.page-about {
  --about-rule: 1px solid var(--hairline);
  --about-rule-soft: 1px solid var(--hairline-soft);
  --about-gap: clamp(20px, 3vw, 40px);
  background: var(--ink-950);
  color: var(--text-md);
}

.page-about .about-crumb {
  padding-top: 26px;
}

/* ---------------- 通用小标题 ---------------- */

.page-about .about-h2 {
  margin: 0;
  font-size: clamp(24px, 3.2vw, 32px);
  font-weight: 800;
  line-height: 1.15;
  letter-spacing: -0.02em;
  color: var(--text-hi);
}

.page-about .about-h2--light {
  color: var(--text-hi);
}

/* ---------------- 首屏 ---------------- */

.page-about .about-hero {
  padding: 44px 0 60px;
  border-bottom: var(--about-rule);
}

.page-about .about-hero__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 40px;
}

.page-about .about-hero__kicker {
  margin: 0 0 20px;
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--cyan-400);
}

.page-about .about-hero__title {
  margin: 0 0 22px;
  font-size: clamp(32px, 7vw, 60px);
  font-weight: 800;
  line-height: 1.06;
  letter-spacing: -0.02em;
  color: var(--text-hi);
}

.page-about .about-hero__text {
  margin: 0 0 30px;
  max-width: 62ch;
  font-size: 17px;
  line-height: 1.8;
  color: var(--text-md);
}

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

.page-about .about-figures {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 0;
  background: var(--hairline);
  border: var(--about-rule);
}

.page-about .about-figure {
  display: flex;
  flex-direction: column;
  padding: 20px 18px 22px;
  background: var(--ink-800);
  transition: background var(--ease), border-color var(--ease);
  border-top: 2px solid transparent;
}

.page-about .about-figure:hover {
  background: var(--ink-950);
  border-top-color: var(--orange-500);
}

.page-about .about-figure dt {
  order: 2;
  font-family: var(--f-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--text-lo);
}

.page-about .about-figure:hover dt {
  color: var(--cyan-400);
}

.page-about .about-figure__num {
  order: 1;
  display: block;
  margin: 0 0 12px;
  font-size: clamp(32px, 5vw, 48px);
  font-weight: 800;
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--text-hi);
  transition: color var(--ease);
}

.page-about .about-figure:hover .about-figure__num {
  color: var(--orange-500);
}

.page-about .about-figure__num--word {
  font-size: clamp(20px, 2.6vw, 26px);
  letter-spacing: 0.02em;
  color: var(--lemon-300);
}

/* ---------------- 时间线 ---------------- */

.page-about .about-timeline {
  padding: 64px 0;
  border-bottom: var(--about-rule);
}

.page-about .about-timeline__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 40px;
}

.page-about .about-timeline__lede {
  margin: 18px 0 28px;
  max-width: 52ch;
  font-size: 16px;
  line-height: 1.8;
  color: var(--text-md);
}

.page-about .about-timeline__figure {
  margin: 0;
  border: var(--about-rule);
  background: var(--ink-800);
}

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

.page-about .about-timeline__list {
  border-top: var(--about-rule);
}

.page-about .about-tl__item {
  border-bottom: var(--about-rule-soft);
}

.page-about .about-tl__item > summary {
  display: grid;
  grid-template-columns: 62px minmax(0, 1fr) 18px;
  align-items: center;
  gap: 14px;
  padding: 20px 0;
  cursor: pointer;
  list-style: none;
  transition: background var(--ease);
}

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

.page-about .about-tl__item > summary:focus-visible {
  outline: 2px solid var(--cyan-400);
  outline-offset: 2px;
}

.page-about .about-tl__idx {
  display: inline-block;
  padding: 3px 6px;
  border: 1px solid var(--hairline);
  background: var(--ink-800);
  color: var(--lemon-300);
  font-size: 13px;
  text-align: center;
  transition: background var(--ease), color var(--ease), border-color var(--ease);
}

.page-about .about-tl__item[open] > summary .about-tl__idx {
  background: var(--orange-500);
  border-color: var(--orange-500);
  color: var(--ink-950);
}

.page-about .about-tl__item > summary:hover .about-tl__title {
  color: var(--cyan-400);
}

.page-about .about-tl__title {
  font-size: 18px;
  font-weight: 700;
  line-height: 1.35;
  letter-spacing: -0.01em;
  color: var(--text-hi);
  transition: color var(--ease);
}

.page-about .about-tl__chev {
  justify-self: end;
  width: 10px;
  height: 10px;
  border-right: 1px solid var(--cyan-400);
  border-bottom: 1px solid var(--cyan-400);
  transform: rotate(45deg) translate(-2px, -2px);
  transition: transform var(--ease);
}

.page-about .about-tl__item[open] .about-tl__chev {
  transform: rotate(-135deg) translate(-2px, -2px);
}

.page-about .about-tl__body {
  padding: 0 0 26px 76px;
  max-width: 62ch;
}

.page-about .about-tl__body p {
  margin: 0;
  font-size: 16px;
  line-height: 1.8;
  color: var(--text-md);
}

/* ---------------- 数据带 ---------------- */

.page-about .about-band {
  padding: 56px 0;
  background: var(--ink-800);
  border-top: 1px solid var(--cyan-400);
  border-bottom: 1px solid var(--cyan-400);
}

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

.page-about .about-band__cell {
  padding: 26px 20px 28px;
  border-top: var(--about-rule-soft);
  transition: background var(--ease);
}

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

.page-about .about-band__cell:hover {
  background: var(--ink-950);
}

.page-about .about-band__num {
  margin: 0 0 8px;
  font-size: clamp(36px, 8vw, 60px);
  font-weight: 800;
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--text-hi);
  transition: color var(--ease);
}

.page-about .about-band__cell:hover .about-band__num {
  color: var(--orange-500);
}

.page-about .about-band__label {
  margin: 0 0 10px;
  font-size: 15px;
  font-weight: 700;
  color: var(--text-hi);
  transition: color var(--ease);
}

.page-about .about-band__cell:hover .about-band__label {
  color: var(--cyan-400);
}

.page-about .about-band__note {
  margin: 0;
  font-size: 13px;
  line-height: 1.7;
  color: var(--text-lo);
}

/* ---------------- 两栏正文 ---------------- */

.page-about .about-columns {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 44px;
  padding: 64px 0 72px;
}

.page-about .about-block + .about-block {
  margin-top: 68px;
}

.page-about .about-block__lede {
  margin: 18px 0 26px;
  max-width: 62ch;
  font-size: 16px;
  line-height: 1.8;
  color: var(--text-md);
}

.page-about .about-block__figure {
  margin: 0 0 32px;
  border: var(--about-rule);
  background: var(--ink-800);
}

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

.page-about .about-block a,
.page-about .about-boundary a,
.page-about .about-next a:not(.btn) {
  color: var(--cyan-400);
  text-decoration: none;
  border-bottom: 1px solid var(--cyan-900);
  transition: color var(--ease), border-color var(--ease);
}

.page-about .about-block a:hover,
.page-about .about-boundary a:hover {
  color: var(--orange-500);
  border-bottom-color: var(--orange-500);
}

/* 工序 */

.page-about .about-steps {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--hairline);
  border: var(--about-rule);
}

.page-about .about-steps__item {
  padding: 24px 22px 26px;
  background: var(--ink-950);
}

.page-about .about-steps__idx {
  display: block;
  margin-bottom: 12px;
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--lemon-300);
}

.page-about .about-steps__title {
  margin: 0 0 10px;
  font-size: 17px;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--text-hi);
}

.page-about .about-steps__item p {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--text-md);
}

/* 团队 */

.page-about .about-team {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 28px;
  margin-top: 24px;
}

.page-about .about-team__text p {
  margin: 0 0 18px;
  max-width: 62ch;
  font-size: 16px;
  line-height: 1.8;
  color: var(--text-md);
}

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

.page-about .about-team__figure {
  margin: 0;
  border: var(--about-rule);
  background: var(--ink-800);
}

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

/* 资质 */

.page-about .about-record {
  margin: 0;
  padding: 0;
  list-style: none;
  border-top: var(--about-rule);
}

.page-about .about-record li {
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding: 16px 0;
  border-bottom: var(--about-rule-soft);
  font-size: 16px;
  line-height: 1.7;
  color: var(--text-md);
  transition: color var(--ease);
}

.page-about .about-record li:hover {
  color: var(--text-hi);
}

.page-about .about-record__mark {
  flex: 0 0 auto;
  width: 8px;
  height: 8px;
  background: var(--cyan-400);
  transform: translateY(-1px);
  transition: background var(--ease);
}

.page-about .about-record li:hover .about-record__mark {
  background: var(--orange-500);
}

/* ---------------- 旁注目录 ---------------- */

.page-about .about-toc {
  border: var(--about-rule);
  background: var(--ink-800);
  padding: 22px 20px 24px;
}

.page-about .about-toc__title {
  margin: 0 0 16px;
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--text-lo);
}

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

.page-about .about-toc__list a {
  display: flex;
  align-items: baseline;
  gap: 10px;
  padding: 9px 8px;
  font-size: 15px;
  color: var(--text-md);
  text-decoration: none;
  border-left: 2px solid transparent;
  transition: color var(--ease), background var(--ease), border-color var(--ease);
}

.page-about .about-toc__list a .mono {
  font-size: 12px;
  color: var(--text-lo);
  transition: color var(--ease);
}

.page-about .about-toc__list a:hover {
  color: var(--text-hi);
  background: var(--ink-950);
  border-left-color: var(--orange-500);
}

.page-about .about-toc__list a:hover .mono {
  color: var(--orange-500);
}

/* ---------------- 边界条 ---------------- */

.page-about .about-boundary {
  padding: 60px 0 62px;
  background: var(--ink-800);
  border-top: 1px solid var(--cyan-400);
  border-bottom: var(--about-rule);
  background-image:
    linear-gradient(var(--hairline-soft) 1px, transparent 1px),
    linear-gradient(90deg, var(--hairline-soft) 1px, transparent 1px);
  background-size: 24px 24px;
}

.page-about .about-boundary__list {
  margin: 26px 0 0;
  padding: 0;
  list-style: none;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--hairline);
  border: var(--about-rule);
}

.page-about .about-boundary__list li {
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding: 18px 20px;
  background: var(--ink-800);
  font-size: 16px;
  line-height: 1.6;
  color: var(--text-hi);
}

.page-about .about-boundary__x {
  color: var(--orange-500);
  font-size: 14px;
}

.page-about .about-boundary__note {
  margin: 26px 0 0;
  max-width: 62ch;
  font-size: 14px;
  line-height: 1.8;
  color: var(--text-lo);
}

/* ---------------- 收尾 ---------------- */

.page-about .about-next {
  padding: 56px 0 68px;
}

.page-about .about-next__inner {
  border-left: 3px solid var(--orange-500);
  padding-left: 22px;
}

.page-about .about-next__kicker {
  margin: 0 0 12px;
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--lemon-300);
}

.page-about .about-next__text {
  margin: 0 0 24px;
  max-width: 54ch;
  font-size: 17px;
  line-height: 1.8;
  color: var(--text-hi);
}

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

/* ---------------- 响应式 ---------------- */

@media (min-width: 640px) {
  .page-about .about-figures {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

  .page-about .about-band__cell {
    border-top: 0;
    border-left: var(--about-rule-soft);
  }

  .page-about .about-band__cell:nth-child(odd) {
    border-left: 0;
  }

  .page-about .about-band__cell:nth-child(n + 3) {
    border-top: var(--about-rule-soft);
  }

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

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

@media (min-width: 900px) {
  .page-about .about-hero {
    padding: 56px 0 76px;
  }

  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 6fr) minmax(0, 5fr);
    gap: 0;
  }

  .page-about .about-hero__lead {
    padding-right: 48px;
    border-right: 1px solid var(--cyan-400);
  }

  .page-about .about-figures {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    margin-left: 48px;
  }

  .page-about .about-timeline {
    padding: 80px 0;
  }

  .page-about .about-timeline__grid {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    gap: 56px;
  }

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

  .page-about .about-band__cell {
    border-left: var(--about-rule-soft);
    border-top: 0;
  }

  .page-about .about-band__cell:nth-child(odd) {
    border-left: var(--about-rule-soft);
  }

  .page-about .about-band__cell:first-child {
    border-left: 0;
  }

  .page-about .about-band__cell:nth-child(n + 3) {
    border-top: 0;
  }

  .page-about .about-columns {
    grid-template-columns: minmax(0, 8fr) minmax(0, 3fr);
    gap: 48px;
    padding: 80px 0 88px;
  }

  .page-about .about-columns__aside {
    position: relative;
  }

  .page-about .about-toc {
    position: sticky;
    top: 120px;
  }

  .page-about .about-team {
    grid-template-columns: minmax(0, 1fr) 300px;
    gap: 36px;
    align-items: start;
  }

  .page-about .about-boundary {
    padding: 76px 0 80px;
  }
}

@media (min-width: 1100px) {
  .page-about .about-team {
    grid-template-columns: minmax(0, 1fr) 340px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about *,
  .page-about *::before,
  .page-about *::after {
    transition-duration: 0ms !important;
    animation-duration: 0ms !important;
  }
}