.page-about {
  --about-space: clamp(20px, 3vw, 40px);
  --about-line-soft: rgba(36, 64, 111, 0.7);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  padding: clamp(20px, 4vw, 40px) 0 clamp(28px, 5vw, 56px);
  border-bottom: 1px solid var(--line);
}

.page-about .about-hero .index {
  display: block;
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--gold);
}

.page-about .about-title {
  margin: 0;
  max-width: 17ch;
  font-family: var(--font-sans);
  font-size: clamp(32px, 7.2vw, 88px);
  font-weight: 200;
  line-height: 1.03;
  letter-spacing: -0.015em;
  color: var(--white);
}

.page-about .about-lede {
  margin: clamp(16px, 3vw, 28px) 0 0;
  max-width: 48ch;
  font-size: clamp(15px, 1.6vw, 17px);
  line-height: 1.9;
  color: var(--white);
  opacity: 0.82;
}

.page-about .about-sub {
  margin: 12px 0 0;
  max-width: 44ch;
  font-size: 14px;
  line-height: 1.8;
  color: var(--muted);
}

/* 章节快速跳转 */
.page-about .about-jump {
  list-style: none;
  margin: clamp(24px, 4vw, 44px) 0 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 .about-jump li {
  background: var(--ink-900);
  min-width: 0;
}

.page-about .about-jump a {
  display: flex;
  align-items: baseline;
  gap: 10px;
  padding: 13px 14px;
  font-size: 14px;
  line-height: 1.5;
  color: var(--white);
  text-decoration: none;
  transition: background 0.18s var(--ease), color 0.18s var(--ease);
}

.page-about .about-jump a:hover,
.page-about .about-jump a:focus-visible {
  background: var(--ink-800);
  color: var(--gold);
}

.page-about .about-jump .jn {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--gold);
  flex: none;
}

/* ---------- 主体框架 ---------- */
.page-about .about-shell {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--about-space);
  padding-top: clamp(28px, 5vw, 60px);
  padding-bottom: clamp(40px, 7vw, 96px);
}

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

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

/* ---------- 章节 ---------- */
.page-about .chapter {
  padding: clamp(24px, 4vw, 46px) 0;
  border-top: 1px solid var(--about-line-soft);
}

.page-about .chapter:first-child {
  border-top: 0;
  padding-top: 0;
}

.page-about .ch-head {
  max-width: 62ch;
}

.page-about .ch-index {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  color: var(--gold);
}

.page-about .ch-title {
  margin: 0;
  font-size: clamp(24px, 4.2vw, 50px);
  font-weight: 200;
  line-height: 1.1;
  letter-spacing: -0.01em;
  color: var(--white);
}

.page-about .ch-lede {
  margin: 14px 0 0;
  max-width: 44ch;
  font-size: 15px;
  line-height: 1.9;
  color: var(--muted);
}

.page-about .chapter-foot {
  margin: clamp(20px, 3vw, 30px) 0 0;
  max-width: 52ch;
  font-size: 14px;
  line-height: 1.9;
  color: var(--muted);
}

.page-about .chapter-foot a {
  color: var(--orange);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color 0.18s var(--ease);
}

.page-about .chapter-foot a:hover,
.page-about .chapter-foot a:focus-visible {
  border-bottom-color: var(--orange);
}

/* ---------- 图片 ---------- */
.page-about .about-figure {
  margin: clamp(20px, 3vw, 32px) 0 0;
  border: 1px solid var(--line);
  background: var(--ink-700);
  overflow: hidden;
}

.page-about .about-figure img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: cover;
  filter: saturate(0.72) contrast(1.06) brightness(0.9);
  transition: filter 0.5s var(--ease), transform 0.6s var(--ease);
}

.page-about .about-figure:hover img {
  filter: saturate(0.9) contrast(1.02) brightness(0.96);
}

.page-about .about-figure figcaption {
  padding: 9px 12px;
  border-top: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--muted);
}

.page-about .about-figure--wide {
  margin-top: clamp(22px, 3.4vw, 36px);
}

/* ---------- 时间线 ---------- */
.page-about .timeline {
  list-style: none;
  margin: clamp(26px, 4vw, 44px) 0 0;
  padding: 0;
  position: relative;
}

.page-about .timeline::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 8px;
  bottom: 8px;
  width: 1px;
  background: linear-gradient(180deg, var(--gold), var(--line) 60%, var(--orange));
}

.page-about .tl {
  position: relative;
  padding-left: 32px;
  padding-bottom: clamp(22px, 3.2vw, 34px);
}

.page-about .tl:last-child {
  padding-bottom: 0;
}

.page-about .tl::before {
  content: "";
  position: absolute;
  left: 0;
  top: 5px;
  width: 11px;
  height: 11px;
  background: var(--ink-900);
  border: 1px solid var(--gold);
}

.page-about .tl--now::before {
  background: var(--orange);
  border-color: var(--orange);
}

.page-about .tl-year {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--gold);
}

.page-about .tl--now .tl-year {
  color: var(--orange);
}

.page-about .tl-h {
  margin: 8px 0 6px;
  font-size: clamp(17px, 2vw, 20px);
  font-weight: 600;
  line-height: 1.45;
  color: var(--white);
}

.page-about .tl-body p {
  margin: 0;
  max-width: 52ch;
  font-size: 14px;
  line-height: 1.9;
  color: var(--muted);
}

/* ---------- 归档流程 ---------- */
.page-about .archive-grid {
  margin-top: clamp(22px, 3.4vw, 36px);
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(18px, 3vw, 32px);
  align-items: start;
}

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

.page-about .flow-step {
  background: var(--ink-800);
  padding: clamp(16px, 2.4vw, 24px);
  min-width: 0;
  transition: background 0.2s var(--ease);
}

.page-about .flow-step:hover {
  background: var(--ink-700);
}

.page-about .flow-num {
  display: block;
  margin-bottom: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--orange);
}

.page-about .flow-step h3 {
  margin: 0 0 8px;
  font-size: 16px;
  font-weight: 600;
  line-height: 1.5;
  color: var(--white);
}

.page-about .flow-step p {
  margin: 0;
  font-size: 13.5px;
  line-height: 1.85;
  color: var(--muted);
}

/* ---------- 团队 ---------- */
.page-about .roles {
  margin-top: clamp(22px, 3.4vw, 36px);
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .role {
  background: var(--ink-900);
  padding: clamp(18px, 2.6vw, 28px);
  border-top: 2px solid var(--gold);
  min-width: 0;
}

.page-about .role h3 {
  margin: 0 0 10px;
  font-size: 16px;
  font-weight: 600;
  letter-spacing: 0.04em;
  color: var(--gold);
}

.page-about .role p {
  margin: 0;
  font-size: 13.5px;
  line-height: 1.9;
  color: var(--muted);
}

/* ---------- 规模仪表 ---------- */
.page-about .stats {
  margin-top: clamp(22px, 3.4vw, 36px);
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .stat {
  background: linear-gradient(180deg, var(--ink-800), var(--ink-900));
  padding: clamp(18px, 2.6vw, 28px);
  display: flex;
  flex-direction: column;
  gap: 5px;
  min-width: 0;
  transition: background 0.2s var(--ease);
}

.page-about .stat:hover {
  background: var(--ink-700);
}

.page-about .stat-num {
  font-family: var(--font-mono);
  font-size: clamp(32px, 6vw, 54px);
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--gold);
  transition: color 0.2s var(--ease);
}

.page-about .stat:hover .stat-num {
  color: var(--orange);
}

.page-about .stat-label {
  font-size: 13px;
  letter-spacing: 0.04em;
  color: var(--white);
}

.page-about .stat-note {
  margin-top: 4px;
  font-size: 12px;
  line-height: 1.75;
  color: var(--muted);
  opacity: 0.85;
  transition: opacity 0.2s var(--ease);
}

.page-about .stat:hover .stat-note {
  opacity: 1;
}

/* ---------- 使用场景 ---------- */
.page-about .who {
  list-style: none;
  margin: clamp(22px, 3.4vw, 36px) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(18px, 2.6vw, 28px);
}

.page-about .who li {
  border-left: 1px solid var(--line);
  padding-left: 18px;
  min-width: 0;
}

.page-about .who h3 {
  margin: 0 0 8px;
  font-size: clamp(16px, 1.9vw, 19px);
  font-weight: 600;
  line-height: 1.45;
  color: var(--white);
}

.page-about .who p {
  margin: 0;
  max-width: 42ch;
  font-size: 14px;
  line-height: 1.9;
  color: var(--muted);
}

.page-about .who-tag {
  display: inline-block;
  margin-top: 12px;
  padding: 3px 8px;
  border: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--orange);
}

/* ---------- 服务原则 ---------- */
.page-about .principles {
  list-style: none;
  margin: clamp(22px, 3.4vw, 36px) 0 0;
  padding: 0;
}

.page-about .principles li {
  display: grid;
  gap: 6px;
  padding: 16px 0;
  border-top: 1px solid var(--about-line-soft);
}

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

.page-about .principles h3 {
  margin: 0;
  font-size: 15px;
  font-weight: 600;
  line-height: 1.5;
  color: var(--gold);
}

.page-about .principles p {
  margin: 0;
  max-width: 54ch;
  font-size: 14px;
  line-height: 1.9;
  color: var(--muted);
}

.page-about .about-actions {
  margin-top: clamp(24px, 3.6vw, 36px);
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

/* ---------- 断点 ---------- */
@media (min-width: 620px) {
  .page-about .about-jump {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

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

  .page-about .stat--wide {
    grid-column: span 2;
  }
}

@media (min-width: 760px) {
  .page-about .flow {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

  .page-about .who {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: clamp(22px, 3vw, 40px);
  }

  .page-about .who li:nth-child(even) {
    margin-top: 26px;
  }

  .page-about .about-figure--half {
    max-width: 720px;
  }
}

@media (min-width: 900px) {
  .page-about .archive-grid {
    grid-template-columns: minmax(0, 1.55fr) minmax(0, 1fr);
  }

  .page-about .archive-grid .about-figure {
    margin-top: 0;
  }
}

@media (min-width: 960px) {
  .page-about .about-shell {
    grid-template-columns: 132px minmax(0, 1fr);
    gap: clamp(28px, 4vw, 64px);
  }

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

  .page-about .about-rail ol {
    list-style: none;
    margin: 0;
    padding: 0;
    position: sticky;
    top: calc(var(--topbar-h) + 26px);
    border-left: 1px solid var(--line);
  }

  .page-about .about-rail li {
    min-width: 0;
  }

  .page-about .about-rail a {
    display: flex;
    align-items: baseline;
    gap: 8px;
    padding: 7px 0 7px 14px;
    margin-left: -1px;
    border-left: 1px solid transparent;
    font-size: 12.5px;
    line-height: 1.6;
    color: var(--muted);
    text-decoration: none;
    transition: color 0.18s var(--ease), border-color 0.18s var(--ease);
  }

  .page-about .about-rail a:hover,
  .page-about .about-rail a:focus-visible {
    color: var(--gold);
    border-left-color: var(--gold);
  }

  .page-about .about-rail .rn {
    font-family: var(--font-mono);
    font-size: 10px;
    letter-spacing: 0.08em;
    color: var(--gold);
    flex: none;
  }
}

@media (min-width: 1000px) {
  .page-about .stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .stat--wide {
    grid-column: span 2;
  }

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

@media (min-width: 1180px) {
  .page-about .about-jump {
    grid-template-columns: repeat(6, minmax(0, 1fr));
  }
}
<<<END>>>