.page-about {
  --about-line: 2px;
  --about-gutter: clamp(20px, 4vw, 56px);
  background: var(--navy);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding-top: clamp(20px, 3vw, 32px);
  background:
    radial-gradient(120% 90% at 88% 0%, rgba(37, 214, 236, 0.14), transparent 58%),
    linear-gradient(180deg, rgba(124, 99, 255, 0.08), transparent 62%),
    var(--navy);
  border-bottom: var(--about-line) solid var(--grid);
  overflow: hidden;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(to right, rgba(27, 58, 82, 0.55) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(27, 58, 82, 0.55) 1px, transparent 1px);
  background-size: 24px 24px;
  opacity: 0.5;
  pointer-events: none;
}

.page-about .about-hero > .container {
  position: relative;
  z-index: 1;
}

.page-about .about-hero__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--gap-m);
  padding: clamp(20px, 3.5vw, 34px) 0 clamp(28px, 4vw, 44px);
}

.page-about .about-hero__kicker {
  margin: 0;
  font-size: var(--fs-8);
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--cyan);
  display: flex;
  align-items: center;
  gap: 10px;
}

.page-about .about-hero__kicker::before {
  content: "";
  flex: none;
  width: 11px;
  height: 11px;
  background: var(--coral);
}

.page-about .about-hero__title {
  margin: 14px 0 0;
  font-size: clamp(30px, 6.4vw, var(--fs-1));
  line-height: 1.14;
  font-weight: 800;
  letter-spacing: -0.02em;
  color: var(--ice);
  max-width: 17ch;
}

.page-about .about-hero__desc {
  margin: 20px 0 0;
  max-width: 62ch;
  font-size: var(--fs-6);
  line-height: 1.78;
  color: var(--ice);
}

.page-about .about-hero__stamp {
  position: relative;
  border: var(--about-line) solid var(--grid);
  border-left: 4px solid var(--coral);
  background: var(--board);
  padding: 20px 20px 22px;
  box-shadow: var(--shadow-hard);
}

.page-about .about-hero__stamp-label {
  margin: 0;
  font-size: var(--fs-8);
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--steel);
}

.page-about .about-hero__stamp-num {
  margin: 10px 0 6px;
  font-size: clamp(44px, 9vw, 68px);
  line-height: 1;
  font-weight: 700;
  color: var(--cyan);
}

.page-about .about-hero__stamp-text {
  margin: 0;
  font-size: var(--fs-7);
  line-height: 1.7;
  color: var(--steel);
}

.page-about .about-metrics {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 0;
  background: var(--grid);
  border-top: var(--about-line) solid var(--grid);
}

.page-about .about-metrics__item {
  background: var(--board);
  padding: 16px 14px 18px;
  min-width: 0;
}

.page-about .about-metrics__item dt {
  font-size: var(--fs-8);
  letter-spacing: 0.08em;
  color: var(--steel);
}

.page-about .about-metrics__item dd {
  margin: 8px 0 0;
  font-size: var(--fs-7);
  color: var(--ice);
  line-height: 1.45;
}

.page-about .about-metrics__item dd .mono {
  display: inline-block;
  margin-right: 6px;
  font-size: var(--fs-4);
  font-weight: 700;
  color: var(--cyan);
  line-height: 1;
}

/* ---------- 主体档案布局 ---------- */
.page-about .about-dossier {
  padding: clamp(40px, 6vw, 80px) 0 clamp(48px, 7vw, 96px);
  background:
    linear-gradient(180deg, rgba(15, 36, 56, 0.55), transparent 40%),
    var(--navy);
}

.page-about .about-dossier__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--gap-m);
}

.page-about .about-index__head {
  margin: 0 0 10px;
  padding-bottom: 8px;
  font-size: var(--fs-8);
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--steel);
  border-bottom: var(--about-line) solid var(--grid);
}

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

.page-about .about-index__list a {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  padding: 9px 12px;
  border: 1px solid var(--grid);
  color: var(--steel);
  font-size: var(--fs-8);
  text-decoration: none;
  white-space: nowrap;
  transition: color 160ms var(--ease), border-color 160ms var(--ease), background 160ms var(--ease);
}

.page-about .about-index__list a:hover,
.page-about .about-index__list a:focus-visible {
  color: var(--ice);
  border-color: var(--cyan);
  background: rgba(37, 214, 236, 0.08);
}

.page-about .about-index__list a .mono {
  color: var(--cyan);
  font-size: var(--fs-8);
}

.page-about .about-flow {
  display: flex;
  flex-direction: column;
  gap: clamp(40px, 6vw, 72px);
  min-width: 0;
}

/* ---------- 章节 ---------- */
.page-about .about-section {
  position: relative;
  scroll-margin-top: calc(var(--rail-h) + 20px);
  min-width: 0;
}

.page-about .about-section__head {
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding-bottom: 14px;
  margin-bottom: 22px;
  border-bottom: var(--about-line) solid var(--grid);
}

.page-about .about-section__no {
  flex: none;
  font-size: var(--fs-8);
  letter-spacing: 0.08em;
  color: var(--cyan);
  border: 1px solid var(--cyan);
  padding: 3px 9px;
  line-height: 1.2;
}

.page-about .about-section__head h2 {
  margin: 0;
  font-size: clamp(22px, 3.6vw, var(--fs-3));
  line-height: 1.2;
  letter-spacing: -0.01em;
  color: var(--ice);
}

.page-about .about-section p {
  margin: 0 0 16px;
  max-width: 68ch;
  font-size: var(--fs-6);
  line-height: 1.78;
  color: var(--ice);
}

.page-about .about-tags {
  list-style: none;
  margin: 18px 0 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

/* ---------- 生产流程 ---------- */
.page-about .about-process {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--gap-m);
  margin-top: 8px;
}

.page-about .step-list {
  list-style: none;
  margin: 0;
  padding: 0;
  min-width: 0;
}

.page-about .step-list__item {
  display: grid;
  grid-template-columns: 38px minmax(0, 1fr);
  gap: 14px;
  padding: 16px 0;
  border-bottom: 1px solid var(--grid);
}

.page-about .step-list__item:first-child {
  padding-top: 0;
}

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

.page-about .step-list__no {
  display: grid;
  place-items: center;
  width: 34px;
  height: 34px;
  background: var(--cyan);
  color: var(--ink);
  font-size: var(--fs-8);
  font-weight: 700;
}

.page-about .step-list__body {
  min-width: 0;
}

.page-about .about-section .step-list__title {
  margin: 0 0 5px;
  font-size: var(--fs-5);
  line-height: 1.35;
  color: var(--ice);
}

.page-about .about-section .step-list__text {
  margin: 0;
  max-width: 60ch;
  font-size: var(--fs-7);
  line-height: 1.72;
  color: var(--steel);
}

.page-about .about-figure {
  margin: 0;
  min-width: 0;
}

.page-about .about-figure .figure__frame {
  border: var(--about-line) solid var(--grid);
  background: var(--board-deep);
  overflow: hidden;
}

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

.page-about .about-figure--wide {
  margin-top: clamp(24px, 4vw, 40px);
}

.page-about .about-figure__frame--banner {
  aspect-ratio: 16 / 7;
}

/* ---------- 团队分工 ---------- */
.page-about .crew-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  margin-top: 8px;
  background: var(--grid);
  border: var(--about-line) solid var(--grid);
}

.page-about .crew-card {
  background: var(--board);
  padding: 20px 18px 24px;
  display: flex;
  flex-direction: column;
  gap: 10px;
  min-width: 0;
}

.page-about .crew-card__count {
  margin: 0;
  font-size: clamp(30px, 5vw, var(--fs-2));
  line-height: 1;
  font-weight: 700;
  color: var(--cyan);
}

.page-about .about-section .crew-card__role {
  margin: 0;
  font-size: var(--fs-5);
  line-height: 1.35;
  color: var(--ice);
}

.page-about .about-section .crew-card__text {
  margin: 0;
  font-size: var(--fs-7);
  line-height: 1.7;
  color: var(--steel);
}

/* ---------- 时间线 ---------- */
.page-about .timeline {
  position: relative;
  list-style: none;
  margin: 8px 0 0;
  padding: 4px 0 4px 28px;
  border-left: var(--about-line) solid var(--grid);
}

.page-about .timeline__item {
  position: relative;
  padding-bottom: 26px;
}

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

.page-about .timeline__item::before {
  content: "";
  position: absolute;
  left: -35px;
  top: 6px;
  width: 12px;
  height: 12px;
  background: var(--navy);
  border: var(--about-line) solid var(--cyan);
  transition: background 180ms var(--ease), transform 180ms var(--ease);
}

.page-about .timeline__item:last-child::before {
  background: var(--coral);
  border-color: var(--coral);
}

.page-about .timeline__item:hover::before {
  transform: scale(1.18);
}

.page-about .timeline__year {
  margin: 0 0 4px;
  font-size: var(--fs-8);
  letter-spacing: 0.12em;
  color: var(--cyan);
}

.page-about .about-section .timeline__title {
  margin: 0 0 6px;
  font-size: var(--fs-5);
  line-height: 1.35;
  color: var(--ice);
}

.page-about .about-section .timeline__text {
  margin: 0;
  max-width: 62ch;
  font-size: var(--fs-7);
  line-height: 1.7;
  color: var(--steel);
  transition: color 180ms var(--ease);
}

.page-about .timeline__item:hover .timeline__text {
  color: var(--ice);
}

/* ---------- 数据字段 ---------- */
.page-about .field-groups {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-top: 8px;
}

.page-about .field-group {
  border: var(--about-line) solid var(--grid);
  background: var(--board);
}

.page-about .field-group summary {
  list-style: none;
  cursor: pointer;
  padding: 15px 16px;
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: var(--fs-6);
  color: var(--ice);
  border-bottom: 1px solid var(--grid);
}

.page-about .field-group summary::-webkit-details-marker {
  display: none;
}

.page-about .field-group summary::before {
  content: "";
  flex: none;
  width: 9px;
  height: 9px;
  background: var(--mint);
  transition: background 160ms var(--ease);
}

.page-about .field-group:not([open]) summary {
  border-bottom: 0;
}

.page-about .field-group:not([open]) summary::before {
  background: var(--steel);
}

.page-about .field-list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .field-list li {
  display: grid;
  grid-template-columns: 104px minmax(0, 1fr);
  gap: 12px;
  padding: 11px 16px;
  border-top: 1px solid var(--grid);
  font-size: var(--fs-7);
  line-height: 1.6;
  color: var(--ice);
}

.page-about .field-list li:first-child {
  border-top: 0;
}

.page-about .field-list li .mono {
  font-size: var(--fs-8);
  letter-spacing: 0.06em;
  color: var(--cyan);
}

.page-about .field-list li span:last-child {
  color: var(--steel);
}

/* ---------- 合作卡片 ---------- */
.page-about .partner-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--gap-m);
  margin-top: 10px;
}

.page-about .partner-card {
  border: var(--about-line) solid var(--grid);
  border-top: 4px solid var(--cyan);
  background: var(--board);
  padding: 20px 18px 22px;
  min-width: 0;
}

.page-about .partner-card:nth-child(2) {
  border-top-color: var(--mint);
}

.page-about .partner-card:nth-child(3) {
  border-top-color: var(--violet);
}

.page-about .partner-card__num {
  margin: 0 0 12px;
  font-size: var(--fs-2);
  line-height: 1;
  font-weight: 700;
  color: var(--ice);
}

.page-about .about-section .partner-card__title {
  margin: 0 0 8px;
  font-size: var(--fs-5);
  line-height: 1.35;
  color: var(--ice);
}

.page-about .about-section .partner-card__text {
  margin: 0;
  font-size: var(--fs-7);
  line-height: 1.72;
  color: var(--steel);
}

/* ---------- 档案信息条 ---------- */
.page-about .about-meta {
  border: var(--about-line) solid var(--grid);
  background: var(--board-deep);
}

.page-about .about-meta__row {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 4px;
  padding: 14px 16px;
  border-bottom: 1px solid var(--grid);
}

.page-about .about-meta__row:last-child {
  border-bottom: 0;
}

.page-about .about-meta__key {
  font-size: var(--fs-8);
  letter-spacing: 0.12em;
  color: var(--amber);
}

.page-about .about-meta__val {
  font-size: var(--fs-7);
  line-height: 1.65;
  color: var(--ice);
}

/* ---------- 结尾行动区 ---------- */
.page-about .about-next {
  padding: clamp(40px, 6vw, 72px) 0 clamp(48px, 7vw, 88px);
  border-top: var(--about-line) solid var(--grid);
  background:
    radial-gradient(90% 120% at 12% 0%, rgba(255, 90, 54, 0.13), transparent 60%),
    var(--board);
}

.page-about .about-next__inner {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--gap-m);
}

.page-about .about-next__lead h2 {
  margin: 0 0 12px;
  font-size: clamp(22px, 3.6vw, var(--fs-3));
  line-height: 1.2;
  color: var(--ice);
}

.page-about .about-next__lead p {
  margin: 0;
  max-width: 60ch;
  font-size: var(--fs-6);
  line-height: 1.78;
  color: var(--steel);
}

.page-about .about-next__links {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px;
}

.page-about .about-next__link {
  font-size: var(--fs-7);
  color: var(--cyan);
  text-decoration: none;
  padding: 6px 2px;
  border-bottom: 1px solid transparent;
  transition: border-color 160ms var(--ease), color 160ms var(--ease);
}

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

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

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

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

  .page-about .about-meta__row {
    grid-template-columns: 130px minmax(0, 1fr);
    gap: 16px;
    align-items: baseline;
  }
}

@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
    gap: var(--gap-l);
    align-items: end;
  }

  .page-about .about-process {
    grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
    gap: var(--gap-l);
    align-items: start;
  }

  .page-about .about-next__inner {
    grid-template-columns: minmax(0, 6fr) minmax(0, 5fr);
    gap: var(--gap-l);
    align-items: center;
  }
}

@media (min-width: 1024px) {
  .page-about .about-dossier__grid {
    grid-template-columns: 196px minmax(0, 1fr);
    gap: clamp(32px, 5vw, 72px);
    align-items: start;
  }

  .page-about .about-index {
    position: sticky;
    top: calc(var(--rail-h) + 24px);
  }

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

  .page-about .about-index__list a {
    display: flex;
    border: 0;
    border-left: 3px solid var(--grid);
    padding: 11px 10px 11px 14px;
    white-space: normal;
    line-height: 1.5;
  }
}

@media (min-width: 1180px) {
  .page-about .crew-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .timeline__item::before,
  .page-about .timeline__text,
  .page-about .about-index__list a,
  .page-about .about-next__link {
    transition: none;
  }

  .page-about .timeline__item:hover::before {
    transform: none;
  }
}