.page-about {
  --about-card-bg: #ffffff;
  --about-band-deep: #0E4A57;
  --about-text-soft: #3a322c;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-body);
  overflow-x: clip;
}

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

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  padding-block: clamp(22px, 4vw, 44px) clamp(40px, 6vw, 76px);
  border-bottom: 1px solid var(--rule);
  background:
    radial-gradient(130% 100% at 100% 0%, rgba(22, 105, 122, 0.12), rgba(251, 247, 240, 0) 62%),
    var(--paper);
}

.page-about .about-hero-inner {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(26px, 5vw, 52px);
}

.page-about .about-kicker {
  display: flex;
  align-items: center;
  gap: 10px;
  margin: 0 0 20px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--ochre);
}

.page-about .about-kicker::before {
  content: "";
  display: block;
  width: 36px;
  height: 1px;
  background: var(--ochre);
}

.page-about .about-h1 {
  margin: 0;
  max-width: 22ch;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(30px, 5.2vw, 56px);
  line-height: 1.14;
  letter-spacing: -0.02em;
}

.page-about .about-lead {
  margin: 22px 0 0;
  max-width: 60ch;
  font-size: clamp(16px, 1.6vw, 18px);
  line-height: 1.9;
  color: var(--about-text-soft);
}

.page-about .about-facts {
  position: relative;
  padding: clamp(20px, 3vw, 28px);
  border-radius: 4px;
  background: var(--about-band-deep);
  color: #f2f7f8;
  box-shadow: var(--shadow-2);
}

.page-about .about-facts::before {
  content: "";
  position: absolute;
  inset: 0 0 auto 0;
  height: 5px;
  border-radius: 4px 4px 0 0;
  background: linear-gradient(90deg, var(--flame), var(--ochre) 32%, var(--lake-pale) 64%, var(--turq));
}

.page-about .about-facts-title {
  margin: 8px 0 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--lake-pale);
}

.page-about .about-fact-list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .about-fact-list li {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 14px;
  padding: 9px 0;
  border-bottom: 1px solid rgba(214, 232, 236, 0.18);
}

.page-about .about-fact-list li:last-child {
  border-bottom: 0;
}

.page-about .about-fact-num {
  font-family: var(--font-mono);
  font-weight: 500;
  font-size: 25px;
  line-height: 1;
  color: #ffffff;
}

.page-about .about-fact-label {
  font-size: 13px;
  color: var(--lake-pale);
}

/* ---------- 主体栏与右侧序号轴 ---------- */
.page-about .about-body {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(22px, 4vw, 36px);
  padding-block: clamp(30px, 5vw, 64px) clamp(40px, 6vw, 80px);
}

.page-about .about-rail {
  order: -1;
}

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

.page-about .about-axis {
  padding: 6px;
  border: 1px solid var(--rule);
  border-radius: 4px;
  background: var(--about-card-bg);
}

.page-about .about-axis .axis-list {
  display: flex;
  gap: 4px;
  margin: 0;
  padding: 0;
  list-style: none;
  overflow-x: auto;
  scrollbar-width: thin;
}

.page-about .about-axis .axis-link {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 12px;
  border: 1px solid transparent;
  border-radius: 3px;
  color: var(--ink);
  text-decoration: none;
  white-space: nowrap;
  font-size: 13px;
  transition: background var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .about-axis .axis-num {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--ochre);
}

.page-about .about-axis .axis-link:hover {
  background: var(--lake-pale);
}

.page-about .about-axis .axis-link[aria-current="true"] {
  background: var(--lake-pale);
  border-color: var(--lake);
}

/* ---------- 章节 ---------- */
.page-about .about-sec {
  scroll-margin-top: 104px;
  padding-block: clamp(30px, 4.4vw, 54px);
  border-top: 1px solid var(--rule);
}

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

.page-about .about-sec-head {
  display: flex;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 8px 18px;
  margin-bottom: 22px;
}

.page-about .about-sec-num {
  margin: 0;
  font-family: var(--font-mono);
  font-weight: 500;
  font-size: clamp(24px, 3vw, 34px);
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--ochre);
}

.page-about .about-sec-title {
  margin: 0;
  max-width: 24ch;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(21px, 2.8vw, 31px);
  line-height: 1.28;
  letter-spacing: -0.01em;
}

.page-about .about-p {
  margin: 0 0 1.25em;
  max-width: 66ch;
  font-size: 16px;
  line-height: 1.9;
  color: var(--about-text-soft);
}

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

.page-about .about-inline-link {
  color: var(--lake);
  text-decoration: underline;
  text-decoration-color: var(--lake-pale);
  text-underline-offset: 4px;
}

.page-about .about-inline-link:hover {
  text-decoration-color: var(--ochre);
}

/* ---------- 三件事卡片 ---------- */
.page-about .about-three {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
  margin: 28px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-three-card {
  padding: 18px 18px 20px;
  border: 1px solid var(--rule);
  border-top: 3px solid var(--lake);
  border-radius: 0 0 4px 4px;
  background: var(--about-card-bg);
  box-shadow: var(--shadow-1);
  transition: transform var(--dur) var(--ease), border-top-color var(--dur) var(--ease);
}

.page-about .about-three-card:hover {
  transform: translateY(-3px);
  border-top-color: var(--ochre);
}

.page-about .about-card-num {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--lake);
}

.page-about .about-card-title {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 17px;
  line-height: 1.4;
}

.page-about .about-card-text {
  margin: 0 0 14px;
  font-size: 14px;
  line-height: 1.85;
  color: var(--about-text-soft);
}

.page-about .about-card-link {
  display: inline-block;
  font-size: 13px;
  color: var(--ochre);
  text-decoration: none;
  border-bottom: 1px solid var(--ochre-pale);
  padding-bottom: 2px;
}

.page-about .about-card-link::after {
  content: " →";
}

.page-about .about-card-link:hover {
  border-bottom-color: var(--ochre);
}

/* ---------- 栏目树与配图 ---------- */
.page-about .about-split {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 20px;
  margin-top: 28px;
}

.page-about .about-tree {
  padding: 16px clamp(14px, 2.4vw, 24px) 20px;
  border: 1px solid var(--rule);
  border-radius: 4px;
  background: var(--paper-2);
}

.page-about .about-tree-cap {
  margin: 0 0 10px;
  font-size: 13px;
  color: var(--note);
}

.page-about .tree-list,
.page-about .tree-sub {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .tree-item summary {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 11px 0;
  border-bottom: 1px dashed var(--rule);
  cursor: pointer;
  list-style: none;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 15px;
}

.page-about .tree-item summary::-webkit-details-marker {
  display: none;
}

.page-about .tree-item summary::after {
  content: "+";
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 16px;
  color: var(--lake);
}

.page-about .tree-item[open] summary::after {
  content: "–";
}

.page-about .tree-item[open] summary {
  border-bottom-color: var(--lake);
}

.page-about .tree-num {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--ochre);
  min-width: 26px;
}

.page-about .tree-hint {
  margin-left: auto;
  padding: 1px 6px;
  border: 1px solid var(--rule);
  border-radius: 2px;
  font-family: var(--font-body);
  font-weight: 400;
  font-size: 11px;
  color: var(--note);
  background: var(--about-card-bg);
}

.page-about .tree-item summary::after {
  margin-left: 4px;
}

.page-about .tree-sub {
  position: relative;
  padding: 6px 0 8px 40px;
}

.page-about .tree-sub::before {
  content: "";
  position: absolute;
  left: 16px;
  top: 0;
  bottom: 14px;
  width: 1px;
  background: var(--rule);
}

.page-about .tree-sub li {
  position: relative;
  display: flex;
  gap: 10px;
  padding: 5px 0;
  font-size: 14px;
  line-height: 1.6;
  color: var(--about-text-soft);
}

.page-about .tree-sub li::before {
  content: "";
  position: absolute;
  left: -24px;
  top: 15px;
  width: 16px;
  height: 1px;
  background: var(--rule);
}

.page-about .sub-num {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--ochre);
  flex: none;
  padding-top: 2px;
}

.page-about .about-figure {
  margin: 26px 0 0;
  border: 1px solid var(--rule);
  border-radius: 4px;
  overflow: hidden;
  background: var(--paper-2);
}

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

.page-about .about-figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  filter: saturate(0.82);
}

.page-about .about-figure figcaption {
  padding: 10px 14px;
  border-top: 1px solid var(--rule);
  background: var(--about-card-bg);
  font-size: 13px;
  line-height: 1.7;
  color: var(--note);
}

.page-about .about-figure--wide {
  margin-top: 28px;
}

.page-about .about-figure--band {
  margin: 0;
  border-left: 0;
  border-right: 0;
  border-radius: 0;
}

.page-about .about-figure--band img {
  aspect-ratio: 1600 / 420;
}

/* ---------- 团队分工 ---------- */
.page-about .about-team {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
  margin-top: 28px;
}

.page-about .about-team-card {
  padding: 18px 18px 18px;
  border: 1px solid var(--rule);
  border-radius: 4px;
  background: var(--about-card-bg);
  box-shadow: var(--shadow-1);
  transition: transform var(--dur) var(--ease), box-shadow var(--dur) var(--ease);
}

.page-about .about-team-card:hover,
.page-about .about-team-card:focus-within {
  transform: translateY(-3px);
  box-shadow: var(--shadow-2);
}

.page-about .about-team-num {
  margin: 0 0 10px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--rule);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--lake);
}

.page-about .about-team-name {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 17px;
}

.page-about .about-team-text {
  margin: 0;
  font-size: 14px;
  line-height: 1.85;
  color: var(--about-text-soft);
}

.page-about .about-team-extra {
  margin: 14px 0 0;
  padding-left: 10px;
  border-left: 2px solid var(--ochre-pale);
  font-size: 13px;
  line-height: 1.7;
  color: var(--note);
  max-height: 200px;
  opacity: 1;
  transition: opacity var(--dur) var(--ease), max-height var(--dur) var(--ease);
}

.page-about .about-flow-title {
  margin: 34px 0 4px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 18px;
}

.page-about .about-flow {
  margin: 12px 0 0;
  padding: 0;
  list-style: none;
  counter-reset: about-flow;
}

.page-about .about-flow li {
  position: relative;
  padding: 14px 0 14px 52px;
  border-top: 1px solid var(--rule);
  font-size: 15px;
  line-height: 1.8;
  color: var(--about-text-soft);
}

.page-about .about-flow li::before {
  counter-increment: about-flow;
  content: counter(about-flow, decimal-leading-zero);
  position: absolute;
  left: 0;
  top: 14px;
  padding: 1px 6px;
  border-radius: 2px;
  background: var(--ochre-pale);
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--ochre);
}

/* ---------- 边注 ---------- */
.page-about .about-note {
  margin-top: 26px;
  padding: 16px 18px;
  border-left: 3px solid var(--ochre);
  border-radius: 0 4px 4px 0;
  background: var(--ochre-pale);
  font-size: 14px;
  line-height: 1.85;
  color: #4a3524;
}

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

.page-about .about-note strong {
  color: #3a2416;
}

/* ---------- 时间带 ---------- */
.page-about .about-timeline {
  list-style: none;
  margin: 28px 0 0;
  padding: 0 0 0 26px;
  position: relative;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 8px;
  bottom: 10px;
  width: 1px;
  background: linear-gradient(180deg, var(--lake), var(--ochre-pale));
}

.page-about .tl-item {
  position: relative;
  padding: 0 0 30px 20px;
}

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

.page-about .tl-item::before {
  content: "";
  position: absolute;
  left: -26px;
  top: 4px;
  width: 15px;
  height: 15px;
  border-radius: 50%;
  background: var(--paper);
  border: 1px solid var(--lake);
  box-shadow: 0 0 0 4px var(--paper);
}

.page-about .tl-item:last-child::before {
  background: var(--ochre);
  border-color: var(--ochre);
}

.page-about .tl-when {
  margin: 0 0 6px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--ochre);
}

.page-about .tl-title {
  margin: 0 0 6px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 17px;
  line-height: 1.4;
}

.page-about .tl-text {
  margin: 0;
  max-width: 62ch;
  font-size: 15px;
  line-height: 1.85;
  color: var(--about-text-soft);
}

/* ---------- 结尾行动区 ---------- */
.page-about .about-cta {
  position: relative;
  margin-top: clamp(36px, 5vw, 60px);
  padding: clamp(26px, 4vw, 44px);
  border-radius: 4px;
  background: var(--about-band-deep);
  color: #eaf3f4;
  overflow: hidden;
}

.page-about .about-cta::after {
  content: "02";
  position: absolute;
  right: 14px;
  bottom: -22px;
  font-family: var(--font-mono);
  font-size: 96px;
  font-weight: 500;
  line-height: 1;
  color: rgba(214, 232, 236, 0.14);
  pointer-events: none;
}

.page-about .about-cta-title {
  position: relative;
  margin: 0 0 12px;
  max-width: 22ch;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(21px, 2.8vw, 29px);
  line-height: 1.3;
  color: #ffffff;
}

.page-about .about-cta-text {
  position: relative;
  margin: 0 0 22px;
  max-width: 56ch;
  font-size: 15px;
  line-height: 1.9;
  color: var(--lake-pale);
}

.page-about .about-cta .btn-row {
  position: relative;
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.page-about .about-cta-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 11px 20px;
  border: 1px solid var(--flame);
  border-radius: 3px;
  background: var(--flame);
  color: #ffffff;
  font-size: 15px;
  text-decoration: none;
  transition: transform var(--dur) var(--ease), background var(--dur) var(--ease), color var(--dur) var(--ease);
}

.page-about .about-cta-btn:hover {
  transform: translateY(-2px);
  background: #d0661f;
  border-color: #d0661f;
}

.page-about .about-cta-btn--ghost {
  background: transparent;
  border-color: rgba(214, 232, 236, 0.45);
  color: var(--lake-pale);
}

.page-about .about-cta-btn--ghost:hover {
  background: rgba(214, 232, 236, 0.14);
  border-color: var(--lake-pale);
  color: #ffffff;
}

/* ---------- 响应式 ---------- */
@media (min-width: 720px) {
  .page-about .about-three {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .about-team {
    grid-template-columns: 1.12fr 0.96fr 0.92fr;
    align-items: start;
  }

  .page-about .about-team-card:nth-child(2) {
    margin-top: 22px;
  }

  .page-about .about-team-card:nth-child(3) {
    margin-top: 44px;
  }

  .page-about .about-team-extra {
    max-height: 0;
    opacity: 0;
    overflow: hidden;
    margin-top: 0;
    transition: opacity var(--dur) var(--ease), max-height var(--dur) var(--ease), margin var(--dur) var(--ease);
  }

  .page-about .about-team-card:hover .about-team-extra,
  .page-about .about-team-card:focus-within .about-team-extra {
    max-height: 200px;
    opacity: 1;
    margin-top: 14px;
  }
}

@media (min-width: 900px) {
  .page-about .about-hero-inner {
    grid-template-columns: minmax(0, 1.55fr) minmax(258px, 0.85fr);
    align-items: end;
  }

  .page-about .about-split {
    grid-template-columns: minmax(0, 1.12fr) minmax(0, 0.88fr);
    align-items: start;
  }
}

@media (min-width: 1000px) {
  .page-about .about-body {
    grid-template-columns: minmax(0, 1fr) 214px;
    gap: clamp(48px, 6vw, 76px);
  }

  .page-about .about-content {
    grid-column: 1;
    grid-row: 1;
  }

  .page-about .about-rail {
    order: 0;
    grid-column: 2;
    grid-row: 1;
    position: sticky;
    top: 110px;
    align-self: start;
  }

  .page-about .about-axis {
    padding: 0;
    border: 0;
    border-left: 1px solid var(--rule);
    border-radius: 0;
    background: transparent;
  }

  .page-about .about-axis .axis-list {
    display: grid;
    gap: 0;
    overflow: visible;
  }

  .page-about .about-axis .axis-link {
    display: block;
    padding: 12px 0 12px 22px;
    border: 0;
    border-radius: 0;
    font-size: 14px;
    line-height: 1.45;
    white-space: normal;
    background: transparent;
  }

  .page-about .about-axis .axis-link::before {
    content: "";
    position: absolute;
    left: -5px;
    top: 19px;
    width: 9px;
    height: 9px;
    border-radius: 50%;
    background: var(--paper);
    border: 1px solid var(--rule);
    transition: background var(--dur) var(--ease), border-color var(--dur) var(--ease), box-shadow var(--dur) var(--ease);
  }

  .page-about .about-axis .axis-link {
    position: relative;
  }

  .page-about .about-axis .axis-num {
    display: block;
    font-size: 11px;
    letter-spacing: 0.1em;
    color: var(--note);
    margin-bottom: 2px;
    transition: color var(--dur) var(--ease);
  }

  .page-about .about-axis .axis-link:hover {
    background: transparent;
  }

  .page-about .about-axis .axis-link:hover .axis-text {
    color: var(--lake);
  }

  .page-about .about-axis .axis-link[aria-current="true"] {
    background: transparent;
  }

  .page-about .about-axis .axis-link[aria-current="true"]::before {
    background: var(--ochre);
    border-color: var(--ochre);
    box-shadow: 0 0 0 4px var(--ochre-pale);
  }

  .page-about .about-axis .axis-link[aria-current="true"] .axis-num,
  .page-about .about-axis .axis-link[aria-current="true"] .axis-text {
    color: var(--ochre);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-three-card,
  .page-about .about-team-card,
  .page-about .about-cta-btn,
  .page-about .about-team-extra {
    transition: opacity var(--dur) var(--ease);
  }

  .page-about .about-three-card:hover,
  .page-about .about-team-card:hover,
  .page-about .about-team-card:focus-within,
  .page-about .about-cta-btn:hover {
    transform: none;
  }
}
<<<END>>>