoration: none;
  font-size: 15px;
  line-height: 1.5;
  transition: background 0.2s var(--ease), color 0.2s var(--ease);
}

.page-about .hero-index a .num {
  flex: none;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--gold);
  transition: color 0.2s var(--ease);
}

.page-about .hero-index a:hover,
.page-about .hero-index a:focus-visible {
  background: var(--surface-2);
  color: var(--cyan);
}

.page-about .hero-index a:hover .num,
.page-about .hero-index a:focus-visible .num {
  color: var(--cyan);
}

.page-about .hero-media {
  position: relative;
  margin: 0;
  border-radius: 0 var(--r-xl) 0 var(--r-lg);
  overflow: hidden;
  border: 1px solid var(--line);
  background: linear-gradient(150deg, var(--surface-2), var(--tunnel));
}

.page-about .hero-media img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 14 / 9;
  object-fit: cover;
}

.page-about .hero-media .media-tag {
  position: absolute;
  top: 16px;
  left: 16px;
  z-index: 1;
}

.page-about .hero-media .media-caption {
  padding: 12px 16px;
  font-size: 13px;
  line-height: 1.65;
  color: var(--text-dim);
  background: rgba(5, 16, 13, 0.72);
}

/* ---------- 主体两栏 ---------- */
.page-about .about-body {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(20px, 3vw, 42px);
  align-items: start;
}

.page-about .about-rail {
  display: none;
}

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

.page-about .flow-section {
  position: relative;
  padding: clamp(36px, 5.6vw, 72px) 0;
  scroll-margin-top: 88px;
}

.page-about .flow-section > .eyebrow {
  margin: 0 0 10px;
}

.page-about .flow-section > .h2 {
  margin: 0 0 clamp(14px, 2vw, 20px);
  max-width: 20em;
}

.page-about .flow-section > .prose {
  margin: 0 0 clamp(11px, 1.6vw, 15px);
  max-width: 42em;
}

.page-about .flow-section > .prose:last-child {
  margin-bottom: 0;
}

.page-about .slant-divider {
  height: 12px;
  background: linear-gradient(90deg, var(--wine) 0%, var(--wine) 46%, var(--indigo) 46%, var(--indigo) 100%);
  clip-path: polygon(0 36%, 100% 0, 100% 64%, 0 100%);
  opacity: 0.78;
  margin: clamp(4px, 1.4vw, 10px) 0;
}

/* ---------- 服务对象 ---------- */
.page-about .what-list {
  list-style: none;
  margin: clamp(20px, 2.8vw, 28px) 0 0;
  padding: 0;
  display: grid;
  gap: 12px;
}

.page-about .what-item {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 16px;
  align-items: start;
  padding: clamp(16px, 2.4vw, 24px);
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  background: var(--surface);
  transition: border-color 0.22s var(--ease), transform 0.22s var(--ease);
}

.page-about .what-item:hover {
  border-color: rgba(55, 232, 208, 0.5);
  transform: translateX(4px);
}

.page-about .what-num {
  font-family: var(--font-mono);
  font-size: clamp(22px, 3vw, 28px);
  font-weight: 800;
  line-height: 1;
  color: var(--gold);
  letter-spacing: -0.02em;
  font-variant-numeric: tabular-nums;
  padding-top: 2px;
}

.page-about .what-body .h3 {
  margin: 0 0 8px;
}

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

/* ---------- 时间线 ---------- */
.page-about .filter-bar {
  margin: clamp(16px, 2.4vw, 24px) 0 clamp(18px, 2.6vw, 26px);
  flex-wrap: wrap;
}

.page-about .timeline {
  list-style: none;
  margin: 0;
  padding: 0 0 0 var(--about-tl-pad);
  position: relative;
}

.page-about .timeline::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 14px;
  bottom: 14px;
  width: 2px;
  border-radius: 2px;
  background: linear-gradient(180deg, var(--cyan) 0%, var(--indigo) 46%, var(--wine) 76%, var(--gold) 100%);
  opacity: 0.85;
}

.page-about .tl-item {
  position: relative;
  padding-bottom: clamp(10px, 1.8vw, 18px);
}

.page-about .tl-item[hidden] {
  display: none;
}

.page-about .tl-item::before {
  content: "";
  position: absolute;
  top: 20px;
  left: calc(2px - var(--about-tl-pad));
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--ink);
  border: 2px solid var(--cyan);
  box-shadow: 0 0 0 4px rgba(55, 232, 208, 0.1);
  z-index: 1;
}

.page-about .tl-card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  overflow: hidden;
  transition: border-color 0.2s var(--ease);
}

.page-about .tl-card:hover {
  border-color: var(--line-strong);
}

.page-about .tl-summary {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 8px 14px;
  padding: 15px clamp(15px, 2.2vw, 22px);
  cursor: pointer;
  list-style: none;
  transition: background 0.2s var(--ease);
}

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

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

.page-about .tl-card[open] .tl-summary::after {
  content: "–";
}

.page-about .tl-card[open] .tl-summary {
  background: var(--surface-2);
}

.page-about .tl-year {
  font-family: var(--font-mono);
  font-size: clamp(17px, 2.4vw, 20px);
  font-weight: 800;
  letter-spacing: -0.01em;
  color: var(--gold);
  font-variant-numeric: tabular-nums;
}

.page-about .tl-title {
  font-size: 15px;
  font-weight: 600;
  line-height: 1.5;
  color: var(--chalk);
}

.page-about .tl-body {
  padding: 0 clamp(15px, 2.2vw, 22px) 18px;
}

.page-about .tl-body p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--text-soft);
}

/* ---------- 收录范围 ---------- */
.page-about .scope-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin-top: clamp(20px, 2.8vw, 28px);
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  overflow: hidden;
}

.page-about .scope-cell {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: clamp(16px, 2.4vw, 26px);
  background: var(--ink);
}

.page-about .scope-num {
  align-self: flex-start;
  display: inline-block;
  font-family: var(--font-mono);
  font-size: clamp(28px, 5vw, 44px);
  font-weight: 800;
  line-height: 1;
  letter-spacing: -0.03em;
  color: var(--chalk);
  font-variant-numeric: tabular-nums;
  padding-bottom: 8px;
  border-bottom: 3px solid var(--gold);
}

.page-about .scope-label {
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.08em;
  color: var(--cyan);
}

.page-about .scope-text {
  margin: 0;
  font-size: 13.5px;
  line-height: 1.7;
  color: var(--text-dim);
}

/* ---------- 数据流程 ---------- */
.page-about .step-list {
  list-style: none;
  margin: clamp(20px, 2.8vw, 28px) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(10px, 1.6vw, 16px);
}

.page-about .step-item {
  position: relative;
  padding: clamp(18px, 2.6vw, 28px);
  border-radius: var(--r-md);
  border: 1px solid var(--line);
  background: linear-gradient(165deg, var(--surface-2), var(--surface-3));
  overflow: hidden;
}

.page-about .step-item::after {
  content: "";
  position: absolute;
  right: -42px;
  bottom: -52px;
  width: 150px;
  height: 150px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(55, 232, 208, 0.16), transparent 70%);
  pointer-events: none;
}

.page-about .step-num {
  display: inline-block;
  margin-bottom: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--gold);
}

.page-about .step-item .h3 {
  margin: 0 0 8px;
}

.page-about .step-item p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--text-soft);
  position: relative;
  z-index: 1;
}

.page-about .process-media {
  margin: clamp(24px, 4vw, 40px) 0 0;
  border-radius: var(--r-lg) 0 var(--r-lg) 0;
  overflow: hidden;
  border: 1px solid var(--line);
  background: linear-gradient(160deg, var(--surface-2), var(--tunnel));
}

.page-about .process-media img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 3 / 2;
  object-fit: cover;
}

.page-about .process-media .media-caption {
  padding: 12px 16px;
  font-size: 13px;
  line-height: 1.65;
  color: var(--text-dim);
  background: rgba(5, 16, 13, 0.66);
}

/* ---------- 团队 ---------- */
.page-about .team-list {
  list-style: none;
  margin: clamp(18px, 2.6vw, 26px) 0 clamp(18px, 2.6vw, 24px);
  padding: 0;
}

.page-about .team-row {
  display: grid;
  grid-template-columns: 58px minmax(0, 1fr);
  gap: 16px;
  align-items: start;
  padding: clamp(15px, 2.2vw, 20px) 0;
  border-bottom: 1px solid var(--line);
}

.page-about .team-row:first-child {
  border-top: 1px solid var(--line);
}

.page-about .team-count {
  font-family: var(--font-mono);
  font-size: clamp(24px, 3.4vw, 32px);
  font-weight: 800;
  line-height: 1;
  color: var(--cyan);
  font-variant-numeric: tabular-nums;
  letter-spacing: -0.02em;
  padding-top: 2px;
}

.page-about .team-body .h3 {
  margin: 0 0 7px;
}

.page-about .team-body p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--text-soft);
}

/* ---------- 合作与荣誉 ---------- */
.page-about .flow-section--indigo {
  position: relative;
  margin: clamp(18px, 3vw, 34px) 0;
  padding: 0;
  border-radius: var(--r-xl);
  overflow: hidden;
  background: linear-gradient(160deg, var(--indigo), #1A1940 72%);
}

.page-about .flow-section--indigo::after {
  content: "";
  position: absolute;
  inset: 0;
  background: repeating-linear-gradient(115deg, rgba(255, 255, 255, 0.035) 0 2px, transparent 2px 22px);
  pointer-events: none;
}

.page-about .partners-media {
  position: relative;
  margin: 0;
  z-index: 1;
}

.page-about .partners-media img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 8 / 3;
  object-fit: cover;
  opacity: 0.62;
}

.page-about .partners-inner {
  position: relative;
  z-index: 1;
  padding: clamp(24px, 4vw, 46px);
}

.page-about .partners-inner > .eyebrow {
  margin: 0 0 10px;
  color: var(--cyan);
}

.page-about .partners-inner > .h2 {
  margin: 0 0 clamp(14px, 2vw, 20px);
  max-width: 20em;
}

.page-about .partners-inner > .prose {
  margin: 0;
  max-width: 42em;
  color: rgba(241, 247, 243, 0.88);
}

.page-about .partner-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
  margin-top: clamp(20px, 3vw, 30px);
}

.page-about .partner-item {
  padding: clamp(16px, 2.4vw, 22px);
  border-radius: var(--r-md);
  background: rgba(11, 30, 26, 0.52);
  border: 1px solid rgba(55, 232, 208, 0.24);
}

.page-about .partner-num {
  display: block;
  margin-bottom: 10px;
  font-family: var(--font-mono);
  font-size: clamp(24px, 3.4vw, 30px);
  font-weight: 800;
  line-height: 1;
  color: var(--gold);
  font-variant-numeric: tabular-nums;
}

.page-about .partner-item .h3 {
  margin: 0 0 8px;
}

.page-about .partner-item p {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: rgba(241, 247, 243, 0.82);
}

.page-about .honor-line {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 10px;
  margin: clamp(18px, 2.6vw, 24px) 0 0;
  font-size: 14.5px;
  line-height: 1.75;
  color: rgba(241, 247, 243, 0.86);
}

/* ---------- 疑问反馈 ---------- */
.page-about .flow-section--wine {
  position: relative;
  padding: clamp(28px, 4.4vw, 52px) clamp(20px, 3.6vw, 44px);
  margin: clamp(16px, 3vw, 30px) 0;
  border-radius: var(--r-lg) 0 var(--r-lg) 0;
  background: linear-gradient(150deg, rgba(108, 33, 54, 0.72), rgba(108, 33, 54, 0.28));
  border-left: 3px solid var(--wine);
}

.page-about .flow-section--wine > .prose {
  max-width: 40em;
}

.page-about .check-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: clamp(18px, 2.6vw, 26px);
}

.page-about .check-note {
  margin: 14px 0 0;
  font-size: 13px;
  line-height: 1.7;
  color: var(--text-dim);
}

/* ---------- 下一步 ---------- */
.page-about .next-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
  margin-top: clamp(20px, 2.8vw, 28px);
}

.page-about .next-card {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: clamp(18px, 2.4vw, 26px);
  border-radius: var(--r-md);
  border: 1px solid var(--line);
  background: linear-gradient(170deg, var(--surface-2), var(--ink));
  color: var(--chalk);
  text-decoration: none;
  transition: border-color 0.22s var(--ease), transform 0.22s var(--ease);
}

.page-about .next-card:hover,
.page-about .next-card:focus-visible {
  border-color: rgba(55, 232, 208, 0.55);
  transform: translateY(-3px);
}

.page-about .next-num {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--gold);
}

.page-about .next-card h3 {
  margin: 0;
  font-size: 17px;
  font-weight: 800;
  line-height: 1.4;
}

.page-about .next-card p {
  margin: 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--text-dim);
}

/* ---------- 平板 ---------- */
@media (min-width: 640px) {
  .page-about .hero-index {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

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

@media (min-width: 760px) {
  .page-about .step-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .step-item:nth-child(2),
  .page-about .step-item:nth-child(4) {
    margin-top: 28px;
  }

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

  .page-about .next-card:nth-child(2) {
    margin-top: 20px;
  }

  .page-about .next-card:nth-child(3) {
    margin-top: 40px;
  }
}

/* ---------- 桌面 ---------- */
@media (min-width: 900px) {
  .page-about .hero-grid {
    grid-template-columns: 7fr 5fr;
    align-items: start;
  }
}

@media (min-width: 1024px) {
  .page-about .about-body {
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
  }

  .page-about .about-rail {
    display: block;
    position: sticky;
    top: var(--about-rail-top);
    align-self: start;
    max-height: calc(100vh - var(--about-rail-top) - 32px);
    overflow-y: auto;
    padding: clamp(36px, 5.6vw, 72px) 0 24px;
  }

  .page-about .rail-label {
    margin: 0 0 16px;
    font-family: var(--font-mono);
    font-size: 11.5px;
    letter-spacing: 0.16em;
    text-transform: uppercase;
    color: var(--mist);
  }

  .page-about .rail-list {
    position: relative;
    list-style: none;
    margin: 0;
    padding: 0;
  }

  .page-about .rail-list::before {
    content: "";
    position: absolute;
    left: 2px;
    top: 10px;
    bottom: 10px;
    width: 1px;
    background: linear-gradient(180deg, transparent, var(--line-strong) 12%, var(--line-strong) 88%, transparent);
  }

  .page-about .rail-link {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 7px 0;
    color: var(--mist);
    text-decoration: none;
    font-size: 13.5px;
    line-height: 1.45;
    transition: color 0.18s var(--ease);
  }

  .page-about .rail-link::before {
    content: "";
    flex: none;
    width: 5px;
    height: 5px;
    border-radius: 50%;
    background: var(--mist);
    transition: background 0.18s var(--ease), box-shadow 0.18s var(--ease);
  }

  .page-about .rail-link:hover,
  .page-about .rail-link:focus-visible {
    color: var(--cyan);
  }

  .page-about .rail-link:hover::before,
  .page-about .rail-link:focus-visible::before {
    background: var(--cyan);
    box-shadow: 0 0 0 4px rgba(55, 232, 208, 0.16);
  }
}

/* ---------- 动效降级 ---------- */
@media (prefers-reduced-motion: reduce) {
  .page-about *,
  .page-about *::before,
  .page-about *::after {
    transition: none !important;
    animation: none !important;
  }
}