.page-about {
  --about-rail: 168px;
  --about-gap: clamp(40px, 6vw, 76px);
  background-color: var(--paper);
  background-image: radial-gradient(rgba(36, 35, 31, .028) 1px, transparent 1px);
  background-size: 4px 4px;
}

/* ---------- 封面 ---------- */
.page-about .about-cover {
  padding-top: calc(var(--header-h) + 28px);
  padding-bottom: clamp(36px, 5vw, 68px);
  background-image: linear-gradient(180deg, rgba(235, 227, 214, .9) 0%, rgba(235, 227, 214, 0) 100%);
}

.page-about .breadcrumb {
  margin: 0 0 32px;
}

.page-about .breadcrumb ol {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .04em;
  color: var(--blue);
}

.page-about .breadcrumb li + li::before {
  content: "/";
  margin-right: 8px;
  color: var(--blue-mid);
}

.page-about .breadcrumb a {
  color: var(--blue);
  text-decoration: none;
}

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

.page-about .cover-grid {
  display: grid;
  gap: 32px;
}

.page-about .cover-main {
  min-width: 0;
}

.page-about .title-display {
  font-size: clamp(30px, 4.2vw, 44px);
  line-height: 1.24;
  letter-spacing: -.01em;
  color: var(--ink);
  margin: 10px 0 0;
}

.page-about .about-lede {
  max-width: 34em;
  margin: 20px 0 0;
  font-size: 17px;
  line-height: 1.85;
  color: var(--charcoal);
}

.page-about .cover-index {
  border-top: 1px solid var(--line-paper);
  padding-top: 18px;
}

.page-about .cover-index-title {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--blue);
}

.page-about .cover-index ul {
  list-style: none;
  margin: 14px 0 0;
  padding: 0;
  display: grid;
  gap: 4px;
}

.page-about .cover-index a {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding: 8px 0;
  font-size: 15px;
  color: var(--ink);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color var(--t-fast) var(--ease), border-color var(--t-fast) var(--ease);
}

.page-about .cover-index a:hover {
  color: var(--orange-deep);
  border-bottom-color: var(--orange);
}

.page-about .ci-num {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--orange-deep);
}

/* ---------- 章节骨架 ---------- */
.page-about .chapter {
  display: grid;
  gap: 16px;
  padding: var(--about-gap) 0;
  border-top: 1px solid var(--line-paper);
  background-image: linear-gradient(180deg, rgba(235, 227, 214, .5) 0, rgba(235, 227, 214, 0) 150px);
  scroll-margin-top: calc(var(--header-h) + 16px);
}

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

.page-about .chapter-num {
  display: block;
  font-family: var(--font-mono);
  font-size: 28px;
  line-height: 1;
  letter-spacing: .02em;
  color: transparent;
  -webkit-text-stroke: 1px var(--blue-mid);
}

.page-about .chapter-tag {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--blue);
}

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

.page-about .chapter-body > p {
  max-width: 34em;
  color: var(--charcoal);
  line-height: 1.85;
}

.page-about .chapter-body a {
  color: var(--orange-deep);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
}

.page-about .chapter-body a:hover {
  color: var(--ink);
  background: var(--orange-soft);
}

.page-about .title-section {
  font-size: clamp(23px, 2.6vw, 28px);
  line-height: 1.35;
  color: var(--ink);
  margin: 0 0 14px;
}

.page-about .chapter-foot,
.page-about .chapter-end {
  margin-top: 24px;
  font-size: 15px;
  line-height: 1.8;
  color: var(--charcoal);
  max-width: 36em;
}

/* ---------- 编号便签 ---------- */
.page-about .note {
  margin: 26px 0 0;
  max-width: 36em;
  padding: 16px 18px;
  background: var(--blue-soft);
  border-left: 3px solid var(--blue);
  border-radius: var(--radius);
}

.page-about .note-label {
  margin: 0 0 6px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--blue);
}

.page-about .note p {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--charcoal);
}

/* ---------- 四步流程 ---------- */
.page-about .steps {
  list-style: none;
  margin: 26px 0 0;
  padding: 0;
}

.page-about .step {
  display: grid;
  grid-template-columns: 28px minmax(0, 1fr);
  gap: 16px;
  padding: 18px 0;
  border-top: 1px dashed var(--line-paper);
}

.page-about .step:first-child {
  border-top: 1px solid var(--line-paper);
}

.page-about .step-num {
  width: 26px;
  height: 26px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--orange-deep);
  background: var(--card);
  border: 1px solid var(--orange);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

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

.page-about .step-title {
  margin: 0 0 4px;
  font-size: 17px;
  font-weight: 700;
  line-height: 1.5;
  color: var(--ink);
}

.page-about .step-text p {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--charcoal);
  max-width: 34em;
}

/* ---------- 配图 ---------- */
.page-about .about-figure {
  margin: 30px 0 0;
}

.page-about .about-figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  border: 1px solid var(--line-paper);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  filter: saturate(.55) sepia(.05);
}

.page-about .about-figure .media-cap {
  margin: 10px 0 0;
  font-family: var(--font-mono);
  font-size: 12px;
  line-height: 1.7;
  letter-spacing: .02em;
  color: var(--blue);
}

/* ---------- 小组折叠 ---------- */
.page-about .team-acc {
  margin-top: 24px;
  border-top: 1px solid var(--line-paper);
}

.page-about .team-item {
  border-bottom: 1px solid var(--line-paper);
}

.page-about .team-head {
  margin: 0;
  font-size: 1rem;
  font-weight: 400;
}

.page-about .team-trigger {
  width: 100%;
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding: 15px 2px;
  background: none;
  border: 0;
  cursor: pointer;
  text-align: left;
  font-family: inherit;
  color: var(--ink);
  transition: background var(--t-fast) var(--ease);
}

.page-about .team-trigger:hover {
  background: rgba(255, 233, 216, .55);
}

.page-about .team-name {
  font-size: 17px;
  font-weight: 700;
}

.page-about .team-trigger:hover .team-name {
  color: var(--orange-deep);
}

.page-about .team-role {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--blue-mid);
}

.page-about .team-trigger::after {
  content: "+";
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 16px;
  color: var(--orange);
}

.page-about .team-trigger[aria-expanded="true"]::after {
  content: "−";
}

.page-about .team-panel {
  padding: 0 2px 16px;
}

.page-about .team-panel ul {
  margin: 0;
  padding-left: 18px;
  font-size: 15px;
  line-height: 1.8;
  color: var(--charcoal);
}

.page-about .team-panel li + li {
  margin-top: 4px;
}

/* ---------- 规模数据 ---------- */
.page-about .data-grid {
  margin: 26px 0 0;
  grid-template-columns: 1fr;
  gap: 1px;
  background: var(--line-paper);
  border: 1px solid var(--line-paper);
  border-radius: var(--radius);
  overflow: hidden;
}

.page-about .data-tile {
  display: flex;
  flex-direction: column;
  gap: 2px;
  padding: 20px 18px;
  background: var(--card);
  transition: background var(--t-fast) var(--ease);
}

.page-about .data-tile:hover {
  background: var(--sand);
}

.page-about .data-tile .stat {
  font-family: var(--font-display);
  font-size: clamp(28px, 4vw, 38px);
  font-weight: 800;
  line-height: 1.08;
  letter-spacing: -.01em;
  font-variant-numeric: tabular-nums;
  color: var(--ink);
}

.page-about .data-tile .stat-label {
  font-size: 14px;
  line-height: 1.6;
  color: var(--charcoal);
}

.page-about .data-example {
  margin-top: 6px;
  font-family: var(--font-mono);
  font-size: 12px;
  line-height: 1.6;
  letter-spacing: .02em;
  color: var(--blue-mid);
  transition: color var(--t-fast) var(--ease);
}

.page-about .data-tile:hover .data-example {
  color: var(--orange-deep);
}

/* ---------- 版本时间轴 ---------- */
.page-about .tl-wrap {
  margin-top: 26px;
  display: grid;
  gap: 32px;
}

.page-about .tl {
  position: relative;
  margin: 0;
  padding-left: 24px;
}

.page-about .tl::before {
  content: "";
  position: absolute;
  left: 6px;
  top: 18px;
  bottom: 18px;
  width: 1px;
  background: linear-gradient(180deg, var(--orange) 0%, var(--blue-mid) 100%);
}

.page-about .tl-item {
  position: relative;
  border-bottom: 1px solid var(--line-paper);
}

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

.page-about .tl-item::before {
  content: "";
  position: absolute;
  left: -22px;
  top: 21px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--card);
  border: 1px solid var(--orange);
}

.page-about .tl-trigger {
  width: 100%;
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding: 14px 0;
  background: none;
  border: 0;
  cursor: pointer;
  text-align: left;
  font-family: inherit;
  color: var(--ink);
}

.page-about .tl-year {
  min-width: 46px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .04em;
  color: var(--orange-deep);
}

.page-about .tl-title {
  font-size: 16px;
  font-weight: 700;
  line-height: 1.5;
  transition: color var(--t-fast) var(--ease);
}

.page-about .tl-trigger:hover .tl-title {
  color: var(--orange-deep);
}

.page-about .tl-trigger::after {
  content: "+";
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 15px;
  color: var(--blue-mid);
}

.page-about .tl-trigger[aria-expanded="true"]::after {
  content: "−";
  color: var(--orange-deep);
}

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

.page-about .tl-panel p {
  margin: 0;
  max-width: 32em;
  font-size: 15px;
  line-height: 1.8;
  color: var(--charcoal);
}

.page-about .about-figure--side {
  margin: 0;
}

/* ---------- 纠错流程 ---------- */
.page-about .flow {
  counter-reset: fstep;
  list-style: none;
  margin: 24px 0 0;
  padding: 0;
  display: grid;
  gap: 14px;
  max-width: 44em;
}

.page-about .flow li {
  counter-increment: fstep;
  position: relative;
  padding-left: 32px;
  font-size: 15px;
  line-height: 1.8;
  color: var(--charcoal);
}

.page-about .flow li::before {
  content: counter(fstep);
  position: absolute;
  left: 0;
  top: 2px;
  width: 20px;
  height: 20px;
  display: grid;
  place-items: center;
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--clay);
  background: var(--card);
  border: 1px solid var(--clay);
  border-radius: 50%;
}

/* ---------- 响应式 ---------- */
@media (min-width: 560px) {
  .page-about .data-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .flow {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 16px 28px;
  }
}

@media (min-width: 900px) {
  .page-about .cover-grid {
    grid-template-columns: minmax(0, 1.3fr) minmax(0, .7fr);
    gap: 56px;
    align-items: end;
  }

  .page-about .cover-index {
    border-top: 0;
    border-left: 1px solid var(--line-paper);
    padding: 4px 0 4px 26px;
  }

  .page-about .chapter {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: 48px;
  }

  .page-about .chapter-rail {
    display: block;
    position: sticky;
    top: calc(var(--header-h) + 24px);
    align-self: start;
  }

  .page-about .chapter-num {
    font-size: 42px;
  }

  .page-about .chapter-tag {
    display: block;
    margin-top: 10px;
  }

  .page-about .tl-wrap {
    grid-template-columns: minmax(0, 1.1fr) minmax(0, .9fr);
    gap: 44px;
    align-items: start;
  }
}

@media (min-width: 980px) {
  .page-about .data-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .cover-index a,
  .page-about .data-tile,
  .page-about .data-example,
  .page-about .team-trigger,
  .page-about .tl-title {
    transition: none;
  }
}
<<<PAGE_CSS_END>>>