.page-about {
  position: relative;
  padding-bottom: clamp(48px, 7vw, 96px);
  background:
    radial-gradient(880px 480px at 88% -6%, rgba(139, 108, 255, .16), transparent 62%),
    radial-gradient(700px 420px at 2% 4%, rgba(61, 232, 210, .10), transparent 66%);
}

.page-about .about-crumbs {
  padding-top: clamp(18px, 3vw, 32px);
}

/* ---------- 首屏框景 ---------- */
.page-about .about-hero {
  padding: clamp(16px, 2.6vw, 28px) 0 clamp(30px, 4.4vw, 56px);
}

.page-about .about-hero__frame {
  position: relative;
  border: 1px solid var(--line);
  padding: clamp(18px, 3.2vw, 42px);
  background:
    linear-gradient(158deg, rgba(19, 32, 61, .92), rgba(6, 10, 22, .66) 68%),
    repeating-linear-gradient(90deg, rgba(43, 58, 93, .28) 0 1px, transparent 1px 68px);
}

.page-about .about-hero__frame::before,
.page-about .about-hero__frame::after {
  content: "";
  position: absolute;
  width: 20px;
  height: 20px;
  border: 1px solid var(--cyan);
  pointer-events: none;
}

.page-about .about-hero__frame::before {
  top: -1px;
  left: -1px;
  border-right: 0;
  border-bottom: 0;
}

.page-about .about-hero__frame::after {
  right: -1px;
  bottom: -1px;
  border-top: 0;
  border-left: 0;
}

.page-about .about-hero__grid {
  display: grid;
  gap: clamp(20px, 3.2vw, 36px);
}

.page-about .about-hero__copy .index-tag {
  margin: 0 0 14px;
  color: var(--violet);
}

.page-about .about-hero__copy h1 {
  margin: 0 0 18px;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(36px, 8.4vw, 74px);
  line-height: 1.02;
  letter-spacing: -.012em;
  color: var(--text);
}

.page-about .about-hero__lede {
  margin: 0 0 22px;
  max-width: 46ch;
  font-size: clamp(15px, 1.5vw, 17px);
  line-height: 1.78;
  color: var(--muted);
}

.page-about .about-hero__media {
  align-self: end;
}

.page-about .about-hero__stats {
  list-style: none;
  margin: clamp(22px, 3vw, 34px) 0 0;
  padding: clamp(16px, 2.4vw, 22px) 0 0;
  border-top: 1px solid var(--line);
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px 12px;
}

.page-about .about-hero__num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(20px, 3vw, 26px);
  color: var(--cyan);
  letter-spacing: .02em;
}

.page-about .about-hero__label {
  display: block;
  margin-top: 4px;
  font-size: 12.5px;
  color: var(--muted);
  letter-spacing: .03em;
}

/* ---------- 时间轴主体 ---------- */
.page-about .about-body__grid {
  display: grid;
  gap: clamp(18px, 3vw, 26px);
}

.page-about .about-track {
  position: relative;
}

.page-about .about-track__list {
  list-style: none;
  margin: 0;
  padding: 0 0 4px;
  display: flex;
  gap: 6px;
  overflow-x: auto;
  scrollbar-width: thin;
}

.page-about .about-track__link {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 12px;
  white-space: nowrap;
  text-decoration: none;
  font-size: 13.5px;
  color: var(--muted);
  border: 1px solid var(--line);
  background: rgba(12, 21, 43, .7);
  transition: color .12s var(--ease), border-color .12s var(--ease), background .12s var(--ease);
}

.page-about .about-track__link .mono {
  color: var(--violet);
  font-size: 11.5px;
}

.page-about .about-track__link:hover,
.page-about .about-track__link:focus-visible {
  color: var(--text);
  border-color: var(--cyan);
  background: rgba(61, 232, 210, .08);
}

.page-about .about-drawers {
  display: grid;
  gap: clamp(16px, 2.4vw, 24px);
  min-width: 0;
}

.page-about .about-drawer {
  position: relative;
  padding: clamp(20px, 3vw, 36px);
  border: 1px solid var(--line);
  background: linear-gradient(180deg, rgba(12, 21, 43, .97), rgba(12, 21, 43, .74));
  scroll-margin-top: 108px;
  transition: border-color .2s var(--ease), box-shadow .2s var(--ease);
}

.page-about .about-drawer::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 3px;
  height: 34px;
  background: var(--violet);
}

.page-about .about-drawer:target {
  border-color: var(--cyan);
  box-shadow: 0 0 0 1px rgba(61, 232, 210, .26), 0 18px 48px -28px rgba(61, 232, 210, .5);
}

.page-about .about-drawer:target::before {
  background: var(--cyan);
}

.page-about .about-drawer .index-tag {
  display: block;
  margin: 0 0 10px;
  color: var(--muted);
}

.page-about .about-drawer h3 {
  margin: 0 0 14px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(24px, 3.6vw, 34px);
  line-height: 1.16;
  letter-spacing: -.005em;
  color: var(--text);
}

.page-about .about-drawer h4 {
  margin: 0 0 6px;
  font-size: clamp(15px, 1.6vw, 17px);
  font-weight: 700;
  color: var(--text);
}

.page-about .about-drawer p {
  margin: 0 0 14px;
  font-size: 15.5px;
  line-height: 1.78;
  color: var(--muted);
  max-width: 62ch;
}

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

/* ---------- 团队卡片 ---------- */
.page-about .team-strip {
  list-style: none;
  margin: 20px 0 22px;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .team-card {
  background: var(--float);
  padding: 18px 18px 20px;
  transition: background .12s var(--ease), transform .12s var(--ease);
}

.page-about .team-card:hover,
.page-about .team-card:focus-within {
  background: #17264a;
  transform: translateY(-1px);
}

.page-about .team-card__count {
  display: inline-block;
  margin-bottom: 10px;
  padding: 2px 8px;
  font-size: 11.5px;
  color: var(--gold);
  border: 1px solid rgba(255, 196, 107, .42);
  letter-spacing: .06em;
}

.page-about .team-card p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.72;
}

/* ---------- 发展历程 ---------- */
.page-about .roadmap {
  list-style: none;
  margin: 22px 0 0;
  padding: 0 0 0 20px;
  border-left: 1px solid var(--line);
}

.page-about .roadmap__item {
  position: relative;
  padding: 0 0 24px 6px;
}

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

.page-about .roadmap__item::before {
  content: "";
  position: absolute;
  left: -25px;
  top: 8px;
  width: 7px;
  height: 7px;
  background: var(--violet);
  box-shadow: 0 0 0 3px rgba(139, 108, 255, .16);
}

.page-about .roadmap__item:nth-child(odd)::before {
  background: var(--cyan);
  box-shadow: 0 0 0 3px rgba(61, 232, 210, .16);
}

.page-about .roadmap__year {
  display: block;
  margin-bottom: 6px;
  font-size: 20px;
  letter-spacing: .08em;
  color: var(--cyan);
}

.page-about .roadmap__item p {
  margin: 0;
}

/* ---------- 归档四步 ---------- */
.page-about .steps {
  list-style: none;
  margin: 22px 0 22px;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .step {
  background: var(--panel);
  padding: 18px 18px 20px;
}

.page-about .step__num {
  display: block;
  margin-bottom: 10px;
  font-size: 26px;
  line-height: 1;
  color: transparent;
  -webkit-text-stroke: 1px var(--violet);
  letter-spacing: .04em;
}

.page-about .step p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.72;
}

/* ---------- 媒体框微调 ---------- */
.page-about .media {
  margin: clamp(18px, 2.6vw, 24px) 0 0;
}

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

/* ---------- 下一步 ---------- */
.page-about .about-next__panel {
  border: 1px solid var(--line);
  border-top: 2px solid var(--gold);
  padding: clamp(20px, 3vw, 36px);
  background: linear-gradient(120deg, rgba(19, 32, 61, .95), rgba(6, 10, 22, .8));
}

.page-about .about-next__head {
  margin-bottom: clamp(16px, 2.4vw, 24px);
}

.page-about .about-next__head .index-tag {
  display: block;
  margin: 0 0 10px;
  color: var(--gold);
}

.page-about .about-next__head h2 {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(24px, 4vw, 38px);
  line-height: 1.14;
  color: var(--text);
}

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

.page-about .about-next__list li {
  background: rgba(6, 10, 22, .6);
}

.page-about .about-next__list a {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 14px 16px;
  text-decoration: none;
  font-size: 15px;
  color: var(--text);
  transition: background .12s var(--ease), color .12s var(--ease);
}

.page-about .about-next__list a .mono {
  font-size: 11.5px;
  color: var(--violet);
}

.page-about .about-next__list a:hover,
.page-about .about-next__list a:focus-visible {
  background: rgba(61, 232, 210, .1);
  color: var(--cyan);
}

.page-about .about-next__arrow {
  margin-left: auto;
  color: var(--muted);
  transition: transform .12s var(--ease), color .12s var(--ease);
}

.page-about .about-next__list a:hover .about-next__arrow,
.page-about .about-next__list a:focus-visible .about-next__arrow {
  color: var(--cyan);
  transform: translateX(2px);
}

/* ---------- 断点 ---------- */
@media (min-width: 560px) {
  .page-about .about-hero__stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 16px 18px;
  }

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

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

@media (min-width: 880px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 1fr);
    align-items: end;
    gap: clamp(24px, 3.4vw, 44px);
  }
}

@media (min-width: 960px) {
  .page-about .about-body__grid {
    grid-template-columns: 186px minmax(0, 1fr);
    gap: clamp(26px, 3.4vw, 56px);
    align-items: start;
  }

  .page-about .about-track {
    position: sticky;
    top: 108px;
    padding-left: 18px;
  }

  .page-about .about-track::before {
    content: "";
    position: absolute;
    left: 0;
    top: 2px;
    bottom: 2px;
    width: 7px;
    background-image: repeating-linear-gradient(to bottom, var(--line) 0 1px, transparent 1px 12px);
  }

  .page-about .about-track__list {
    flex-direction: column;
    gap: 2px;
    overflow: visible;
    padding: 0;
  }

  .page-about .about-track__link {
    border: 0;
    border-left: 2px solid transparent;
    background: transparent;
    padding: 9px 10px;
    font-size: 14px;
  }

  .page-about .about-track__link:hover,
  .page-about .about-track__link:focus-visible {
    border-left-color: var(--cyan);
    background: rgba(61, 232, 210, .07);
  }

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

@media (min-width: 1040px) {
  .page-about .team-strip {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

@media (prefers-reduced-motion: reduce) {
  .page-about .about-drawer,
  .page-about .team-card,
  .page-about .about-track__link,
  .page-about .about-next__arrow {
    transition: none;
  }
}