.page-about {
  --ab-line: rgba(232, 241, 237, .14);
  --ab-line-soft: rgba(232, 241, 237, .08);
  --ab-year-col: 104px;
  display: block;
  overflow-x: hidden;
}

.page-about img {
  max-width: 100%;
  height: auto;
  display: block;
}

.page-about .breadcrumb-sep {
  color: var(--c-neutral);
  margin: 0 8px;
  font-size: 12px;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  display: grid;
  grid-template-columns: 1fr;
  gap: 34px;
  padding-top: 32px;
  padding-bottom: 48px;
  align-items: center;
}

.page-about .about-kicker {
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .28em;
  text-transform: uppercase;
  color: var(--c-cyan);
}

.page-about .about-hero h1 {
  margin: 0 0 18px;
  font-size: clamp(30px, 7.6vw, 52px);
  line-height: 1.12;
  letter-spacing: -0.02em;
  font-weight: 800;
  color: var(--c-mist);
}

.page-about .about-lede {
  margin: 0 0 26px;
  max-width: 48ch;
  font-size: 15.5px;
  line-height: 1.8;
  color: var(--c-body);
}

.page-about .about-hero-visual {
  position: relative;
  border: 1px solid var(--glass-line);
  border-radius: var(--radius);
  background:
    radial-gradient(120% 88% at 80% 6%, rgba(40, 240, 200, .16), transparent 62%),
    linear-gradient(165deg, var(--c-ink) 0%, var(--c-carbon) 84%);
  padding: 20px 18px 12px;
  overflow: hidden;
}

.page-about .about-hero-visual::after {
  content: "";
  position: absolute;
  inset: 0;
  background-image: linear-gradient(rgba(232, 241, 237, .045) 1px, transparent 1px);
  background-size: 100% 34px;
  pointer-events: none;
}

.page-about .hero-chart {
  position: relative;
  z-index: 1;
  display: block;
  width: 100%;
  height: auto;
}

/* ---------- 通用章节头 ---------- */
.page-about .section {
  padding: 46px 0;
}

.page-about .about-head {
  max-width: 64ch;
  margin-bottom: 26px;
}

.page-about .about-index {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .3em;
  text-transform: uppercase;
  color: var(--c-cyan);
}

.page-about .about-title {
  margin: 0 0 12px;
  font-size: clamp(21px, 4.4vw, 31px);
  line-height: 1.3;
  letter-spacing: -0.01em;
  font-weight: 800;
  color: var(--c-mist);
}

.page-about .about-desc {
  margin: 0;
  font-size: 15px;
  line-height: 1.78;
  color: var(--c-body);
}

.page-about .about-text {
  margin: 0 0 16px;
  max-width: 66ch;
  font-size: 15.5px;
  line-height: 1.8;
  color: var(--c-body);
}

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

/* ---------- 起点章节 ---------- */
.page-about .about-chapter {
  display: grid;
  grid-template-columns: 1fr;
  gap: 26px;
  align-items: start;
}

.page-about .about-chapter-media {
  margin: 0;
}

.page-about .about-chapter-media img {
  width: 100%;
  aspect-ratio: 14 / 9;
  object-fit: cover;
  border: 1px solid var(--ab-line);
  border-radius: var(--radius);
  filter: saturate(.86) contrast(1.06);
}

.page-about .about-chapter-media figcaption,
.page-about .media-caption {
  margin-top: 10px;
  font-size: 12.5px;
  line-height: 1.6;
  color: var(--c-neutral);
}

/* ---------- 时间轴 ---------- */
.page-about .tl-wrap {
  display: grid;
  grid-template-columns: 1fr;
  gap: 22px;
}

.page-about .tl-nav {
  display: flex;
  gap: 6px;
  overflow-x: auto;
  padding: 10px;
  -webkit-overflow-scrolling: touch;
}

.page-about .tl-nav a {
  flex: 0 0 auto;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--c-neutral);
  text-decoration: none;
  padding: 6px 10px;
  border: 1px solid transparent;
  border-radius: var(--radius);
  white-space: nowrap;
  transition: color var(--t-fast) ease, border-color var(--t-fast) ease,
              background var(--t-fast) ease;
}

.page-about .tl-nav a:hover,
.page-about .tl-nav a:focus-visible {
  color: var(--c-cyan);
  border-color: var(--glass-line);
  background: rgba(40, 240, 200, .08);
}

.page-about .tl-nav a:focus-visible {
  outline: 2px solid var(--c-cyan);
  outline-offset: 2px;
}

.page-about .tl {
  list-style: none;
  margin: 0;
  padding: 0 0 0 30px;
  position: relative;
}

.page-about .tl::before {
  content: "";
  position: absolute;
  top: 12px;
  bottom: 12px;
  left: 8px;
  width: 1px;
  background: linear-gradient(180deg,
    var(--glass-line) 0%,
    var(--ab-line) 22%,
    var(--ab-line) 72%,
    transparent 100%);
}

.page-about .tl-item {
  position: relative;
  padding-bottom: 24px;
  scroll-margin-top: 110px;
}

.page-about .tl-item::before {
  content: "";
  position: absolute;
  top: 12px;
  left: -26px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--c-carbon);
  border: 1px solid var(--glass-line);
  transition: background var(--t-base) ease, border-color var(--t-base) ease,
              box-shadow var(--t-base) ease;
}

.page-about .tl-year {
  margin: 0 0 8px;
  font-family: var(--font-mono);
  font-size: 19px;
  letter-spacing: .04em;
  color: var(--c-neutral);
  font-variant-numeric: tabular-nums;
  transition: color var(--t-base) ease;
}

.page-about .tl-body {
  border: 1px solid var(--glass-line);
  border-radius: var(--radius);
  background: var(--glass);
  padding: 16px 18px;
  transition: transform var(--t-base) ease, background var(--t-base) ease,
              border-color var(--t-base) ease;
}

.page-about .tl-body:hover {
  transform: translateY(-3px);
  background: rgba(40, 240, 200, .14);
}

.page-about .tl-body:focus-within {
  border-color: var(--c-cyan);
}

.page-about .tl-title {
  margin: 0 0 8px;
  font-size: 17px;
  line-height: 1.45;
  font-weight: 700;
  color: var(--c-mist);
}

.page-about .tl-text {
  margin: 0;
  max-width: 62ch;
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--c-body);
}

.page-about .tl-detail {
  margin-top: 12px;
  border-top: 1px solid var(--ab-line-soft);
}

.page-about .tl-detail summary {
  display: inline-block;
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .16em;
  color: var(--c-cyan);
  cursor: pointer;
  list-style: none;
}

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

.page-about .tl-detail summary::after {
  content: "  ＋";
}

.page-about .tl-detail[open] summary::after {
  content: "  －";
}

.page-about .tl-detail summary:focus-visible {
  outline: 2px solid var(--c-cyan);
  outline-offset: 3px;
}

.page-about .tl-detail .tl-text {
  margin-top: 10px;
  font-size: 14px;
}

.page-about .tl-item:target::before {
  background: var(--c-cyan);
  border-color: var(--c-cyan);
  box-shadow: 0 0 0 4px rgba(40, 240, 200, .18);
}

.page-about .tl-item:target .tl-year {
  color: var(--c-cyan);
}

.page-about .tl-item:target .tl-body {
  border-color: var(--c-cyan);
  background: rgba(40, 240, 200, .12);
}

/* ---------- 记录数据板 ---------- */
.page-about .about-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin-top: 28px;
  border: 1px solid var(--ab-line-soft);
  background: var(--ab-line-soft);
  border-radius: var(--radius);
  overflow: hidden;
}

.page-about .about-stat {
  background: linear-gradient(180deg, var(--c-ink) 0%, rgba(14, 43, 36, .72) 100%);
  padding: 18px 16px;
}

.page-about .about-stat-value {
  display: block;
  margin-bottom: 8px;
  font-family: var(--font-mono);
  font-size: clamp(22px, 5vw, 30px);
  line-height: 1.1;
  letter-spacing: -0.01em;
  color: var(--c-cyan);
  font-variant-numeric: tabular-nums;
}

.page-about .about-stat-label {
  display: block;
  font-size: 12.5px;
  line-height: 1.55;
  color: var(--c-neutral);
}

/* ---------- 团队 ---------- */
.page-about .team-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
  margin-top: 22px;
}

.page-about .team-card {
  border: 1px solid var(--ab-line);
  border-left: 2px solid var(--c-cyan);
  border-radius: var(--radius);
  background: linear-gradient(180deg, rgba(20, 69, 58, .52) 0%, rgba(14, 43, 36, .28) 100%);
  padding: 16px 16px 18px;
  transition: transform var(--t-base) ease, border-color var(--t-base) ease;
}

.page-about .team-card:hover {
  transform: translateY(-3px);
  border-color: var(--glass-line);
  border-left-color: var(--c-orange);
}

.page-about .team-num {
  margin: 0 0 6px;
  font-family: var(--font-mono);
  font-size: 20px;
  color: var(--c-orange);
  font-variant-numeric: tabular-nums;
}

.page-about .team-name {
  margin: 0 0 8px;
  font-size: 15px;
  font-weight: 700;
  color: var(--c-mist);
}

.page-about .team-text {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--c-body);
}

/* ---------- 覆盖列表 ---------- */
.page-about .cover-list {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--ab-line-soft);
}

.page-about .cover-list li {
  display: grid;
  grid-template-columns: 1fr;
  gap: 4px;
  padding: 16px 0;
  border-bottom: 1px solid var(--ab-line-soft);
}

.page-about .cover-key {
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: .1em;
  color: var(--c-cyan);
}

.page-about .cover-val {
  font-size: 15px;
  line-height: 1.75;
  color: var(--c-body);
}

/* ---------- 迭代节奏 ---------- */
.page-about .about-release .cta-row {
  margin-top: 24px;
}

/* ---------- 下一步 ---------- */
.page-about .next-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
  margin-bottom: 20px;
}

.page-about .next-card {
  border-top: 2px solid var(--c-cyan);
  background: var(--glass);
  border-radius: 0 0 var(--radius) var(--radius);
  padding: 18px 18px 6px;
}

.page-about .next-title {
  margin: 0 0 10px;
  font-size: 16px;
  font-weight: 700;
  color: var(--c-mist);
}

.page-about .next-card .about-text {
  font-size: 14.5px;
}

/* ---------- 页尾宽幅 ---------- */
.page-about .about-finale {
  position: relative;
  border: 1px solid var(--ab-line);
  border-radius: var(--radius);
  overflow: hidden;
}

.page-about .about-finale img {
  width: 100%;
  height: 340px;
  object-fit: cover;
  opacity: .5;
  filter: saturate(.9);
}

.page-about .about-finale-inner {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  padding: 22px 18px;
  background: linear-gradient(180deg,
    rgba(11, 15, 14, .18) 0%,
    rgba(11, 15, 14, .72) 52%,
    rgba(11, 15, 14, .94) 100%);
}

.page-about .about-finale-inner .about-title {
  margin-bottom: 10px;
  font-size: clamp(19px, 4vw, 26px);
}

.page-about .about-finale-inner .about-text {
  margin: 0;
  font-size: 14px;
  line-height: 1.7;
  max-width: 56ch;
}

/* ---------- 响应式 ---------- */
@media (min-width: 720px) {
  .page-about .about-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

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

  .page-about .cover-list li {
    grid-template-columns: minmax(0, 190px) 1fr;
    gap: 28px;
    align-items: baseline;
  }

  .page-about .about-finale img {
    height: 400px;
  }

  .page-about .about-finale-inner {
    padding: 30px 26px;
  }
}

@media (min-width: 880px) {
  .page-about .about-hero {
    grid-template-columns: 5fr 7fr;
    gap: 52px;
    padding-top: 56px;
    padding-bottom: 72px;
  }

  .page-about .about-chapter {
    grid-template-columns: 6fr 5fr;
    gap: 52px;
  }

  .page-about .about-chapter--flip .about-chapter-media {
    order: -1;
  }

  .page-about .section {
    padding: 62px 0;
  }

  .page-about .about-head {
    margin-bottom: 32px;
  }
}

@media (min-width: 1080px) {
  .page-about .tl-wrap {
    grid-template-columns: 158px minmax(0, 1fr);
    gap: 44px;
    align-items: start;
  }

  .page-about .tl-nav {
    flex-direction: column;
    overflow: visible;
    padding: 14px 12px;
    position: sticky;
    top: 96px;
  }

  .page-about .tl-nav a {
    display: block;
    text-align: left;
  }

  .page-about .tl {
    padding-left: 0;
  }

  .page-about .tl::before {
    left: var(--ab-year-col);
  }

  .page-about .tl-item {
    display: grid;
    grid-template-columns: var(--ab-year-col) minmax(0, 1fr);
    column-gap: 44px;
    padding-bottom: 28px;
  }

  .page-about .tl-item::before {
    left: calc(var(--ab-year-col) - 4px);
    top: 15px;
  }

  .page-about .tl-year {
    margin: 0;
    padding-top: 5px;
    text-align: right;
    font-size: 21px;
  }

  .page-about .tl-body {
    padding: 18px 22px;
  }

  .page-about .cover-list li {
    grid-template-columns: minmax(0, 220px) 1fr;
    gap: 36px;
  }

  .page-about .about-finale img {
    height: 440px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .tl-body,
  .page-about .team-card,
  .page-about .tl-item::before,
  .page-about .tl-nav a {
    transition: none;
  }

  .page-about .tl-body:hover,
  .page-about .team-card:hover {
    transform: none;
  }
}
<<<END>>>