.page-about {
  --about-rail-w: 168px;
}

/* ---------- 面包屑 ---------- */
.page-about .about-crumbs {
  padding-top: clamp(16px, 3vw, 28px);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  padding-block: clamp(22px, 4vw, 44px) clamp(28px, 5vw, 48px);
}

.page-about .about-hero__label {
  color: var(--orange);
  margin: 0 0 14px;
}

.page-about .about-hero__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(34px, 6vw, 76px);
  line-height: 1.06;
  letter-spacing: -0.02em;
  color: var(--paper);
  max-width: 16ch;
}

.page-about .about-hero__lede {
  margin: clamp(18px, 2.6vw, 28px) 0 0;
  padding-left: clamp(14px, 2vw, 22px);
  border-left: 2px solid var(--orange);
  max-width: 60ch;
  font-size: clamp(16px, 1.35vw, 18px);
  line-height: 1.8;
  color: rgba(244, 240, 230, .78);
}

.page-about .about-hero__figure {
  margin: clamp(28px, 4.5vw, 48px) 0 0;
}

.page-about .about-hero__figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 21 / 9;
  object-fit: cover;
  border-radius: var(--r-lg);
}

/* ---------- 布局 ---------- */
.page-about .about-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(24px, 4vw, 40px);
  padding-block: clamp(26px, 4.5vw, 52px) clamp(48px, 8vw, 96px);
}

@media (min-width: 980px) {
  .page-about .about-layout {
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
    gap: clamp(36px, 5vw, 76px);
    align-items: start;
  }
}

/* ---------- 粘性章节索引 ---------- */
.page-about .about-rail {
  min-width: 0;
}

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

.page-about .about-rail__list {
  display: flex;
  gap: 8px;
  margin: 0;
  padding: 0 0 12px;
  list-style: none;
  overflow-x: auto;
  scrollbar-width: thin;
}

.page-about .about-rail__link {
  display: block;
  white-space: nowrap;
  padding: 8px 13px;
  border: 1px solid var(--line);
  border-radius: 999px;
  font-size: 13px;
  letter-spacing: .06em;
  color: var(--grey);
  text-decoration: none;
  transition: color .2s var(--ease), border-color .2s var(--ease), background-color .2s var(--ease);
}

.page-about .about-rail__link:hover,
.page-about .about-rail__link:focus-visible {
  color: var(--paper);
  border-color: var(--orange);
  background: rgba(240, 101, 30, .1);
}

@media (min-width: 980px) {
  .page-about .about-rail {
    position: sticky;
    top: 112px;
  }

  .page-about .about-rail__kicker {
    display: block;
    color: var(--grey);
    margin: 0 0 12px;
  }

  .page-about .about-rail__list {
    flex-direction: column;
    gap: 2px;
    overflow: visible;
    padding: 0;
    border-left: 1px solid var(--line);
  }

  .page-about .about-rail__link {
    border: 0;
    border-left: 2px solid transparent;
    border-radius: 0 var(--r-sm) var(--r-sm) 0;
    margin-left: -1px;
    padding: 9px 12px;
    letter-spacing: .04em;
  }

  .page-about .about-rail__link:hover,
  .page-about .about-rail__link:focus-visible {
    background: rgba(240, 101, 30, .08);
  }
}

/* ---------- 内容流 ---------- */
.page-about .about-flow {
  display: flex;
  flex-direction: column;
  gap: clamp(52px, 7vw, 92px);
  min-width: 0;
}

.page-about .about-section {
  position: relative;
  scroll-margin-top: 118px;
  min-width: 0;
}

.page-about .about-prose {
  display: flex;
  flex-direction: column;
  gap: clamp(14px, 2vw, 20px);
  margin-top: clamp(20px, 3vw, 30px);
}

.page-about .about-prose p {
  margin: 0;
  max-width: 38em;
  font-size: clamp(15px, 1.2vw, 17px);
  line-height: 1.85;
  color: rgba(244, 240, 230, .8);
}

/* ---------- 数据带 ---------- */
.page-about .stat-band {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin-top: clamp(26px, 4vw, 40px);
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  overflow: hidden;
}

@media (min-width: 720px) {
  .page-about .stat-band {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

.page-about .stat-band__cell {
  background: var(--ink-900);
  padding: clamp(15px, 2.2vw, 24px);
}

.page-about .stat-band__value {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-weight: 700;
  font-size: clamp(26px, 3.2vw, 38px);
  line-height: 1.1;
  color: var(--paper);
}

.page-about .stat-band__unit {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--orange);
  margin-left: 5px;
}

.page-about .stat-band__label {
  display: block;
  margin-top: 9px;
  font-size: 13px;
  line-height: 1.65;
  color: var(--grey);
}

/* ---------- 脚注型说明 ---------- */
.page-about .about-footnote {
  margin: clamp(20px, 3vw, 28px) 0 0;
  padding: clamp(14px, 2vw, 20px) clamp(16px, 2.4vw, 24px);
  border-left: 3px solid var(--blue);
  background: rgba(46, 125, 166, .1);
  border-radius: 0 var(--r-md) var(--r-md) 0;
  font-size: 14.5px;
  line-height: 1.8;
  color: rgba(244, 240, 230, .82);
  max-width: 46em;
}

.page-about .about-footnote a {
  color: var(--blue);
  text-decoration-color: rgba(46, 125, 166, .5);
  text-underline-offset: 3px;
}

.page-about .about-footnote a:hover {
  color: var(--orange-soft);
}

/* ---------- 四步环形流程 ---------- */
.page-about .about-flow-figure {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(26px, 4vw, 40px);
  margin-top: clamp(24px, 3.6vw, 38px);
}

@media (min-width: 880px) {
  .page-about .about-flow-figure {
    grid-template-columns: 280px minmax(0, 1fr);
    gap: clamp(32px, 4.5vw, 56px);
    align-items: start;
  }
}

.page-about .about-ring {
  margin: 0;
  max-width: 340px;
}

.page-about .about-ring svg {
  display: block;
  width: 100%;
  height: auto;
}

.page-about .about-ring__track {
  fill: none;
  stroke: var(--line-soft);
  stroke-width: 1.5;
  stroke-dasharray: 3 7;
}

.page-about .about-ring__node {
  fill: var(--ink-900);
  stroke-width: 1.6;
}

.page-about .about-ring__node--a { stroke: var(--orange); }
.page-about .about-ring__node--b { stroke: var(--blue); }
.page-about .about-ring__node--c { stroke: var(--grass); }
.page-about .about-ring__node--d { stroke: var(--orange-soft); }

.page-about .about-ring__num {
  font-family: var(--font-mono);
  font-size: 16px;
  font-weight: 700;
  fill: var(--paper);
  text-anchor: middle;
}

.page-about .about-ring__cap {
  margin-top: 14px;
  text-align: center;
}

/* ---------- 四步折叠卡 ---------- */
.page-about .about-steps {
  display: grid;
  gap: 12px;
  margin: 0;
  padding: 0;
  list-style: none;
  min-width: 0;
}

.page-about .about-step {
  border: 1px solid var(--line);
  border-radius: var(--r-md) var(--r-md) var(--r-xs) var(--r-md);
  background: linear-gradient(180deg, rgba(18, 64, 62, .8), rgba(8, 33, 31, .88));
  overflow: hidden;
  transition: border-color .24s var(--ease);
}

.page-about .about-step:hover {
  border-color: rgba(247, 185, 138, .42);
}

.page-about .about-step__trigger {
  display: flex;
  align-items: center;
  gap: 14px;
  width: 100%;
  padding: clamp(14px, 2vw, 19px) clamp(16px, 2.4vw, 24px);
  background: none;
  border: 0;
  color: var(--paper);
  font: inherit;
  text-align: left;
  cursor: pointer;
}

.page-about .about-step__trigger .disclosure__sign {
  margin-left: auto;
  flex: none;
}

.page-about .about-step__no {
  flex: none;
  padding: 3px 8px;
  border: 1px solid rgba(240, 101, 30, .42);
  border-radius: var(--r-xs);
  font-size: 13px;
  font-weight: 700;
  color: var(--orange);
}

.page-about .about-step__name {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: clamp(17px, 1.9vw, 21px);
  letter-spacing: .01em;
}

.page-about .about-step__panel {
  padding: 0 clamp(16px, 2.4vw, 24px) clamp(16px, 2.4vw, 22px);
  font-size: 14.5px;
  line-height: 1.85;
  color: rgba(244, 240, 230, .76);
}

.page-about .about-step__panel p {
  margin: 0 0 10px;
}

.page-about .about-step__output {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 8px;
  padding-top: 10px;
  border-top: 1px dashed var(--line);
  color: var(--grass);
  margin-bottom: 0 !important;
}

.page-about .about-step__output .label {
  color: var(--grey);
}

/* ---------- 分工卡片 ---------- */
.page-about .about-teams {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
  margin: clamp(24px, 3.6vw, 36px) 0 0;
  padding: 0;
  list-style: none;
}

@media (min-width: 620px) {
  .page-about .about-teams {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 1080px) {
  .page-about .about-teams {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

.page-about .about-team {
  position: relative;
  padding: clamp(18px, 2.3vw, 24px);
  border: 1px solid var(--line);
  border-radius: var(--r-md) var(--r-md) var(--r-xs) var(--r-md);
  background: rgba(14, 58, 56, .46);
  transition: border-color .24s var(--ease), transform .24s var(--ease);
}

.page-about .about-team:hover {
  border-color: rgba(123, 168, 141, .55);
}

.page-about .about-team__idx {
  position: absolute;
  top: 15px;
  right: 17px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--grey);
}

.page-about .about-team__name {
  margin: 0 0 10px;
  padding-right: 26px;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 17px;
  letter-spacing: -0.005em;
  color: var(--paper);
}

.page-about .about-team__desc {
  margin: 0;
  font-size: 14px;
  line-height: 1.78;
  color: rgba(244, 240, 230, .72);
}

/* ---------- 版本时间轴 ---------- */
.page-about .about-pitch {
  margin: clamp(24px, 3.6vw, 36px) 0 0;
}

.page-about .about-pitch img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 12 / 5;
  object-fit: cover;
  border-radius: var(--r-md);
  filter: saturate(.55) contrast(1.05);
}

.page-about .about-axis {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0;
  margin: clamp(22px, 3.4vw, 34px) 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-axis::before {
  content: "";
  position: absolute;
  left: 11px;
  top: 10px;
  bottom: 10px;
  width: 2px;
  background: linear-gradient(180deg, var(--orange), var(--blue));
  opacity: .55;
}

.page-about .about-version {
  position: relative;
  padding: 0 0 clamp(24px, 3.6vw, 34px) clamp(36px, 5vw, 50px);
}

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

.page-about .about-version::before {
  content: "";
  position: absolute;
  top: 10px;
  border-radius: 50%;
  background: var(--ink-900);
  border: 2px solid var(--orange);
  box-sizing: border-box;
}

.page-about .about-version--lg::before {
  left: 2px;
  width: 20px;
  height: 20px;
}

.page-about .about-version--md::before {
  left: 4px;
  width: 16px;
  height: 16px;
  border-color: var(--blue);
}

.page-about .about-version--sm::before {
  left: 6px;
  width: 12px;
  height: 12px;
  background: var(--orange);
  border-color: var(--orange);
}

.page-about .about-version__tag {
  display: inline-block;
  margin-bottom: 10px;
  padding: 3px 9px;
  border: 1px solid rgba(240, 101, 30, .36);
  border-radius: var(--r-xs);
  background: rgba(240, 101, 30, .1);
  font-family: var(--font-mono);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: .02em;
  color: var(--orange);
}

.page-about .about-version__title {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: clamp(17px, 1.8vw, 20px);
  color: var(--paper);
}

.page-about .about-version__text {
  margin: 0;
  max-width: 40em;
  font-size: 14.5px;
  line-height: 1.8;
  color: rgba(244, 240, 230, .74);
}

@media (min-width: 900px) {
  .page-about .about-axis {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: clamp(16px, 2.4vw, 28px);
  }

  .page-about .about-axis::before {
    left: 0;
    right: 0;
    top: 10px;
    bottom: auto;
    width: auto;
    height: 2px;
    background: linear-gradient(90deg, var(--orange), var(--blue));
  }

  .page-about .about-version {
    padding: 42px 0 0 0;
  }

  .page-about .about-version--lg::before { left: 0; top: 1px; }
  .page-about .about-version--md::before { left: 0; top: 3px; }
  .page-about .about-version--sm::before { left: 0; top: 5px; }
}

/* ---------- 勘误登记 ---------- */
.page-about .about-errata {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(24px, 3.6vw, 40px);
  margin-top: clamp(22px, 3.4vw, 34px);
}

@media (min-width: 880px) {
  .page-about .about-errata {
    grid-template-columns: minmax(0, 1.25fr) minmax(0, .85fr);
    align-items: start;
  }
}

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

.page-about .about-errata__main p {
  margin: 0 0 16px;
  max-width: 38em;
  font-size: 15px;
  line-height: 1.85;
  color: rgba(244, 240, 230, .8);
}

.page-about .about-checklist {
  margin: 0 0 18px;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 8px;
}

.page-about .about-checklist li {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding: 11px 14px;
  border: 1px solid var(--line);
  border-left: 2px solid var(--amber);
  border-radius: 0 var(--r-sm) var(--r-sm) 0;
  background: rgba(227, 179, 65, .07);
  font-size: 14px;
  line-height: 1.7;
  color: rgba(244, 240, 230, .84);
}

.page-about .about-checklist .num {
  flex: none;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  color: var(--amber);
}

.page-about .about-links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 0 !important;
}

.page-about .about-errata__figure {
  margin: 0;
}

.page-about .about-errata__figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 3 / 2;
  object-fit: cover;
  border-radius: var(--r-md);
  filter: saturate(.6) contrast(1.04);
}

/* ---------- 备案与通信 ---------- */
.page-about .about-meta {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  margin: clamp(22px, 3.4vw, 34px) 0 0;
  padding: 0;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  overflow: hidden;
}

@media (min-width: 700px) {
  .page-about .about-meta {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

.page-about .about-meta__item {
  background: var(--ink-900);
  padding: clamp(16px, 2.3vw, 24px);
  min-width: 0;
}

.page-about .about-meta__item dt {
  color: var(--blue);
  margin: 0 0 8px;
}

.page-about .about-meta__value {
  margin: 0;
  font-size: 15px;
  line-height: 1.7;
  color: var(--paper);
  overflow-wrap: anywhere;
}

.page-about .about-meta__note {
  margin: 6px 0 0;
  font-size: 13px;
  line-height: 1.65;
  color: var(--grey);
}

/* ---------- 收尾指引 ---------- */
.page-about .about-next {
  margin: clamp(30px, 4.5vw, 48px) 0 0;
  padding-top: clamp(18px, 2.6vw, 26px);
  border-top: 1px solid var(--line);
  max-width: 44em;
  font-size: 15px;
  line-height: 1.85;
  color: rgba(244, 240, 230, .78);
}

.page-about .about-next a {
  color: var(--orange-soft);
  text-decoration-color: rgba(247, 185, 138, .5);
  text-underline-offset: 3px;
}

.page-about .about-next a:hover {
  color: var(--paper);
}

/* ---------- 数字统一 ---------- */
.page-about .num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-weight: 600;
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-team,
  .page-about .about-step,
  .page-about .about-rail__link {
    transition: none;
  }
}
<<<END>>>