.page-about {
  --about-index-w: 196px;
  --about-gap-x: clamp(24px, 3.5vw, 56px);
  --about-rule: var(--line-300);
  background-color: var(--snow-50);
  color: var(--ink-950);
  font-family: var(--font-body);
  padding-block: clamp(16px, 3vw, 36px) clamp(48px, 7vw, 96px);
  overflow-x: hidden;
}

.page-about .about-wrap {
  width: 100%;
  max-width: var(--content-max);
  margin-inline: auto;
  padding-inline: clamp(16px, 4vw, 40px);
}

.page-about a:focus-visible,
.page-about button:focus-visible {
  outline: 2px solid var(--sky-500);
  outline-offset: 2px;
  border-radius: 4px;
}

.page-about .about-crumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin-bottom: clamp(16px, 2.5vw, 24px);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .02em;
  color: var(--slate-600);
}

.page-about .about-crumb a {
  color: var(--sky-700);
  text-decoration: none;
}

.page-about .about-crumb a:hover {
  text-decoration: underline;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  isolation: isolate;
  overflow: hidden;
  border-radius: var(--radius-xl);
  padding: clamp(24px, 4.4vw, 56px);
  color: var(--snow-50);
  background:
    radial-gradient(115% 95% at 88% 6%, rgba(27, 141, 191, .55) 0%, rgba(27, 141, 191, 0) 58%),
    linear-gradient(155deg, var(--blueprint-800) 0%, var(--ink-950) 72%);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  background-image:
    linear-gradient(to right, rgba(220, 239, 247, .09) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(220, 239, 247, .09) 1px, transparent 1px);
  background-size: 48px 48px;
  pointer-events: none;
}

.page-about .about-hero__inner {
  display: grid;
  gap: clamp(24px, 3.5vw, 48px);
}

.page-about .about-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin: 0;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--sky-100);
}

.page-about .about-eyebrow::before {
  content: "";
  width: 24px;
  height: 2px;
  background: var(--gold-500);
}

.page-about .about-hero h1 {
  margin: 16px 0 0;
  font-family: var(--font-head);
  font-weight: 900;
  font-size: clamp(2rem, 5.4vw, 3.8rem);
  line-height: 1.1;
  letter-spacing: -.02em;
  overflow-wrap: break-word;
}

.page-about .about-hero h1 em {
  font-style: normal;
  color: var(--gold-500);
}

.page-about .about-hero__lede {
  max-width: 54ch;
  margin: 18px 0 0;
  font-size: clamp(.975rem, .45vw + .88rem, 1.0625rem);
  line-height: 1.8;
  color: rgba(247, 250, 252, .82);
}

.page-about .about-hero__stats {
  list-style: none;
  margin: 0;
  padding: 20px 0 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px 16px;
  border-top: 1px solid rgba(220, 239, 247, .22);
}

.page-about .about-hero__num {
  display: block;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(1.35rem, 2.6vw, 1.85rem);
  font-weight: 700;
  line-height: 1.1;
  color: var(--snow-50);
}

.page-about .about-hero__num--gold {
  color: var(--gold-500);
}

.page-about .about-hero__label {
  display: block;
  margin-top: 6px;
  font-size: 12px;
  letter-spacing: .05em;
  color: rgba(220, 239, 247, .72);
}

/* ---------- 索引 + 主体 ---------- */
.page-about .about-shell {
  margin-top: clamp(32px, 5vw, 64px);
  display: grid;
  gap: clamp(24px, 4vw, 40px);
}

.page-about .about-index {
  border-top: 2px solid var(--ink-950);
  padding-top: 12px;
}

.page-about .about-index__label {
  margin: 0 0 12px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--slate-600);
}

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

.page-about .about-index__list li {
  flex: 0 0 auto;
}

.page-about .about-index__link {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  padding: 7px 13px;
  border-radius: 999px;
  border: 1px solid var(--line-300);
  background: var(--white);
  color: var(--ink-950);
  font-size: 13px;
  line-height: 1.4;
  text-decoration: none;
  white-space: nowrap;
  transition: background-color .18s var(--ease), border-color .18s var(--ease), color .18s var(--ease);
}

.page-about .about-index__no {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--gold-ink);
}

.page-about .about-index__link:hover,
.page-about .about-index__link:focus-visible {
  background: var(--sky-700);
  border-color: var(--sky-700);
  color: var(--white);
}

.page-about .about-index__link:hover .about-index__no,
.page-about .about-index__link:focus-visible .about-index__no {
  color: var(--gold-500);
}

/* ---------- 章节 ---------- */
.page-about .about-section {
  scroll-margin-top: 88px;
  padding-top: clamp(24px, 3.5vw, 40px);
  border-top: 1px solid var(--about-rule);
}

.page-about .about-section:first-child {
  padding-top: 0;
  border-top: 0;
}

.page-about .about-section + .about-section {
  margin-top: clamp(32px, 5vw, 64px);
}

.page-about .about-chapter {
  display: flex;
  align-items: baseline;
  gap: 12px;
  margin: 0 0 18px;
  font-family: var(--font-head);
  font-weight: 800;
  font-size: clamp(1.3rem, 2.6vw, 1.95rem);
  line-height: 1.28;
  letter-spacing: -.01em;
  color: var(--ink-950);
}

.page-about .about-chapter__no {
  flex: 0 0 auto;
  font-family: var(--font-mono);
  font-size: clamp(1.35rem, 3vw, 2.1rem);
  font-weight: 700;
  line-height: 1;
  letter-spacing: .02em;
  color: var(--gold-500);
}

.page-about .about-lede {
  max-width: 62ch;
  margin: 0 0 22px;
  font-size: clamp(.97rem, .35vw + .9rem, 1.0625rem);
  line-height: 1.8;
  color: var(--slate-600);
}

.page-about .about-p {
  max-width: 66ch;
  margin: 0 0 16px;
  font-size: 1rem;
  line-height: 1.8;
  color: var(--ink-950);
}

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

.page-about .about-p--after {
  max-width: 66ch;
  margin-top: 20px;
  font-size: .9375rem;
  color: var(--slate-600);
}

/* ---------- 图片 ---------- */
.page-about .about-figure {
  position: relative;
  margin: 0;
  border-radius: var(--radius-lg);
  overflow: hidden;
  background: var(--blueprint-800);
}

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

.page-about .about-figure::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(165deg, rgba(11, 94, 125, .32), rgba(10, 15, 20, .5));
  mix-blend-mode: multiply;
  pointer-events: none;
}

.page-about .about-figure figcaption {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 1;
  padding: 16px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .06em;
  color: rgba(247, 250, 252, .9);
  background: linear-gradient(180deg, rgba(10, 15, 20, 0), rgba(10, 15, 20, .74));
}

.page-about .about-figure--band {
  margin-bottom: clamp(24px, 3.5vw, 36px);
}

/* ---------- 01 分栏 ---------- */
.page-about .about-split {
  display: grid;
  gap: clamp(20px, 3vw, 32px);
}

/* ---------- 02 团队 ---------- */
.page-about .about-team {
  display: grid;
  gap: clamp(20px, 3vw, 32px);
}

.page-about .about-roles {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 12px;
}

.page-about .about-role {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 14px;
  padding: 16px 18px;
  background: var(--white);
  border: 1px solid var(--line-300);
  border-left: 3px solid var(--sky-500);
  border-radius: var(--radius-md);
}

.page-about .about-role__num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 1.55rem;
  font-weight: 700;
  line-height: 1;
  color: var(--sky-700);
}

.page-about .about-role__name {
  margin: 0 0 5px;
  font-family: var(--font-head);
  font-size: 1rem;
  font-weight: 800;
  line-height: 1.4;
  color: var(--ink-950);
}

.page-about .about-role__text {
  margin: 0;
  font-size: .9375rem;
  line-height: 1.75;
  color: var(--slate-600);
}

/* ---------- 03 时间轴 ---------- */
.page-about .timeline {
  list-style: none;
  margin: 0;
  padding: 4px 0 0 28px;
  border-left: 2px solid var(--line-300);
  display: grid;
  gap: 4px;
}

.page-about .timeline__item {
  position: relative;
  padding-bottom: 22px;
}

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

.page-about .timeline__item::before {
  content: "";
  position: absolute;
  left: -36px;
  top: 10px;
  width: 14px;
  height: 14px;
  box-sizing: border-box;
  border-radius: 50%;
  background: var(--snow-50);
  border: 2px solid var(--sky-700);
}

.page-about .timeline__item:last-child::before {
  background: var(--sky-700);
  box-shadow: 0 0 0 4px rgba(27, 141, 191, .16);
}

.page-about .timeline__head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 8px 14px;
  margin-bottom: 6px;
}

.page-about .timeline__year {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 1.05rem;
  font-weight: 700;
  letter-spacing: .04em;
  color: var(--gold-ink);
}

.page-about .timeline__title {
  margin: 0;
  font-family: var(--font-head);
  font-size: 1.0625rem;
  font-weight: 800;
  line-height: 1.45;
  color: var(--ink-950);
}

.page-about .timeline__summary {
  margin: 0 0 10px;
  font-size: .9375rem;
  line-height: 1.75;
  color: var(--slate-600);
}

.page-about .timeline .disclosure__toggle {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .04em;
  color: var(--sky-700);
  background: var(--sky-100);
  border: 1px solid transparent;
  border-radius: 999px;
  cursor: pointer;
  transition: background-color .18s var(--ease), color .18s var(--ease);
}

.page-about .timeline .disclosure__toggle:hover,
.page-about .timeline .disclosure__toggle:focus-visible {
  background: var(--sky-700);
  color: var(--white);
}

.page-about .timeline .disclosure__panel {
  margin-top: 10px;
  padding: 14px 16px;
  border-radius: var(--radius-md);
  background: var(--white);
  border: 1px solid var(--line-300);
  border-left: 3px solid var(--gold-500);
}

.page-about .timeline .disclosure__panel[hidden] {
  display: none;
}

.page-about .timeline .disclosure__panel p {
  margin: 0;
  font-size: .9375rem;
  line-height: 1.8;
  color: var(--slate-600);
}

/* ---------- 04 步骤 ---------- */
.page-about .about-steps {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 14px;
}

.page-about .about-step {
  padding: 20px 20px 22px;
  background: var(--white);
  border: 1px solid var(--line-300);
  border-top: 3px solid var(--sky-700);
  border-radius: var(--radius-md);
}

.page-about .about-step--sky {
  background: var(--sky-100);
  border-color: transparent;
  border-top-color: var(--gold-500);
}

.page-about .about-step__label {
  display: block;
  margin-bottom: 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .14em;
  color: var(--gold-ink);
}

.page-about .about-step__title {
  margin: 0 0 8px;
  font-family: var(--font-head);
  font-size: 1.0625rem;
  font-weight: 800;
  line-height: 1.45;
  color: var(--ink-950);
}

.page-about .about-step__text {
  margin: 0;
  font-size: .9375rem;
  line-height: 1.78;
  color: var(--slate-600);
}

/* ---------- 05 数据面板 ---------- */
.page-about .about-figures {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 22px 18px;
  padding: clamp(24px, 3.5vw, 40px);
  border-radius: var(--radius-xl);
  color: var(--snow-50);
  background:
    radial-gradient(90% 80% at 92% 4%, rgba(27, 141, 191, .42) 0%, rgba(27, 141, 191, 0) 62%),
    linear-gradient(160deg, var(--blueprint-800), var(--ink-950));
}

.page-about .about-stat__num {
  display: block;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(1.35rem, 3vw, 1.9rem);
  font-weight: 700;
  line-height: 1.1;
  color: var(--snow-50);
}

.page-about .about-stat__label {
  display: block;
  margin-top: 7px;
  font-size: 12.5px;
  line-height: 1.6;
  color: rgba(220, 239, 247, .74);
}

/* ---------- 06 合作 ---------- */
.page-about .about-partners {
  display: grid;
  gap: 14px;
}

.page-about .about-partner {
  padding: 20px;
  border-radius: var(--radius-md);
  background: var(--sky-100);
  border: 1px solid transparent;
  transition: background-color .2s var(--ease), border-color .2s var(--ease), transform .2s var(--ease);
}

.page-about .about-partner:hover,
.page-about .about-partner:focus-within {
  background: var(--white);
  border-color: var(--sky-500);
  transform: translateY(-2px);
}

.page-about .about-partner__type {
  display: block;
  margin-bottom: 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .14em;
  color: var(--sky-700);
}

.page-about .about-partner__title {
  margin: 0 0 8px;
  font-family: var(--font-head);
  font-size: 1rem;
  font-weight: 800;
  line-height: 1.4;
  color: var(--ink-950);
}

.page-about .about-partner__text {
  margin: 0;
  font-size: .9375rem;
  line-height: 1.75;
  color: var(--slate-600);
}

/* ---------- 07 原则 ---------- */
.page-about .about-principles {
  display: grid;
}

.page-about .about-principle {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 16px;
  padding: 20px 0;
  border-top: 1px solid var(--line-300);
}

.page-about .about-principle:last-child {
  border-bottom: 1px solid var(--line-300);
}

.page-about .about-principle__mark {
  padding-top: 3px;
  font-family: var(--font-mono);
  font-size: .875rem;
  letter-spacing: .08em;
  color: var(--gold-ink);
}

.page-about .about-principle__title {
  margin: 0 0 6px;
  font-family: var(--font-head);
  font-size: clamp(1.0625rem, 1.6vw, 1.25rem);
  font-weight: 800;
  line-height: 1.4;
  color: var(--ink-950);
}

.page-about .about-principle__text {
  max-width: 68ch;
  margin: 0;
  font-size: .9375rem;
  line-height: 1.8;
  color: var(--slate-600);
}

/* ---------- 收尾 ---------- */
.page-about .about-next {
  margin-top: clamp(32px, 5vw, 64px);
  padding: clamp(22px, 3vw, 36px);
  border-radius: var(--radius-xl);
  background: var(--sky-100);
  border: 1px solid var(--line-300);
  display: grid;
  gap: 20px;
}

.page-about .about-next__title {
  margin: 0 0 8px;
  font-family: var(--font-head);
  font-size: clamp(1.15rem, 2vw, 1.5rem);
  font-weight: 800;
  line-height: 1.35;
  color: var(--ink-950);
}

.page-about .about-next__text {
  max-width: 56ch;
  margin: 0;
  font-size: .9375rem;
  line-height: 1.78;
  color: var(--slate-600);
}

.page-about .about-next__links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

/* ---------- 响应式 ---------- */
@media (min-width: 720px) {
  .page-about .about-steps,
  .page-about .about-partners {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

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

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

@media (min-width: 820px) {
  .page-about .about-split {
    grid-template-columns: minmax(0, 1.1fr) minmax(0, .9fr);
    align-items: start;
  }

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

  .page-about .about-next__links {
    justify-content: flex-end;
  }
}

@media (min-width: 860px) {
  .page-about .about-hero__inner {
    grid-template-columns: minmax(0, 1.35fr) minmax(0, .78fr);
    align-items: end;
    gap: clamp(28px, 3.5vw, 52px);
  }

  .page-about .about-hero__stats {
    border-top: 0;
    border-left: 1px solid rgba(220, 239, 247, .22);
    padding: 0 0 0 24px;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 22px 20px;
  }

  .page-about .about-team {
    grid-template-columns: minmax(0, 300px) minmax(0, 1fr);
    align-items: start;
    gap: clamp(24px, 3.5vw, 40px);
  }
}

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

  .page-about .about-index {
    position: sticky;
    top: 24px;
  }

  .page-about .about-index__list {
    flex-direction: column;
    gap: 2px;
    overflow: visible;
    padding-bottom: 0;
  }

  .page-about .about-index__list li {
    flex: 1 1 auto;
  }

  .page-about .about-index__link {
    width: 100%;
    box-sizing: border-box;
    padding: 8px 10px;
    border: 0;
    border-left: 2px solid transparent;
    border-radius: 0;
    background: transparent;
    white-space: normal;
    justify-content: flex-start;
  }

  .page-about .about-index__link:hover,
  .page-about .about-index__link:focus-visible {
    background: var(--sky-100);
    border-color: transparent;
    border-left-color: var(--gold-500);
    color: var(--sky-700);
  }

  .page-about .about-index__link:hover .about-index__no,
  .page-about .about-index__link:focus-visible .about-index__no {
    color: var(--gold-ink);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-partner,
  .page-about .about-index__link,
  .page-about .timeline .disclosure__toggle {
    transition: none;
  }

  .page-about .about-partner:hover,
  .page-about .about-partner:focus-within {
    transform: none;
  }
}
</main>