.page-about {
  --about-flow-gap: 0px;
  --about-card-pad: 18px;
}

.page-about .about-hero {
  position: relative;
  padding: 34px 0 44px;
  border-bottom: 1px solid var(--grid);
  overflow: hidden;
  background:
    radial-gradient(95% 120% at 92% -18%, rgba(255, 106, 26, .18), transparent 62%),
    radial-gradient(70% 90% at -6% 108%, rgba(34, 224, 214, .09), transparent 58%),
    var(--ink);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  opacity: .45;
  background-image:
    repeating-linear-gradient(0deg, rgba(42, 49, 56, .6) 0 1px, transparent 1px 46px),
    repeating-linear-gradient(90deg, rgba(42, 49, 56, .6) 0 1px, transparent 1px 46px);
}

.page-about .about-hero .wrap {
  position: relative;
  z-index: 1;
}

.page-about .about-hero .breadcrumb {
  margin-bottom: 22px;
}

.page-about .about-title {
  margin: 12px 0 0;
  font-family: var(--font-display);
  font-size: clamp(40px, 11vw, 116px);
  font-weight: 900;
  line-height: .94;
  letter-spacing: -.02em;
  color: var(--white);
}

.page-about .hero-main .lede {
  margin: 20px 0 0;
  max-width: 40em;
  color: var(--soft);
}

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

.page-about .hero-stats {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--grid);
  border: 1px solid var(--grid);
}

.page-about .hero-stat {
  background: var(--panel-2);
  padding: 15px 14px 16px;
}

.page-about .stat-num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(26px, 7.5vw, 38px);
  line-height: 1;
  color: var(--amber);
  font-variant-numeric: tabular-nums;
}

.page-about .stat-num em {
  font-style: normal;
  font-size: .44em;
  color: var(--muted);
  margin-left: 2px;
}

.page-about .stat-key {
  display: block;
  margin-top: 9px;
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--muted);
}

.page-about .about-body {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0;
}

/* 章节锚点索引：移动端为横向条，桌面为粘性竖列 */
.page-about .about-index {
  position: relative;
  padding: 18px 0 0;
  border-bottom: 1px solid var(--grid);
}

.page-about .index-title {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .24em;
  color: var(--muted);
}

.page-about .index-list {
  list-style: none;
  margin: 0;
  padding: 0 0 14px;
  display: flex;
  gap: 8px;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

.page-about .index-link {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  white-space: nowrap;
  padding: 7px 12px;
  border: 1px solid var(--grid);
  font-size: 13px;
  color: var(--soft);
  text-decoration: none;
}

.page-about .index-link .index-num {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--muted);
}

.page-about .index-link.is-active {
  border-color: var(--lava);
  color: var(--white);
  background: rgba(255, 106, 26, .09);
}

.page-about .index-link.is-active .index-num {
  color: var(--lava);
}

.page-about .about-sec {
  padding: 52px 0;
  border-bottom: 1px solid var(--grid);
}

.page-about .sec-head {
  display: grid;
  gap: 10px;
  margin-bottom: 26px;
}

.page-about .sec-num {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .22em;
  color: var(--lava);
}

.page-about .sec-title {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(27px, 5.6vw, 46px);
  font-weight: 900;
  line-height: 1.06;
  letter-spacing: -.01em;
  color: var(--white);
}

.page-about .sec-lede {
  margin: 0;
  max-width: 44em;
  font-size: 15px;
  line-height: 1.65;
  color: var(--muted);
}

.page-about .sec-body {
  display: grid;
  gap: 16px;
}

.page-about .sec-body p {
  margin: 0;
  max-width: 40em;
  color: var(--soft);
}

.page-about .data-list {
  margin-top: 10px;
  border-top: 1px solid var(--grid);
}

.page-about .data-row {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
  padding: 11px 0;
  border-bottom: 1px solid var(--grid);
  font-size: 14px;
}

.page-about .data-key {
  color: var(--muted);
}

.page-about .data-val {
  font-family: var(--font-mono);
  color: var(--amber);
  font-variant-numeric: tabular-nums;
  text-align: right;
}

/* 02 内容体系 */
.page-about .sec-system {
  margin-left: calc(-1 * var(--pad-x));
  margin-right: calc(-1 * var(--pad-x));
  padding-left: var(--pad-x);
  padding-right: var(--pad-x);
  border-left: 2px solid rgba(34, 224, 214, .28);
  background: linear-gradient(155deg, rgba(12, 43, 44, .92) 0%, rgba(12, 43, 44, .32) 100%);
}

.page-about .system-grid {
  display: grid;
  gap: 24px;
}

.page-about .line-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--grid);
  border: 1px solid var(--grid);
}

.page-about .line-card {
  display: grid;
  gap: 10px;
  padding: var(--about-card-pad);
  background: var(--panel);
}

.page-about .line-head {
  display: flex;
  align-items: baseline;
  gap: 10px;
}

.page-about .line-idx {
  font-family: var(--font-mono);
  font-size: 21px;
  line-height: 1;
  color: var(--cyan);
}

.page-about .line-title {
  margin: 0;
  font-size: 18px;
  color: var(--white);
}

.page-about .line-text {
  margin: 0;
  font-size: 14px;
  line-height: 1.62;
  color: var(--soft);
}

.page-about .line-link {
  justify-self: start;
  font-size: 13px;
  color: var(--lava);
  text-decoration: none;
  border-bottom: 1px solid rgba(255, 106, 26, .45);
}

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

/* 图片容器 */
.page-about .about-figure {
  margin: 0;
  display: grid;
  grid-template-rows: 1fr auto;
  overflow: hidden;
  border: 1px solid var(--grid);
  background: var(--panel-2);
}

.page-about .about-figure img {
  display: block;
  width: 100%;
  height: 100%;
  max-width: 100%;
  object-fit: cover;
  filter: saturate(1.05) contrast(1.05);
}

.page-about .about-figure figcaption {
  padding: 10px 12px;
  border-top: 1px solid var(--grid);
  font-size: 12px;
  letter-spacing: .05em;
  color: var(--muted);
}

.page-about .system-figure {
  aspect-ratio: 16 / 11;
  align-self: start;
}

/* 03 发展历程 */
.page-about .timeline-figure {
  aspect-ratio: 16 / 9;
  margin-bottom: 22px;
}

.page-about .timeline-scroll {
  overflow-x: auto;
  scroll-snap-type: x mandatory;
  -webkit-overflow-scrolling: touch;
  border: 1px solid var(--grid);
  background: var(--grid);
}

.page-about .timeline-scroll:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 3px;
}

.page-about .timeline-track {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  gap: 1px;
  width: max-content;
  min-width: 100%;
}

.page-about .tl-item {
  position: relative;
  flex: 0 0 auto;
  width: 244px;
  scroll-snap-align: start;
  display: grid;
  align-content: start;
  gap: 8px;
  padding: 20px 16px 22px;
  background: var(--panel-2);
}

.page-about .tl-item::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 3px;
  background: var(--grid);
}

.page-about .tl-item:first-child::before,
.page-about .tl-item:last-child::before {
  background: var(--lava);
}

.page-about .tl-year {
  font-family: var(--font-mono);
  font-size: 26px;
  line-height: 1;
  color: var(--amber);
  font-variant-numeric: tabular-nums;
}

.page-about .tl-title {
  margin: 0;
  font-size: 16px;
  color: var(--white);
}

.page-about .tl-text {
  margin: 0;
  font-size: 13px;
  line-height: 1.6;
  color: var(--muted);
}

/* 04 团队 */
.page-about .team-figure {
  aspect-ratio: 4 / 3;
  margin-bottom: 24px;
}

.page-about .role-grid {
  display: grid;
  gap: 1px;
  background: var(--grid);
  border: 1px solid var(--grid);
}

.page-about .role-card {
  padding: var(--about-card-pad);
  background: var(--panel);
}

.page-about .role-top {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
}

.page-about .role-name {
  margin: 0;
  font-size: 17px;
  color: var(--white);
}

.page-about .role-count {
  font-family: var(--font-mono);
  font-size: 24px;
  line-height: 1;
  color: var(--amber);
  font-variant-numeric: tabular-nums;
}

.page-about .role-count em {
  font-style: normal;
  font-size: 12px;
  color: var(--muted);
  margin-left: 2px;
}

.page-about .role-text {
  margin: 11px 0 0;
  font-size: 14px;
  line-height: 1.62;
  color: var(--soft);
}

/* 05 数据流程 */
.page-about .step-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--grid);
  border-top: 1px solid var(--grid);
  border-bottom: 1px solid var(--grid);
}

.page-about .step {
  display: grid;
  grid-template-columns: 52px minmax(0, 1fr);
  gap: 14px;
  padding: 20px 0;
  background: var(--ink);
}

.page-about .step-num {
  font-family: var(--font-mono);
  font-size: 20px;
  line-height: 1.2;
  color: var(--lava);
  padding-left: 8px;
  border-left: 2px solid rgba(255, 106, 26, .45);
}

.page-about .step-body h3 {
  margin: 0 0 7px;
  font-size: 17px;
  color: var(--white);
}

.page-about .step-body p {
  margin: 0;
  max-width: 40em;
  font-size: 14px;
  line-height: 1.62;
  color: var(--soft);
}

.page-about .sec-note {
  margin: 22px 0 0;
  padding-left: 12px;
  border-left: 2px solid var(--grid);
  max-width: 42em;
  font-size: 13px;
  line-height: 1.7;
  color: var(--muted);
}

/* 06 合作生态 */
.page-about .eco-list {
  display: grid;
}

.page-about .eco-item {
  border: 1px solid var(--grid);
  border-top: 0;
  background: var(--panel-2);
}

.page-about .eco-item:first-child {
  border-top: 1px solid var(--grid);
}

.page-about .eco-item[open] {
  background: linear-gradient(180deg, rgba(36, 27, 58, .55) 0%, rgba(16, 20, 25, .9) 100%);
  border-left: 2px solid var(--lava);
}

.page-about .eco-summary {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 16px var(--about-card-pad);
  cursor: pointer;
  list-style: none;
  font-size: 16px;
  color: var(--white);
}

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

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

.page-about .eco-item[open] .eco-summary::after {
  content: "–";
  color: var(--lava);
}

.page-about .eco-summary:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: -2px;
}

.page-about .eco-count {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .04em;
  color: var(--amber);
  white-space: nowrap;
}

.page-about .eco-panel {
  padding: 0 var(--about-card-pad) 18px;
}

.page-about .eco-panel p {
  margin: 0 0 9px;
  max-width: 42em;
  font-size: 14px;
  line-height: 1.65;
  color: var(--soft);
}

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

/* 页尾行动区 */
.page-about .about-cta {
  display: grid;
  gap: 20px;
  padding: 40px 0 8px;
  border-top: 1px solid var(--grid);
}

.page-about .cta-text {
  margin: 0;
  max-width: 36em;
  font-size: 17px;
  line-height: 1.6;
  color: var(--white);
}

.page-about .cta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

@media (min-width: 768px) {
  .page-about .hero-grid {
    grid-template-columns: minmax(0, 1.5fr) minmax(0, 1fr);
    align-items: end;
    gap: 36px;
  }

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

  .page-about .sec-system {
    padding-top: 56px;
    padding-bottom: 56px;
  }

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

  .page-about .system-grid {
    grid-template-columns: minmax(0, 1.6fr) minmax(0, 1fr);
    gap: 28px;
  }

  .page-about .system-figure {
    aspect-ratio: 3 / 4;
  }

  .page-about .team-figure {
    aspect-ratio: 14 / 9;
  }

  .page-about .timeline-figure {
    aspect-ratio: 8 / 3;
  }

  .page-about .step {
    grid-template-columns: 76px minmax(0, 1fr);
    gap: 20px;
    padding: 24px 0;
  }
}

@media (min-width: 1024px) {
  .page-about .about-body {
    grid-template-columns: 208px minmax(0, 1fr);
    gap: 56px;
  }

  .page-about .about-index {
    position: sticky;
    top: calc(var(--strip-h) + 26px);
    align-self: start;
    padding-top: 56px;
    border-bottom: 0;
  }

  .page-about .index-list {
    flex-direction: column;
    gap: 0;
    padding-bottom: 0;
    overflow: visible;
    border-left: 1px solid var(--grid);
  }

  .page-about .index-link {
    width: 100%;
    border: 0;
    border-left: 2px solid transparent;
    padding: 11px 12px;
    transition: color 180ms var(--ease), background 180ms var(--ease);
  }

  .page-about .index-link.is-active {
    border-left-color: var(--lava);
    background: linear-gradient(90deg, rgba(255, 106, 26, .16) 0%, transparent 85%);
  }

  .page-about .about-sec {
    padding: 68px 0;
  }

  .page-about .sec-system {
    margin-left: 0;
    margin-right: 0;
    padding-left: 34px;
    padding-right: 34px;
  }

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

  .page-about .about-cta {
    padding: 48px 0 12px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .index-link {
    transition: none;
  }
}