.page-about {
  --about-panel: rgba(20, 26, 69, .78);
  --about-panel-deep: rgba(6, 10, 30, .72);
  --about-rail-w: 0px;
  overflow-x: hidden;
}

/* ---------- 面包屑之上的呼吸 ---------- */
.page-about .breadcrumb {
  padding-top: 18px;
}

/* ---------- 首屏拼贴 ---------- */
.page-about .about-hero {
  padding: 18px 0 6px;
}

.page-about .about-hero__grid {
  display: grid;
  gap: 22px;
}

.page-about .about-hero__main {
  position: relative;
  padding: 28px 20px 30px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background:
    radial-gradient(120% 140% at 0% 0%, rgba(123, 77, 255, .34), transparent 58%),
    radial-gradient(95% 120% at 100% 100%, rgba(53, 230, 208, .16), transparent 62%),
    var(--ink-2);
  overflow: hidden;
}

.page-about .about-hero__main::after {
  content: "";
  position: absolute;
  inset: auto -40% -60% auto;
  width: 240px;
  height: 240px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(255, 196, 107, .22), transparent 68%);
  pointer-events: none;
}

.page-about .about-hero__title {
  margin: 14px 0 16px;
  font-size: clamp(27px, 6.4vw, 52px);
  line-height: 1.2;
  letter-spacing: .01em;
  color: var(--paper);
  text-shadow: 0 0 22px rgba(123, 77, 255, .45);
}

.page-about .about-hero__lede {
  max-width: 62ch;
  color: var(--muted);
}

.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 22px;
}

.page-about .about-facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
}

.page-about .about-fact {
  padding: 15px 14px 16px;
  border: 1px solid var(--line);
  border-left: 2px solid var(--violet);
  border-radius: var(--radius);
  background: linear-gradient(180deg, var(--about-panel), var(--about-panel-deep));
}

.page-about .about-fact:nth-child(2) {
  border-left-color: var(--violet-soft);
}

.page-about .about-fact:nth-child(3) {
  border-left-color: var(--cyan);
}

.page-about .about-fact:nth-child(4) {
  border-left-color: var(--gold);
}

.page-about .about-fact__num {
  margin: 0 0 6px;
  font-size: 17px;
  letter-spacing: .06em;
  color: var(--paper);
  white-space: nowrap;
}

.page-about .about-fact__label {
  margin: 0;
  font-size: 12.5px;
  line-height: 1.6;
  color: var(--muted);
}

/* ---------- 主栅格：左侧年份索引 + 右侧长卷 ---------- */
.page-about .about-layout {
  display: grid;
  gap: 10px;
  padding-top: 30px;
  min-width: 0;
}

.page-about .about-rail__label {
  margin: 0 0 8px;
  font-size: 11px;
  letter-spacing: .22em;
  color: var(--violet-soft);
  text-transform: uppercase;
}

.page-about .about-rail__list {
  display: flex;
  gap: 8px;
  margin: 0;
  padding: 0 0 8px;
  list-style: none;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

.page-about .about-rail__item {
  flex: 0 0 auto;
}

.page-about .about-rail__link {
  display: flex;
  flex-direction: column;
  gap: 3px;
  min-width: 116px;
  padding: 9px 12px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--about-panel-deep);
  color: var(--muted);
  text-decoration: none;
  transition: color .25s var(--ease), border-color .25s var(--ease), background-color .25s var(--ease);
}

.page-about .about-rail__link:hover,
.page-about .about-rail__link:focus-visible {
  border-color: var(--line-strong);
  color: var(--paper);
}

.page-about .about-rail__year {
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--cyan);
  white-space: nowrap;
}

.page-about .about-rail__text {
  font-size: 12px;
  white-space: nowrap;
}

.page-about .about-flow {
  min-width: 0;
}

/* ---------- 章节 ---------- */
.page-about .about-section {
  padding: 34px 0 30px;
  border-top: 1px solid var(--line);
  scroll-margin-top: 92px;
}

.page-about .about-section:first-child {
  border-top: 0;
  padding-top: 10px;
}

.page-about .about-section__head {
  margin-bottom: 20px;
}

.page-about .about-section__title {
  margin: 12px 0 0;
  font-size: clamp(21px, 4.4vw, 32px);
  line-height: 1.32;
  color: var(--paper);
}

.page-about .about-section__meta {
  margin: 12px 0 0;
  max-width: 60ch;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--muted);
}

.page-about .about-section__body {
  display: grid;
  gap: 18px;
  min-width: 0;
}

.page-about .about-prose {
  min-width: 0;
}

.page-about .about-prose p {
  margin: 0 0 16px;
  font-size: 15.5px;
  line-height: 1.85;
  color: var(--paper);
}

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

.page-about .about-link {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(53, 230, 208, .4);
  transition: border-color .25s var(--ease), color .25s var(--ease);
}

.page-about .about-link:hover,
.page-about .about-link:focus-visible {
  color: var(--gold);
  border-bottom-color: var(--gold);
}

/* 旁注条 */
.page-about .about-note {
  position: relative;
  padding: 16px 16px 16px 18px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: linear-gradient(180deg, var(--about-panel), var(--about-panel-deep));
}

.page-about .about-note::before {
  content: "";
  position: absolute;
  left: 0;
  top: 14px;
  bottom: 14px;
  width: 2px;
  background: linear-gradient(180deg, var(--violet), var(--cyan));
  border-radius: 2px;
}

.page-about .about-note__title {
  margin: 0 0 8px;
  font-size: 11px;
  letter-spacing: .18em;
  color: var(--violet-soft);
  text-transform: uppercase;
}

.page-about .about-note p:last-child {
  margin: 0;
  font-size: 13.5px;
  line-height: 1.82;
  color: var(--muted);
}

/* 插图 */
.page-about .about-figure {
  margin: 26px 0 0;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--ink-0);
}

.page-about .about-figure .media-frame__img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
}

.page-about .about-figure .media-frame__caption {
  padding: 11px 14px 13px;
  font-size: 12.5px;
  line-height: 1.7;
  color: var(--muted);
  border-top: 1px solid var(--line);
}

/* ---------- 版本时间线 ---------- */
.page-about .about-timeline {
  display: grid;
  gap: 12px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-timeline__item {
  position: relative;
  padding: 18px 16px 18px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: linear-gradient(180deg, var(--about-panel), var(--about-panel-deep));
  transition: transform .3s var(--ease), border-color .3s var(--ease), box-shadow .3s var(--ease);
}

.page-about .about-timeline__item:hover,
.page-about .about-timeline__item:focus-within {
  transform: translateY(-4px);
  border-color: var(--line-strong);
  box-shadow: 0 0 0 1px rgba(123, 77, 255, .28), 0 16px 34px rgba(6, 10, 30, .62);
}

.page-about .about-timeline__dot {
  position: absolute;
  top: 0;
  left: 16px;
  width: 34px;
  height: 2px;
  border-radius: 2px;
  background: linear-gradient(90deg, var(--violet), var(--cyan));
}

.page-about .about-timeline__item:nth-child(4) .about-timeline__dot {
  background: linear-gradient(90deg, var(--gold), var(--violet));
}

.page-about .about-timeline__ver {
  margin: 0 0 8px;
  font-size: 20px;
  letter-spacing: .1em;
  color: var(--cyan);
  white-space: nowrap;
}

.page-about .about-timeline__item:nth-child(1) .about-timeline__ver {
  color: var(--violet-soft);
}

.page-about .about-timeline__item:nth-child(4) .about-timeline__ver {
  color: var(--gold);
}

.page-about .about-timeline__title {
  margin: 0 0 8px;
  font-size: 16px;
  line-height: 1.5;
  color: var(--paper);
}

.page-about .about-timeline__text {
  margin: 0 0 12px;
  font-size: 13.5px;
  line-height: 1.82;
  color: var(--muted);
}

.page-about .about-timeline__sum {
  margin: 0;
  padding-top: 10px;
  border-top: 1px solid var(--line);
  font-size: 11px;
  letter-spacing: .08em;
  color: var(--violet-soft);
}

/* ---------- 质量机制 ---------- */
.page-about .about-section--slab {
  position: relative;
  margin: 8px 0;
  padding: 34px 18px 32px;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  border-radius: var(--radius);
  background:
    radial-gradient(110% 120% at 100% 0%, rgba(53, 230, 208, .12), transparent 60%),
    linear-gradient(180deg, var(--ink-2), var(--ink-0));
}

.page-about .about-checks {
  display: grid;
  gap: 12px;
  margin-bottom: 22px;
}

.page-about .about-check {
  padding: 16px 16px 18px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: rgba(11, 16, 48, .72);
}

.page-about .about-check__no {
  margin: 0 0 8px;
  font-size: 11px;
  letter-spacing: .18em;
  color: var(--cyan);
}

.page-about .about-check__title {
  margin: 0 0 8px;
  font-size: 16px;
  color: var(--paper);
}

.page-about .about-check__text {
  margin: 0;
  font-size: 13.5px;
  line-height: 1.82;
  color: var(--muted);
}

.page-about .about-section__body--tight {
  margin-top: 4px;
}

.page-about .about-honors {
  padding: 16px 16px 18px;
  border: 1px dashed var(--line-strong);
  border-radius: var(--radius);
  background: rgba(6, 10, 30, .6);
}

.page-about .about-honors__list {
  display: grid;
  gap: 12px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-honors__item {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-size: 13.5px;
  line-height: 1.7;
  color: var(--paper);
}

/* ---------- 合作生态 ---------- */
.page-about .about-partners {
  display: grid;
  gap: 12px;
}

.page-about .about-partner {
  padding: 20px 18px 22px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: linear-gradient(160deg, rgba(123, 77, 255, .16), rgba(6, 10, 30, .8) 62%);
}

.page-about .about-partner__num {
  margin: 0 0 6px;
  font-size: 34px;
  line-height: 1;
  letter-spacing: .04em;
  color: var(--gold);
  white-space: nowrap;
}

.page-about .about-partner__title {
  margin: 0 0 10px;
  font-size: 16px;
  color: var(--paper);
}

.page-about .about-partner__text {
  margin: 0;
  font-size: 13.5px;
  line-height: 1.82;
  color: var(--muted);
}

/* ---------- 收束 ---------- */
.page-about .about-section--closing {
  border-top: 1px solid var(--line-strong);
}

.page-about .about-cta {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 24px;
  padding-top: 22px;
  border-top: 1px solid var(--line);
}

/* ---------- 响应式 ---------- */
@media (min-width: 700px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.5fr) minmax(0, 1fr);
    gap: 20px;
    align-items: start;
  }

  .page-about .about-hero__main {
    padding: 36px 30px 38px;
  }

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

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

  .page-about .about-checks {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

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

@media (min-width: 1000px) {
  .page-about .about-layout {
    grid-template-columns: 192px minmax(0, 1fr);
    gap: 46px;
    padding-top: 42px;
  }

  .page-about .about-rail {
    position: sticky;
    top: calc(var(--head-h) + 26px);
    align-self: start;
    padding-bottom: 20px;
  }

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

  .page-about .about-rail__item {
    flex: 1 1 auto;
  }

  .page-about .about-rail__link {
    min-width: 0;
    padding: 9px 0 9px 15px;
    border: 0;
    border-left: 2px solid var(--line);
    border-radius: 0;
    background: transparent;
  }

  .page-about .about-rail__link:hover,
  .page-about .about-rail__link:focus-visible {
    border-left-color: var(--line-strong);
    background: linear-gradient(90deg, rgba(123, 77, 255, .14), transparent 82%);
  }

  .page-about .about-rail__link.is-active {
    border-left-color: var(--cyan);
    color: var(--paper);
    background: linear-gradient(90deg, rgba(53, 230, 208, .14), transparent 84%);
  }

  .page-about .about-rail__link.is-active .about-rail__year {
    color: var(--gold);
  }

  .page-about .about-section {
    padding: 48px 0 44px;
  }

  .page-about .about-section--slab {
    padding: 44px 40px 42px;
  }

  .page-about .about-section__body {
    grid-template-columns: minmax(0, 1.7fr) minmax(0, 1fr);
    gap: 40px;
    align-items: start;
  }

  .page-about .about-note {
    margin-top: 42px;
  }

  .page-about .about-honors {
    margin-top: 42px;
  }

  .page-about .about-figure {
    margin-top: 36px;
  }
}

@media (min-width: 1200px) {
  .page-about .about-timeline {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.65fr) minmax(0, 1fr);
    gap: 28px;
  }
}