.page-about {
  --about-num-size: clamp(26px, 4vw, 32px);
  position: relative;
  padding-bottom: 88px;
}

.page-about::before {
  content: "";
  position: absolute;
  top: -20px;
  left: 0;
  right: 0;
  height: 460px;
  pointer-events: none;
  z-index: 0;
  background:
    radial-gradient(58% 96% at 12% 0%, rgba(87, 217, 163, .10), transparent 72%),
    radial-gradient(52% 88% at 88% 6%, rgba(142, 123, 239, .12), transparent 72%);
}

.page-about .ab-hero,
.page-about .about-layout {
  position: relative;
  z-index: 1;
}

/* ---------- 首屏 ---------- */

.page-about .ab-hero {
  padding: 4px 0 40px;
  border-bottom: 1px solid var(--line);
  margin-bottom: 36px;
}

.page-about .ab-hero h1 {
  margin: 16px 0 0;
  font-size: clamp(30px, 6.2vw, 54px);
  line-height: 1.14;
  letter-spacing: -0.02em;
  font-weight: 900;
  max-width: 17em;
}

.page-about .ab-hero__lede {
  margin: 20px 0 0;
  max-width: 64ch;
  color: var(--text);
  opacity: .9;
}

.page-about .ab-hero__stats {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0;
  margin: 34px 0 0;
  padding: 0;
}

.page-about .ab-stat {
  padding: 14px 0;
  border-top: 1px solid var(--line);
}

.page-about .ab-stat dt {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--muted);
}

.page-about .ab-stat dd {
  margin: 8px 0 0;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: var(--about-num-size);
  line-height: 1;
  letter-spacing: -0.01em;
}

.page-about .ab-stat--amber dd { color: var(--amber); }
.page-about .ab-stat--lime dd { color: var(--lime); }
.page-about .ab-stat--violet dd { color: var(--violet); }

/* ---------- 左侧章节轨道 ---------- */

.page-about .about-layout {
  display: block;
}

.page-about .tl-rail {
  margin-bottom: 30px;
}

.page-about .tl-rail__title {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--muted-dim);
  margin: 0 0 10px;
  display: none;
}

.page-about .tl-rail__list {
  display: flex;
  gap: 18px;
  margin: 0;
  padding: 0 0 4px;
  list-style: none;
  overflow-x: auto;
  scrollbar-width: none;
  border-bottom: 1px solid var(--line);
}

.page-about .tl-rail__list::-webkit-scrollbar {
  display: none;
}

.page-about .tl-rail__link {
  display: inline-flex;
  align-items: baseline;
  gap: 7px;
  white-space: nowrap;
  padding-bottom: 8px;
  font-size: 14px;
  color: var(--muted);
  text-decoration: none;
  border-bottom: 2px solid transparent;
  transition: color .25s var(--ease), border-color .25s var(--ease);
}

.page-about .tl-rail__link .num {
  font-size: 12px;
  color: var(--violet);
}

.page-about .tl-rail__link:hover,
.page-about .tl-rail__link:focus-visible {
  color: var(--text);
  border-bottom-color: var(--violet);
}

/* ---------- 章节 ---------- */

.page-about .ab-sec {
  padding: 0 0 46px;
}

.page-about .ab-sec + .ab-sec {
  padding-top: 4px;
}

.page-about .ab-sec__body {
  margin-top: 20px;
  display: grid;
  gap: 22px;
}

.page-about .ab-sec p {
  max-width: 66ch;
  margin: 0;
}

.page-about .ab-sec__body > p + p {
  margin-top: -4px;
}

.page-about .ab-sec .rule-strip {
  margin-top: 38px;
}

.page-about .ab-sub {
  font-size: 18px;
  font-weight: 700;
  letter-spacing: -0.01em;
  margin: 0 0 12px;
  color: var(--text);
}

.page-about .ab-split {
  display: grid;
  gap: 24px;
}

.page-about .ab-split > div + div {
  padding-top: 22px;
  border-top: 1px solid var(--line);
}

.page-about .ab-prose {
  display: grid;
  gap: 16px;
}

.page-about .ab-prose__link {
  color: var(--muted);
  font-size: 14px;
}

.page-about .ab-prose__link a {
  color: var(--lime);
  text-decoration: none;
  border-bottom: 1px solid rgba(87, 217, 163, .4);
}

.page-about .ab-prose__link a:hover,
.page-about .ab-prose__link a:focus-visible {
  border-bottom-color: var(--lime);
}

/* ---------- 要点列表 ---------- */

.page-about .ab-points {
  list-style: none;
  margin: 6px 0 0;
  padding: 0;
  display: grid;
  gap: 0;
}

.page-about .ab-points li {
  display: grid;
  grid-template-columns: 30px minmax(0, 1fr);
  gap: 14px;
  align-items: baseline;
  padding: 13px 0;
  border-top: 1px solid var(--line);
  max-width: 68ch;
}

.page-about .ab-points li:last-child {
  border-bottom: 1px solid var(--line);
}

.page-about .ab-points .idx {
  color: var(--violet);
  font-size: 12px;
}

.page-about .ab-points--compact li {
  padding: 10px 0;
}

.page-about .ab-points--compact .idx {
  color: var(--amber);
}

/* ---------- 版本演进 ---------- */

.page-about .ab-figure {
  margin: 0;
}

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

.page-about .media-frame__cap {
  font-size: 13px;
  line-height: 1.7;
  color: var(--muted);
}

.page-about .ver-track {
  list-style: none;
  margin: 8px 0 0;
  padding: 0;
  display: grid;
  gap: 16px;
}

.page-about .ver-card {
  position: relative;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 3px;
  padding: 20px 18px 22px;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, .04);
  outline: none;
  transition: transform .3s var(--ease), border-color .3s var(--ease);
}

.page-about .ver-card::before {
  content: "";
  position: absolute;
  top: -1px;
  left: 18px;
  right: 18px;
  height: 2px;
  background: linear-gradient(90deg, var(--violet), rgba(142, 123, 239, 0));
}

.page-about .ver-card:hover,
.page-about .ver-card:focus-visible {
  transform: translateY(-3px);
  border-color: rgba(142, 123, 239, .5);
}

.page-about .ver-card__tag {
  display: inline-block;
  margin: 0 0 14px;
}

.page-about .ver-card__title {
  margin: 0 0 10px;
  font-size: 20px;
  font-weight: 800;
  letter-spacing: -0.01em;
}

.page-about .ver-card__sum {
  font-size: 15px;
  line-height: 1.8;
  color: var(--text);
  opacity: .88;
}

.page-about .ver-card__more {
  margin: 12px 0 0;
  padding-top: 12px;
  border-top: 1px dashed var(--line);
  font-size: 13px;
  line-height: 1.75;
  color: var(--muted);
}

/* ---------- 团队 ---------- */

.page-about .team-grid {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 14px;
}

.page-about .team-cell {
  border: 1px solid var(--line);
  border-top: 2px solid var(--line);
  border-radius: 2px;
  padding: 18px 16px 20px;
  background: linear-gradient(180deg, rgba(22, 47, 71, .72), rgba(18, 41, 63, .48));
}

.page-about .team-cell--lime { border-top-color: var(--lime); }
.page-about .team-cell--amber { border-top-color: var(--amber); }
.page-about .team-cell--violet { border-top-color: var(--violet); }
.page-about .team-cell--orange { border-top-color: var(--orange); }

.page-about .team-cell__num {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 28px;
  line-height: 1;
  margin: 0 0 10px;
  color: var(--text);
}

.page-about .team-cell__name {
  margin: 0 0 8px;
  font-size: 16px;
  font-weight: 700;
}

.page-about .team-cell p {
  max-width: none;
  font-size: 14px;
  line-height: 1.75;
  color: var(--muted);
}

/* ---------- 处理流程 ---------- */

.page-about .flow {
  list-style: none;
  margin: 4px 0 0;
  padding: 0;
}

.page-about .flow li {
  display: grid;
  grid-template-columns: 34px minmax(0, 1fr);
  gap: 16px;
  padding: 16px 0;
  border-top: 1px solid var(--line);
}

.page-about .flow li:last-child {
  border-bottom: 1px solid var(--line);
}

.page-about .flow__step {
  font-size: 13px;
  color: var(--amber);
  padding-top: 3px;
}

.page-about .flow__text h3 {
  margin: 0 0 6px;
  font-size: 16px;
  font-weight: 700;
}

.page-about .flow__text p {
  max-width: 62ch;
  font-size: 14px;
  line-height: 1.75;
  color: var(--muted);
}

/* ---------- 节奏分栏 ---------- */

.page-about .ab-sec__body--split {
  display: grid;
  gap: 26px;
}

/* ---------- 对照表 ---------- */

.page-about .ab-table {
  margin: 6px 0 0;
}

.page-about .ab-table caption {
  text-align: left;
  padding-bottom: 10px;
}

/* ---------- 保障 ---------- */

.page-about .assure-grid {
  display: grid;
  gap: 14px;
}

.page-about .assure-card {
  border: 1px solid var(--line);
  border-radius: 3px;
  padding: 20px 18px 22px;
  background: var(--panel);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, .04);
}

.page-about .assure-card__num {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: var(--about-num-size);
  line-height: 1;
  margin: 0 0 12px;
  color: var(--lime);
}

.page-about .assure-card h3 {
  margin: 0 0 10px;
  font-size: 16px;
  font-weight: 700;
}

.page-about .assure-card p {
  max-width: none;
  font-size: 14px;
  line-height: 1.8;
  color: var(--muted);
}

.page-about .ab-cta {
  margin-top: 10px;
  padding: 22px 20px;
  border: 1px solid var(--line);
  border-left: 3px solid var(--amber);
  border-radius: 2px;
  background: linear-gradient(90deg, rgba(242, 193, 78, .07), rgba(18, 41, 63, .3) 60%);
}

.page-about .ab-cta p {
  margin: 0 0 16px;
  max-width: 58ch;
  color: var(--text);
}

.page-about .ab-cta__row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

/* ---------- 中等宽度 ---------- */

@media (min-width: 640px) {
  .page-about .ab-hero__stats {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .ab-stat {
    padding: 16px 20px;
    border-top: 0;
    border-left: 1px solid var(--line);
  }

  .page-about .ab-stat:first-child {
    padding-left: 0;
    border-left: 0;
  }

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

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

  .page-about .ab-split {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 32px;
  }

  .page-about .ab-split > div + div {
    padding-top: 0;
    padding-left: 32px;
    border-top: 0;
    border-left: 1px solid var(--line);
  }
}

/* ---------- 桌面：左侧长轴 + 右侧长卷 ---------- */

@media (min-width: 1024px) {
  .page-about .about-layout {
    display: grid;
    grid-template-columns: 176px minmax(0, 1fr);
    column-gap: 58px;
  }

  .page-about .tl-rail {
    grid-column: 1;
    grid-row: 1;
    position: sticky;
    top: 44px;
    align-self: start;
    margin-bottom: 0;
  }

  .page-about .tl-rail__title {
    display: block;
  }

  .page-about .tl-rail__list {
    flex-direction: column;
    gap: 0;
    padding: 0;
    overflow: visible;
    border-bottom: 0;
    border-left: 1px solid var(--line);
  }

  .page-about .tl-rail__link {
    display: flex;
    gap: 10px;
    padding: 9px 0 9px 14px;
    margin-left: -1px;
    font-size: 13px;
    border-bottom: 0;
    border-left: 2px solid transparent;
  }

  .page-about .tl-rail__link:hover,
  .page-about .tl-rail__link:focus-visible {
    border-bottom-color: transparent;
    border-left-color: var(--violet);
  }

  .page-about .about-main {
    grid-column: 2;
    min-width: 0;
  }

  .page-about .ab-sec__body--split {
    grid-template-columns: minmax(0, 1fr) minmax(0, 400px);
    gap: 40px;
    align-items: start;
  }

  .page-about .ver-track {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 18px;
  }

  .page-about .ver-card:not(:last-child)::after {
    content: "";
    position: absolute;
    top: 46px;
    right: -18px;
    width: 18px;
    height: 1px;
    background: var(--line);
  }
}

@media (min-width: 1100px) {
  .page-about .team-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

/* ---------- 仅悬停设备：版本卡片展开要点 ---------- */

@media (hover: hover) and (min-width: 1024px) {
  .page-about .ver-card__more {
    display: grid;
    grid-template-rows: 0fr;
    opacity: 0;
    margin-top: 0;
    padding-top: 0;
    border-top-color: transparent;
    transition: grid-template-rows .38s var(--ease), opacity .3s var(--ease),
      margin-top .38s var(--ease), padding-top .38s var(--ease);
  }

  .page-about .ver-card__more-inner {
    overflow: hidden;
  }

  .page-about .ver-card:hover .ver-card__more,
  .page-about .ver-card:focus-visible .ver-card__more {
    grid-template-rows: 1fr;
    opacity: 1;
    margin-top: 12px;
    padding-top: 12px;
    border-top-color: var(--line);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ver-card,
  .page-about .tl-rail__link,
  .page-about .ver-card__more {
    transition: none;
  }

  .page-about .ver-card:hover,
  .page-about .ver-card:focus-visible {
    transform: none;
  }
}
<<<END>>>