.page-about {
  --about-rail-w: 14rem;
  --about-gap: clamp(2rem, 5vw, 4.5rem);
  position: relative;
  color: var(--white);
  background: var(--abyss);
}

/* ---------- 面包屑 ---------- */
.page-about .about-crumbs {
  display: flex;
  align-items: center;
  gap: .5rem;
  padding-top: 1.4rem;
  padding-bottom: .4rem;
  font-family: var(--font-mono);
  font-size: .74rem;
  letter-spacing: .08em;
  color: var(--mist);
}
.page-about .about-crumbs a {
  color: var(--mist);
  text-decoration: none;
  border-bottom: 1px solid var(--line);
  transition: color .2s var(--ease), border-color .2s var(--ease);
}
.page-about .about-crumbs a:hover {
  color: var(--cyan);
  border-bottom-color: var(--cyan);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding: clamp(2rem, 6vw, 4.4rem) 0 clamp(2.6rem, 7vw, 5rem);
  border-bottom: 2px solid var(--line-strong);
}
.page-about .about-hero__bg {
  position: absolute;
  inset: 0;
  z-index: 0;
  opacity: .3;
}
.page-about .about-hero__bg img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: saturate(.68) contrast(1.08);
}
.page-about .about-hero::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 1;
  background:
    linear-gradient(160deg, rgba(7, 26, 51, .58) 0%, rgba(7, 26, 51, .9) 58%, var(--abyss) 100%),
    repeating-linear-gradient(90deg, rgba(143, 166, 196, .07) 0 1px, transparent 1px 96px);
  pointer-events: none;
}
.page-about .about-hero__inner {
  position: relative;
  z-index: 2;
}
.page-about .about-hero__title {
  margin: .9rem 0 1.3rem;
  max-width: 17em;
  font-size: clamp(2rem, 6.2vw, 4.2rem);
  font-weight: 900;
  line-height: 1.14;
  letter-spacing: -.02em;
}
.page-about .about-hero__lead {
  max-width: 36em;
  margin: 0;
  font-size: clamp(1rem, 1.6vw, 1.075rem);
  line-height: 1.85;
  color: rgba(242, 246, 255, .82);
}
.page-about .about-hero__kpi {
  list-style: none;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 2px;
  margin: 2.4rem 0 0;
  padding: 2px;
  background: var(--line-soft);
  border: 2px solid var(--line-strong);
}
.page-about .about-hero__kpi > li {
  padding: .95rem 1rem;
  background: var(--darker);
}
.page-about .about-hero__k,
.page-about .about-hero__v {
  display: block;
}
.page-about .about-hero__k {
  margin-bottom: .35rem;
  font-family: var(--font-mono);
  font-size: .95rem;
  letter-spacing: .04em;
  color: var(--cyan);
}
.page-about .about-hero__v {
  font-size: .8rem;
  line-height: 1.6;
  color: var(--mist);
}

/* ---------- 布局：左索引 + 右正文 ---------- */
.page-about .about-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 2rem;
  padding-top: clamp(2.4rem, 6vw, 4.6rem);
  padding-bottom: clamp(2.4rem, 6vw, 4.6rem);
}

/* ---------- 章节索引 ---------- */
.page-about .about-rail {
  min-width: 0;
}
.page-about .about-rail__title {
  margin: 0 0 .7rem;
  font-family: var(--font-mono);
  font-size: .68rem;
  letter-spacing: .24em;
  text-transform: uppercase;
  color: var(--mist);
}
.page-about .about-rail__list {
  list-style: none;
  display: flex;
  gap: .4rem;
  margin: 0;
  padding: 0 0 .5rem;
  overflow-x: auto;
  scrollbar-width: thin;
}
.page-about .about-rail__link {
  display: flex;
  align-items: baseline;
  gap: .55rem;
  white-space: nowrap;
  padding: .55rem .8rem;
  border: 1px solid var(--line);
  color: var(--mist);
  font-size: .88rem;
  text-decoration: none;
  transition: color .2s var(--ease), border-color .2s var(--ease), background .2s var(--ease);
}
.page-about .about-rail__link:hover {
  color: var(--white);
  border-color: var(--cyan);
  background: rgba(46, 242, 200, .07);
}
.page-about .about-rail__num {
  font-family: var(--font-mono);
  font-size: .72rem;
  letter-spacing: .08em;
  color: var(--cyan);
}

/* ---------- 正文主体 ---------- */
.page-about .about-body {
  min-width: 0;
}
.page-about .about-chapter {
  border-top: 2px solid var(--line-strong);
  padding-top: 1.5rem;
  margin-bottom: clamp(2.6rem, 6vw, 4.6rem);
  scroll-margin-top: 8rem;
}
.page-about .about-chapter:last-child {
  margin-bottom: 0;
}
.page-about .about-chapter__num {
  margin: 0 0 .5rem;
  font-family: var(--font-mono);
  font-size: .76rem;
  letter-spacing: .22em;
  color: var(--cyan);
}
.page-about .about-chapter--violet .about-chapter__num {
  color: var(--violet);
}
.page-about .about-chapter--coral .about-chapter__num {
  color: var(--coral);
}
.page-about .about-chapter__title {
  margin: 0 0 1rem;
  font-size: clamp(1.5rem, 3.2vw, 2.4rem);
  font-weight: 900;
  line-height: 1.2;
  letter-spacing: -.01em;
}
.page-about .about-principle {
  max-width: 30em;
  margin: 0 0 1.5rem;
  padding-left: 1rem;
  border-left: 3px solid var(--cyan);
  font-size: clamp(1.02rem, 1.9vw, 1.26rem);
  font-weight: 700;
  line-height: 1.6;
}
.page-about .about-chapter--violet .about-principle {
  border-left-color: var(--violet);
}
.page-about .about-chapter--coral .about-principle {
  border-left-color: var(--coral);
}
.page-about .about-prose p {
  max-width: 36em;
  margin: 0 0 1rem;
  font-size: 1rem;
  line-height: 1.85;
  color: rgba(242, 246, 255, .84);
}
.page-about .about-prose p:last-child {
  margin-bottom: 0;
}

/* ---------- 要点网格 ---------- */
.page-about .about-points {
  list-style: none;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(13rem, 1fr));
  gap: 2px;
  margin: 1.8rem 0 0;
  padding: 2px;
  background: var(--line-soft);
  border: 2px solid var(--line-strong);
}
.page-about .about-point {
  padding: 1.05rem 1.1rem;
  background: var(--deep);
}
.page-about .about-point__k,
.page-about .about-point__v {
  display: block;
}
.page-about .about-point__k {
  margin-bottom: .45rem;
  font-size: .98rem;
  font-weight: 800;
  line-height: 1.45;
  color: var(--white);
}
.page-about .about-point__v {
  font-size: .88rem;
  line-height: 1.7;
  color: var(--mist);
}

/* ---------- 三条主线卡片 ---------- */
.page-about .about-lines {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1.3rem;
  margin-top: 1.8rem;
}
.page-about .about-line {
  position: relative;
  overflow: hidden;
  padding: 1.7rem 1.2rem 1.4rem;
  border: 2px solid var(--line-strong);
  background: var(--deep);
}
.page-about .about-line::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 6px;
  background: var(--band-a);
}
.page-about .about-line--center::before {
  background: var(--band-b);
}
.page-about .about-line--price::before {
  background: var(--band-c);
}
.page-about .about-line__tag {
  margin: 0;
  font-family: var(--font-mono);
  font-size: .7rem;
  letter-spacing: .18em;
  color: var(--cyan);
}
.page-about .about-line--center .about-line__tag {
  color: var(--violet);
}
.page-about .about-line--price .about-line__tag {
  color: var(--coral);
}
.page-about .about-line__title {
  margin: .6rem 0 .7rem;
  font-size: 1.12rem;
  font-weight: 800;
  line-height: 1.4;
}
.page-about .about-line__text {
  margin: 0 0 1rem;
  font-size: .9rem;
  line-height: 1.78;
  color: var(--mist);
}
.page-about .about-line__facts {
  list-style: none;
  display: grid;
  gap: .38rem;
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--line-soft);
  padding-top: .9rem;
}
.page-about .about-line__facts li {
  position: relative;
  padding-left: 1rem;
  font-size: .84rem;
  line-height: 1.65;
  color: rgba(242, 246, 255, .78);
}
.page-about .about-line__facts li::before {
  content: "—";
  position: absolute;
  left: 0;
  color: var(--mist);
}

/* ---------- 团队分工 ---------- */
.page-about .about-crew {
  list-style: none;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: .8rem;
  margin: 1.8rem 0 0;
  padding: 0;
}
.page-about .about-crew__item {
  padding: .95rem 1.1rem;
  border: 2px solid var(--line);
  border-left: 4px solid var(--cyan);
  background: rgba(14, 42, 78, .55);
}
.page-about .about-crew__k,
.page-about .about-crew__v {
  display: block;
}
.page-about .about-crew__k {
  font-family: var(--font-mono);
  font-size: .82rem;
  letter-spacing: .1em;
  color: var(--cyan);
  margin-bottom: .35rem;
}
.page-about .about-crew__v {
  font-size: .88rem;
  line-height: 1.7;
  color: var(--mist);
}

/* ---------- 图片 ---------- */
.page-about .about-figure {
  margin: 2rem 0 0;
  border: 2px solid var(--line-strong);
  background: var(--darker);
}
.page-about .about-figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 3 / 2;
  object-fit: cover;
}
.page-about .about-figure--wide img {
  aspect-ratio: 12 / 5;
}
.page-about .about-figure__cap {
  padding: .7rem .9rem;
  border-top: 1px solid var(--line-soft);
  font-family: var(--font-mono);
  font-size: .72rem;
  letter-spacing: .05em;
  line-height: 1.6;
  color: var(--mist);
}

/* ---------- 发展节点 ---------- */
.page-about .about-track {
  list-style: none;
  display: grid;
  gap: 0;
  margin: 2rem 0 0;
  padding: 0;
}
.page-about .about-stage {
  position: relative;
  padding: 0 0 1.7rem 1.3rem;
  border-left: 2px solid var(--line-strong);
}
.page-about .about-stage::before {
  content: "";
  position: absolute;
  left: -8px;
  top: .35rem;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--abyss);
  border: 2px solid var(--cyan);
}
.page-about .about-stage:nth-child(2)::before {
  border-color: var(--violet);
}
.page-about .about-stage:nth-child(3)::before {
  border-color: var(--coral);
}
.page-about .about-stage:nth-child(4)::before {
  border-color: var(--gold);
}
.page-about .about-stage:last-child {
  padding-bottom: 0;
}
.page-about .about-stage__time {
  margin: 0;
  font-family: var(--font-mono);
  font-size: .72rem;
  letter-spacing: .2em;
  color: var(--mist);
}
.page-about .about-stage__title {
  margin: .25rem 0 .35rem;
  font-size: 1.05rem;
  font-weight: 800;
  line-height: 1.4;
}
.page-about .about-stage__text {
  max-width: 34em;
  margin: 0;
  font-size: .9rem;
  line-height: 1.78;
  color: var(--mist);
}

/* ---------- 收口区 ---------- */
.page-about .about-next {
  border-top: 2px solid var(--line-strong);
  background:
    linear-gradient(120deg, rgba(46, 242, 200, .1) 0%, rgba(7, 26, 51, 0) 46%),
    var(--darker);
  padding: clamp(2.2rem, 6vw, 4rem) 0;
}
.page-about .about-next__inner {
  display: grid;
  gap: 1.6rem;
}
.page-about .about-next__title {
  margin: .7rem 0 .9rem;
  max-width: 20em;
  font-size: clamp(1.4rem, 3vw, 2.1rem);
  font-weight: 900;
  line-height: 1.25;
  letter-spacing: -.01em;
}
.page-about .about-next__text {
  max-width: 36em;
  margin: 0;
  font-size: .96rem;
  line-height: 1.85;
  color: rgba(242, 246, 255, .82);
}
.page-about .about-next__text a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(46, 242, 200, .45);
}
.page-about .about-next__text a:hover {
  border-bottom-color: var(--cyan);
}
.page-about .about-next__acts {
  display: flex;
  flex-wrap: wrap;
  gap: .7rem;
}
.page-about .about-next__fine {
  margin: 0;
  padding-top: 1.1rem;
  border-top: 1px solid var(--line-soft);
  font-size: .82rem;
  line-height: 1.7;
  color: var(--mist);
}
.page-about .about-next__fine a {
  color: var(--coral);
  text-decoration: none;
  border-bottom: 1px solid rgba(255, 107, 74, .45);
}
.page-about .about-next__fine a:hover {
  border-bottom-color: var(--coral);
}

/* ---------- 响应式 ---------- */
@media (min-width: 40rem) {
  .page-about .about-hero__kpi {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
  .page-about .about-crew {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 2px;
    padding: 2px;
    background: var(--line-soft);
    border: 2px solid var(--line-strong);
  }
  .page-about .about-crew__item {
    border: none;
    border-left: 4px solid var(--cyan);
    background: var(--deep);
  }
}
@media (min-width: 52rem) {
  .page-about .about-lines {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
  .page-about .about-next__inner {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: end;
  }
  .page-about .about-next__copy {
    grid-column: 1;
  }
  .page-about .about-next__acts {
    grid-column: 2;
    justify-content: flex-end;
  }
  .page-about .about-next__fine {
    grid-column: 1 / -1;
  }
}
@media (min-width: 64rem) {
  .page-about .about-layout {
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
    gap: var(--about-gap);
    align-items: start;
  }
  .page-about .about-rail {
    position: sticky;
    top: var(--sticky-top);
  }
  .page-about .about-rail__list {
    display: block;
    padding-bottom: 0;
    overflow: visible;
  }
  .page-about .about-rail__list > li + li {
    margin-top: .15rem;
  }
  .page-about .about-rail__link {
    border: none;
    border-left: 2px solid var(--line-soft);
    padding: .55rem .2rem .55rem .85rem;
  }
  .page-about .about-rail__link:hover {
    background: transparent;
    border-left-color: var(--cyan);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-rail__link,
  .page-about .about-crumbs a {
    transition-duration: .01ms;
  }
}