.page-about {
  --about-rail-w: 236px;
  --about-glow: rgba(124, 77, 255, .55);
  padding-bottom: 80px;
}

/* ---------- 面包屑 ---------- */
.page-about .about-crumbs {
  padding-top: 28px;
}
.page-about .about-crumbs .arc-crumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
  margin: 0;
  padding: 0;
  list-style: none;
  font-size: 13px;
  letter-spacing: .04em;
  color: var(--arc-mist);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  isolation: isolate;
  padding: 34px 0 52px;
}
.page-about .about-hero::after {
  content: "";
  position: absolute;
  right: -14%;
  top: -70px;
  width: 360px;
  height: 360px;
  z-index: -1;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(52, 241, 211, .16), transparent 68%);
  pointer-events: none;
}
.page-about .about-hero__title {
  margin: 16px 0 0;
  max-width: 15em;
  font-size: clamp(30px, 5.4vw, 68px);
  line-height: 1.1;
  letter-spacing: -.025em;
  color: var(--arc-ice);
}
.page-about .about-hero__lede {
  max-width: 660px;
  margin: 22px 0 0;
  font-size: 18px;
  line-height: 1.85;
  color: var(--arc-ice);
}
.page-about .about-hero__facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 36px 0 0;
  padding: 1px;
  list-style: none;
  background: var(--arc-line);
  border: 2px solid var(--arc-line-strong);
  box-shadow: var(--arc-shadow-sm);
}
.page-about .about-hero__fact {
  display: flex;
  flex-direction: column;
  gap: 7px;
  padding: 18px 16px;
  background: var(--arc-abyss);
}
.page-about .about-hero__fact-num {
  font-family: var(--arc-font-mono);
  font-size: clamp(24px, 4vw, 34px);
  font-weight: 700;
  line-height: 1;
  color: var(--arc-cyan);
}
.page-about .about-hero__fact-label {
  font-size: 13px;
  line-height: 1.5;
  letter-spacing: .04em;
  color: var(--arc-mist);
}

/* ---------- 主体两栏 ---------- */
.page-about .about-body {
  padding-top: 12px;
}
.page-about .about-canvas {
  min-width: 0;
}

/* ---------- 左侧索引 ---------- */
.page-about .about-rail {
  margin-bottom: 28px;
}
.page-about .about-rail__label {
  margin: 0 0 12px;
  font-size: 12px;
  letter-spacing: .16em;
  color: var(--arc-mist);
}
.page-about .about-rail__list {
  display: flex;
  gap: 8px;
  margin: 0;
  padding: 0 0 6px;
  list-style: none;
  overflow-x: auto;
  scrollbar-width: none;
}
.page-about .about-rail__list::-webkit-scrollbar {
  display: none;
}
.page-about .about-rail__link {
  position: relative;
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  padding: 9px 14px;
  border: 1px solid var(--arc-line);
  border-radius: 999px;
  background: rgba(12, 27, 51, .62);
  color: var(--arc-mist);
  font-size: 14px;
  font-weight: 600;
  white-space: nowrap;
  text-decoration: none;
  transition: color .2s var(--arc-ease), border-color .2s var(--arc-ease), background .2s var(--arc-ease);
}
.page-about .about-rail__link .arc-num {
  font-family: var(--arc-font-mono);
  font-size: 12px;
  color: var(--arc-cyan);
}
.page-about .about-rail__link:hover,
.page-about .about-rail__link:focus-visible {
  border-color: var(--arc-violet);
  background: rgba(124, 77, 255, .16);
  color: var(--arc-ice);
}

/* ---------- 章节 ---------- */
.page-about .about-sec {
  padding: 40px 0 8px;
  scroll-margin-top: 118px;
}
.page-about .about-sec__head {
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding-bottom: 14px;
  margin-bottom: 24px;
  border-bottom: 2px solid var(--arc-line-strong);
}
.page-about .about-sec__num {
  flex: none;
  font-family: var(--arc-font-mono);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: .1em;
  color: var(--arc-cyan);
}
.page-about .about-sec__title {
  margin: 0;
  font-size: clamp(23px, 3.1vw, 36px);
  line-height: 1.2;
  letter-spacing: -.02em;
  color: var(--arc-ice);
}
.page-about .about-sec__body {
  max-width: 720px;
}
.page-about .about-sec__body p {
  margin: 0 0 18px;
  font-size: 17px;
  line-height: 1.85;
  color: var(--arc-ice);
}
.page-about .about-sec__body p:last-child {
  margin-bottom: 0;
}
.page-about .about-sec__body--after {
  margin-top: 26px;
}

/* ---------- 数字块 ---------- */
.page-about .about-statrow {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 28px 0 0;
  padding: 1px;
  list-style: none;
  background: var(--arc-line);
  border: 2px solid var(--arc-line-strong);
  box-shadow: var(--arc-shadow-sm);
}
.page-about .about-stat {
  display: flex;
  flex-direction: column;
  gap: 9px;
  padding: 20px 18px;
  background: var(--arc-abyss);
}
.page-about .about-stat__num {
  font-family: var(--arc-font-mono);
  font-size: clamp(26px, 4.4vw, 38px);
  font-weight: 700;
  line-height: 1;
  color: var(--arc-cyan);
}
.page-about .about-stat__label {
  font-size: 13px;
  line-height: 1.55;
  color: var(--arc-mist);
}

/* ---------- 图片框 ---------- */
.page-about .about-figure {
  margin: 28px 0 0;
  border: 2px solid var(--arc-line-strong);
  background: var(--arc-abyss);
  box-shadow: var(--arc-shadow-sm);
  overflow: hidden;
}
.page-about .about-figure--flush {
  margin-top: 30px;
}
.page-about .about-figure .arc-media__img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
}
.page-about .about-figure .arc-media__caption {
  padding: 12px 16px;
  border-top: 1px solid var(--arc-line);
  font-size: 13px;
  line-height: 1.6;
  color: var(--arc-mist);
}

/* ---------- 团队分工 ---------- */
.page-about .about-team {
  display: grid;
  gap: 18px;
  margin: 26px 0 0;
  padding: 0;
  list-style: none;
}
.page-about .about-team__row {
  display: grid;
  grid-template-columns: 56px minmax(0, 1fr);
  gap: 7px 16px;
  align-items: center;
}
.page-about .about-team__num {
  grid-row: 1 / span 2;
  font-family: var(--arc-font-mono);
  font-size: clamp(26px, 4vw, 36px);
  font-weight: 700;
  line-height: 1;
  text-align: right;
  color: var(--arc-ice);
}
.page-about .about-team__track {
  display: block;
  height: 10px;
  border: 1px solid var(--arc-line-strong);
  background: rgba(6, 12, 27, .82);
  overflow: hidden;
}
.page-about .about-team__fill {
  display: block;
  height: 100%;
}
.page-about .about-team__fill--a { width: 40%; background: var(--arc-cyan); }
.page-about .about-team__fill--b { width: 26.7%; background: var(--arc-violet); }
.page-about .about-team__fill--c { width: 20%; background: var(--arc-gold); }
.page-about .about-team__fill--d { width: 13.3%; background: var(--arc-ember); }
.page-about .about-team__name {
  font-size: 14px;
  line-height: 1.6;
  color: var(--arc-mist);
}

/* ---------- 版本刻度 ---------- */
.page-about .about-timeline {
  position: relative;
  display: grid;
  gap: 26px;
  margin: 30px 0 0;
  padding: 0;
  list-style: none;
}
.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 8px;
  top: 8px;
  bottom: 8px;
  width: 1px;
  background: linear-gradient(180deg, var(--arc-cyan), var(--arc-violet), rgba(255, 138, 61, .2));
}
.page-about .about-timeline__node {
  position: relative;
  padding-left: 34px;
}
.page-about .about-timeline__node::before {
  content: "";
  position: absolute;
  left: 0;
  top: 3px;
  width: 17px;
  height: 17px;
  border: 2px solid var(--arc-cyan);
  border-radius: 50%;
  background: var(--arc-void);
  box-shadow: 0 0 14px rgba(52, 241, 211, .5);
}
.page-about .about-timeline__ver {
  display: inline-block;
  font-family: var(--arc-font-mono);
  font-size: 20px;
  font-weight: 700;
  line-height: 1;
  color: var(--arc-cyan);
}
.page-about .about-timeline__year {
  display: inline-block;
  margin-left: 10px;
  font-family: var(--arc-font-mono);
  font-size: 13px;
  color: var(--arc-gold);
  letter-spacing: .06em;
}
.page-about .about-timeline__text {
  margin: 10px 0 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--arc-mist);
}

/* ---------- 合作标签 ---------- */
.page-about .about-chiprow {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 26px 0 0;
  padding: 0;
  list-style: none;
}
.page-about .about-chip {
  padding: 9px 16px;
  border: 2px solid var(--arc-line-strong);
  border-radius: 999px;
  background: rgba(12, 27, 51, .6);
  color: var(--arc-ice);
  font-size: 14px;
  font-weight: 600;
  transition: transform .2s var(--arc-ease), border-color .2s var(--arc-ease), box-shadow .2s var(--arc-ease);
}
.page-about .about-chip:hover {
  transform: translate(-2px, -2px);
  border-color: var(--arc-cyan);
  box-shadow: var(--arc-shadow-sm);
}

/* ---------- 酒红使命色带 ---------- */
.page-about .about-band {
  margin: 30px 0 0;
  padding: 32px 22px;
  border: 2px solid var(--arc-line-strong);
  border-radius: var(--arc-radius);
  background: var(--arc-wine);
  box-shadow: var(--arc-shadow);
  transition: opacity .6s var(--arc-ease);
}
.page-about .about-band__title {
  margin: 0 0 22px;
  font-size: clamp(21px, 2.9vw, 31px);
  line-height: 1.25;
  letter-spacing: -.02em;
  color: var(--arc-ice);
}
.page-about .about-band__list {
  display: grid;
  gap: 18px;
  margin: 0;
  padding: 0;
  list-style: none;
}
.page-about .about-band__item {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 14px;
  align-items: baseline;
}
.page-about .about-band__key {
  font-family: var(--arc-font-mono);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: .1em;
  color: var(--arc-gold);
}
.page-about .about-band__text {
  margin: 0;
  font-size: 16px;
  line-height: 1.8;
  color: var(--arc-ice);
}
.page-about .about-band__text strong {
  color: var(--arc-cyan);
}

/* ---------- 尾部 ---------- */
.page-about .about-tail {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  margin-top: 40px;
  padding-top: 28px;
  border-top: 2px solid var(--arc-line);
}
.page-about .about-tail__text {
  max-width: 640px;
  margin: 0;
  font-size: 15px;
  line-height: 1.85;
  color: var(--arc-mist);
}
.page-about .arc-link-host {
  white-space: nowrap;
}

/* ---------- 渐进增强 ---------- */
.page-about [data-reveal] {
  opacity: .74;
}
.page-about [data-reveal][data-visible="true"] {
  opacity: 1;
}

/* ---------- 响应式 ---------- */
@media (min-width: 640px) {
  .page-about .about-hero__facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
  .page-about .about-statrow {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
  .page-about .about-band {
    padding: 40px 32px;
  }
}

@media (min-width: 900px) {
  .page-about .about-split {
    display: grid;
    grid-template-columns: minmax(0, 1.05fr) minmax(0, .95fr);
    gap: 36px;
    align-items: start;
  }
  .page-about .about-split .about-figure {
    margin-top: 0;
  }
  .page-about .about-team {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 22px 32px;
  }
  .page-about .about-timeline {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 20px;
  }
  .page-about .about-timeline::before {
    left: 0;
    right: 0;
    top: 8px;
    bottom: auto;
    width: auto;
    height: 1px;
    background: linear-gradient(90deg, var(--arc-cyan), var(--arc-violet), var(--arc-ember));
  }
  .page-about .about-timeline__node {
    padding-left: 0;
    padding-top: 38px;
  }
  .page-about .about-timeline__node::before {
    left: 0;
    top: 0;
  }
}

@media (min-width: 1024px) {
  .page-about .about-hero {
    padding: 44px 0 60px;
  }
  .page-about .about-body {
    display: grid;
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
    gap: 56px;
    align-items: start;
    padding-top: 20px;
  }
  .page-about .about-rail {
    position: sticky;
    top: 108px;
    margin-bottom: 0;
  }
  .page-about .about-rail__list {
    display: grid;
    gap: 2px;
    overflow: visible;
    padding-bottom: 0;
  }
  .page-about .about-rail__link {
    display: flex;
    padding: 8px 10px 8px 18px;
    border: 0;
    border-radius: 0;
    background: transparent;
    white-space: normal;
  }
  .page-about .about-rail__link::before {
    content: "";
    position: absolute;
    left: 0;
    top: 8px;
    bottom: 8px;
    width: 3px;
    background: var(--arc-line-strong);
    transform: scaleY(.35);
    transform-origin: center;
    transition: transform .26s var(--arc-ease), background .2s var(--arc-ease), box-shadow .26s var(--arc-ease);
  }
  .page-about .about-rail__link:hover,
  .page-about .about-rail__link:focus-visible {
    border-color: transparent;
    background: transparent;
    color: var(--arc-ice);
  }
  .page-about .about-rail__link:hover::before,
  .page-about .about-rail__link:focus-visible::before {
    background: var(--arc-violet);
    transform: scaleY(1);
    box-shadow: 0 0 14px var(--about-glow);
  }
  .page-about .about-sec {
    padding-top: 46px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about *,
  .page-about *::before,
  .page-about *::after {
    transition-duration: .01ms !important;
    animation-duration: .01ms !important;
  }
  .page-about [data-reveal] {
    opacity: 1;
  }
}