.page-about {
  --about-axis: 42px;
  --ver-dim: rgba(108, 59, 255, .42);
  --about-rule: rgba(61, 90, 254, .3);
}

.page-about .breadcrumbs {
  padding-top: 1.25rem;
  padding-bottom: .5rem;
}

/* ---------- 首屏：框景窗口 ---------- */
.page-about .about-hero {
  padding-top: 1.25rem;
}

.page-about .about-hero__window {
  position: relative;
  padding: 1.75rem 1.25rem;
  border: 1px solid var(--line-soft);
  background:
    radial-gradient(120% 140% at 88% 0%, rgba(108, 59, 255, .22), transparent 62%),
    linear-gradient(180deg, rgba(16, 31, 74, .82), rgba(10, 22, 51, .58));
  overflow: hidden;
}

.page-about .about-hero__window::before,
.page-about .about-hero__window::after {
  content: "";
  position: absolute;
  width: 16px;
  height: 16px;
  border: 1px solid var(--cyan);
  opacity: .65;
}

.page-about .about-hero__window::before {
  top: 10px;
  right: 10px;
  border-left: 0;
  border-bottom: 0;
}

.page-about .about-hero__window::after {
  bottom: 10px;
  right: 10px;
  border-left: 0;
  border-top: 0;
}

.page-about .about-hero__rail {
  display: none;
}

.page-about .about-hero__title {
  margin: 0 0 1rem;
  max-width: 20ch;
}

.page-about .about-hero__lede {
  margin: 0;
  color: var(--muted);
}

.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: .75rem;
  margin-top: 1.5rem;
}

/* ---------- 数据条 ---------- */
.page-about .about-facts {
  list-style: none;
  margin: 1.25rem 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1px;
  background: var(--line-soft);
  border: 1px solid var(--line-soft);
}

.page-about .about-facts__item {
  background: var(--ink);
  padding: .95rem 1.05rem;
  display: flex;
  flex-direction: column;
  gap: .3rem;
}

.page-about .about-facts__key {
  font-size: .74rem;
  letter-spacing: .2em;
  color: var(--muted);
}

.page-about .about-facts__value {
  font-size: 1.12rem;
  font-weight: 800;
  font-variant-numeric: tabular-nums;
  color: var(--glass);
  letter-spacing: -.01em;
}

/* ---------- 首屏通栏图 ---------- */
.page-about .about-hero__banner {
  margin: 1.25rem 0 0;
  border: 1px solid var(--line-soft);
  background: var(--ink);
  aspect-ratio: 3 / 2;
  overflow: hidden;
}

.page-about .about-hero__banner img,
.page-about .milestone__figure img,
.page-about .about-team__media img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

/* ---------- 章节头 ---------- */
.page-about .about-section-head {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: .75rem 1.1rem;
  align-items: start;
  margin-bottom: 1.75rem;
}

.page-about .about-section-head__text {
  min-width: 0;
}

.page-about .about-section-head .chapter__num {
  font-size: clamp(1.9rem, 6vw, 3.2rem);
  font-weight: 900;
  line-height: .92;
  letter-spacing: -.03em;
  color: var(--violet);
  font-variant-numeric: tabular-nums;
}

.page-about .about-section-head .chapter__title {
  margin: .15rem 0 0;
}

/* ---------- 版本时间线 ---------- */
.page-about .about-timeline {
  margin-top: 4rem;
  scroll-margin-top: calc(var(--header-h) + 1rem);
}

.page-about .about-timeline__eyebrow {
  margin: 0 0 .5rem;
  color: var(--cyan);
  font-size: .72rem;
  letter-spacing: .28em;
}

.page-about .about-timeline__intro {
  margin: 0 0 1.75rem;
  color: var(--muted);
}

.page-about .about-versions {
  list-style: none;
  margin: 0 0 3rem;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1px;
  background: var(--line-soft);
  border: 1px solid var(--line-soft);
}

.page-about .about-versions__link {
  display: flex;
  align-items: center;
  gap: .55rem;
  padding: .8rem .95rem;
  background: var(--space);
  color: var(--muted);
  text-decoration: none;
  font-size: .88rem;
  font-weight: 600;
  transition: background var(--dur) var(--ease), color var(--dur) var(--ease);
}

.page-about .about-versions__tag {
  font-weight: 900;
  font-variant-numeric: tabular-nums;
  color: var(--violet);
  letter-spacing: -.02em;
  transition: color var(--dur) var(--ease);
}

.page-about .about-versions__link:hover,
.page-about .about-versions__link:focus-visible {
  background: var(--space-2);
  color: var(--glass);
}

.page-about .about-versions__link:hover .about-versions__tag,
.page-about .about-versions__link:focus-visible .about-versions__tag {
  color: var(--cyan);
}

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

.page-about .milestone {
  display: grid;
  grid-template-columns: var(--about-axis) 1fr;
  gap: .9rem;
  padding-bottom: 3.25rem;
  scroll-margin-top: calc(var(--header-h) + 1.5rem);
}

.page-about .milestone:last-child {
  padding-bottom: 0;
}

.page-about .milestone__axis {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  padding-top: .4rem;
}

.page-about .milestone__axis::before {
  content: "";
  position: absolute;
  left: 6px;
  top: 20px;
  bottom: -3.25rem;
  width: 1px;
  background: var(--about-rule);
}

.page-about .milestone:last-child .milestone__axis::before {
  display: none;
}

.page-about .milestone__dot {
  position: relative;
  width: 13px;
  height: 13px;
  border-radius: 50%;
  border: 1px solid var(--cyan);
  transition: transform var(--dur) var(--ease), background var(--dur) var(--ease);
}

.page-about .milestone__dot::after {
  content: "";
  position: absolute;
  inset: 3px;
  border-radius: 50%;
  background: var(--violet);
  transition: background var(--dur) var(--ease);
}

.page-about .milestone__ver {
  margin-top: .7rem;
  margin-left: -.08em;
  font-size: 1.28rem;
  font-weight: 900;
  line-height: .85;
  letter-spacing: -.05em;
  font-variant-numeric: tabular-nums;
  color: var(--ver-dim);
  transition: color var(--dur) var(--ease);
}

.page-about .milestone:hover .milestone__dot,
.page-about .milestone:focus-within .milestone__dot {
  transform: scale(1.45);
  background: rgba(34, 224, 214, .16);
}

.page-about .milestone:hover .milestone__ver,
.page-about .milestone:focus-within .milestone__ver {
  color: var(--violet);
}

.page-about .milestone__card {
  position: relative;
  padding: 1.2rem 1.05rem 1.35rem;
  border: 1px solid var(--line-soft);
  background: var(--glass-bg);
  transition: border-color var(--dur) var(--ease), transform var(--dur) var(--ease);
}

.page-about .milestone:hover .milestone__card,
.page-about .milestone__card:focus-within {
  border-color: var(--cyan-soft);
  transform: translateX(3px);
}

.page-about .milestone__era {
  display: inline-block;
  margin: 0 0 .7rem;
  padding: .18rem .55rem;
  border: 1px solid var(--line-soft);
  background: rgba(34, 224, 214, .07);
  color: var(--cyan);
  font-size: .73rem;
  letter-spacing: .14em;
}

.page-about .milestone__title {
  margin: 0 0 .7rem;
  font-size: 1.2rem;
  font-weight: 700;
  line-height: 1.35;
  color: var(--glass);
}

.page-about .milestone__body {
  margin: 0;
  color: var(--muted);
}

.page-about .milestone__points {
  list-style: none;
  margin: 1.1rem 0 0;
  padding: 0;
  display: grid;
  gap: .5rem;
}

.page-about .milestone__points li {
  position: relative;
  padding-left: 1.2rem;
  font-size: .93rem;
  line-height: 1.7;
  color: var(--muted);
}

.page-about .milestone__points li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .68em;
  width: 8px;
  height: 1px;
  background: var(--cyan);
}

.page-about .milestone__figure {
  margin: 1.4rem 0 0;
  width: min(100%, 340px);
  border: 1px solid var(--line-soft);
  background: var(--ink);
  aspect-ratio: 1 / 1;
  overflow: hidden;
}

/* ---------- 团队 ---------- */
.page-about .about-team {
  margin-top: 4rem;
  scroll-margin-top: calc(var(--header-h) + 1rem);
}

.page-about .about-team__grid {
  display: grid;
  gap: 2rem;
}

.page-about .about-team__copy .prose {
  margin: 0;
  color: var(--muted);
}

.page-about .about-team__roles {
  list-style: none;
  margin: 1.6rem 0 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line-soft);
  border: 1px solid var(--line-soft);
}

.page-about .role {
  background: var(--space);
  padding: .95rem 1.05rem;
  display: grid;
  gap: .28rem;
  transition: background var(--dur) var(--ease);
}

.page-about .role:hover {
  background: var(--space-2);
}

.page-about .role__name {
  font-size: 1rem;
  font-weight: 700;
  color: var(--glass);
}

.page-about .role__desc {
  font-size: .9rem;
  line-height: 1.75;
  color: var(--muted);
}

.page-about .about-team__stats {
  list-style: none;
  margin: 1.6rem 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(110px, 1fr));
  gap: 1.2rem;
}

.page-about .about-team__stat {
  display: grid;
  gap: .3rem;
  padding-top: .85rem;
  border-top: 1px solid var(--about-rule);
}

.page-about .about-team__num {
  font-size: 1.9rem;
  font-weight: 900;
  line-height: 1;
  letter-spacing: -.03em;
  font-variant-numeric: tabular-nums;
  color: var(--glass);
}

.page-about .about-team__num--accent {
  color: var(--orange);
}

.page-about .about-team__unit {
  font-size: .82rem;
  letter-spacing: .06em;
  color: var(--muted);
}

.page-about .about-team__media {
  margin: 0;
  border: 1px solid var(--line-soft);
  background: var(--ink);
  aspect-ratio: 12 / 7;
  overflow: hidden;
}

/* ---------- 命名实践 ---------- */
.page-about .about-practice {
  margin-top: 4rem;
  scroll-margin-top: calc(var(--header-h) + 1rem);
}

.page-about .about-practice__intro {
  margin: 0 0 1.9rem;
  color: var(--muted);
}

.page-about .about-practice__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line-soft);
  border: 1px solid var(--line-soft);
}

.page-about .principle {
  position: relative;
  background: var(--space);
  padding: 1.35rem 1.1rem 1.5rem;
  transition: background var(--dur) var(--ease);
}

.page-about .principle::before {
  content: "";
  position: absolute;
  left: 1.1rem;
  right: 1.1rem;
  top: 0;
  height: 1px;
  background: linear-gradient(90deg, var(--violet), transparent);
}

.page-about .principle:hover {
  background: var(--space-2);
}

.page-about .principle__title {
  margin: 0 0 .55rem;
  font-size: 1.05rem;
  font-weight: 700;
  line-height: 1.4;
  color: var(--glass);
}

.page-about .principle__desc {
  margin: 0;
  font-size: .92rem;
  line-height: 1.8;
  color: var(--muted);
}

/* ---------- 收束区 ---------- */
.page-about .about-next {
  position: relative;
  margin-top: 4.5rem;
  padding: 1.9rem 1.15rem 2.1rem;
  border: 1px solid var(--line-soft);
  background:
    linear-gradient(135deg, rgba(108, 59, 255, .18), rgba(34, 224, 214, .05) 70%),
    var(--space);
  overflow: hidden;
}

.page-about .about-next::after {
  content: "V4";
  position: absolute;
  right: -.06em;
  bottom: -.34em;
  font-size: clamp(5rem, 22vw, 9rem);
  font-weight: 900;
  line-height: 1;
  letter-spacing: -.06em;
  color: rgba(108, 59, 255, .18);
  pointer-events: none;
}

.page-about .about-next__label {
  margin: 0 0 .55rem;
  color: var(--cyan);
  font-size: .72rem;
  letter-spacing: .28em;
}

.page-about .about-next__title {
  margin: 0 0 .8rem;
  position: relative;
  z-index: 1;
}

.page-about .about-next__text {
  margin: 0;
  max-width: 56ch;
  color: var(--muted);
  position: relative;
  z-index: 1;
}

.page-about .about-next__links {
  margin-top: 1.6rem;
  display: grid;
  gap: 1px;
  background: var(--line-soft);
  border: 1px solid var(--line-soft);
  position: relative;
  z-index: 1;
}

.page-about .about-next__link {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: .75rem;
  padding: .9rem 1.05rem;
  background: rgba(7, 16, 38, .78);
  color: var(--muted);
  text-decoration: none;
  font-size: .95rem;
  font-weight: 600;
  transition: color var(--dur) var(--ease), background var(--dur) var(--ease);
}

.page-about .about-next__link::after {
  content: "→";
  color: var(--violet);
  transition: transform var(--dur) var(--ease), color var(--dur) var(--ease);
}

.page-about .about-next__link:hover,
.page-about .about-next__link:focus-visible {
  color: var(--glass);
  background: var(--space-2);
}

.page-about .about-next__link:hover::after,
.page-about .about-next__link:focus-visible::after {
  color: var(--cyan);
  transform: translateX(4px);
}

/* ---------- 桌面 ---------- */
@media (min-width: 760px) {
  .page-about {
    --about-axis: 96px;
  }

  .page-about .about-hero__window {
    padding: 2.4rem 2.25rem 2.4rem 3.6rem;
  }

  .page-about .about-hero__rail {
    display: flex;
    position: absolute;
    left: 1.15rem;
    top: 2.4rem;
    bottom: 2.4rem;
    align-items: flex-start;
    color: var(--muted);
  }

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

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

  .page-about .milestone {
    gap: 1.9rem;
    padding-bottom: 4.75rem;
  }

  .page-about .milestone__axis::before {
    left: 8px;
    top: 24px;
    bottom: -4.75rem;
  }

  .page-about .milestone__dot {
    width: 17px;
    height: 17px;
  }

  .page-about .milestone__dot::after {
    inset: 4px;
  }

  .page-about .milestone__ver {
    margin-top: .95rem;
    font-size: 3rem;
  }

  .page-about .milestone__card {
    padding: 1.7rem 1.75rem 1.9rem;
  }

  .page-about .milestone__title {
    font-size: 1.6rem;
  }

  .page-about .milestone__figure {
    width: min(100%, 380px);
  }

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

  .page-about .about-next {
    padding: 2.6rem 2.25rem 2.9rem;
  }

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

@media (min-width: 960px) {
  .page-about .about-team__grid {
    grid-template-columns: 1.05fr .95fr;
    gap: 3rem;
    align-items: start;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .milestone__card,
  .page-about .milestone__dot,
  .page-about .milestone__ver,
  .page-about .about-next__link::after {
    transition: none;
  }

  .page-about .milestone:hover .milestone__card,
  .page-about .milestone__card:focus-within {
    transform: none;
  }
}