.page-about {
  background: var(--snow-50);
  color: var(--ink-900);
}

.page-about .breadcrumb {
  padding: 22px 0 0;
  font-size: var(--fs-13);
  color: var(--slate);
}

.page-about .breadcrumb ol {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.page-about .breadcrumb li + li::before {
  content: "/";
  margin-right: 8px;
  color: var(--blue-300);
}

.page-about .breadcrumb a {
  color: var(--blue-600);
  text-decoration: none;
}

.page-about .breadcrumb a:hover,
.page-about .breadcrumb a:focus-visible {
  text-decoration: underline;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  padding: 26px 0 48px;
}

.page-about .about-hero__inner {
  display: grid;
  gap: 30px;
}

.page-about .about-hero__copy .display {
  margin: 10px 0 18px;
  letter-spacing: -0.02em;
  line-height: 1.14;
}

.page-about .about-hero__copy .lede {
  margin: 0;
  max-width: 36em;
  color: var(--ink-800);
  line-height: 1.75;
}

.page-about .about-hero__stats {
  list-style: none;
  margin: 28px 0 0;
  padding: 20px 0 0;
  border-top: var(--rule);
  display: flex;
  flex-wrap: wrap;
  gap: 18px 32px;
}

.page-about .about-hero__stat {
  display: flex;
  flex-direction: column;
  gap: 5px;
  min-width: 132px;
}

.page-about .about-hero__stat b {
  font-size: var(--fs-32);
  font-weight: 700;
  line-height: 1;
  color: var(--blue-600);
  letter-spacing: -0.01em;
}

.page-about .about-hero__stat span {
  font-size: var(--fs-13);
  line-height: 1.5;
  color: var(--slate);
}

.page-about .about-hero__visual {
  background-color: var(--paper);
  background-image:
    linear-gradient(rgba(169, 203, 224, 0.4) 1px, transparent 1px),
    linear-gradient(90deg, rgba(169, 203, 224, 0.4) 1px, transparent 1px);
  background-size: 100% 36px, 36px 100%;
  border: var(--rule);
  border-radius: var(--radius);
  padding: 12px;
  box-shadow: 0 28px 52px -36px rgba(10, 27, 42, 0.45);
}

.page-about .about-hero__svg {
  display: block;
  width: 100%;
  height: auto;
}

.page-about .about-hero__svg text {
  font-family: var(--font-sans);
}

/* ---------- 通用章节 ---------- */
.page-about .section {
  padding: 54px 0;
}

.page-about .section__title {
  margin: 10px 0 0;
  letter-spacing: -0.02em;
  line-height: 1.22;
}

/* ---------- 历程 ---------- */
.page-about .about-trail {
  background: var(--paper);
  border-top: var(--rule);
  border-bottom: var(--rule);
}

.page-about .about-trail__head {
  max-width: 44em;
}

.page-about .about-trail__intro {
  margin: 14px 0 0;
  font-size: var(--fs-17);
  line-height: 1.75;
  color: var(--slate);
}

.page-about .trail {
  position: relative;
  list-style: none;
  margin: 34px 0 0;
  padding: 0 0 0 26px;
}

.page-about .trail::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 10px;
  bottom: 10px;
  width: 2px;
  background: var(--mist);
}

.page-about .trail__item {
  position: relative;
  padding-bottom: 10px;
}

.page-about .trail__item::before {
  content: "";
  position: absolute;
  left: -26px;
  top: 20px;
  width: 12px;
  height: 12px;
  box-sizing: border-box;
  border-radius: 50%;
  background: var(--paper);
  border: 2px solid var(--blue-600);
  transition: background 0.2s var(--ease), border-color 0.2s var(--ease);
}

.page-about .trail__item:has(.trail__node[open])::before {
  background: var(--maple);
  border-color: var(--maple);
}

.page-about .trail__summary {
  display: flex;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 10px 14px;
  padding: 13px 16px;
  list-style: none;
  cursor: pointer;
  background: var(--snow-50);
  border: var(--rule);
  border-radius: var(--radius);
  transition: background 0.2s var(--ease), border-color 0.2s var(--ease);
}

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

.page-about .trail__summary:hover {
  border-color: var(--blue-300);
}

.page-about .trail__summary:focus-visible {
  outline: 2px solid var(--blue-600);
  outline-offset: 2px;
}

.page-about .trail__no {
  font-size: var(--fs-15);
  font-weight: 500;
  color: var(--blue-600);
}

.page-about .trail__title {
  font-size: var(--fs-17);
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--ink-900);
}

.page-about .trail__meta {
  font-size: var(--fs-13);
  color: var(--slate);
  letter-spacing: 0.04em;
}

.page-about .trail__summary::after {
  content: "展开";
  margin-left: auto;
  font-size: var(--fs-13);
  color: var(--blue-600);
}

.page-about .trail__node[open] .trail__summary {
  background: var(--paper);
  border-color: var(--blue-300);
}

.page-about .trail__node[open] .trail__title {
  color: var(--maple-dark);
}

.page-about .trail__node[open] .trail__summary::after {
  content: "收起";
  color: var(--maple);
}

.page-about .trail__body {
  margin-top: 10px;
  padding: 2px 0 4px 16px;
  border-left: 3px solid var(--mist);
}

.page-about .trail__node[open] .trail__body {
  border-left-color: var(--maple);
}

.page-about .trail__body p {
  margin: 0;
  font-size: var(--fs-15);
  line-height: 1.8;
  color: var(--ink-800);
  max-width: 40em;
}

.page-about .about-trail__figure {
  margin: 34px 0 0;
}

.page-about .media-frame {
  border: var(--rule);
  border-radius: var(--radius);
  background: var(--snow-50);
  padding: 8px;
}

.page-about .media-frame__inner {
  overflow: hidden;
  border-radius: 2px;
  background:
    linear-gradient(rgba(169, 203, 224, 0.35) 1px, transparent 1px),
    linear-gradient(90deg, rgba(169, 203, 224, 0.35) 1px, transparent 1px);
  background-size: 100% 28px, 28px 100%;
}

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

.page-about .about-trail__figure .media-frame__inner {
  aspect-ratio: 14 / 9;
}

.page-about .about-crew__figinner {
  aspect-ratio: 12 / 7;
}

.page-about .about-sources__figinner {
  aspect-ratio: 1 / 1;
}

/* ---------- 色带 ---------- */
.page-about .about-band {
  background: var(--blue-300);
  padding: 42px 0;
}

.page-about .about-band__inner {
  display: flex;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 14px 26px;
}

.page-about .about-band__num {
  font-size: var(--fs-56);
  font-weight: 700;
  line-height: 1;
  color: var(--ink-900);
  letter-spacing: -0.02em;
}

.page-about .about-band__text {
  margin: 0;
  max-width: 30em;
  font-size: var(--fs-20);
  font-weight: 700;
  line-height: 1.5;
  letter-spacing: -0.01em;
  color: var(--ink-900);
}

/* ---------- 团队分工 ---------- */
.page-about .about-crew__head {
  max-width: 44em;
}

.page-about .about-crew__intro {
  margin: 14px 0 0;
  font-size: var(--fs-17);
  line-height: 1.75;
  color: var(--slate);
}

.page-about .crew {
  display: grid;
  gap: 16px;
  margin-top: 32px;
}

.page-about .crew__col {
  background: var(--paper);
  border: var(--rule);
  border-top: 3px solid var(--blue-600);
  border-radius: var(--radius);
  padding: 24px 20px 22px;
  transition: opacity 0.25s var(--ease), transform 0.25s var(--ease), box-shadow 0.25s var(--ease);
}

.page-about .crew__col--lead {
  background: linear-gradient(180deg, rgba(169, 203, 224, 0.34), var(--paper) 62%);
}

.page-about .crew__no {
  display: block;
  font-size: var(--fs-13);
  color: var(--blue-600);
  letter-spacing: 0.04em;
}

.page-about .crew__name {
  margin: 8px 0 10px;
  font-size: var(--fs-20);
  font-weight: 700;
  letter-spacing: -0.01em;
}

.page-about .crew__desc {
  margin: 0;
  font-size: var(--fs-15);
  line-height: 1.8;
  color: var(--ink-800);
}

.page-about .crew__list {
  list-style: none;
  margin: 16px 0 0;
  padding: 14px 0 0;
  border-top: var(--rule);
  display: grid;
  gap: 8px;
}

.page-about .crew__list li {
  position: relative;
  padding-left: 16px;
  font-size: var(--fs-13);
  line-height: 1.6;
  color: var(--slate);
}

.page-about .crew__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.62em;
  width: 6px;
  height: 6px;
  background: var(--maple);
}

.page-about .about-crew__figure {
  margin: 28px 0 0;
}

.page-about .crew:hover .crew__col {
  opacity: 0.55;
}

.page-about .crew .crew__col:hover,
.page-about .crew .crew__col:focus-within {
  opacity: 1;
  transform: translateY(-3px);
  box-shadow: 0 20px 36px -30px rgba(10, 27, 42, 0.5);
}

/* ---------- 资料来源 ---------- */
.page-about .about-sources {
  background: var(--paper);
  border-top: var(--rule);
  border-bottom: var(--rule);
}

.page-about .about-sources__inner {
  display: grid;
  gap: 30px;
}

.page-about .sources {
  list-style: none;
  margin: 28px 0 0;
  padding: 0;
  display: grid;
  gap: 20px;
}

.page-about .sources__item {
  padding-left: 18px;
  border-left: 2px solid var(--mist);
}

.page-about .sources__item:nth-child(2) {
  border-left-color: var(--blue-300);
}

.page-about .sources__item:nth-child(3) {
  border-left-color: var(--maple);
}

.page-about .sources__name {
  margin: 0 0 6px;
  font-size: var(--fs-17);
  font-weight: 700;
  letter-spacing: -0.01em;
}

.page-about .sources__item p {
  margin: 0;
  font-size: var(--fs-15);
  line-height: 1.8;
  color: var(--ink-800);
}

.page-about .about-sources__note {
  margin: 26px 0 0;
  padding: 16px 18px;
  background: var(--snow-50);
  border-left: 3px solid var(--blue-600);
  font-size: var(--fs-15);
  line-height: 1.8;
  color: var(--ink-800);
}

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

/* ---------- 合作生态 ---------- */
.page-about .about-partners__head {
  max-width: 44em;
}

.page-about .about-partners__intro {
  margin: 14px 0 0;
  font-size: var(--fs-17);
  line-height: 1.75;
  color: var(--slate);
}

.page-about .partners {
  list-style: none;
  margin: 32px 0 0;
  padding: 0;
  display: grid;
  gap: 16px;
}

.page-about .partners__item {
  background: var(--paper);
  border: var(--rule);
  border-left: 3px solid var(--blue-600);
  border-radius: var(--radius);
  padding: 22px 20px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.page-about .partners__item--plain {
  border-left-color: var(--maple);
  background: var(--snow-50);
}

.page-about .partners__num {
  font-size: var(--fs-40);
  font-weight: 700;
  line-height: 1;
  color: var(--blue-600);
  letter-spacing: -0.02em;
}

.page-about .partners__label {
  font-size: var(--fs-15);
  line-height: 1.75;
  color: var(--ink-800);
}

.page-about .about-partners__more {
  margin: 24px 0 0;
  font-size: var(--fs-15);
  line-height: 1.8;
  color: var(--slate);
}

.page-about .about-partners__more a,
.page-about .about-scale__note a {
  color: var(--blue-600);
  text-decoration: none;
  border-bottom: 1px solid var(--blue-300);
}

.page-about .about-partners__more a:hover,
.page-about .about-partners__more a:focus-visible,
.page-about .about-scale__note a:hover,
.page-about .about-scale__note a:focus-visible {
  border-bottom-color: var(--maple);
}

/* ---------- 使用现状 ---------- */
.page-about .about-scale {
  background: var(--ink-900);
  color: var(--snow-50);
  padding: 56px 0 60px;
}

.page-about .about-scale .eyebrow {
  color: var(--blue-300);
}

.page-about .about-scale .section__title {
  color: var(--paper);
}

.page-about .scale {
  display: grid;
  gap: 22px;
  margin: 32px 0 0;
  padding: 0;
}

.page-about .scale__item {
  border-top: 2px solid var(--maple);
  padding-top: 16px;
}

.page-about .scale__item dt {
  font-size: var(--fs-13);
  letter-spacing: 0.08em;
  color: var(--blue-300);
}

.page-about .scale__item dd {
  margin: 10px 0 0;
  font-size: var(--fs-40);
  font-weight: 700;
  line-height: 1.1;
  color: var(--paper);
  letter-spacing: -0.02em;
}

.page-about .about-scale__note {
  margin: 30px 0 0;
  max-width: 46em;
  font-size: var(--fs-15);
  line-height: 1.8;
  color: var(--blue-300);
}

.page-about .about-scale__note a {
  color: var(--paper);
  border-bottom-color: rgba(244, 248, 251, 0.5);
}

/* ---------- 响应式 ---------- */
@media (min-width: 640px) {
  .page-about .about-hero {
    padding: 32px 0 56px;
  }

  .page-about .section {
    padding: 64px 0;
  }

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

  .page-about .partners__item--plain {
    grid-column: 1 / -1;
  }
}

@media (min-width: 900px) {
  .page-about .about-hero__inner {
    grid-template-columns: 7fr 5fr;
    gap: 52px;
    align-items: center;
  }

  .page-about .about-sources__inner {
    grid-template-columns: 7fr 5fr;
    gap: 48px;
    align-items: start;
  }

  .page-about .crew {
    grid-template-columns: 1.5fr 1fr 1fr;
    gap: 20px;
    align-items: start;
  }

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

  .page-about .partners__item--plain {
    grid-column: auto;
  }

  .page-about .scale {
    grid-template-columns: repeat(3, 1fr);
    gap: 36px;
  }

  .page-about .about-band {
    padding: 52px 0;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .crew__col,
  .page-about .trail__summary,
  .page-about .trail__item::before {
    transition: none;
  }

  .page-about .crew .crew__col:hover,
  .page-about .crew .crew__col:focus-within {
    transform: none;
  }
}