.page-about {
  --ab-toc-w: 214px;
  --ab-gap: clamp(20px, 3vw, 34px);
  background: var(--ink);
  color: var(--text);
}

/* ---------- Hero：品牌档案卡 + 等宽数字索引 ---------- */
.page-about .ab-hero {
  position: relative;
  padding: clamp(18px, 3.5vw, 34px) 0 0;
  background:
    radial-gradient(120% 130% at 92% 0%, rgba(14, 59, 52, .9), rgba(7, 26, 22, 0) 62%),
    var(--ink);
  overflow: hidden;
}

.page-about .ab-hero::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image: repeating-linear-gradient(90deg, var(--line-soft) 0 1px, transparent 1px 96px);
  opacity: .55;
}

.page-about .ab-hero > .yb-container {
  position: relative;
  z-index: 1;
}

.page-about .ab-hero__grid {
  display: grid;
  gap: clamp(22px, 4vw, 40px);
  margin-top: clamp(18px, 3vw, 28px);
}

.page-about .ab-hero__dossier .yb-eyebrow {
  margin-bottom: 14px;
}

.page-about .ab-hero__dossier .yb-lede {
  margin-top: 16px;
  max-width: 62ch;
  color: rgba(232, 240, 234, .84);
}

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

.page-about .ab-stat {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 14px 12px 16px;
  background: var(--ink-2);
  min-width: 0;
}

.page-about .ab-stat__num {
  font-family: var(--font-mono);
  font-size: clamp(19px, 3vw, 26px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -.02em;
  color: var(--lime);
  white-space: nowrap;
}

.page-about .ab-stat:nth-child(2) .ab-stat__num,
.page-about .ab-stat:nth-child(5) .ab-stat__num {
  color: var(--orange);
}

.page-about .ab-stat__label {
  font-size: 12px;
  line-height: 1.4;
  letter-spacing: .02em;
  color: var(--steel);
}

.page-about .ab-rule {
  height: 2px;
  margin-top: clamp(26px, 4vw, 46px);
  background: linear-gradient(90deg, var(--wine) 0%, var(--indigo) 38%, var(--jade) 66%, var(--lime) 100%);
}

/* ---------- 主体：左索引 + 右正文 ---------- */
.page-about .ab-body {
  display: grid;
  gap: clamp(24px, 4vw, 44px);
  padding-top: clamp(28px, 5vw, 56px);
  padding-bottom: clamp(40px, 6vw, 76px);
}

.page-about .ab-toc {
  border: 1px solid var(--line);
  background: rgba(13, 18, 17, .78);
  padding: 16px 14px 18px;
}

.page-about .ab-toc__title {
  margin: 0 0 12px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .2em;
  text-transform: uppercase;
  color: var(--steel);
}

.page-about .ab-toc__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 2px;
}

.page-about .ab-toc__link {
  display: grid;
  grid-template-columns: 24px minmax(0, 1fr);
  align-items: baseline;
  gap: 6px;
  padding: 8px 6px 8px 8px;
  border-left: 2px solid transparent;
  font-size: 13.5px;
  line-height: 1.45;
  color: var(--steel);
  text-decoration: none;
  transition: color .22s var(--ease), background .22s var(--ease), border-color .22s var(--ease);
}

.page-about .ab-toc__link:hover,
.page-about .ab-toc__link:focus-visible {
  color: var(--text);
  background: rgba(201, 255, 63, .07);
  outline: none;
}

.page-about .ab-toc__link[aria-current="true"] {
  color: var(--lime);
  border-left-color: var(--orange);
  background: rgba(201, 255, 63, .09);
}

.page-about .ab-toc__idx {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .06em;
  opacity: .85;
}

.page-about .ab-toc__note {
  margin: 16px 0 0;
  padding-top: 12px;
  border-top: 1px solid var(--line-soft);
  font-size: 12.5px;
  line-height: 1.7;
  color: var(--steel);
}

.page-about .ab-toc__note a {
  color: var(--lime);
  text-decoration: none;
  border-bottom: 1px solid rgba(201, 255, 63, .45);
}

.page-about .ab-articles {
  display: grid;
  gap: clamp(34px, 5vw, 68px);
  min-width: 0;
}

/* ---------- 章节骨架 ---------- */
.page-about .ab-sec {
  scroll-margin-top: 116px;
  display: grid;
  gap: clamp(14px, 2vw, 20px);
}

.page-about .ab-sec__head {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 12px;
  align-items: baseline;
  padding-top: 16px;
  border-top: 1px solid var(--line);
}

.page-about .ab-sec__no {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--lime);
}

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

.page-about .ab-sec__cols {
  display: grid;
  gap: clamp(16px, 3vw, 26px);
  min-width: 0;
}

.page-about .ab-sec__text {
  min-width: 0;
}

.page-about .ab-sec__text p {
  margin: 0 0 14px;
  font-size: 15.5px;
  line-height: 1.8;
  color: var(--text);
}

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

.page-about .ab-sec__text--lead {
  margin: 0;
  max-width: 66ch;
  font-size: 15.5px;
  line-height: 1.8;
  color: rgba(232, 240, 234, .86);
}

.page-about .ab-note {
  padding: 6px 0 6px 13px;
  border-left: 2px solid var(--wine);
  font-size: 13px;
  line-height: 1.75;
  color: var(--steel);
}

.page-about .ab-note p {
  margin: 0;
}

.page-about .ab-note a {
  color: var(--lime);
  text-decoration: none;
  border-bottom: 1px solid rgba(201, 255, 63, .45);
}

/* ---------- 版本时间线 ---------- */
.page-about .ab-flow {
  list-style: none;
  margin: 6px 0 0;
  padding: 0 0 0 22px;
  border-left: 1px solid var(--line-strong);
  display: grid;
  gap: 18px;
}

.page-about .ab-flow__item {
  position: relative;
  min-width: 0;
}

.page-about .ab-flow__item::before {
  content: "";
  position: absolute;
  left: -26.5px;
  top: 7px;
  width: 9px;
  height: 9px;
  background: var(--lime);
}

.page-about .ab-flow__item--now::before {
  background: var(--orange);
  box-shadow: 0 0 0 3px rgba(255, 106, 43, .18);
}

.page-about .ab-flow__year {
  margin: 0 0 6px;
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: .08em;
  color: var(--lime);
}

.page-about .ab-flow__item--now .ab-flow__year {
  color: var(--orange);
}

.page-about .ab-flow__box {
  border: 1px solid var(--line-soft);
  background: var(--ink-2);
}

.page-about .ab-flow__box[open] {
  border-color: var(--line-strong);
}

.page-about .ab-flow__summary {
  display: block;
  padding: 12px 14px;
  font-size: 14.5px;
  font-weight: 600;
  line-height: 1.55;
  color: var(--text);
  cursor: pointer;
  list-style: none;
  transition: color .2s var(--ease), background .2s var(--ease);
}

.page-about .ab-flow__summary::-webkit-details-marker {
  display: none;
}

.page-about .ab-flow__summary:hover {
  color: var(--lime);
  background: rgba(201, 255, 63, .05);
}

.page-about .ab-flow__more {
  margin: 0;
  padding: 0 14px 14px;
  font-size: 14px;
  line-height: 1.75;
  color: rgba(232, 240, 234, .8);
  border-top: 1px solid var(--line-soft);
  padding-top: 12px;
}

/* ---------- 图片与数据行 ---------- */
.page-about .ab-figure {
  margin: 0;
  min-width: 0;
}

.page-about .ab-figure .yb-media {
  max-width: 100%;
}

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

.page-about .ab-metrics {
  list-style: none;
  margin: 4px 0 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line-soft);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.page-about .ab-metrics li {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 14px;
  padding: 11px 13px;
  background: var(--ink);
  min-width: 0;
}

.page-about .ab-metrics__k {
  font-size: 13px;
  line-height: 1.5;
  color: var(--steel);
}

.page-about .ab-metrics__v {
  font-family: var(--font-mono);
  font-size: 14.5px;
  font-weight: 600;
  line-height: 1.4;
  color: var(--lime);
  text-align: right;
  white-space: nowrap;
}

.page-about .ab-tags {
  list-style: none;
  margin: 2px 0 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

/* ---------- 收束区 ---------- */
.page-about .ab-close {
  background: linear-gradient(104deg, var(--wine) 0%, var(--indigo) 56%, var(--jade) 100%);
  border-top: 1px solid var(--line);
  padding: clamp(34px, 6vw, 66px) 0 clamp(38px, 6vw, 70px);
}

.page-about .ab-close .yb-eyebrow {
  color: rgba(236, 234, 246, .82);
}

.page-about .ab-close h2 {
  margin: 14px 0 0;
  max-width: 22ch;
  color: #f3f0f8;
}

.page-about .ab-close__lede {
  margin: 16px 0 0;
  max-width: 60ch;
  font-size: 15px;
  line-height: 1.8;
  color: rgba(243, 240, 248, .86);
}

.page-about .ab-close__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 26px;
}

/* ---------- 断点 ---------- */
@media (min-width: 560px) {
  .page-about .ab-hero__stats {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

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

@media (min-width: 780px) {
  .page-about .ab-sec__cols {
    grid-template-columns: minmax(0, 1fr) 208px;
    align-items: start;
  }

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

  .page-about .ab-sec__cols--wide .ab-sec__text {
    max-width: 72ch;
  }
}

@media (min-width: 960px) {
  .page-about .ab-hero__grid {
    grid-template-columns: minmax(0, 1.12fr) minmax(0, .88fr);
    align-items: end;
  }
}

@media (min-width: 1000px) {
  .page-about .ab-body {
    grid-template-columns: var(--ab-toc-w) minmax(0, 1fr);
    gap: clamp(32px, 4.5vw, 68px);
    align-items: start;
  }

  .page-about .ab-toc {
    position: sticky;
    top: 108px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .ab-toc__link,
  .page-about .ab-flow__summary {
    transition: none;
  }
}
<<<END>>>