.page-about {
  --about-rail-w: 208px;
  --about-gap: clamp(30px, 5vw, 72px);
  --about-cell-bg: #0A1A2B;
}

/* ---------- 面包屑 ---------- */
.page-about .about-crumb {
  padding-top: clamp(20px, 3vw, 34px);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding: clamp(26px, 4.5vw, 54px) 0 clamp(30px, 5vw, 58px);
  border-bottom: 1px solid var(--line);
}

.page-about .about-hero__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(26px, 4vw, 44px);
}

.page-about .about-hero__title {
  margin: 0.22em 0 0.4em;
  max-width: 17ch;
  font-family: var(--font-display);
  letter-spacing: -0.01em;
}

.page-about .about-hero__lead {
  max-width: 44ch;
  color: var(--paper);
}

.page-about .about-hero__media {
  border: 1px solid var(--line);
}

.page-about .about-hero__stats {
  list-style: none;
  margin: clamp(28px, 4vw, 42px) 0 0;
  padding: clamp(20px, 3vw, 28px) 0 0;
  border-top: 1px solid var(--line);
  display: flex;
  flex-wrap: wrap;
  gap: clamp(22px, 4vw, 52px);
}

.page-about .about-stat__num {
  display: block;
  font-family: var(--font-num);
  font-size: clamp(1.45rem, 2.6vw, 2.15rem);
  line-height: 1;
  color: var(--amber);
}

.page-about .about-stat__label {
  display: block;
  margin-top: 8px;
  font-size: var(--fs-small);
  color: var(--mist);
}

/* ---------- 双栏骨架 ---------- */
.page-about .about-body {
  margin-top: clamp(40px, 6vw, 80px);
}

.page-about .about-split {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 32px;
}

.page-about .about-split > * {
  min-width: 0;
}

.page-about .about-flow {
  min-width: 0;
}

.page-about .about-rail .rail__title {
  margin: 0 0 14px;
  font-family: var(--font-num);
  font-size: 0.78rem;
  letter-spacing: 0.22em;
  color: var(--mist);
}

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

.page-about .about-rail .rail__link {
  display: block;
  padding: 9px 0 9px 14px;
  border-left: 1px solid var(--line);
  font-size: 0.92rem;
  line-height: 1.5;
  color: var(--mist);
  text-decoration: none;
  transition: color 0.3s var(--ease), border-color 0.3s var(--ease);
}

.page-about .about-rail .rail__link:hover,
.page-about .about-rail .rail__link[aria-current="true"] {
  color: var(--paper);
  border-left-color: var(--amber);
}

/* ---------- 章节 ---------- */
.page-about .about-sec {
  padding: clamp(38px, 5.5vw, 68px) 0;
  border-top: 1px solid var(--line);
}

.page-about .about-sec--first {
  border-top: 0;
  padding-top: 0;
}

.page-about .about-sec__head .section__eyebrow {
  letter-spacing: 0.2em;
  color: var(--clay);
}

.page-about .about-h2 {
  margin: 0.42em 0 0;
  max-width: 24ch;
  font-family: var(--font-display);
  font-size: var(--fs-h2);
  line-height: 1.26;
  color: var(--paper);
}

.page-about .about-sec__body {
  margin-top: clamp(20px, 3vw, 32px);
}

.page-about .about-prose p {
  max-width: 46ch;
  margin: 0 0 1em;
  color: var(--paper);
}

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

.page-about .about-pull {
  position: relative;
  margin: clamp(22px, 3vw, 34px) 0 0;
  padding-left: clamp(16px, 2vw, 24px);
  border-left: 2px solid var(--amber);
  max-width: 30ch;
  font-family: var(--font-display);
  font-size: clamp(1.08rem, 1.9vw, 1.42rem);
  line-height: 1.62;
  color: var(--paper);
}

/* ---------- 归档编号块 ---------- */
.page-about .archive-grid {
  list-style: none;
  margin: clamp(26px, 3.6vw, 42px) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .archive-cell {
  position: relative;
  background: var(--about-cell-bg);
  padding: clamp(20px, 2.4vw, 30px);
  transition: background-color 0.4s var(--ease);
}

.page-about .archive-cell:hover,
.page-about .archive-cell:focus-within {
  background: var(--indigo);
}

.page-about .archive-cell__num {
  display: block;
  font-family: var(--font-num);
  font-size: clamp(1.35rem, 2.2vw, 1.85rem);
  line-height: 1;
  color: var(--clay);
}

.page-about .archive-cell__title {
  margin: 0.7em 0 0.45em;
  font-family: var(--font-display);
  font-size: var(--fs-h3);
  color: var(--paper);
}

.page-about .archive-cell__desc {
  margin: 0;
  font-size: 0.95rem;
  line-height: 1.72;
  color: var(--mist);
  max-width: 26ch;
}

.page-about .archive-cell__hint {
  margin: 12px 0 0;
  font-family: var(--font-num);
  font-size: var(--fs-small);
  letter-spacing: 0.04em;
  color: var(--river);
  opacity: 0;
  transform: translateY(-4px);
  transition: opacity 0.3s var(--ease), transform 0.3s var(--ease);
}

.page-about .archive-cell:hover .archive-cell__hint,
.page-about .archive-cell:focus-within .archive-cell__hint {
  opacity: 1;
  transform: translateY(0);
}

@media (hover: none) {
  .page-about .archive-cell__hint {
    opacity: 1;
    transform: none;
  }
}

/* ---------- 归档配图 ---------- */
.page-about .about-media-row {
  margin-top: clamp(26px, 4vw, 44px);
}

.page-about .about-archive__media {
  max-width: 680px;
  border: 1px solid var(--line);
}

/* ---------- 行业方向 ---------- */
.page-about .trade-block {
  margin-top: clamp(30px, 4vw, 48px);
  padding-top: clamp(22px, 3vw, 32px);
  border-top: 1px solid var(--line);
}

.page-about .about-sub {
  margin: 0 0 0.5em;
  font-family: var(--font-display);
  font-size: var(--fs-h3);
  color: var(--paper);
}

.page-about .about-note {
  margin: 0 0 1em;
  max-width: 48ch;
  font-size: var(--fs-small);
  line-height: 1.8;
  color: var(--mist);
}

.page-about .trade-row {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.page-about .trade {
  font-family: var(--font-num);
  font-size: 0.88rem;
  letter-spacing: 0.05em;
  padding: 8px 16px;
  border: 1px solid var(--line);
  color: var(--paper);
  cursor: default;
  transition: background-color 0.3s var(--ease), border-color 0.3s var(--ease);
}

.page-about .trade:hover {
  background: var(--teal-deep);
  border-color: var(--river);
}

/* ---------- 更新节奏 ---------- */
.page-about .cadence {
  list-style: none;
  margin: clamp(24px, 3.4vw, 40px) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--line);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.page-about .cadence__item {
  background: var(--ink);
  padding: clamp(18px, 2.2vw, 26px) clamp(14px, 1.6vw, 20px);
}

.page-about .cadence__num {
  display: block;
  margin-bottom: 0.4em;
  font-family: var(--font-num);
  font-size: clamp(1.4rem, 2.4vw, 2rem);
  line-height: 1;
  color: var(--amber);
}

.page-about .cadence__text {
  display: block;
  font-size: var(--fs-small);
  line-height: 1.75;
  color: var(--mist);
}

.page-about .cadence__text strong {
  color: var(--paper);
  font-weight: 600;
}

/* ---------- 流程 ---------- */
.page-about .flow {
  list-style: none;
  margin: clamp(26px, 3.6vw, 40px) 0 0;
  padding: 0;
  border-top: 1px solid var(--line);
}

.page-about .flow__step {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: clamp(14px, 2.4vw, 28px);
  align-items: start;
  padding: clamp(16px, 2.2vw, 24px) 0;
  border-bottom: 1px solid var(--line);
}

.page-about .flow__no {
  font-family: var(--font-num);
  font-size: clamp(1.25rem, 2.1vw, 1.85rem);
  line-height: 1;
  padding-top: 0.12em;
  color: var(--clay);
}

.page-about .flow__title {
  margin: 0 0 0.4em;
  font-family: var(--font-display);
  font-size: var(--fs-h3);
  color: var(--paper);
}

.page-about .flow__body p {
  margin: 0;
  max-width: 52ch;
  color: var(--mist);
  line-height: 1.8;
}

/* ---------- 里程碑纸带 ---------- */
.page-about .about-band {
  margin-top: clamp(26px, 3.6vw, 42px);
}

.page-about .about-band .band__track {
  display: flex;
  gap: clamp(14px, 2vw, 22px);
  overflow-x: auto;
  padding: 4px 0 16px;
  scroll-snap-type: x proximity;
  list-style: none;
  margin: 0;
}

.page-about .about-band .band__track:focus-visible {
  outline: 1px solid var(--amber);
  outline-offset: 4px;
}

.page-about .about-milestone {
  flex: 0 0 min(80vw, 320px);
  scroll-snap-align: start;
  background: var(--indigo);
  border: 1px solid var(--line);
  padding: clamp(20px, 2.6vw, 28px);
}

.page-about .band__item--wide.about-milestone {
  flex-basis: min(86vw, 400px);
}

.page-about .about-milestone--now {
  border-left: 2px solid var(--river);
}

.page-about .about-milestone__tag {
  margin: 0;
  font-size: var(--fs-small);
  letter-spacing: 0.16em;
  color: var(--mist);
}

.page-about .about-milestone__no {
  margin: 0.45em 0 0.5em;
  font-family: var(--font-num);
  font-size: clamp(1.8rem, 3.4vw, 2.6rem);
  line-height: 1;
  color: var(--amber);
}

.page-about .about-milestone__title {
  margin: 0 0 0.6em;
  font-family: var(--font-display);
  font-size: var(--fs-h3);
  line-height: 1.42;
  color: var(--paper);
}

.page-about .about-milestone__text {
  margin: 0;
  font-size: 0.95rem;
  line-height: 1.78;
  color: var(--mist);
}

/* ---------- 地域 ---------- */
.page-about .about-local__media {
  margin-top: clamp(24px, 3.4vw, 40px);
  border: 1px solid var(--line);
}

/* ---------- 延伸入口 ---------- */
.page-about .about-cta {
  margin-top: clamp(30px, 4vw, 50px);
  padding: clamp(34px, 5vw, 60px) 0 clamp(20px, 3vw, 40px);
  border-top: 1px solid var(--line);
}

.page-about .about-cta__grid {
  margin-top: clamp(20px, 3vw, 30px);
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-cta__link {
  display: flex;
  flex-direction: column;
  gap: 0.45em;
  background: var(--ink);
  padding: clamp(18px, 2.2vw, 26px);
  text-decoration: none;
  color: var(--paper);
  transition: background-color 0.35s var(--ease);
}

.page-about .about-cta__link:hover {
  background: var(--indigo);
}

.page-about .about-cta__no {
  font-family: var(--font-num);
  font-size: 0.82rem;
  letter-spacing: 0.14em;
  color: var(--clay);
}

.page-about .about-cta__label {
  font-family: var(--font-display);
  font-size: var(--fs-h3);
}

.page-about .about-cta__desc {
  font-size: var(--fs-small);
  line-height: 1.7;
  color: var(--mist);
}

/* ---------- 响应式 ---------- */
@media (min-width: 700px) {
  .page-about .archive-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

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

@media (min-width: 900px) {
  .page-about .about-split {
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
    gap: var(--about-gap);
    align-items: start;
  }

  .page-about .about-rail {
    position: sticky;
    top: calc(var(--header-h) + 28px);
    align-self: start;
  }
}

@media (min-width: 1040px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.18fr) minmax(0, 0.82fr);
    align-items: center;
    gap: clamp(40px, 5vw, 76px);
  }

  .page-about .archive-grid {
    grid-template-columns: 1.25fr 1fr 1fr 1.25fr 1fr;
  }

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

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

/* ---------- 动效降级 ---------- */
@media (prefers-reduced-motion: reduce) {
  .page-about .archive-cell,
  .page-about .trade,
  .page-about .about-cta__link,
  .page-about .archive-cell__hint,
  .page-about .about-rail .rail__link {
    transition-duration: 0.12s;
  }

  .page-about .archive-cell__hint {
    transform: none;
  }

  .page-about .about-band .band__track {
    scroll-behavior: auto;
  }
}