.page-about {
  --about-toc: 232px;
  --edge: rgba(243, 235, 221, 0.16);
  --body-ink: rgba(243, 235, 221, 0.86);
  background: var(--ink);
  color: var(--cream);
  font-family: var(--font-body);
  padding-bottom: 72px;
  overflow-x: clip;
}

.page-about .breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  padding: 20px 0 0;
  font-size: 13px;
  letter-spacing: 0.04em;
  color: var(--rock);
}

.page-about .breadcrumb a {
  color: var(--cream);
  text-decoration: none;
  border-bottom: 1px solid var(--gold-deep);
}

.page-about .breadcrumb a:hover {
  color: var(--gold);
}

/* 首屏 */
.page-about .about-hero {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 22px;
  padding: 22px 0 30px;
  border-bottom: var(--bw) solid var(--haze);
}

.page-about .about-kicker {
  display: inline-block;
  margin: 0;
  padding: 4px 10px;
  background: var(--gold);
  color: var(--ink);
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.18em;
  transform: skewX(-8deg);
}

.page-about .about-hero h1 {
  margin: 16px 0 0;
  font-family: var(--font-display);
  font-size: 32px;
  font-weight: 900;
  line-height: 1.14;
  letter-spacing: -0.02em;
  color: var(--cream);
  text-shadow: 2px 2px 0 rgba(169, 121, 31, 0.5);
}

.page-about .about-lead {
  margin: 16px 0 0;
  max-width: 62ch;
  font-size: 16px;
  line-height: 1.8;
  color: var(--body-ink);
}

.page-about .about-hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 22px;
}

.page-about .about-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 22px;
  border: 3px solid var(--gold);
  background: var(--gold);
  color: var(--ink);
  font-family: var(--font-body);
  font-size: 15px;
  font-weight: 700;
  text-decoration: none;
  box-shadow: 4px 4px 0 rgba(0, 0, 0, 0.55);
  transition: transform 0.16s ease, box-shadow 0.16s ease, background 0.16s ease, border-color 0.16s ease, color 0.16s ease;
}

.page-about .about-btn:hover,
.page-about .about-btn:focus-visible {
  transform: translate(2px, 2px);
  box-shadow: 2px 2px 0 rgba(0, 0, 0, 0.55);
  background: var(--flame);
  border-color: var(--flame);
  color: var(--cream);
}

.page-about .about-btn--ghost {
  background: transparent;
  border-color: var(--cream);
  color: var(--cream);
}

.page-about .about-btn--ghost:hover,
.page-about .about-btn--ghost:focus-visible {
  background: rgba(232, 178, 58, 0.12);
  border-color: var(--gold);
  color: var(--gold);
}

.page-about .about-hero-mark {
  display: none;
}

.page-about .about-figures {
  list-style: none;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 10px;
  margin: 0;
  padding: 14px 0 0;
  border-top: 2px solid var(--haze);
}

.page-about .about-figures li {
  display: flex;
  flex-direction: column;
  gap: 3px;
  min-width: 0;
}

.page-about .fig-num {
  font-family: var(--font-mono);
  font-size: 26px;
  font-weight: 700;
  line-height: 1;
  color: var(--gold);
  font-variant-numeric: tabular-nums;
}

.page-about .fig-label {
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--rock);
}

/* 目录与主体 */
.page-about .about-shell {
  margin-top: 28px;
}

.page-about .about-toc {
  margin-bottom: 24px;
}

.page-about .about-toc-label {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--rock);
}

.page-about .about-toc-list {
  list-style: none;
  display: flex;
  gap: 8px;
  margin: 0;
  padding: 0 0 6px;
  overflow-x: auto;
  scroll-snap-type: x proximity;
}

.page-about .about-toc-list li {
  flex: none;
  scroll-snap-align: start;
}

.page-about .about-toc-list a {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 12px;
  border: 2px solid var(--haze);
  background: var(--charcoal);
  color: var(--cream);
  font-size: 13px;
  text-decoration: none;
  white-space: nowrap;
  transition: border-color 0.16s ease, color 0.16s ease;
}

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

.page-about .toc-num {
  font-family: var(--font-mono);
  font-weight: 700;
  color: var(--gold);
  font-variant-numeric: tabular-nums;
}

.page-about .about-toc-foot {
  display: none;
}

.page-about .about-body {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 24px;
}

/* 章节卡 */
.page-about .about-chapter {
  position: relative;
  padding: 20px 16px 24px;
  background: var(--charcoal);
  border: var(--bw) solid var(--haze);
  box-shadow: var(--shadow-hard);
}

.page-about .ch-head {
  display: flex;
  align-items: flex-start;
  gap: 14px;
}

.page-about .ch-num {
  flex: none;
  display: grid;
  place-items: center;
  width: 46px;
  height: 46px;
  background: var(--clay);
  color: var(--cream);
  font-family: var(--font-mono);
  font-size: 19px;
  font-weight: 700;
  transform: skewX(-6deg);
  box-shadow: 4px 4px 0 rgba(0, 0, 0, 0.5);
  font-variant-numeric: tabular-nums;
}

.page-about .ch-head-text {
  min-width: 0;
}

.page-about .ch-label {
  margin: 0 0 4px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--gold);
}

.page-about .about-chapter h2 {
  margin: 0;
  font-family: var(--font-display);
  font-size: 21px;
  font-weight: 900;
  line-height: 1.28;
  letter-spacing: -0.01em;
  color: var(--cream);
}

.page-about .ch-lead {
  margin: 18px 0 0;
  padding-left: 12px;
  border-left: 3px solid var(--clay);
  font-family: var(--font-serif);
  font-size: 18px;
  font-weight: 600;
  line-height: 1.6;
  color: var(--cream);
}

.page-about .ch-text {
  margin: 14px 0 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--body-ink);
}

.page-about .about-chapter h3 {
  margin: 16px 0 6px;
  font-family: var(--font-display);
  font-size: 16px;
  font-weight: 700;
  line-height: 1.4;
  color: var(--gold);
}

.page-about .about-chapter p + h3 {
  margin-top: 20px;
}

.page-about .split-text p {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--body-ink);
}

.page-about .split-note {
  margin-top: 14px !important;
  font-size: 13px !important;
  color: var(--rock) !important;
}

.page-about .split-note a {
  color: var(--gold);
  text-decoration: none;
  border-bottom: 1px solid var(--gold-deep);
}

.page-about .split-note a:hover {
  color: var(--flame);
}

/* 时间线 */
.page-about .about-timeline {
  list-style: none;
  position: relative;
  margin: 20px 0 0;
  padding: 0 0 0 24px;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 6px;
  top: 8px;
  bottom: 10px;
  width: 3px;
  background: repeating-linear-gradient(180deg, var(--gold-deep) 0 9px, transparent 9px 15px);
}

.page-about .tl-item {
  position: relative;
  padding-bottom: 18px;
}

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

.page-about .tl-item::before {
  content: "";
  position: absolute;
  left: -24px;
  top: 5px;
  width: 13px;
  height: 13px;
  border: 3px solid var(--ink);
  border-radius: 50%;
  background: var(--gold);
}

.page-about .tl-phase {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--jade);
}

.page-about .tl-item h3 {
  margin: 6px 0 4px;
  font-family: var(--font-body);
  font-size: 16px;
  font-weight: 700;
  color: var(--cream);
}

.page-about .tl-item p {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--body-ink);
}

/* 折叠说明 */
.page-about .about-details {
  margin-top: 10px;
  padding-left: 12px;
  border-left: 2px solid var(--haze);
}

.page-about .about-details summary {
  display: flex;
  align-items: center;
  gap: 8px;
  list-style: none;
  cursor: pointer;
  font-size: 13px;
  font-weight: 700;
  color: var(--gold);
}

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

.page-about .about-details summary::before {
  content: "+";
  font-family: var(--font-mono);
  font-size: 15px;
  line-height: 1;
}

.page-about .about-details[open] summary::before {
  content: "–";
}

.page-about .about-details p {
  margin: 8px 0 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--body-ink);
}

/* 小组卡 */
.page-about .team-list {
  list-style: none;
  display: grid;
  gap: 12px;
  margin: 20px 0 0;
  padding: 0;
}

.page-about .team-card {
  padding: 14px;
  background: rgba(30, 58, 82, 0.35);
  border: 2px solid var(--haze);
}

.page-about .team-card h3 {
  margin: 8px 0 6px;
  font-size: 16px;
  color: var(--cream);
}

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

.page-about .team-code {
  display: inline-block;
  padding: 2px 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--ink);
  background: var(--gold);
}

.page-about .team-code--2 {
  background: var(--flame);
  color: var(--cream);
}

.page-about .team-code--3 {
  background: var(--jade);
  color: var(--ink);
}

/* 图片 */
.page-about .about-figure {
  margin: 20px 0 0;
  background: var(--haze);
  border: var(--bw) solid var(--haze);
  box-shadow: var(--shadow-hard);
  overflow: hidden;
}

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

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

.page-about .about-figure figcaption {
  padding: 9px 11px;
  border-top: 2px solid var(--charcoal);
  background: var(--charcoal);
  font-size: 12px;
  line-height: 1.6;
  letter-spacing: 0.03em;
  color: var(--rock);
}

/* 数据侧栏 */
.page-about .about-data {
  align-self: start;
  padding: 18px 16px;
  background: var(--haze);
  border: 2px solid var(--haze);
  border-left: 6px solid var(--gold);
  box-shadow: var(--shadow-gold);
}

.page-about .data-title {
  margin: 0 0 12px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--gold);
}

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

.page-about .data-list li {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 10px;
  padding: 9px 0;
  border-bottom: 1px dashed rgba(243, 235, 221, 0.2);
  min-width: 0;
}

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

.page-about .data-key {
  font-size: 13px;
  color: rgba(243, 235, 221, 0.78);
}

.page-about .data-val {
  font-family: var(--font-mono);
  font-size: 15px;
  font-weight: 700;
  color: var(--cream);
  white-space: nowrap;
  font-variant-numeric: tabular-nums;
}

.page-about .data-note {
  margin: 12px 0 0;
  padding-top: 10px;
  border-top: 1px solid var(--edge);
  font-size: 12px;
  line-height: 1.7;
  color: rgba(243, 235, 221, 0.66);
}

/* 双栏内容 */
.page-about .about-split {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 18px;
  margin-top: 16px;
}

/* 合作入口 */
.page-about .chapter--cta {
  background: linear-gradient(135deg, rgba(30, 58, 82, 0.95), var(--charcoal) 62%);
  border-color: var(--gold-deep);
}

.page-about .cta-points {
  list-style: none;
  display: grid;
  gap: 10px;
  margin: 18px 0 0;
  padding: 0;
}

.page-about .cta-points li {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  padding: 10px 12px;
  border: 2px solid var(--haze);
  background: rgba(11, 27, 43, 0.55);
  font-size: 14px;
  line-height: 1.7;
  color: var(--cream);
}

.page-about .cta-dot {
  flex: none;
  width: 9px;
  height: 9px;
  margin-top: 7px;
  background: var(--flame);
  transform: rotate(45deg);
}

/* 返回顶部 */
.page-about .about-to-top {
  position: fixed;
  right: 16px;
  bottom: 20px;
  z-index: 20;
  width: 46px;
  height: 46px;
  border: var(--bw) solid var(--gold);
  background: var(--ink);
  color: var(--gold);
  font-family: var(--font-mono);
  font-size: 18px;
  cursor: pointer;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.2s ease, color 0.16s ease, border-color 0.16s ease;
}

.page-about .about-to-top[data-visible] {
  opacity: 1;
  pointer-events: auto;
}

.page-about .about-to-top:hover {
  color: var(--flame);
  border-color: var(--flame);
}

/* 平板 */
@media (min-width: 720px) {
  .page-about .about-hero h1 {
    font-size: 46px;
  }

  .page-about .about-lead {
    font-size: 17px;
  }

  .page-about .about-chapter {
    padding: 24px 22px 28px;
  }

  .page-about .about-chapter h2 {
    font-size: 26px;
  }

  .page-about .ch-lead {
    font-size: 20px;
  }

  .page-about .ch-text,
  .page-about .split-text p {
    font-size: 16px;
  }

  .page-about .fig-num {
    font-size: 34px;
  }

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

  .page-about .about-split {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    align-items: start;
  }
}

/* 桌面：粘性目录 + 12 列信息板 */
@media (min-width: 960px) {
  .page-about .about-hero {
    grid-template-columns: minmax(0, 1fr) 190px;
    align-items: end;
    gap: 28px;
  }

  .page-about .about-hero-mark {
    display: flex;
    flex-direction: column;
    align-items: flex-end;
    gap: 8px;
    padding-bottom: 6px;
  }

  .page-about .mark-num {
    font-family: var(--font-mono);
    font-size: 40px;
    font-weight: 700;
    line-height: 1;
    color: var(--gold);
    font-variant-numeric: tabular-nums;
  }

  .page-about .mark-caption {
    font-family: var(--font-mono);
    font-size: 11px;
    letter-spacing: 0.24em;
    color: var(--rock);
  }

  .page-about .mark-bar {
    display: block;
    width: 100%;
    height: 4px;
    background: repeating-linear-gradient(90deg, var(--clay) 0 12px, transparent 12px 18px);
  }

  .page-about .about-figures {
    grid-column: 1 / -1;
    max-width: 560px;
  }

  .page-about .about-shell {
    display: grid;
    grid-template-columns: var(--about-toc) minmax(0, 1fr);
    gap: 36px;
    align-items: start;
  }

  .page-about .about-toc {
    position: sticky;
    top: calc(var(--header-h) + 20px);
    margin-bottom: 0;
  }

  .page-about .about-toc-list {
    display: block;
    overflow: visible;
    padding: 0;
  }

  .page-about .about-toc-list li + li {
    margin-top: 4px;
  }

  .page-about .about-toc-list a {
    border: 0;
    border-left: 3px solid var(--haze);
    background: transparent;
    padding: 9px 10px;
    font-size: 14px;
    white-space: normal;
  }

  .page-about .about-toc-list a:hover,
  .page-about .about-toc-list a:focus-visible {
    border-left-color: var(--gold);
    background: rgba(232, 178, 58, 0.08);
  }

  .page-about .about-toc-foot {
    display: block;
    margin-top: 18px;
    padding-top: 12px;
    border-top: 1px solid var(--edge);
  }

  .page-about .about-toc-foot p {
    margin: 0 0 4px;
    font-family: var(--font-mono);
    font-size: 12px;
    letter-spacing: 0.06em;
    color: var(--rock);
  }

  .page-about .about-chapter h2 {
    font-size: 30px;
  }

  .page-about .ch-num {
    width: 56px;
    height: 56px;
    font-size: 23px;
  }
}

@media (min-width: 1020px) {
  .page-about .about-body {
    grid-template-columns: repeat(12, minmax(0, 1fr));
    gap: 24px;
  }

  .page-about .chapter--wide {
    grid-column: span 12;
  }

  .page-about .chapter--main {
    grid-column: span 8;
  }

  .page-about .about-data {
    grid-column: span 4;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-btn,
  .page-about .about-to-top,
  .page-about .about-toc-list a {
    transition: none;
  }

  .page-about .about-btn:hover,
  .page-about .about-btn:focus-visible {
    transform: none;
  }
}
<<<END>>>