.page-about {
  --about-rail: 1px solid var(--midline);
  --about-block: clamp(28px, 5vw, 52px);
  background: var(--line-white);
  color: var(--ink);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  background: var(--paper);
  border-bottom: 1px solid var(--midline);
  padding: clamp(22px, 4vw, 42px) 0 clamp(26px, 5vw, 56px);
}

.page-about .crumbs {
  margin-bottom: clamp(16px, 2.6vw, 28px);
}

.page-about .about-hero-inner {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(20px, 3.4vw, 40px);
}

.page-about .about-hero h1 {
  margin: 10px 0 0;
  font-family: var(--sans);
  font-weight: 800;
  font-size: clamp(30px, 6.4vw, 54px);
  line-height: 1.1;
  letter-spacing: -0.02em;
  max-width: 22ch;
}

.page-about .about-hero .lede {
  margin-top: 14px;
  max-width: 46ch;
  color: var(--ink);
}

.page-about .about-facts {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.page-about .about-fact {
  flex: 1 1 130px;
  min-width: 0;
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 12px 14px;
  background: var(--line-white);
  border: 1px solid var(--midline);
  border-radius: 14px;
}

.page-about .about-fact-num {
  font-family: var(--mono);
  font-variant-numeric: tabular-nums;
  font-weight: 700;
  font-size: clamp(24px, 4.4vw, 34px);
  line-height: 1;
  color: var(--turf-deep);
}

.page-about .about-fact-plus {
  font-size: 0.62em;
  vertical-align: super;
  margin-left: 1px;
}

.page-about .about-fact-key {
  color: var(--mute);
  letter-spacing: 0.06em;
}

/* ---------- 版式骨架 ---------- */
.page-about .about-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(24px, 4vw, 40px);
  padding-top: clamp(28px, 5vw, 60px);
  padding-bottom: clamp(48px, 8vw, 96px);
}

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

.page-about .about-index-title {
  margin: 0 0 10px;
  color: var(--mute);
}

.page-about .about-index .stack-index {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.page-about .about-index .stack-index-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 13px;
  background: var(--paper);
  border: 1px solid var(--midline);
  border-radius: var(--r-pill);
  color: var(--ink);
  text-decoration: none;
  font-size: 14px;
  line-height: 1.2;
  transition: background-color var(--t), color var(--t), border-color var(--t);
}

.page-about .about-index .stack-index-link[aria-current="true"] {
  background: var(--turf);
  border-color: var(--turf);
  color: var(--line-white);
}

.page-about .about-index .stack-index-link[aria-current="true"] .about-index-num {
  color: var(--line-white);
}

.page-about .about-index-num {
  font-family: var(--mono);
  font-variant-numeric: tabular-nums;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--mute);
}

/* ---------- 编号条款 ---------- */
.page-about .about-body {
  min-width: 0;
}

.page-about .clause {
  position: relative;
  padding-left: clamp(20px, 4vw, 34px);
  padding-bottom: var(--about-block);
  border-left: var(--about-rail);
}

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

.page-about .clause::before {
  content: "";
  position: absolute;
  left: -5px;
  top: 9px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--turf);
  box-shadow: 0 0 0 4px var(--line-white);
}

.page-about .clause-head {
  display: flex;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 10px 12px;
  margin-bottom: clamp(14px, 2.4vw, 22px);
}

.page-about .clause-num {
  font-family: var(--mono);
  font-variant-numeric: tabular-nums;
  font-weight: 700;
  font-size: 13px;
  letter-spacing: 0.1em;
  line-height: 1.3;
  color: var(--turf);
  padding: 3px 8px;
  border: 1px solid currentColor;
  border-radius: 6px;
}

.page-about .clause-head h2 {
  margin: 0;
  font-family: var(--sans);
  font-weight: 800;
  font-size: clamp(22px, 3.8vw, 32px);
  line-height: 1.2;
  letter-spacing: -0.02em;
}

.page-about .clause-body > p,
.page-about .clause-text > p,
.page-about .rule p,
.page-about .version-item p,
.page-about .team-desc,
.page-about .boundary-text {
  font-size: 17px;
  line-height: 1.75;
}

.page-about .clause-body > p {
  margin: 0 0 1.05em;
  max-width: 62ch;
}

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

.page-about .clause-text > p {
  margin: 0 0 1.05em;
  max-width: 60ch;
}

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

/* ---------- 图文栅格 ---------- */
.page-about .clause-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(18px, 3.4vw, 32px);
  align-items: start;
}

.page-about .clause-figure {
  margin: 0;
  min-width: 0;
}

.page-about .figure {
  margin: 0;
  min-width: 0;
}

.page-about .clause-figure .media,
.page-about .rules-figure .media {
  border: 1px solid var(--midline);
  border-radius: var(--r-panel);
  overflow: hidden;
  background: var(--paper);
}

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

.page-about .figure figcaption {
  margin-top: 10px;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.06em;
  line-height: 1.65;
  color: var(--mute);
}

/* ---------- 三条规则 ---------- */
.page-about .rules-figure {
  margin: clamp(18px, 3.4vw, 30px) 0 0;
}

.page-about .rules {
  display: flex;
  flex-direction: column;
  gap: 14px;
  margin-top: clamp(20px, 3.6vw, 32px);
}

.page-about .rule {
  background: var(--paper);
  border: 1px solid var(--midline);
  border-radius: var(--r-panel);
  padding: clamp(16px, 3vw, 26px);
}

.page-about .rule-key {
  display: inline-block;
  font-family: var(--mono);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.14em;
  line-height: 1.4;
  color: var(--turf-deep);
  background: var(--line-white);
  border: 1px solid var(--midline);
  border-radius: var(--r-pill);
  padding: 2px 11px;
  margin-bottom: 10px;
}

.page-about .rule h3 {
  margin: 0 0 8px;
  font-family: var(--sans);
  font-weight: 800;
  font-size: clamp(18px, 2.4vw, 21px);
  line-height: 1.3;
  letter-spacing: -0.01em;
}

.page-about .rule p {
  margin: 0;
  max-width: 58ch;
  color: var(--ink);
}

.page-about .rule-toggle {
  margin-top: 12px;
  padding: 6px 14px;
  font-family: var(--sans);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.06em;
  color: var(--turf-deep);
  background: transparent;
  border: 1px solid var(--turf);
  border-radius: var(--r-pill);
  cursor: pointer;
  transition: background-color var(--t), color var(--t);
}

.page-about .rule-toggle:hover {
  background: var(--turf);
  color: var(--line-white);
}

.page-about .rule-example {
  margin-top: 12px;
  padding: 14px 16px;
  background: var(--line-white);
  border-left: 3px solid var(--yellow);
  border-radius: 0 12px 12px 0;
  font-size: 15px;
  line-height: 1.72;
  color: var(--ink);
}

/* ---------- 版本演进 ---------- */
.page-about .version-list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .version-item {
  position: relative;
  padding: 0 0 clamp(24px, 4vw, 38px) clamp(22px, 4vw, 34px);
  border-left: 2px solid var(--midline);
}

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

.page-about .version-item::before {
  content: "";
  position: absolute;
  left: -8px;
  top: 5px;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--line-white);
  border: 2px solid var(--turf);
}

.page-about .version-item.is-current::before {
  background: var(--yellow);
  border-color: var(--yellow);
}

.page-about .version-tag {
  display: inline-block;
  font-family: var(--mono);
  font-variant-numeric: tabular-nums;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.06em;
  line-height: 1.4;
  padding: 3px 10px;
  border-radius: 6px;
  background: var(--turf-deep);
  color: var(--line-white);
  margin-bottom: 10px;
}

.page-about .version-item .tag {
  margin-left: 8px;
}

.page-about .version-item h3 {
  margin: 0 0 8px;
  font-family: var(--sans);
  font-weight: 800;
  font-size: clamp(18px, 2.4vw, 21px);
  line-height: 1.3;
}

.page-about .version-item p {
  margin: 0;
  max-width: 58ch;
}

/* ---------- 团队分工 ---------- */
.page-about .team-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
}

.page-about .team-item {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 12px 16px;
  align-items: start;
  padding: 16px 0;
  border-bottom: 1px solid var(--midline);
}

.page-about .team-item:first-child {
  padding-top: 0;
}

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

.page-about .team-num {
  font-family: var(--mono);
  font-variant-numeric: tabular-nums;
  font-weight: 700;
  font-size: clamp(22px, 3.4vw, 30px);
  line-height: 1;
  color: var(--turf-deep);
}

.page-about .team-role {
  margin: 0 0 5px;
  font-family: var(--sans);
  font-weight: 800;
  font-size: 16px;
  letter-spacing: -0.01em;
  line-height: 1.35;
}

.page-about .team-desc {
  margin: 0;
  font-size: 15px;
  line-height: 1.72;
  color: var(--mute);
}

/* ---------- 边界与纠错 ---------- */
.page-about .boundary-list {
  list-style: none;
  counter-reset: boundary;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.page-about .boundary-item {
  counter-increment: boundary;
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 14px;
  align-items: start;
  padding: 16px 18px;
  background: var(--paper);
  border: 1px solid var(--midline);
  border-radius: 16px;
}

.page-about .boundary-item::before {
  content: counter(boundary, decimal-leading-zero);
  font-family: var(--mono);
  font-variant-numeric: tabular-nums;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.06em;
  color: var(--turf-deep);
  padding-top: 4px;
}

.page-about .boundary-fix {
  margin-top: clamp(18px, 3vw, 26px);
  padding: clamp(16px, 3vw, 22px);
  background: var(--line-white);
  border: 1px dashed var(--midline);
  border-radius: 16px;
}

.page-about .boundary-fix p {
  margin: 0 0 14px;
  font-size: 16px;
  line-height: 1.75;
  max-width: 58ch;
}

.page-about .boundary-fix .contact-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
}

.page-about .boundary-fix .contact-value {
  font-family: var(--mono);
  font-size: 14px;
  font-weight: 700;
  word-break: break-all;
  color: var(--ink);
}

.page-about .clause-end {
  margin: clamp(22px, 4vw, 34px) 0 0;
  padding-top: clamp(18px, 3vw, 26px);
  border-top: 1px solid var(--midline);
  font-size: 15px;
  line-height: 1.78;
  color: var(--mute);
}

.page-about .clause-body a,
.page-about .clause-end a {
  color: var(--turf-deep);
  text-underline-offset: 3px;
}

.page-about .clause-body a:hover,
.page-about .clause-end a:hover {
  color: var(--turf);
}

/* ---------- 响应式 ---------- */
@media (min-width: 640px) {
  .page-about .about-facts {
    flex-wrap: nowrap;
  }
}

@media (min-width: 820px) {
  .page-about .clause-grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: clamp(22px, 4vw, 40px);
  }

  .page-about .rule:nth-child(even) {
    margin-left: clamp(18px, 4vw, 52px);
  }
}

@media (min-width: 1000px) {
  .page-about .about-hero-inner {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    align-items: end;
    gap: clamp(28px, 5vw, 64px);
  }

  .page-about .about-facts {
    flex-direction: column;
    gap: 8px;
  }

  .page-about .about-fact {
    flex: 0 0 auto;
  }

  .page-about .about-layout {
    grid-template-columns: 208px minmax(0, 1fr);
    gap: clamp(36px, 5vw, 72px);
  }

  .page-about .about-index {
    position: sticky;
    top: calc(var(--header-space) + 16px);
    align-self: start;
  }

  .page-about .about-index .stack-index {
    flex-direction: column;
    flex-wrap: nowrap;
    gap: 4px;
  }

  .page-about .about-index .stack-index-link {
    background: transparent;
    border-color: transparent;
    border-radius: 12px;
    padding: 9px 10px;
  }

  .page-about .about-index .stack-index-link:hover {
    background: var(--paper);
  }

  .page-about .about-index .stack-index-link[aria-current="true"] {
    background: var(--turf);
    border-color: var(--turf);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about *,
  .page-about *::before,
  .page-about *::after {
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
  }
}
<<<END>>>