/* ============================================================
   品牌档案 / mission —— 页面专属样式（作用域：.page-about）
   ============================================================ */

.page-about {
  --about-col: 158px;
  --about-gap: 64px;
  position: relative;
  isolation: isolate;
  padding-bottom: 96px;
}

.page-about::before {
  content: "";
  position: absolute;
  inset: 0 0 auto 0;
  height: 760px;
  background:
    radial-gradient(118% 62% at 82% -6%, rgba(0, 225, 123, 0.10), transparent 62%),
    radial-gradient(88% 54% at 6% 4%, rgba(61, 123, 255, 0.10), transparent 60%);
  pointer-events: none;
  z-index: -1;
}

/* ---------- 面包屑 ---------- */
.page-about .breadcrumb-nav {
  margin: 18px 0 4px;
}

/* ---------- 索引头 ---------- */
.page-about .about-head {
  padding: 26px 0 68px;
}

.page-about .about-head-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 36px;
  align-items: end;
}

@media (min-width: 900px) {
  .page-about .about-head-grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: 56px;
  }
}

.page-about .about-title {
  margin: 20px 0 0;
  font-family: var(--font-sans);
  font-weight: 900;
  font-size: clamp(2rem, 5.6vw, 3.75rem);
  line-height: 1.08;
  letter-spacing: -0.02em;
  color: var(--mica);
}

.page-about .about-title-line {
  display: block;
}

.page-about .about-title-line--accent {
  color: var(--pitch);
}

.page-about .about-lede {
  margin: 24px 0 0;
  max-width: 34em;
  font-size: 1.0625rem;
  line-height: 1.82;
  color: var(--muted);
}

.page-about .about-facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  margin: 40px 0 0;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--rule);
  border-left: 1px solid var(--rule);
}

@media (min-width: 720px) {
  .page-about .about-facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

.page-about .about-facts li {
  padding: 18px 16px 20px;
  border-right: 1px solid var(--rule);
  border-bottom: 1px solid var(--rule);
}

.page-about .about-fact-num {
  display: block;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 1.375rem;
  line-height: 1.15;
  letter-spacing: -0.01em;
  color: var(--mica);
}

.page-about .about-fact-label {
  display: block;
  margin-top: 8px;
  font-size: 0.75rem;
  line-height: 1.6;
  letter-spacing: 0.06em;
  color: var(--muted-soft);
}

.page-about .about-head-figure {
  position: relative;
  margin: 0;
  border-radius: 3px;
  overflow: hidden;
  aspect-ratio: 14 / 9;
}

.page-about .about-head-figure img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.page-about .about-head-figure::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, transparent 42%, rgba(10, 13, 16, 0.72) 100%);
  pointer-events: none;
}

/* ---------- 主体布局：左侧索引 + 纵向阅读流 ---------- */
.page-about .about-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
}

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

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

@media (min-width: 1024px) {
  .page-about .about-toc {
    display: block;
    grid-column: 1;
    position: sticky;
    top: calc(var(--header-h) + 28px);
  }

  .page-about .about-stream {
    grid-column: 2;
  }

  .page-about .about-toc--spacer {
    display: block;
    min-height: 1px;
  }
}

.page-about .toc-title {
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--muted-soft);
}

.page-about .toc-list {
  display: grid;
  gap: 2px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .toc-list a {
  display: grid;
  grid-template-columns: 26px minmax(0, 1fr);
  gap: 10px;
  align-items: baseline;
  padding: 7px 0 7px 10px;
  border-left: 1px solid var(--rule);
  text-decoration: none;
  font-size: 0.8125rem;
  line-height: 1.55;
  color: var(--muted-soft);
  transition: color 0.3s var(--ease), border-color 0.3s var(--ease);
}

.page-about .toc-list a:hover {
  color: var(--mica);
}

.page-about .toc-num {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.1em;
  color: var(--muted-soft);
  transition: color 0.3s var(--ease);
}

.page-about .toc-list a[aria-current="true"] {
  color: var(--mica);
  border-left-color: var(--pitch);
}

.page-about .toc-list a[aria-current="true"] .toc-num {
  color: var(--pitch);
}

/* ---------- 章节 ---------- */
.page-about .about-chapter {
  padding: 60px 0;
  border-top: 1px solid var(--rule);
  scroll-margin-top: calc(var(--header-h) + 24px);
}

.page-about .about-stream > .about-chapter:first-child {
  padding-top: 12px;
  border-top: none;
}

.page-about .chapter-head {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 28px;
}

.page-about .chapter-seq {
  flex: 0 0 auto;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  border: 1px solid var(--graphite);
  border-radius: 2px;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 0.875rem;
  letter-spacing: 0.04em;
  color: var(--pitch);
}

.page-about .chapter-title {
  margin: 0;
}

.page-about .about-panel {
  padding: 32px 24px;
  border-radius: 3px;
}

@media (min-width: 720px) {
  .page-about .about-panel {
    padding: 44px 46px;
  }
}

.page-about .about-panel .prose + .prose {
  margin-top: 20px;
}

.page-about .body-copy {
  max-width: 38em;
  margin: 0 0 18px;
  font-size: 1rem;
  line-height: 1.85;
  color: var(--muted);
}

.page-about .body-copy:last-child {
  margin-bottom: 0;
}

/* ---------- 档案字段说明 ---------- */
.page-about .about-specs {
  margin: 28px 0 0;
  padding: 0;
  border-top: 1px solid var(--rule);
}

.page-about .about-spec {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 6px;
  padding: 18px 0;
  border-bottom: 1px solid var(--rule);
}

@media (min-width: 720px) {
  .page-about .about-spec {
    grid-template-columns: 132px minmax(0, 1fr);
    gap: 24px;
    align-items: baseline;
  }
}

.page-about .spec-key {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.12em;
  color: var(--pitch);
}

.page-about .spec-val {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.75;
  color: var(--mica);
}

/* ---------- 服务理念留白 ---------- */
.page-about .about-declaration {
  padding: 118px 0 124px;
}

.page-about .declaration-line {
  margin: 0;
  max-width: 15em;
  font-family: var(--font-sans);
  font-weight: 900;
  font-size: clamp(1.75rem, 5.6vw, 3.625rem);
  line-height: 1.2;
  letter-spacing: -0.02em;
  color: var(--mica);
}

.page-about .declaration-note {
  margin: 28px 0 0;
  max-width: 32em;
  font-size: 0.9375rem;
  line-height: 1.9;
  color: var(--muted-soft);
}

/* ---------- 时间带 ---------- */
.page-about .about-timeline {
  position: relative;
  padding: 88px 0 96px;
  background-color: var(--teal);
  background-image:
    linear-gradient(180deg, rgba(0, 225, 123, 0.06), transparent 46%),
    repeating-linear-gradient(90deg, rgba(245, 247, 246, 0.035) 0 1px, transparent 1px 72px);
  scroll-margin-top: calc(var(--header-h) + 16px);
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 1px;
  background: linear-gradient(
    90deg,
    var(--pitch) 0%,
    var(--pitch) 16%,
    rgba(245, 247, 246, 0.16) 16%,
    rgba(245, 247, 246, 0.16) 100%
  );
}

.page-about .timeline-title {
  margin: 16px 0 0;
}

.page-about .timeline-lede {
  margin: 18px 0 0;
  max-width: 40em;
  font-size: 0.9375rem;
  line-height: 1.85;
  color: var(--muted);
}

.page-about .timeline-figure {
  margin: 44px 0 0;
  border-radius: 3px;
  overflow: hidden;
}

.page-about .timeline-figure img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
}

.page-about .timeline-track {
  display: flex;
  gap: 18px;
  margin: 48px 0 0;
  padding: 0 0 14px;
  list-style: none;
  overflow-x: auto;
  scroll-snap-type: x proximity;
  -webkit-overflow-scrolling: touch;
}

.page-about .timeline-item {
  flex: 0 0 236px;
  position: relative;
  padding-top: 34px;
  border-top: 1px solid rgba(245, 247, 246, 0.18);
  scroll-snap-align: start;
}

.page-about .timeline-item::before {
  content: "";
  position: absolute;
  top: -4.5px;
  left: 0;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--pitch);
  transition: transform 0.3s var(--ease);
}

@media (min-width: 900px) {
  .page-about .timeline-track {
    display: grid;
    grid-template-columns: repeat(5, minmax(0, 1fr));
    gap: 22px;
    overflow: visible;
    padding-bottom: 0;
  }

  .page-about .timeline-item {
    flex: none;
  }
}

.page-about .timeline-year {
  display: block;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 1.375rem;
  letter-spacing: -0.01em;
  color: var(--pitch);
}

.page-about .timeline-card {
  margin-top: 14px;
}

.page-about .timeline-card-title {
  margin: 0 0 8px;
  font-size: 0.9375rem;
  font-weight: 700;
  line-height: 1.5;
  color: var(--mica);
  transition: color 0.3s var(--ease);
}

.page-about .timeline-card-text {
  margin: 0;
  font-size: 0.8125rem;
  line-height: 1.78;
  color: var(--muted-soft);
  transition: color 0.3s var(--ease);
}

.page-about .timeline-item:hover::before,
.page-about .timeline-item:focus-within::before {
  transform: scale(1.4);
}

.page-about .timeline-item:hover .timeline-card-title,
.page-about .timeline-item:focus-within .timeline-card-title {
  color: var(--pitch);
}

.page-about .timeline-item:hover .timeline-card-text,
.page-about .timeline-item:focus-within .timeline-card-text {
  color: var(--muted);
}

/* ---------- 客服支持 ---------- */
.page-about .support-list {
  margin: 26px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--rule);
  border: 1px solid var(--rule);
}

@media (min-width: 760px) {
  .page-about .support-list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

.page-about .support-item {
  padding: 24px 22px 26px;
  background: var(--obsidian);
}

.page-about .support-title {
  margin: 0;
  font-size: 0.9375rem;
  font-weight: 700;
  line-height: 1.5;
  color: var(--mica);
}

.page-about .support-text {
  margin: 10px 0 0;
  font-size: 0.8125rem;
  line-height: 1.8;
  color: var(--muted-soft);
}

/* ---------- 数据协作统计 ---------- */
.page-about .network-stats {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  margin: 28px 0 0;
  padding: 0;
  list-style: none;
  background: var(--rule);
  border: 1px solid var(--rule);
}

@media (min-width: 700px) {
  .page-about .network-stats {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

.page-about .network-stats li {
  padding: 22px 20px 24px;
  background: var(--obsidian);
}

.page-about .network-num {
  display: block;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 1.375rem;
  letter-spacing: -0.01em;
  color: var(--blue);
}

.page-about .network-label {
  display: block;
  margin-top: 8px;
  font-size: 0.8125rem;
  line-height: 1.6;
  color: var(--muted-soft);
}

/* ---------- 地域与运营 ---------- */
.page-about .region-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 32px;
  align-items: start;
}

@media (min-width: 900px) {
  .page-about .region-grid {
    grid-template-columns: minmax(0, 6fr) minmax(0, 6fr);
    gap: 52px;
  }
}

.page-about .region-copy .body-copy + .body-copy {
  margin-top: 18px;
}

.page-about .about-region-figure {
  margin: 0;
  border-radius: 3px;
  overflow: hidden;
}

.page-about .about-region-figure img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
}

/* ---------- 下一条线索 ---------- */
.page-about .about-next {
  padding: 88px 0 0;
}

.page-about .next-head {
  border-top: 1px solid var(--rule);
  padding-top: 40px;
}

.page-about .next-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 18px;
  margin-top: 36px;
}

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

@media (min-width: 1080px) {
  .page-about .next-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

.page-about .next-card {
  display: flex;
  flex-direction: column;
  gap: 12px;
  padding: 26px 22px 28px;
  border: 1px solid var(--graphite);
  border-radius: 3px;
  background: rgba(28, 35, 41, 0.35);
  text-decoration: none;
  transition: border-color 0.3s var(--ease), transform 0.3s var(--ease), background-color 0.3s var(--ease);
}

.page-about .next-card:hover,
.page-about .next-card:focus-visible {
  border-color: var(--pitch);
  background: rgba(0, 225, 123, 0.06);
  transform: translateY(-4px);
}

.page-about .next-idx {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.12em;
  color: var(--muted-soft);
}

.page-about .next-title {
  font-size: 1.0625rem;
  font-weight: 700;
  line-height: 1.4;
  color: var(--mica);
}

.page-about .next-text {
  font-size: 0.8125rem;
  line-height: 1.8;
  color: var(--muted-soft);
}

/* ---------- 动效退化 ---------- */
@media (prefers-reduced-motion: reduce) {
  .page-about .next-card,
  .page-about .toc-list a,
  .page-about .toc-num,
  .page-about .timeline-item::before,
  .page-about .timeline-card-title,
  .page-about .timeline-card-text {
    transition: none;
  }

  .page-about .next-card:hover,
  .page-about .next-card:focus-visible {
    transform: none;
  }

  .page-about .timeline-item:hover::before,
  .page-about .timeline-item:focus-within::before {
    transform: none;
  }
}