.page-about {
  --rail-w: 196px;
  --about-gap: clamp(32px, 4vw, 64px);
  background: var(--bg);
  color: var(--text);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  border-bottom: 1px solid var(--line);
  padding: clamp(20px, 3vw, 32px) 0 clamp(40px, 7vw, 80px);
}
.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(140deg, var(--c-ink-800) 0%, var(--c-ink-900) 62%);
  clip-path: polygon(0 0, 100% 0, 100% 44%, 0 80%);
}
.page-about .about-hero-field {
  position: absolute;
  inset: 0;
  pointer-events: none;
  opacity: 0.55;
  background-image:
    linear-gradient(var(--c-ink-700) 1px, transparent 1px),
    linear-gradient(90deg, var(--c-ink-700) 1px, transparent 1px);
  background-size: 32px 32px;
  clip-path: polygon(0 0, 58% 0, 24% 100%, 0 100%);
}
.page-about .about-hero-wrap {
  position: relative;
  z-index: 1;
}
.page-about .about-hero .breadcrumbs {
  margin-bottom: clamp(20px, 3vw, 36px);
}
.page-about .about-hero-inner {
  display: grid;
  gap: 32px;
}
.page-about .about-hero h1 {
  margin: 12px 0 0;
  max-width: 16em;
  font-family: var(--font-head);
  font-weight: 800;
  font-size: clamp(30px, 5.2vw, 52px);
  line-height: 1.12;
  letter-spacing: -0.02em;
  color: var(--c-frost);
}
.page-about .about-hero-lede {
  margin: 18px 0 0;
  max-width: 34em;
  font-size: 16px;
  line-height: 1.8;
  color: var(--text);
}
.page-about .about-figures {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px 20px;
  margin: 28px 0 0;
  padding-top: 20px;
  border-top: 1px solid var(--line);
}
.page-about .about-figure {
  margin: 0;
}
.page-about .about-figure-num {
  display: block;
  margin: 0;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(20px, 3vw, 28px);
  line-height: 1.1;
  color: var(--c-amber);
}
.page-about .about-figure-label {
  display: block;
  margin-top: 6px;
  font-size: 13px;
  line-height: 1.5;
  color: var(--text-dim);
}
.page-about .about-hero-figure {
  margin: 0;
}
.page-about .about-hero-figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 14 / 9;
  object-fit: cover;
  border: 1px solid var(--line);
}
.page-about .about-hero-figure .media-caption {
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  line-height: 1.6;
  color: var(--text-dim);
}

/* ---------- 画册长卷框架 ---------- */
.page-about .about-body {
  padding: clamp(32px, 5vw, 64px) 0 clamp(48px, 7vw, 96px);
}
.page-about .about-rail {
  position: sticky;
  top: calc(var(--header-h) + 8px);
  z-index: 5;
  margin-bottom: 24px;
  padding: 6px 0;
  background: var(--bg);
  border-bottom: 1px solid var(--line);
  overflow-x: auto;
  scrollbar-width: none;
}
.page-about .about-rail::-webkit-scrollbar {
  display: none;
}
.page-about .about-rail-list {
  display: flex;
  gap: 6px;
  margin: 0;
  padding: 0;
  list-style: none;
}
.page-about .about-rail-link {
  display: flex;
  align-items: center;
  gap: 8px;
  min-height: 44px;
  padding: 6px 12px;
  font-family: var(--font-mono);
  font-size: 13px;
  line-height: 1.4;
  white-space: nowrap;
  color: var(--text-dim);
  text-decoration: none;
  border-left: 2px solid transparent;
  transition: color var(--dur-fast) var(--ease), border-color var(--dur-fast) var(--ease);
}
.page-about .about-rail-num {
  color: var(--c-amber);
  font-weight: 700;
}
.page-about .about-rail-link:hover,
.page-about .about-rail-link:focus-visible {
  color: var(--text);
  border-left-color: var(--c-amber);
}

.page-about .about-chapter {
  padding: clamp(36px, 5.5vw, 72px) 0;
  border-top: 1px solid var(--line);
}
.page-about .about-chapter:first-child {
  border-top: 0;
  padding-top: 0;
}
.page-about .about-chapter p {
  max-width: 38em;
  margin: 0 0 16px;
  font-size: 16px;
  line-height: 1.8;
}
.page-about .about-chapter p:last-child {
  margin-bottom: 0;
}
.page-about .about-chapter-head {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  align-items: baseline;
  gap: 6px 16px;
  margin-bottom: 24px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--line);
}
.page-about .about-chapter-num {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(26px, 4.6vw, 44px);
  line-height: 1;
  color: var(--c-amber);
}
.page-about .about-chapter h2 {
  margin: 0;
  font-family: var(--font-head);
  font-weight: 800;
  font-size: clamp(21px, 3.2vw, 30px);
  line-height: 1.28;
  letter-spacing: -0.01em;
  color: var(--c-frost);
}
.page-about .about-chapter-lede {
  font-family: var(--font-mono);
  font-size: 13px;
  line-height: 1.8;
  color: var(--text-dim);
}
.page-about .about-inline-link {
  color: var(--c-celadon);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color var(--dur-fast) var(--ease), color var(--dur-fast) var(--ease);
}
.page-about .about-inline-link:hover,
.page-about .about-inline-link:focus-visible {
  color: var(--c-amber);
  border-bottom-color: var(--c-amber);
}

/* 米白纸面章节 */
.page-about .about-chapter--paper {
  --line: var(--c-slate);
  background: var(--c-paper);
  color: var(--c-ink-900);
  padding: clamp(32px, 5vw, 64px) clamp(18px, 4vw, 44px);
}
.page-about .about-chapter--paper h2,
.page-about .about-chapter--paper h3 {
  color: var(--c-ink-900);
}
.page-about .about-chapter--paper p,
.page-about .about-chapter--paper li {
  color: var(--c-ink-800);
}
.page-about .about-chapter--paper .about-chapter-num {
  color: var(--c-clay);
}
.page-about .about-chapter--paper .about-inline-link {
  color: var(--c-clay);
}
.page-about .about-chapter--paper .about-inline-link:hover,
.page-about .about-chapter--paper .about-inline-link:focus-visible {
  color: var(--c-ink-900);
  border-bottom-color: var(--c-ink-900);
}

/* ---------- 版本时间线 ---------- */
.page-about .about-timeline {
  margin: 8px 0 0;
  padding: 0;
  list-style: none;
}
.page-about .about-timeline-item {
  display: grid;
  grid-template-columns: 68px minmax(0, 1fr);
  gap: 4px 16px;
  padding: 22px 12px 22px 0;
  border-top: 1px solid var(--line);
  transition: background var(--dur) var(--ease);
}
.page-about .about-timeline-item:hover {
  background: var(--c-ink-800);
}
.page-about .about-timeline-mark {
  display: flex;
  flex-direction: column;
  gap: 4px;
}
.page-about .about-version {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(24px, 4vw, 34px);
  line-height: 1;
  color: var(--text-dim);
  transition: color var(--dur-fast) var(--ease);
}
.page-about .about-timeline-item:hover .about-version,
.page-about .about-timeline-item--current .about-version {
  color: var(--c-amber);
}
.page-about .about-year {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--c-slate);
}
.page-about .about-timeline-body h3 {
  margin: 0 0 6px;
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 17px;
  line-height: 1.5;
  color: var(--c-frost);
}
.page-about .about-timeline-body p {
  margin: 0;
  font-size: 15px;
  line-height: 1.75;
  color: var(--text);
}

/* ---------- 图 ---------- */
.page-about .about-wide-figure {
  margin: 32px 0 0;
}
.page-about .about-wide-figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 3 / 2;
  object-fit: cover;
  border: 1px solid var(--line);
}
.page-about .about-wide-figure .media-caption {
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  line-height: 1.6;
  color: var(--text-dim);
}
.page-about .about-wide-figure--narrow {
  max-width: 640px;
}

/* ---------- 团队分工 ---------- */
.page-about .about-split {
  display: flex;
  gap: 2px;
  height: 14px;
  margin: 20px 0 28px;
}
.page-about .about-split-seg {
  display: block;
  height: 100%;
}
.page-about .about-split-seg--content {
  flex: 7 1 0;
  background: var(--c-celadon);
}
.page-about .about-split-seg--tech {
  flex: 6 1 0;
  background: var(--c-clay);
}
.page-about .about-split-seg--care {
  flex: 5 1 0;
  background: var(--c-moss);
}
.page-about .about-roles {
  gap: 24px;
}
.page-about .about-role {
  padding-top: 14px;
  border-top: 3px solid var(--line);
}
.page-about .about-role--content {
  border-top-color: var(--c-celadon);
}
.page-about .about-role--tech {
  border-top-color: var(--c-clay);
}
.page-about .about-role--care {
  border-top-color: var(--c-moss);
}
.page-about .about-role-num {
  margin: 0;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(26px, 4vw, 36px);
  line-height: 1;
  color: var(--c-ink-900);
}
.page-about .about-role h3 {
  margin: 8px 0 6px;
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 17px;
  line-height: 1.5;
  color: var(--c-ink-900);
}
.page-about .about-role p {
  margin: 0;
  font-size: 15px;
  line-height: 1.75;
  color: var(--c-ink-800);
}

/* ---------- 服务与合作 ---------- */
.page-about .about-ecosystem {
  display: grid;
  gap: 28px;
}
.page-about .about-map svg {
  display: block;
  width: 100%;
  height: auto;
  max-width: 420px;
  margin: 0 auto;
}
.page-about .about-map-note {
  margin: 12px 0 0;
  font-family: var(--font-mono);
  font-size: 12px;
  line-height: 1.7;
  color: var(--c-ink-800);
  text-align: center;
}
.page-about .about-methods > p {
  margin-bottom: 12px;
}
.page-about .about-method {
  border-top: 1px solid var(--line);
}
.page-about .about-method:last-of-type {
  border-bottom: 1px solid var(--line);
}
.page-about .about-method summary {
  display: flex;
  align-items: center;
  gap: 10px;
  min-height: 48px;
  padding: 8px 0;
  cursor: pointer;
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 16px;
  line-height: 1.5;
  color: var(--c-ink-900);
  list-style: none;
}
.page-about .about-method summary::-webkit-details-marker {
  display: none;
}
.page-about .about-method summary::before {
  content: "+";
  font-family: var(--font-mono);
  font-weight: 700;
  color: var(--c-clay);
  width: 1em;
}
.page-about .about-method[open] summary::before {
  content: "–";
}
.page-about .about-method summary:focus-visible {
  outline: 2px solid var(--c-clay);
  outline-offset: 2px;
}
.page-about .about-method p {
  margin: 0 0 16px;
  padding-left: calc(1em + 10px);
  font-size: 15px;
  line-height: 1.75;
  color: var(--c-ink-800);
}
.page-about .about-methods-foot {
  margin-top: 20px;
  font-size: 15px;
}

/* ---------- 荣誉资质 ---------- */
.page-about .about-honors {
  margin: 8px 0 0;
  padding: 0;
  counter-reset: honor;
  list-style: none;
}
.page-about .about-honors li {
  counter-increment: honor;
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 14px;
  padding: 20px 0;
  border-top: 1px solid var(--line);
  transition: background var(--dur) var(--ease);
}
.page-about .about-honors li:hover {
  background: var(--c-ink-800);
}
.page-about .about-honors li::before {
  content: "0" counter(honor);
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 13px;
  line-height: 1.6;
  color: var(--c-amber);
}
.page-about .about-honors h3 {
  margin: 0 0 6px;
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 17px;
  line-height: 1.5;
  color: var(--c-frost);
}
.page-about .about-honors p {
  margin: 0;
  font-size: 15px;
  line-height: 1.75;
  color: var(--text);
}

/* ---------- 收尾 ---------- */
.page-about .about-next {
  position: relative;
  background: var(--c-ink-800);
  border-top: 1px solid var(--line);
  padding: clamp(36px, 5vw, 64px) 0 clamp(40px, 6vw, 72px);
}
.page-about .about-next::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--c-celadon), var(--c-moss), var(--c-amber));
}
.page-about .about-next h2 {
  margin: 10px 0 0;
  font-family: var(--font-head);
  font-weight: 800;
  font-size: clamp(21px, 3.2vw, 28px);
  line-height: 1.3;
  color: var(--c-frost);
}
.page-about .about-next-text {
  margin: 12px 0 0;
  max-width: 34em;
  font-size: 15px;
  line-height: 1.8;
  color: var(--text);
}
.page-about .about-next-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 22px;
}
.page-about .about-next-mail {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px;
  margin: 20px 0 0;
  padding-top: 18px;
  border-top: 1px solid var(--line);
}
.page-about .about-mail {
  font-family: var(--font-mono);
  font-size: 13px;
  line-height: 1.6;
  color: var(--c-celadon);
  word-break: break-all;
}

/* ---------- 断点 ---------- */
@media (min-width: 720px) {
  .page-about .about-figures {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
  .page-about .about-hero-inner {
    grid-template-columns: minmax(0, 1.08fr) minmax(0, 0.92fr);
    align-items: end;
    gap: 40px;
  }
  .page-about .about-ecosystem {
    grid-template-columns: minmax(0, 0.85fr) minmax(0, 1.15fr);
    align-items: start;
    gap: 32px;
  }
  .page-about .about-map-note {
    text-align: left;
  }
}

@media (min-width: 960px) {
  .page-about .about-body {
    display: grid;
    grid-template-columns: var(--rail-w) minmax(0, 1fr);
    gap: var(--about-gap);
    align-items: start;
  }
  .page-about .about-rail {
    top: calc(var(--header-h) + 24px);
    overflow: visible;
    margin-bottom: 0;
    padding: 0 0 0 14px;
    background: transparent;
    border-bottom: 0;
    border-left: 1px solid var(--line);
  }
  .page-about .about-rail-list {
    flex-direction: column;
    gap: 2px;
  }
  .page-about .about-rail-link {
    padding: 8px 10px 8px 8px;
    border-left: 2px solid transparent;
    margin-left: -16px;
    padding-left: 14px;
  }
  .page-about .about-chapter-head {
    gap: 8px 24px;
  }
  .page-about .about-timeline-item {
    grid-template-columns: 96px minmax(0, 1fr);
    padding: 26px 16px;
  }
  .page-about .about-wide-figure {
    margin-top: 40px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-rail-link,
  .page-about .about-inline-link,
  .page-about .about-timeline-item,
  .page-about .about-version,
  .page-about .about-honors li {
    transition: none;
  }
}
<<<END>>>