/* ============ 品牌使命 · 页面专属样式（作用域 .page-about） ============ */

.page-about {
  --about-rail-w: 200px;
  --about-indent: 34px;
  --about-mid: #B9C8E2;
  --about-body: #C6D3EA;
  --about-paper-line: #D8E0F0;
  --about-paper-ink: #3B4C70;
  --about-paper-accent: #0E8C82;
  display: block;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding: calc(var(--header-h) + 44px) 0 0;
  background:
    radial-gradient(760px 360px at 84% -8%, rgba(53, 224, 208, 0.16), transparent 68%),
    radial-gradient(600px 320px at 2% 46%, rgba(255, 138, 61, 0.10), transparent 70%);
  overflow: hidden;
}

.page-about .about-hero .breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin: 0 0 30px;
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.04em;
  color: var(--muted);
}

.page-about .about-hero .breadcrumb a {
  color: var(--muted);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color var(--t-fast) var(--ease), border-color var(--t-fast) var(--ease);
}

.page-about .about-hero .breadcrumb a:hover,
.page-about .about-hero .breadcrumb a:focus-visible {
  color: var(--cyan);
  border-bottom-color: var(--cyan);
}

.page-about .about-hero .breadcrumb .crumb-sep {
  color: var(--line);
}

.page-about .about-hero .breadcrumb [aria-current="page"] {
  color: var(--cyan);
}

.page-about .about-eyebrow {
  margin: 0 0 16px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--cyan);
}

.page-about .about-hero h1 {
  margin: 0 0 22px;
  max-width: 15em;
  font-family: var(--font-display);
  font-size: clamp(30px, 6.2vw, 52px);
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.01em;
  color: var(--white);
}

.page-about .about-lede {
  margin: 0 0 8px;
  max-width: 44em;
  font-size: 16.5px;
  line-height: 1.85;
  color: var(--about-body);
}

.page-about .about-banner {
  margin: 42px 0 0;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  background: var(--ink-2);
}

.page-about .about-banner img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 2 / 1;
  object-fit: cover;
}

/* ---------- 统计数字带 ---------- */
.page-about .about-band {
  border-bottom: 1px solid var(--line);
  background: linear-gradient(90deg, rgba(16, 31, 68, 0.92), rgba(10, 22, 51, 0.55));
}

.page-about .about-figures {
  list-style: none;
  margin: 0;
  padding: 32px 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 24px;
}

.page-about .about-fig {
  display: grid;
  gap: 8px;
  padding-left: 20px;
  border-left: 1px solid var(--line);
}

.page-about .about-fig-num {
  font-family: var(--font-mono);
  font-size: clamp(28px, 5.4vw, 42px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--cyan);
  font-variant-numeric: tabular-nums;
}

.page-about .about-fig-label {
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.06em;
  color: var(--muted);
}

/* ---------- 轨道 + 正文两栏 ---------- */
.page-about .about-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0;
}

.page-about .about-rail {
  padding: 18px 0;
  border-bottom: 1px solid var(--line);
  overflow-x: auto;
  scrollbar-width: none;
}

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

.page-about .about-toc {
  margin: 0;
}

.page-about .about-toc-head {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.2em;
  color: var(--muted);
}

.page-about .about-toc-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  gap: 20px;
  white-space: nowrap;
}

.page-about .about-toc-link {
  display: inline-flex;
  align-items: baseline;
  gap: 7px;
  padding: 5px 0;
  font-size: 13.5px;
  color: var(--muted);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color var(--t-fast) var(--ease), border-color var(--t-fast) var(--ease);
}

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

.page-about .about-toc-num {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--orange);
  font-variant-numeric: tabular-nums;
}

/* ---------- 正文纵轴 ---------- */
.page-about .about-flow {
  position: relative;
  min-width: 0;
}

.page-about .about-flow::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 1px;
  background: linear-gradient(180deg, rgba(53, 224, 208, 0.6), var(--line) 16%, var(--line) 84%, rgba(255, 138, 61, 0.55));
  pointer-events: none;
}

.page-about .about-section {
  position: relative;
  padding: 46px 0 50px;
  border-bottom: 1px solid var(--line);
}

.page-about .about-section-idx {
  margin: 0 0 12px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.18em;
  color: var(--cyan);
}

.page-about .about-section h2 {
  margin: 0 0 20px;
  max-width: 20em;
  font-family: var(--font-display);
  font-size: clamp(23px, 4.2vw, 32px);
  font-weight: 600;
  line-height: 1.34;
  letter-spacing: -0.01em;
  color: var(--white);
}

.page-about .about-section p {
  margin: 0 0 18px;
  max-width: 42em;
  font-size: 16.5px;
  line-height: 1.85;
  color: var(--about-body);
}

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

/* ---------- 时间线 ---------- */
.page-about .about-timeline-grid {
  margin-top: 32px;
}

.page-about .about-timeline {
  list-style: none;
  margin: 0;
  padding: 0 0 0 26px;
  position: relative;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 3px;
  top: 10px;
  bottom: 14px;
  width: 1px;
  background: linear-gradient(180deg, var(--cyan), var(--line) 42%, var(--line) 72%, var(--orange));
  opacity: 0.75;
}

.page-about .about-step {
  position: relative;
  padding-bottom: 30px;
}

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

.page-about .about-step::before {
  content: "";
  position: absolute;
  left: -26px;
  top: 6px;
  width: 9px;
  height: 9px;
  background: var(--ink);
  border: 1px solid var(--cyan);
  transition: background var(--t-fast) var(--ease), box-shadow var(--t-fast) var(--ease);
}

.page-about .about-step:hover::before,
.page-about .about-step:focus-within::before {
  background: var(--cyan);
  box-shadow: 0 0 0 4px rgba(53, 224, 208, 0.14);
}

.page-about .about-step-idx {
  margin: 0 0 6px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.16em;
  color: var(--orange);
}

.page-about .about-step-title {
  margin: 0 0 8px;
  font-family: var(--font-body);
  font-size: 17px;
  font-weight: 600;
  line-height: 1.5;
  color: var(--white);
}

.page-about .about-step-text {
  margin: 0;
  max-width: 40em;
  font-size: 15.5px;
  line-height: 1.82;
  color: var(--about-mid);
}

.page-about .about-timeline-fig {
  margin: 30px 0 0;
  max-width: 300px;
}

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

/* ---------- 反色阅读区（团队） ---------- */
.page-about .section--paper {
  background: var(--paper);
  border-bottom-color: transparent;
}

.page-about .section--paper h2 {
  color: var(--ink);
}

.page-about .section--paper p {
  color: var(--about-paper-ink);
}

.page-about .section--paper .about-section-idx {
  color: var(--about-paper-accent);
}

.page-about .about-team-fig {
  margin: 26px 0 0;
  border: 1px solid var(--about-paper-line);
  background: #E8EDF8;
}

.page-about .about-team-fig img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 4 / 3;
  object-fit: cover;
}

.page-about .about-roles {
  list-style: none;
  margin: 30px 0 0;
  padding: 0;
  border-top: 1px solid var(--about-paper-line);
}

.page-about .about-role {
  display: grid;
  gap: 8px;
  padding: 20px 0;
  border-bottom: 1px solid var(--about-paper-line);
}

.page-about .about-role-head {
  display: flex;
  align-items: baseline;
  gap: 8px;
  margin: 0;
  font-family: var(--font-mono);
  font-size: 13.5px;
  letter-spacing: 0.04em;
  color: var(--about-paper-accent);
}

.page-about .about-role-num {
  font-size: 22px;
  font-weight: 700;
  line-height: 1;
  color: var(--ink);
  font-variant-numeric: tabular-nums;
}

.page-about .about-role-text {
  margin: 0;
  font-size: 15.5px;
  line-height: 1.8;
  color: var(--about-paper-ink);
}

/* ---------- 引文式主张 ---------- */
.page-about .about-claim {
  margin: 34px 0 0;
  padding: 24px 26px 24px 28px;
  border-left: 3px solid var(--cyan);
  border-top: 1px solid var(--line);
  border-right: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  background: linear-gradient(115deg, rgba(53, 224, 208, 0.13), rgba(53, 224, 208, 0.02) 46%, rgba(255, 138, 61, 0.09));
}

.page-about .about-claim p {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(20px, 3.8vw, 28px);
  font-weight: 600;
  line-height: 1.5;
  letter-spacing: -0.01em;
  color: var(--white);
}

/* ---------- 合作伙伴数据 ---------- */
.page-about .about-partner-facts {
  margin: 30px 0 0;
  border-top: 1px solid var(--line);
}

.page-about .about-partner-facts > div {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
  padding: 13px 0;
  border-bottom: 1px solid var(--line);
}

.page-about .about-partner-facts dt {
  font-size: 14px;
  color: var(--muted);
}

.page-about .about-partner-facts dd {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 15px;
  color: var(--cyan);
  font-variant-numeric: tabular-nums;
  white-space: nowrap;
}

/* ---------- 下一步计划 ---------- */
.page-about .about-next {
  list-style: none;
  margin: 30px 0 0;
  padding: 0;
  counter-reset: nextstep;
}

.page-about .about-next > li {
  counter-increment: nextstep;
  position: relative;
  padding: 20px 0 20px 54px;
  border-top: 1px solid var(--line);
}

.page-about .about-next > li:last-child {
  border-bottom: 1px solid var(--line);
}

.page-about .about-next > li::before {
  content: counter(nextstep, decimal-leading-zero);
  position: absolute;
  left: 0;
  top: 22px;
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.06em;
  color: var(--orange);
}

.page-about .about-next h3 {
  margin: 0 0 8px;
  font-family: var(--font-body);
  font-size: 16.5px;
  font-weight: 600;
  line-height: 1.5;
  color: var(--white);
}

.page-about .about-next p {
  margin: 0;
  max-width: 40em;
  font-size: 15.5px;
  line-height: 1.8;
  color: var(--about-mid);
}

/* ---------- 结尾链接 ---------- */
.page-about .about-outro {
  border-bottom: 0;
}

.page-about .about-links {
  list-style: none;
  margin: 26px 0 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-link-card {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 4px 18px;
  padding: 20px 22px;
  background: var(--ink-2);
  text-decoration: none;
  box-shadow: inset 0 0 0 0 var(--cyan);
  transition: background var(--t-mid) var(--ease), box-shadow var(--t-mid) var(--ease);
}

.page-about .about-link-card:hover,
.page-about .about-link-card:focus-visible {
  background: #15264F;
  box-shadow: inset 3px 0 0 0 var(--cyan);
}

.page-about .about-link-title {
  font-family: var(--font-display);
  font-size: 17px;
  font-weight: 600;
  color: var(--white);
}

.page-about .about-link-desc {
  grid-column: 1 / 2;
  font-size: 14.5px;
  line-height: 1.7;
  color: var(--muted);
}

.page-about .about-link-arrow {
  grid-row: 1 / 3;
  align-self: center;
  font-family: var(--font-mono);
  font-size: 17px;
  color: var(--cyan);
  transition: transform var(--t-fast) var(--ease);
}

.page-about .about-link-card:hover .about-link-arrow,
.page-about .about-link-card:focus-visible .about-link-arrow {
  transform: translateX(4px);
}

/* ============ 断点 ============ */

@media (max-width: 640px) {
  .page-about .about-banner img {
    aspect-ratio: 4 / 3;
  }

  .page-about .about-timeline-fig {
    max-width: 100%;
  }
}

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

@media (min-width: 900px) {
  .page-about .about-layout {
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
    gap: 48px;
  }

  .page-about .about-rail {
    padding: 0 26px 40px 0;
    border-bottom: 0;
    border-right: 1px solid var(--line);
    overflow: visible;
  }

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

  .page-about .about-toc-list {
    flex-direction: column;
    gap: 4px;
    white-space: normal;
  }

  .page-about .about-section {
    padding: 52px 0 58px var(--about-indent);
  }

  .page-about .section--paper {
    margin-left: calc(var(--about-indent) * -1);
    padding: 50px 30px 54px 36px;
    border-left: 3px solid var(--cyan);
  }

  .page-about .about-claim {
    max-width: 46em;
  }

  .page-about .about-partner-facts,
  .page-about .about-next {
    max-width: 46em;
  }
}

@media (min-width: 1100px) {
  .page-about .about-timeline-grid {
    display: grid;
    grid-template-columns: minmax(0, 1fr) 220px;
    gap: 36px;
    align-items: start;
  }

  .page-about .about-timeline-fig {
    margin: 0;
    max-width: none;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-step,
  .page-about .about-step::before,
  .page-about .about-link-card,
  .page-about .about-link-arrow,
  .page-about .about-toc-link,
  .page-about .about-hero .breadcrumb a {
    transition: none;
  }

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