.page-about {
  --about-gap: var(--space-4);
  display: block;
  padding-block: var(--space-6) var(--space-8);
}

.page-about .breadcrumb {
  margin-bottom: var(--space-6);
}

/* ---------- 开场 ---------- */
.page-about .about-intro {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  max-width: 66ch;
  padding-bottom: var(--space-6);
}

.page-about .about-intro__title {
  margin: 0;
  font-family: var(--font-heading);
  font-size: var(--text-2xl);
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  color: var(--color-ink);
  transform: skewX(-1.2deg);
  transform-origin: left center;
}

.page-about .about-intro__lead {
  margin: 0;
  color: var(--color-ink-soft);
}

.page-about .about-lede {
  display: flex;
  align-items: flex-start;
  gap: var(--space-3);
  margin-top: var(--space-2);
  padding: var(--space-4);
  border-radius: var(--radius-lg);
  background: var(--color-primary-soft);
  box-shadow: var(--shadow-1);
}

.page-about .about-lede__num {
  margin: 0;
  flex: none;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: var(--text-3xl);
  font-weight: var(--weight-heading);
  line-height: 1;
  color: var(--color-primary);
}

.page-about .about-lede__text {
  margin: 0;
  align-self: center;
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: var(--color-ink);
}

/* ---------- 分段 ---------- */
.page-about .about-section {
  margin-top: var(--space-8);
  padding-top: var(--space-4);
  border-top: var(--border-thin) solid var(--color-line);
}

.page-about .about-section__head {
  display: flex;
  align-items: baseline;
  gap: var(--space-2);
  margin-bottom: var(--space-4);
}

.page-about .about-section__index {
  flex: none;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: var(--text-sm);
  letter-spacing: 0.08em;
  color: var(--color-accent);
}

.page-about .about-section__title {
  margin: 0;
  font-family: var(--font-heading);
  font-size: var(--text-xl);
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
  color: var(--color-ink);
}

.page-about .about-section__body > .about-copy {
  max-width: var(--measure);
}

.page-about .about-copy p {
  margin: 0 0 var(--space-2);
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: var(--color-ink);
}

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

.page-about .about-copy--after {
  margin-top: var(--space-4);
}

.page-about .about-link {
  color: var(--color-accent);
  font-weight: var(--weight-heading);
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-thickness: var(--border-thin);
}

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

/* ---------- 数据小模块 ---------- */
.page-about .about-note {
  margin-top: var(--space-4);
  padding: var(--space-3);
  border-radius: var(--radius-md);
  background: var(--color-surface-alt);
  box-shadow: var(--shadow-1);
}

.page-about .about-note__label {
  margin: 0 0 var(--space-2);
  font-size: var(--text-sm);
  letter-spacing: 0.04em;
  color: var(--color-ink-soft);
}

.page-about .about-note__rows {
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
}

.page-about .about-note__row {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: var(--space-2);
  padding-bottom: var(--space-1);
  border-bottom: var(--border-thin) solid var(--color-line);
}

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

.page-about .about-note__row dt {
  font-size: var(--text-sm);
  color: var(--color-ink-soft);
}

.page-about .about-note__row dd {
  margin: 0;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: var(--text-base);
  color: var(--color-ink);
}

@media (min-width: 900px) {
  .page-about .about-section__body--split {
    display: grid;
    grid-template-columns: minmax(0, 1fr) minmax(250px, 330px);
    column-gap: var(--space-6);
    align-items: start;
  }

  .page-about .about-section__body--split > .about-note {
    margin-top: var(--space-1);
  }

  .page-about .about-intro__title {
    font-size: var(--text-3xl);
  }
}

/* ---------- 四道核对 ---------- */
.page-about .about-steps {
  list-style: none;
  margin: var(--space-4) 0 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.page-about .about-steps__item {
  position: relative;
  padding: var(--space-3) 0 0;
  border-top: var(--border-thin) solid var(--color-line);
}

.page-about .about-steps__item::before {
  content: "";
  position: absolute;
  top: calc(var(--border-thin) * -1);
  left: 0;
  height: 3px;
  width: 100%;
  border-radius: var(--radius-pill);
  background: var(--color-accent);
}

.page-about .about-steps__n {
  margin: 0 0 var(--space-1);
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  letter-spacing: 0.06em;
  color: var(--color-ink-muted);
}

.page-about .about-steps__t {
  margin: 0 0 var(--space-1);
  font-family: var(--font-heading);
  font-size: var(--text-lg);
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
  color: var(--color-ink);
}

.page-about .about-steps__d {
  margin: 0;
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: var(--color-ink-soft);
}

@media (min-width: 860px) {
  .page-about .about-steps {
    flex-direction: row;
    align-items: stretch;
    gap: var(--space-3);
  }

  .page-about .about-steps__item {
    flex: 1 1 0;
    min-width: 0;
    padding-right: var(--space-2);
  }

  .page-about .about-steps__item::before {
    width: 100%;
  }

  .page-about .about-steps__item:nth-child(2)::before {
    width: 76%;
  }

  .page-about .about-steps__item:nth-child(3)::before {
    width: 56%;
  }

  .page-about .about-steps__item:nth-child(4)::before {
    width: 36%;
  }
}

/* ---------- 团队三块 ---------- */
.page-about .about-team {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-3);
  margin-top: var(--space-4);
}

.page-about .about-team__card {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
  padding: var(--space-3);
  border-radius: var(--radius-md);
  background: var(--color-surface-alt);
  box-shadow: var(--shadow-1);
}

.page-about .about-team__card:focus-visible {
  outline: 2px solid var(--color-focus);
  outline-offset: 2px;
}

.page-about .about-team__count {
  margin: 0;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: var(--text-lg);
  color: var(--color-accent);
}

.page-about .about-team__name {
  margin: 0;
  font-family: var(--font-heading);
  font-size: var(--text-lg);
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
  color: var(--color-ink);
}

.page-about .about-team__desc {
  margin: 0;
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: var(--color-ink-soft);
}

.page-about .about-team__reveal {
  margin: var(--space-1) 0 0;
  padding-top: var(--space-2);
  border-top: var(--border-thin) solid var(--color-line);
  font-size: var(--text-sm);
  line-height: var(--leading-body);
  color: var(--color-ink-muted);
}

@media (min-width: 720px) {
  .page-about .about-team {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    align-items: start;
  }

  .page-about .about-team__card:nth-child(2) {
    margin-top: var(--space-4);
  }

  .page-about .about-team__card:nth-child(3) {
    margin-top: var(--space-2);
  }
}

@media (min-width: 900px) {
  .page-about .about-team__card {
    transition: transform 0.25s ease, box-shadow 0.25s ease;
  }

  .page-about .about-team__reveal {
    max-height: 0;
    padding-top: 0;
    border-top-color: transparent;
    opacity: 0;
    overflow: hidden;
    transition: max-height 0.35s ease, opacity 0.25s ease, padding-top 0.25s ease;
  }

  .page-about .about-team__card:hover,
  .page-about .about-team__card:focus-within {
    transform: translateY(-2px);
    box-shadow: var(--shadow-2);
  }

  .page-about .about-team__card:hover .about-team__reveal,
  .page-about .about-team__card:focus-within .about-team__reveal {
    max-height: 12em;
    padding-top: var(--space-2);
    border-top-color: var(--color-line);
    opacity: 1;
  }
}

/* ---------- 阶段轴 ---------- */
.page-about .about-track {
  position: relative;
  list-style: none;
  margin: var(--space-4) 0 0;
  padding: 0 0 0 28px;
}

.page-about .about-track::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 1em;
  bottom: 1em;
  width: var(--border-thin);
  background: var(--color-line);
}

.page-about .about-track__item {
  position: relative;
  padding-bottom: var(--space-2);
}

.page-about .about-track__item::before {
  content: "";
  position: absolute;
  left: -25px;
  top: 1.05em;
  width: 9px;
  height: 9px;
  border-radius: var(--radius-pill);
  background: var(--color-accent);
  box-shadow: 0 0 0 4px var(--color-highlight);
}

.page-about .about-stage {
  border-radius: var(--radius-sm);
}

.page-about .about-stage__head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: var(--space-1) var(--space-2);
  padding: var(--space-2) var(--space-2) var(--space-2) 0;
  cursor: pointer;
  list-style: none;
}

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

.page-about .about-stage__head:focus-visible {
  outline: 2px solid var(--color-focus);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}

.page-about .about-stage__head::after {
  content: "＋";
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  color: var(--color-accent);
}

.page-about .about-stage[open] .about-stage__head::after {
  content: "－";
}

.page-about .about-stage__dot {
  display: none;
}

.page-about .about-stage__label {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: var(--text-sm);
  letter-spacing: 0.04em;
  color: var(--color-ink-muted);
}

.page-about .about-stage__title {
  font-family: var(--font-heading);
  font-size: var(--text-lg);
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
  color: var(--color-ink);
}

.page-about .about-stage__body {
  padding: 0 var(--space-2) var(--space-3) 0;
  max-width: var(--measure);
}

.page-about .about-stage__body p {
  margin: 0;
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: var(--color-ink-soft);
}

.page-about .about-stage[open] .about-stage__body {
  animation: about-fade 0.28s ease-out;
}

@keyframes about-fade {
  from {
    opacity: 0;
    transform: translateY(-4px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@media (min-width: 900px) {
  .page-about .about-track {
    padding-left: 64px;
  }

  .page-about .about-track::before {
    left: 43px;
  }
}

/* ---------- 图片 ---------- */
.page-about .about-figure {
  margin: var(--space-4) 0 0;
  max-width: 640px;
  border-radius: var(--radius-lg);
  overflow: hidden;
  background: var(--color-surface-deep);
  box-shadow: var(--shadow-1);
}

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

.page-about .about-figure__cap {
  padding: var(--space-2) var(--space-3);
  background: var(--color-surface-alt);
  font-size: var(--text-sm);
  line-height: var(--leading-body);
  color: var(--color-ink-soft);
}

@media (min-width: 900px) {
  .page-about .about-figure--wide {
    max-width: 860px;
    margin-left: auto;
  }

  .page-about .about-figure--narrow {
    max-width: 520px;
  }

  .page-about .about-figure--offset {
    margin-left: auto;
    max-width: 560px;
  }
}

/* ---------- 接下来三件事 ---------- */
.page-about .about-next {
  list-style: none;
  margin: var(--space-4) 0 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.page-about .about-next__item {
  display: flex;
  align-items: flex-start;
  gap: var(--space-3);
  padding-top: var(--space-3);
  border-top: var(--border-thin) solid var(--color-line);
}

.page-about .about-next__n {
  flex: none;
  margin: 0;
  width: 2ch;
  font-family: var(--font-mono);
  font-size: var(--text-lg);
  line-height: var(--leading-heading);
  color: var(--color-primary);
}

.page-about .about-next__t {
  margin: 0 0 var(--space-1);
  font-family: var(--font-heading);
  font-size: var(--text-lg);
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
  color: var(--color-ink);
}

.page-about .about-next__d {
  margin: 0;
  max-width: var(--measure);
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: var(--color-ink-soft);
}

/* ---------- 收尾 ---------- */
.page-about .about-outro {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  margin-top: var(--space-8);
  padding: var(--space-6) var(--space-4);
  border-radius: var(--radius-lg);
  background: var(--color-primary);
  color: var(--color-primary-ink);
  box-shadow: var(--shadow-2);
}

.page-about .about-outro__title {
  margin: 0;
  font-family: var(--font-heading);
  font-size: var(--text-xl);
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
  color: var(--color-primary-ink);
}

.page-about .about-outro__text {
  margin: 0;
  max-width: var(--measure);
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: var(--color-primary-ink);
}

.page-about .about-outro__contact {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
  padding: var(--space-3) 0;
  border-top: var(--border-thin) solid var(--color-contrast-line);
  border-bottom: var(--border-thin) solid var(--color-contrast-line);
  font-style: normal;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: var(--text-sm);
  line-height: var(--leading-body);
  color: var(--color-primary-ink);
}

.page-about .about-outro__note {
  margin: 0;
  max-width: var(--measure);
  font-size: var(--text-sm);
  line-height: var(--leading-body);
  color: var(--color-primary-ink);
}

.page-about .about-outro__link {
  color: var(--color-primary-ink);
  font-weight: var(--weight-heading);
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-thickness: var(--border-thin);
}

.page-about .about-outro__link:hover,
.page-about .about-outro__link:focus-visible {
  text-decoration-thickness: 2px;
}

.page-about .about-outro__link:focus-visible {
  outline: 2px solid var(--color-primary-ink);
  outline-offset: 2px;
}

@media (min-width: 900px) {
  .page-about .about-outro {
    padding: var(--space-8) var(--space-6);
  }
}

/* ---------- 动效退化 ---------- */
@media (prefers-reduced-motion: reduce) {
  .page-about .about-team__card,
  .page-about .about-team__reveal,
  .page-about .about-stage__body {
    transition: none;
    animation: none;
  }

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