.page-about {
  --about-axis: 4.5rem;
  --about-gap: clamp(2.5rem, 5vw, 4.5rem);
  --about-body-max: 52rem;
  background: var(--ink-900);
  color: var(--cloud);
  overflow-x: clip;
}

.page-about .about-shell {
  padding-bottom: clamp(2rem, 5vw, 4rem);
}

.page-about .about-crumbs {
  padding-block: clamp(1rem, 2.5vw, 1.75rem) 0.5rem;
}

/* ---------- 首屏 ---------- */

.page-about .about-hero {
  padding-block: clamp(1.5rem, 4vw, 3rem) clamp(1.5rem, 3vw, 2.25rem);
}

.page-about .about-hero__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1.25rem;
}

.page-about .about-hero__eyebrow {
  margin: 0 0 0.85rem;
  font-size: 0.72rem;
  letter-spacing: 0.35em;
  color: var(--celadon-soft);
}

.page-about .about-hero__title {
  margin: 0 0 1.35rem;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(2.35rem, 7.2vw, 5.25rem);
  line-height: 1.04;
  letter-spacing: -0.02em;
  color: var(--white);
  max-width: 16em;
}

.page-about .about-hl {
  color: var(--amber);
  box-shadow: inset 0 -0.14em 0 rgba(228, 145, 58, 0.42);
}

.page-about .about-hero__lede {
  margin: 0 0 1.6rem;
  max-width: 36em;
  font-size: 1.0625rem;
  line-height: 1.9;
  color: var(--cloud);
}

.page-about .about-hero__chips {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
  margin: 0 0 1.75rem;
  padding: 0;
}

.page-about .about-chip {
  padding: 0.45rem 0.95rem;
  border: 1px solid var(--line-mid);
  border-radius: 999px;
  background: rgba(20, 41, 62, 0.6);
  font-size: 0.8125rem;
  letter-spacing: 0.02em;
  color: var(--cloud);
}

.page-about .about-chip--amber {
  border-color: var(--line-amber);
  color: var(--amber-soft);
}

.page-about .about-chip--celadon {
  border-color: var(--line-celadon);
  color: var(--celadon-soft);
}

.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}

.page-about .about-hero__vertical {
  display: none;
  margin: 0;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.34em;
  color: var(--moss);
  writing-mode: vertical-rl;
  transform: rotate(180deg);
  justify-self: end;
}

/* ---------- 图片区 ---------- */

.page-about .about-figure {
  margin: 0 0 clamp(1.5rem, 3vw, 2.5rem);
  overflow: hidden;
  border-radius: var(--radius);
  background: var(--ink-700);
}

.page-about .about-figure--wide {
  margin-block: clamp(1.5rem, 3.5vw, 2.75rem) clamp(2rem, 4vw, 3rem);
  aspect-ratio: 16 / 9;
}

.page-about .about-figure--photo {
  margin-block: clamp(1.75rem, 3.5vw, 2.5rem) 0;
  aspect-ratio: 3 / 2;
}

.page-about .about-figure--band {
  margin-block: 1.75rem 0;
  aspect-ratio: 7 / 3;
}

.page-about .about-figure .media-frame__img {
  width: 100%;
  height: 100%;
  max-width: 100%;
  object-fit: cover;
}

/* ---------- 章节骨架 ---------- */

.page-about .about-flow {
  position: relative;
  padding-top: clamp(0.5rem, 2vw, 1.5rem);
}

.page-about .about-chapter {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1rem;
  padding-block: var(--about-gap);
}

.page-about .about-chapter__mark {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  color: var(--moss);
}

.page-about .about-chapter__mark--moss { color: var(--moss); }
.page-about .about-chapter__mark--celadon { color: var(--celadon); }
.page-about .about-chapter__mark--amber { color: var(--amber); }

.page-about .about-chapter__num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(1.6rem, 3.2vw, 2.4rem);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.02em;
  color: inherit;
}

.page-about .about-chapter__dot {
  flex: none;
  color: inherit;
}

.page-about .about-chapter__stage {
  font-size: 0.7rem;
  letter-spacing: 0.3em;
  color: var(--cloud);
  opacity: 0.72;
  white-space: nowrap;
}

.page-about .about-chapter__body {
  max-width: var(--about-body-max);
}

.page-about .about-chapter__body > h2 {
  margin: 0 0 1.2rem;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(1.6rem, 3.6vw, 2.6rem);
  line-height: 1.22;
  letter-spacing: -0.01em;
  color: var(--white);
  max-width: 20em;
}

.page-about .about-chapter__body > p {
  margin: 0 0 1.15rem;
  max-width: 38em;
  font-size: 1.0625rem;
  line-height: 1.88;
  color: var(--cloud);
}

/* ---------- 人群卡片 ---------- */

.page-about .about-cards {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1rem;
  margin: 1.75rem 0 1.5rem;
}

.page-about .about-card {
  padding: 1.4rem 1.5rem 1.5rem;
  border: 1px solid var(--line-mid);
  border-radius: var(--radius);
  background: var(--ink-700);
  transition: background-color 0.2s var(--ease), border-color 0.2s var(--ease);
}

.page-about .about-card:hover {
  background: var(--ink-600);
  border-color: var(--line-amber);
}

.page-about .about-card__title {
  margin: 0 0 0.6rem;
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--celadon-soft);
}

.page-about .about-card p {
  margin: 0;
  font-size: 0.95rem;
  line-height: 1.8;
  color: var(--cloud);
}

.page-about .about-stats {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(12rem, 1fr));
  gap: 1.25rem;
  margin-top: 1.75rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--line-soft);
}

.page-about .about-stat {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.page-about .about-stat__num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(1.9rem, 4vw, 2.6rem);
  font-weight: 700;
  line-height: 1;
  color: var(--amber-soft);
}

.page-about .about-stat__label {
  max-width: 18em;
  font-size: 0.875rem;
  line-height: 1.7;
  color: var(--cloud);
  opacity: 0.82;
}

/* ---------- 三类问题 ---------- */

.page-about .about-paths {
  list-style: none;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1rem;
  margin: 1.75rem 0 1.5rem;
  padding: 0;
}

.page-about .about-path {
  padding: 1.3rem 1.35rem 1.5rem;
  border: 1px solid var(--line-soft);
  border-top: 3px solid var(--celadon);
  border-radius: 0 0 var(--radius) var(--radius);
  background: rgba(20, 41, 62, 0.5);
  transition: background-color 0.2s var(--ease), border-color 0.2s var(--ease);
}

.page-about .about-path:nth-child(2) { border-top-color: var(--amber); }
.page-about .about-path:nth-child(3) { border-top-color: var(--moss); }

.page-about .about-path:hover {
  background: rgba(43, 55, 66, 0.72);
  border-color: var(--line-amber);
}

.page-about .about-path__kicker {
  display: inline-block;
  margin-bottom: 0.55rem;
  font-size: 0.72rem;
  letter-spacing: 0.26em;
  color: var(--amber-soft);
}

.page-about .about-path__title {
  margin: 0 0 0.6rem;
  font-size: 1rem;
  font-weight: 700;
  color: var(--white);
}

.page-about .about-path p {
  margin: 0;
  font-size: 0.925rem;
  line-height: 1.78;
  color: var(--cloud);
}

/* ---------- 团队 ---------- */

.page-about .about-crew {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1rem;
  margin: 1.5rem 0 0;
}

.page-about .about-crew__item {
  padding: 1.4rem 1.5rem 1.55rem;
  border: 1px solid rgba(198, 205, 212, 0.1);
  border-left: 3px solid var(--moss);
  border-radius: 0 var(--radius) var(--radius) 0;
  background: var(--ink-600);
  transition: border-color 0.2s var(--ease), background-color 0.2s var(--ease);
}

.page-about .about-crew__item:nth-child(2) { border-left-color: var(--celadon); }
.page-about .about-crew__item:nth-child(3) { border-left-color: var(--amber); }
.page-about .about-crew__item:nth-child(4) { border-left-color: var(--clay); }

.page-about .about-crew__item:hover {
  background: var(--ink-700);
  border-color: var(--line-amber);
}

.page-about .about-crew__item h3 {
  margin: 0 0 0.55rem;
  font-size: 1.02rem;
  font-weight: 700;
  color: var(--white);
}

.page-about .about-crew__item p {
  margin: 0;
  font-size: 0.925rem;
  line-height: 1.8;
  color: var(--cloud);
}

/* ---------- 时间轴 ---------- */

.page-about .about-timeline {
  position: relative;
  list-style: none;
  display: grid;
  gap: 1.1rem;
  margin: 1.75rem 0 0;
  padding: 0 0 0 1.6rem;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.7rem;
  bottom: 0.7rem;
  width: 2px;
  border-radius: 2px;
  background: linear-gradient(to bottom, var(--moss), var(--celadon) 48%, var(--amber));
  opacity: 0.58;
}

.page-about .about-node {
  position: relative;
  padding: 0.95rem 1.15rem 1.1rem;
  border: 1px solid transparent;
  border-radius: 0.85rem;
  transition: background-color 0.2s var(--ease), border-color 0.2s var(--ease);
}

.page-about .about-node::before {
  content: "";
  position: absolute;
  left: -1.6rem;
  top: 1.55rem;
  width: 0.7rem;
  height: 0.7rem;
  border-radius: 50%;
  transform: translate(-50%, -50%);
  background: var(--ink-900);
  border: 2px solid var(--moss);
  transition: background-color 0.2s var(--ease), border-color 0.2s var(--ease);
}

.page-about .about-node:nth-child(2)::before { border-color: var(--celadon); }
.page-about .about-node:nth-child(3)::before { border-color: var(--amber); }
.page-about .about-node:nth-child(4)::before { border-color: var(--moss); }
.page-about .about-node:nth-child(5)::before { border-color: var(--celadon); }
.page-about .about-node:nth-child(6)::before { border-color: var(--amber); }

.page-about .about-node:hover,
.page-about .about-node:focus-within {
  background: rgba(20, 41, 62, 0.85);
  border-color: var(--line-amber);
}

.page-about .about-node:hover::before,
.page-about .about-node:focus-within::before {
  background: var(--amber);
  border-color: var(--amber);
}

.page-about .about-node__phase {
  display: inline-block;
  margin-bottom: 0.35rem;
  font-size: 0.72rem;
  letter-spacing: 0.24em;
  color: var(--celadon-soft);
}

.page-about .about-node__title {
  margin: 0 0 0.4rem;
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--white);
}

.page-about .about-node__text {
  margin: 0;
  max-width: 40em;
  font-size: 0.925rem;
  line-height: 1.8;
  color: var(--cloud);
}

/* ---------- 价值主张 ---------- */

.page-about .about-why {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1rem;
  margin-top: 1.75rem;
}

.page-about .about-why__card {
  padding: 1.6rem 1.5rem 1.8rem;
  border: 1px solid rgba(198, 205, 212, 0.12);
  border-radius: var(--radius);
  background: var(--ink-600);
  transition: background-color 0.25s var(--ease), border-color 0.25s var(--ease);
}

.page-about .about-why__card:hover {
  background: var(--ink-700);
  border-color: var(--line-amber);
}

.page-about .about-why__card h3 {
  margin: 0 0 1rem;
  font-family: var(--font-display);
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--white);
}

.page-about .about-why__card h3::after {
  content: "";
  display: block;
  width: 1.75rem;
  height: 2px;
  margin-top: 0.75rem;
  background: var(--amber);
}

.page-about .about-why__card p {
  margin: 0;
  font-size: 0.925rem;
  line-height: 1.8;
  color: var(--cloud);
}

/* ---------- 收尾 ---------- */

.page-about .about-cta {
  margin-top: clamp(1.5rem, 4vw, 2.5rem);
  padding: clamp(1.75rem, 4vw, 3rem);
  border: 1px solid var(--line-celadon);
  border-radius: 1.2rem;
  background: linear-gradient(140deg, rgba(92, 143, 123, 0.2), rgba(20, 41, 62, 0.9) 58%);
}

.page-about .about-cta h2 {
  margin: 0 0 0.85rem;
  font-family: var(--font-display);
  font-size: clamp(1.4rem, 3.2vw, 2rem);
  font-weight: 700;
  line-height: 1.25;
  color: var(--white);
}

.page-about .about-cta p {
  margin: 0 0 1.6rem;
  max-width: 36em;
  font-size: 1rem;
  line-height: 1.85;
  color: var(--cloud);
}

.page-about .about-cta__links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}

/* ---------- 中等屏幕 ---------- */

@media (min-width: 640px) {
  .page-about .about-cards {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 760px) {
  .page-about .about-paths {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

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

  .page-about .about-crew {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 1.25rem;
    padding-bottom: 2.25rem;
  }

  .page-about .about-crew__item:nth-child(2n) {
    margin-top: 2.25rem;
  }
}

/* ---------- 桌面：纵向时间轴贯穿全页 ---------- */

@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: start;
    gap: 0 2.75rem;
  }

  .page-about .about-hero__vertical {
    display: block;
  }

  .page-about .about-flow::before {
    content: "";
    position: absolute;
    left: calc(var(--about-axis) / 2);
    top: 2.5rem;
    bottom: 3rem;
    width: 1px;
    background: linear-gradient(
      to bottom,
      transparent,
      var(--line-celadon) 5%,
      var(--line-celadon) 95%,
      transparent
    );
  }

  .page-about .about-chapter {
    grid-template-columns: var(--about-axis) minmax(0, 1fr);
    gap: 0 3rem;
  }

  .page-about .about-chapter__mark {
    position: sticky;
    top: 6rem;
    align-self: start;
    flex-direction: column;
    align-items: center;
    gap: 0.7rem;
    padding: 0.6rem 0;
    background: var(--ink-900);
  }

  .page-about .about-timeline {
    padding-left: 1.9rem;
  }

  .page-about .about-node::before {
    left: -1.9rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-card,
  .page-about .about-path,
  .page-about .about-crew__item,
  .page-about .about-node,
  .page-about .about-node::before,
  .page-about .about-why__card {
    transition: none;
  }
}