.page-about {
  position: relative;
  background: var(--pitch-900);
  isolation: isolate;
}

.page-about::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background-image:
    linear-gradient(var(--line-soft) 1px, transparent 1px),
    linear-gradient(90deg, var(--line-soft) 1px, transparent 1px);
  background-size: 76px 76px;
  opacity: .28;
  -webkit-mask-image: linear-gradient(to bottom, #000 0, #000 46%, transparent 76%);
  mask-image: linear-gradient(to bottom, #000 0, #000 46%, transparent 76%);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding: clamp(1.6rem, 4vw, 3rem) 0 clamp(2rem, 5vw, 3.4rem);
}

.page-about .about-hero__inner,
.page-about .about-banner,
.page-about .about-body {
  max-width: var(--shell);
  margin-inline: auto;
  padding-inline: var(--gut);
}

.page-about .about-hero__eyebrow {
  margin: 1.6rem 0 0;
  font-family: var(--font-mono);
  font-size: .78rem;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--mint);
}

.page-about .about-hero h1 {
  margin: .9rem 0 0;
  font-family: var(--font-sans);
  font-weight: 900;
  font-size: clamp(2rem, 5.6vw, 4rem);
  line-height: 1.18;
  letter-spacing: -.015em;
  color: var(--ink);
  max-width: 20ch;
}

.page-about .about-hero__lead {
  margin: 1.2rem 0 0;
  max-width: 62ch;
  font-size: clamp(.95rem, 1.4vw, 1.05rem);
  line-height: 1.9;
  color: var(--mist);
}

.page-about .about-hero__facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: clamp(1.8rem, 4vw, 2.8rem) 0 0;
  padding: 0;
  background: var(--grid);
  border-block: 1px solid var(--line);
}

.page-about .about-hero__facts > div {
  background: var(--pitch-900);
  padding: .95rem 1rem 1.05rem;
}

.page-about .about-hero__facts dt {
  font-size: .72rem;
  letter-spacing: .14em;
  color: var(--mist);
}

.page-about .about-hero__facts dd {
  margin: .4rem 0 0;
  font-family: var(--font-mono);
  font-size: clamp(1.5rem, 3.4vw, 2rem);
  font-weight: 800;
  color: var(--ink);
  font-variant-numeric: tabular-nums;
}

/* ---------- 宽幅开篇图 ---------- */
.page-about .about-banner {
  margin-bottom: clamp(2.4rem, 6vw, 4.6rem);
}

.page-about .about-banner .figure {
  margin: 0;
}

.page-about .about-banner .figure__media {
  aspect-ratio: 16 / 9;
  overflow: hidden;
  border: 1px solid var(--line);
  background: var(--pitch-800);
}

.page-about .about-banner .figure__media img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.page-about .figure__caption {
  margin: .85rem 0 0;
  font-size: .82rem;
  line-height: 1.7;
  color: var(--mist);
}

/* ---------- 非对称分栏 ---------- */
.page-about .about-body {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(1.4rem, 4vw, 2.4rem);
  padding-bottom: clamp(3rem, 8vw, 6rem);
}

.page-about .about-rail__title {
  margin: 0 0 .7rem;
  font-family: var(--font-mono);
  font-size: .72rem;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--mint);
}

.page-about .year-list {
  list-style: none;
  margin: 0;
  padding: 0 0 .3rem;
  display: flex;
  gap: .5rem;
  overflow-x: auto;
  scrollbar-width: none;
}

.page-about .year-list::-webkit-scrollbar {
  display: none;
}

.page-about .year-list li {
  flex: 0 0 auto;
}

.page-about .year-list a {
  display: inline-flex;
  align-items: center;
  gap: .45rem;
  padding: .42rem .85rem;
  border: 1px solid var(--line);
  border-radius: 999px;
  color: var(--mist);
  text-decoration: none;
  white-space: nowrap;
  transition: color .2s var(--ease), background-color .2s var(--ease), border-color .2s var(--ease);
}

.page-about .year-list a:hover,
.page-about .year-list a:focus-visible {
  color: var(--pitch-900);
  background: var(--cyan);
  border-color: var(--cyan);
}

.page-about .year-list__num {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: .85rem;
  color: var(--cyan);
  font-variant-numeric: tabular-nums;
}

.page-about .year-list a:hover .year-list__num,
.page-about .year-list a:focus-visible .year-list__num {
  color: var(--pitch-900);
}

.page-about .year-list__txt {
  display: none;
  font-size: .75rem;
  letter-spacing: .04em;
}

/* ---------- 章节流 ---------- */
.page-about .about-stream {
  display: grid;
  gap: clamp(2.6rem, 6vw, 4.4rem);
  min-width: 0;
}

.page-about .stage {
  scroll-margin-top: 96px;
  border-top: 1px solid var(--line);
  padding-top: clamp(1.4rem, 3vw, 2rem);
}

.page-about .stage__head {
  display: grid;
  grid-template-columns: auto 1fr;
  grid-template-areas:
    "num year"
    "num title";
  column-gap: clamp(1rem, 3vw, 2rem);
  align-items: start;
}

.page-about .stage__num {
  grid-area: num;
  font-family: var(--font-mono);
  font-size: clamp(2.4rem, 7vw, 4.2rem);
  font-weight: 800;
  line-height: 1;
  letter-spacing: -.03em;
  color: rgba(124, 247, 212, .16);
  font-variant-numeric: tabular-nums;
}

.page-about .stage__year {
  grid-area: year;
  margin: 0 0 .5rem;
  font-family: var(--font-mono);
  font-size: .76rem;
  letter-spacing: .16em;
  color: var(--mint);
}

.page-about .stage__title {
  grid-area: title;
  margin: 0;
  font-size: clamp(1.35rem, 3.2vw, 2.1rem);
  font-weight: 800;
  line-height: 1.3;
  letter-spacing: -.01em;
  color: var(--ink);
  max-width: 24ch;
}

.page-about .stage__body {
  margin: clamp(1.1rem, 2.6vw, 1.6rem) 0 0;
  display: grid;
  gap: .95rem;
  max-width: 68ch;
}

.page-about .stage__body p {
  margin: 0;
  font-size: clamp(.93rem, 1.3vw, 1rem);
  line-height: 1.9;
  color: var(--mist);
}

.page-about .stage__body p:first-child {
  color: var(--ink);
}

.page-about .stage__body strong {
  color: var(--cyan);
  font-weight: 700;
}

/* ---------- 数据条 ---------- */
.page-about .fact-panel {
  list-style: none;
  margin: clamp(1.3rem, 3vw, 1.9rem) 0 0;
  padding: 0;
  display: grid;
  gap: 1px;
  max-width: 68ch;
  background: var(--grid);
  border: 1px solid var(--line);
}

.page-about .fact-panel li {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
  padding: .8rem 1rem;
  background: var(--pitch-800);
}

.page-about .fact-panel__k {
  font-size: .78rem;
  letter-spacing: .1em;
  color: var(--mist);
}

.page-about .fact-panel__v {
  font-family: var(--font-mono);
  font-size: .92rem;
  font-weight: 700;
  color: var(--cyan);
  text-align: right;
  font-variant-numeric: tabular-nums;
}

/* ---------- 图表 ---------- */
.page-about .growth {
  margin: clamp(1.4rem, 3vw, 2rem) 0 0;
  max-width: 68ch;
  border: 1px solid var(--line);
  background: var(--pitch-800);
  padding: 1.1rem 1rem .9rem;
}

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

.page-about .growth__label {
  font-family: var(--font-mono);
  font-size: 10px;
  fill: var(--mist);
  letter-spacing: .08em;
}

.page-about .growth__note {
  margin: .75rem 0 0;
  font-size: .8rem;
  line-height: 1.7;
  color: var(--mist);
}

/* ---------- 章节配图 ---------- */
.page-about .about-team__fig,
.page-about .about-partner__fig {
  margin: clamp(1.4rem, 3vw, 2rem) 0 0;
}

.page-about .about-team__fig .figure__media,
.page-about .about-partner__fig .figure__media {
  overflow: hidden;
  border: 1px solid var(--line);
  background: var(--pitch-800);
}

.page-about .about-team__fig .figure__media {
  aspect-ratio: 3 / 2;
}

.page-about .about-partner__fig .figure__media {
  aspect-ratio: 2 / 1;
}

.page-about .about-team__fig .figure__media img,
.page-about .about-partner__fig .figure__media img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

/* ---------- 收束 CTA ---------- */
.page-about .about-cta {
  position: relative;
  margin-top: clamp(.6rem, 2vw, 1.2rem);
  padding: clamp(1.6rem, 4vw, 2.6rem) clamp(1.2rem, 3vw, 2.2rem);
  background:
    linear-gradient(135deg, rgba(18, 60, 44, .9), rgba(6, 20, 15, .95));
  border: 1px solid var(--line);
}

.page-about .about-cta::after {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 72px;
  height: 3px;
  background: linear-gradient(90deg, var(--cyan), var(--flare));
}

.page-about .about-cta__eyebrow {
  margin: 0;
  font-family: var(--font-mono);
  font-size: .74rem;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--mint);
}

.page-about .about-cta__title {
  margin: .7rem 0 0;
  font-size: clamp(1.3rem, 3vw, 1.9rem);
  font-weight: 800;
  line-height: 1.32;
  color: var(--ink);
  max-width: 24ch;
}

.page-about .about-cta__lead {
  margin: .85rem 0 0;
  max-width: 60ch;
  font-size: .93rem;
  line-height: 1.85;
  color: var(--mist);
}

.page-about .about-cta__links {
  display: flex;
  flex-wrap: wrap;
  gap: .7rem;
  margin-top: 1.4rem;
}

/* ---------- 页脚前注脚 ---------- */
.page-about .about-footnote {
  margin: 0;
  padding-top: .4rem;
}

.page-about .to-top {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: .78rem;
  letter-spacing: .12em;
  color: var(--mist);
  text-decoration: none;
  border-bottom: 1px solid var(--line);
  padding-bottom: .2rem;
  transition: color .2s var(--ease), border-color .2s var(--ease);
}

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

/* ---------- 入场 ---------- */
.page-about [data-reveal] {
  opacity: 1;
  transform: none;
  transition: opacity .24s var(--ease), transform .24s var(--ease);
}

/* ---------- 平板及以上 ---------- */
@media (min-width: 720px) {
  .page-about .about-hero__facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

/* ---------- 桌面端：左侧粘性索引 ---------- */
@media (min-width: 1080px) {
  .page-about .about-body {
    grid-template-columns: 210px minmax(0, 1fr);
    gap: clamp(2.4rem, 5vw, 4.6rem);
  }

  .page-about .about-rail {
    position: sticky;
    top: 104px;
    align-self: start;
  }

  .page-about .year-list {
    display: grid;
    gap: 0;
    overflow: visible;
    padding: 0;
    border-left: 1px solid var(--line);
  }

  .page-about .year-list li {
    flex: none;
  }

  .page-about .year-list a {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    gap: .2rem;
    border: 0;
    border-radius: 0;
    padding: .68rem 0 .68rem 1.05rem;
    position: relative;
    background: none;
    color: var(--mist);
  }

  .page-about .year-list a::before {
    content: "";
    position: absolute;
    left: -4.5px;
    top: 1.15rem;
    width: 8px;
    height: 8px;
    background: var(--pitch-700);
    transform: rotate(45deg);
    transition: background-color .2s var(--ease);
  }

  .page-about .year-list a:hover,
  .page-about .year-list a:focus-visible {
    background: none;
    color: var(--ink);
    border-color: transparent;
  }

  .page-about .year-list a:hover::before,
  .page-about .year-list a:focus-visible::before {
    background: var(--cyan);
  }

  .page-about .year-list__num {
    font-size: .9rem;
    color: var(--cyan);
  }

  .page-about .year-list a:hover .year-list__num,
  .page-about .year-list a:focus-visible .year-list__num {
    color: var(--cyan);
  }

  .page-about .year-list__txt {
    display: block;
    color: var(--mist);
  }

  .page-about .stage__head {
    grid-template-columns: 5.6rem 1fr;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about *,
  .page-about *::before,
  .page-about *::after {
    transition-duration: .01ms !important;
    animation-duration: .01ms !important;
  }
}