.page-about {
  --about-rail: 96px;
  --about-hair: rgba(79, 190, 134, .28);
  --about-panel: rgba(11, 51, 42, .72);
  padding-block: clamp(16px, 2.4vw, 28px) clamp(56px, 9vw, 104px);
}

.page-about a:focus-visible,
.page-about summary:focus-visible {
  outline: 2px solid var(--volt-200);
  outline-offset: 3px;
}

/* ---------- 面包屑 ---------- */
.page-about .breadcrumb {
  margin-bottom: clamp(18px, 3vw, 30px);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  display: grid;
  gap: clamp(22px, 3.4vw, 40px);
  margin-bottom: clamp(26px, 4vw, 46px);
}

.page-about .about-hero__kicker {
  margin: 0 0 12px;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--pitch-300);
}

.page-about .about-hero__title {
  margin: 0 0 16px;
  font-family: var(--font-display);
  font-size: clamp(30px, 6vw, 56px);
  font-weight: 600;
  line-height: 1.1;
  letter-spacing: -0.01em;
  color: var(--mist-050);
}

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

.page-about .lede {
  margin: 0 0 16px;
  font-size: clamp(16px, 1.7vw, 18px);
  line-height: 1.8;
  color: var(--mist-050);
  max-width: 64ch;
}

.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 0 0 clamp(20px, 3vw, 30px);
}

.page-about .about-hero__figure {
  position: relative;
  margin: 0;
  overflow: hidden;
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  background: var(--ink-800);
}

.page-about .about-hero__figure::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, rgba(6, 35, 28, 0) 42%, rgba(6, 35, 28, .62));
  pointer-events: none;
}

.page-about .about-hero__figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  aspect-ratio: 14 / 9;
  object-fit: cover;
}

@media (min-width: 940px) {
  .page-about .about-hero {
    grid-template-columns: minmax(0, 1.06fr) minmax(0, .94fr);
    align-items: start;
  }
  .page-about .about-hero__copy {
    padding-top: clamp(6px, 1.4vw, 20px);
  }
  .page-about .about-hero__br {
    display: inline;
  }
  .page-about .about-hero__figure {
    margin-top: clamp(0px, 1vw, 14px);
  }
}

/* ---------- 数据胶囊 ---------- */
.page-about .stat-strip {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(148px, 1fr));
  gap: 12px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .stat {
  padding: 14px 16px;
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  background: var(--about-panel);
  transition: transform var(--t), border-color var(--t), box-shadow var(--t);
}

.page-about .stat:hover,
.page-about .stat:focus-within {
  transform: translateY(-2px);
  border-color: rgba(201, 242, 77, .45);
  box-shadow: var(--shadow-1);
}

.page-about .stat__num {
  display: block;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(22px, 2.8vw, 30px);
  line-height: 1.12;
  color: var(--volt-400);
  letter-spacing: -0.01em;
}

.page-about .stat__label {
  display: block;
  margin-top: 5px;
  font-size: 13px;
  line-height: 1.5;
  color: var(--text-dim);
}

.page-about .stat__note {
  display: block;
  max-height: 0;
  margin-top: 0;
  padding-top: 0;
  overflow: hidden;
  opacity: 0;
  border-top: 1px dashed transparent;
  font-size: 12.5px;
  line-height: 1.65;
  color: var(--text-dim);
  transition: max-height 220ms ease, opacity 220ms ease, margin-top 220ms ease, padding-top 220ms ease, border-color 220ms ease;
}

.page-about .stat:hover .stat__note,
.page-about .stat:focus-within .stat__note {
  max-height: 120px;
  margin-top: 9px;
  padding-top: 9px;
  opacity: 1;
  border-top-color: rgba(159, 184, 172, .3);
}

@media (max-width: 719px) {
  .page-about .stat__note {
    max-height: none;
    margin-top: 9px;
    padding-top: 9px;
    opacity: 1;
    border-top-color: rgba(159, 184, 172, .3);
  }
}

/* ---------- 章节索引条 ---------- */
.page-about .about-index {
  margin: 0 0 clamp(20px, 3vw, 34px);
  padding: 10px 0;
  border-top: 1px solid var(--about-hair);
  border-bottom: 1px solid var(--about-hair);
  overflow-x: auto;
  scrollbar-width: thin;
}

.page-about .about-index__list {
  display: flex;
  gap: 10px;
  margin: 0;
  padding: 0;
  list-style: none;
  min-width: max-content;
}

.page-about .about-index__link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 15px;
  border: 1px solid var(--border);
  border-radius: var(--radius-pill);
  background: rgba(11, 51, 42, .6);
  color: var(--mist-050);
  font-size: 14px;
  line-height: 1.2;
  text-decoration: none;
  white-space: nowrap;
  transition: border-color var(--t), background var(--t), transform var(--t);
}

.page-about .about-index__link:hover {
  border-color: var(--volt-400);
  background: rgba(201, 242, 77, .1);
  transform: translateY(-2px);
}

.page-about .about-index__num {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 12px;
  color: var(--pitch-300);
}

/* ---------- 章节 ---------- */
.page-about .chapter {
  display: grid;
  gap: 14px;
  padding-top: clamp(30px, 4.6vw, 56px);
  scroll-margin-top: 104px;
}

.page-about .chapter::after {
  content: "";
  grid-column: 1 / -1;
  height: 2px;
  margin-top: clamp(22px, 3.4vw, 38px);
  border-radius: 2px;
  background: linear-gradient(90deg, var(--pitch-500), var(--pitch-300) 40%, rgba(79, 190, 134, 0) 94%);
}

.page-about .chapter__rail {
  display: flex;
  align-items: baseline;
  gap: 12px;
}

.page-about .chapter__num {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 30px;
  line-height: 1;
  letter-spacing: .02em;
  color: var(--pitch-300);
  opacity: .85;
}

@supports (-webkit-text-stroke: 1px red) {
  .page-about .chapter__num {
    color: transparent;
    -webkit-text-stroke: 1.5px var(--pitch-300);
    opacity: 1;
  }
}

.page-about .chapter__tag {
  font-size: 12px;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--text-dim);
}

.page-about .chapter__title {
  margin: 0 0 14px;
  font-family: var(--font-display);
  font-size: clamp(23px, 3.3vw, 34px);
  font-weight: 600;
  line-height: 1.22;
  letter-spacing: -0.01em;
  color: var(--mist-050);
}

.page-about .chapter__body > p,
.page-about .chapter__text > p {
  margin: 0 0 14px;
  font-size: clamp(16px, 1.45vw, 17px);
  line-height: 1.85;
  color: var(--mist-050);
  max-width: 68ch;
}

.page-about .chapter__figure {
  margin: 4px 0 0;
  overflow: hidden;
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  background: var(--ink-800);
}

.page-about .chapter__figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  aspect-ratio: 3 / 2;
  object-fit: cover;
}

.page-about .chapter__figure .media__cap {
  padding: 10px 14px 12px;
  font-size: 12.5px;
  line-height: 1.6;
  color: var(--text-dim);
}

@media (min-width: 880px) {
  .page-about .chapter {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    column-gap: clamp(24px, 4vw, 54px);
  }
  .page-about .chapter__rail {
    flex-direction: column;
    gap: 10px;
    align-self: start;
    position: sticky;
    top: 92px;
  }
  .page-about .chapter__num {
    font-size: 40px;
  }
}

@media (min-width: 980px) {
  .page-about .chapter__body--split {
    display: grid;
    grid-template-columns: minmax(0, 1.25fr) minmax(0, .75fr);
    gap: clamp(22px, 3vw, 40px);
    align-items: start;
  }
  .page-about .chapter__body--split .chapter__figure {
    margin-top: 6px;
  }
}

/* ---------- 时间轴 ---------- */
.page-about .timeline {
  position: relative;
  display: grid;
  gap: 12px;
  margin: 6px 0 0;
  padding: 0 0 0 28px;
  list-style: none;
}

.page-about .timeline::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 16px;
  bottom: 16px;
  width: 2px;
  border-radius: 2px;
  background: linear-gradient(180deg, var(--pitch-500), rgba(30, 138, 85, .12));
}

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

.page-about .timeline__item::before {
  content: "";
  position: absolute;
  left: -28px;
  top: 15px;
  width: 12px;
  height: 12px;
  box-sizing: border-box;
  border: 2px solid var(--pitch-300);
  border-radius: 50%;
  background: var(--ink-900);
}

.page-about .tl-node {
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  background: linear-gradient(160deg, rgba(11, 51, 42, .92), rgba(6, 35, 28, .92));
  overflow: hidden;
  transition: transform var(--t), border-color var(--t), box-shadow var(--t);
}

.page-about .tl-node:hover {
  transform: translateY(-2px);
  border-color: rgba(79, 190, 134, .55);
  box-shadow: var(--shadow-1);
}

.page-about .tl-node__head {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 14px 16px;
  cursor: pointer;
  list-style: none;
}

.page-about .tl-node__head::-webkit-details-marker {
  display: none;
}

.page-about .tl-node__head::after {
  content: "";
  flex: none;
  margin-left: auto;
  width: 8px;
  height: 8px;
  border-right: 2px solid var(--pitch-300);
  border-bottom: 2px solid var(--pitch-300);
  transform: rotate(45deg);
  transition: transform var(--t);
}

.page-about .tl-node[open] .tl-node__head::after {
  transform: rotate(-135deg);
}

.page-about .tl-node__year {
  flex: none;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 19px;
  letter-spacing: .02em;
  color: var(--amber-500);
}

.page-about .tl-node__title {
  font-family: var(--font-display);
  font-size: 17px;
  font-weight: 600;
  line-height: 1.4;
  color: var(--mist-050);
}

.page-about .tl-node__body {
  padding: 0 16px 16px;
}

.page-about .tl-node__body p {
  margin: 0;
  font-size: 15.5px;
  line-height: 1.8;
  color: var(--text-dim);
  max-width: 64ch;
}

/* ---------- 收尾 ---------- */
.page-about .closing {
  margin-top: clamp(34px, 5vw, 58px);
  padding: clamp(22px, 3.4vw, 38px);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  background:
    radial-gradient(120% 140% at 100% 0%, rgba(201, 242, 77, .12), transparent 58%),
    var(--ink-800);
}

.page-about .closing__title {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-size: clamp(21px, 2.8vw, 28px);
  font-weight: 600;
  line-height: 1.25;
  color: var(--mist-050);
}

.page-about .closing__desc {
  margin: 0 0 18px;
  font-size: 16px;
  line-height: 1.8;
  color: var(--text-dim);
  max-width: 62ch;
}

.page-about .closing__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}
<<<END>>>