.page-about {
  --about-gap: clamp(20px, 3vw, 40px);
  --about-pad: clamp(56px, 8vw, 112px);
  display: block;
}

/* ---- 页面题头 ---- */
.page-about .about-head {
  border-bottom: var(--hair-dark);
  padding-bottom: clamp(40px, 5vw, 72px);
}
.page-about .about-head .page-title {
  letter-spacing: 0.02em;
}
.page-about .about-head .page-title strong {
  display: inline-block;
  font-weight: 900;
  color: var(--saffron);
}
.page-about .about-head-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 28px;
}

/* ---- 页内锚点目录 ---- */
.page-about .about-toc {
  border-bottom: var(--hair-dark);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px 20px;
  padding: 18px 0;
}
.page-about .about-toc .toc-title {
  letter-spacing: 0.18em;
  font-size: 12px;
  text-transform: uppercase;
  color: var(--muted-2);
  margin-right: 8px;
}
.page-about .about-toc .toc-link {
  font-size: 13px;
  letter-spacing: 0.04em;
  text-decoration: none;
  color: var(--ink);
  padding-bottom: 2px;
  border-bottom: 1px solid transparent;
  transition: border-color 200ms ease, color 200ms ease;
}
.page-about .about-toc .toc-link:hover,
.page-about .about-toc .toc-link:focus-visible {
  border-bottom-color: var(--saffron);
  color: var(--saffron);
}
.page-about .about-toc .toc-link.is-visible {
  border-bottom-color: var(--saffron);
  color: var(--saffron);
  font-weight: 700;
}

/* ---- 通用区块题头 ---- */
.page-about .about-section-head {
  max-width: 62ch;
  margin-bottom: var(--about-gap);
}
.page-about .about-section-head .lede {
  margin-top: 14px;
}

/* ---- 沿革时间线 ---- */
.page-about .about-timeline {
  padding: var(--about-pad) 0;
}
.page-about .about-timeline-media {
  margin: 0 0 var(--about-gap);
  border: var(--hair-light);
}
.page-about .about-timeline-media .media-caption {
  padding: 10px 14px;
  font-size: 12px;
  letter-spacing: 0.06em;
  color: rgba(246, 244, 239, 0.7);
}

.page-about .about-versions {
  border-top: var(--hair-light);
}
.page-about .about-versions .about-version {
  border-bottom: var(--hair-light);
}
.page-about .about-versions .accordion-btn {
  display: grid;
  grid-template-columns: auto 1fr auto;
  grid-template-areas: "key tag sign";
  align-items: center;
  gap: 12px 20px;
  width: 100%;
  background: none;
  border: 0;
  color: inherit;
  text-align: left;
  padding: 22px 4px;
  cursor: pointer;
  font: inherit;
}
.page-about .about-versions .accordion-btn:focus-visible {
  outline: 2px solid var(--orange);
  outline-offset: 2px;
}
.page-about .about-version-key {
  grid-area: key;
  font-size: clamp(18px, 2vw, 24px);
  letter-spacing: 0.02em;
  display: flex;
  align-items: baseline;
  gap: 14px;
}
.page-about .about-version-key .mono {
  color: var(--gold);
  font-size: 15px;
  letter-spacing: 0.08em;
}
.page-about .about-version-tag {
  grid-area: tag;
  justify-self: start;
  font-size: 12px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: rgba(246, 244, 239, 0.55);
  border-left: 1px solid rgba(246, 244, 239, 0.25);
  padding-left: 14px;
}
.page-about .about-versions .accordion-sign {
  grid-area: sign;
}
.page-about .about-versions .accordion-sign::before,
.page-about .about-versions .accordion-sign::after {
  background: var(--snow);
}
.page-about .about-versions .accordion-inner {
  padding: 0 4px 26px;
  max-width: 62ch;
  color: rgba(246, 244, 239, 0.82);
  line-height: 1.85;
}

/* ---- 团队 ---- */
.page-about .about-team {
  padding: var(--about-pad) 0;
}
.page-about .about-team-grid {
  display: grid;
  gap: var(--about-gap);
  align-items: start;
}
.page-about .about-team-media {
  margin: 0;
  border: var(--hair-dark);
}
.page-about .about-team-media .media-caption {
  padding: 10px 14px;
  font-size: 12px;
  color: var(--muted-2);
  letter-spacing: 0.05em;
}
.page-about .about-roles {
  margin-top: 30px;
  border-top: var(--hair-dark);
}
.page-about .about-roles .accordion-item {
  border-bottom: var(--hair-dark);
}
.page-about .about-roles .accordion-btn {
  display: flex;
  align-items: center;
  gap: 14px;
  width: 100%;
  background: none;
  border: 0;
  font: inherit;
  color: inherit;
  text-align: left;
  padding: 16px 2px;
  cursor: pointer;
}
.page-about .about-roles .accordion-btn:focus-visible {
  outline: 2px solid var(--saffron);
  outline-offset: 2px;
}
.page-about .about-role-key {
  flex: 1;
  font-size: 15px;
  letter-spacing: 0.04em;
  display: flex;
  align-items: baseline;
  gap: 12px;
}
.page-about .about-role-key .mono {
  color: var(--saffron);
  font-weight: 700;
  min-width: 2ch;
}
.page-about .about-roles .accordion-inner {
  padding: 0 2px 18px 30px;
  color: var(--muted);
  line-height: 1.85;
  max-width: 48ch;
}

/* ---- 分类体系 ---- */
.page-about .about-taxonomy {
  padding: var(--about-pad) 0;
}
.page-about .about-taxonomy-grid {
  display: grid;
  gap: var(--about-gap);
  align-items: start;
}
.page-about .about-taxonomy-map {
  border: var(--hair-dark);
  background: rgba(246, 244, 239, 0.55);
  padding: 18px;
}
.page-about .about-svg {
  display: block;
  width: 100%;
  height: auto;
}
.page-about .about-svg-line {
  stroke: var(--ink);
  stroke-width: 1;
  opacity: 0.35;
}
.page-about .about-svg-line--accent {
  stroke: var(--saffron);
  opacity: 0.85;
}
.page-about .about-svg-node {
  fill: var(--saffron);
}
.page-about .about-svg-box {
  fill: none;
  stroke: var(--ink);
  stroke-width: 1;
  opacity: 0.5;
}
.page-about .about-svg-text {
  font-family: var(--sans);
  font-size: 14px;
  fill: var(--ink);
}
.page-about .about-svg-text--muted {
  fill: var(--muted-2);
  font-size: 12px;
  letter-spacing: 0.16em;
}

.page-about .about-taxonomy-list {
  border-top: var(--hair-dark);
}
.page-about .about-taxonomy-row {
  display: grid;
  grid-template-columns: 3ch 1fr;
  grid-template-areas:
    "num title"
    ". body"
    ". tag";
  gap: 6px 16px;
  padding: 20px 0;
  border-bottom: var(--hair-dark);
}
.page-about .about-taxonomy-num {
  grid-area: num;
  color: var(--gold);
  font-size: 13px;
  padding-top: 4px;
}
.page-about .about-taxonomy-row .h3 {
  grid-area: title;
}
.page-about .about-taxonomy-row p {
  grid-area: body;
  color: var(--muted);
  line-height: 1.8;
  max-width: 52ch;
}
.page-about .about-taxonomy-row .tag {
  grid-area: tag;
  justify-self: start;
  margin-top: 6px;
}
.page-about .about-taxonomy-media {
  margin: var(--about-gap) 0 0;
  border: var(--hair-dark);
  max-width: 520px;
}
.page-about .about-taxonomy-media .media-caption {
  padding: 10px 14px;
  font-size: 12px;
  color: var(--muted-2);
}

/* ---- 覆盖与规模 ---- */
.page-about .about-reach {
  padding: var(--about-pad) 0;
}
.page-about .about-stat-row {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1px;
  background: var(--hair-dark);
  border: var(--hair-dark);
  margin-bottom: var(--about-gap);
}
.page-about .about-stat {
  background: var(--snow);
  padding: clamp(20px, 3vw, 32px);
  border: 0;
  display: flex;
  flex-direction: column;
  gap: 6px;
}
.page-about .about-stat .stat-num {
  font-family: var(--mono);
  font-size: clamp(34px, 6vw, 56px);
  font-weight: 700;
  line-height: 1;
  color: var(--ink);
  letter-spacing: -0.01em;
}
.page-about .about-stat .stat-num em {
  font-size: 0.42em;
  font-style: normal;
  margin-left: 4px;
  color: var(--saffron);
}
.page-about .about-stat .stat-label {
  font-size: 13px;
  letter-spacing: 0.04em;
  color: var(--muted-2);
}
.page-about .about-reach-grid {
  gap: var(--about-gap);
}
.page-about .about-reach-note {
  border-top: 2px solid var(--ink);
  padding-top: 18px;
}
.page-about .about-reach-note .h3 {
  margin-bottom: 10px;
}
.page-about .about-reach-note p {
  color: var(--muted);
  line-height: 1.8;
}
.page-about .about-reach-note--accent {
  border-top-color: var(--saffron);
}
.page-about .about-reach-quote {
  font-size: 15px;
  letter-spacing: 0.02em;
  color: var(--saffron);
  margin-bottom: 12px;
}

/* ---- 更新节律 ---- */
.page-about .about-cadence {
  padding: var(--about-pad) 0;
  background: var(--snow);
}
.page-about .about-cadence-band {
  display: grid;
  gap: 1px;
  background: var(--warmgray);
  border: 1px solid var(--warmgray);
}
.page-about .about-cadence-item {
  background: var(--snow);
  padding: clamp(22px, 3vw, 34px);
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.page-about .about-cadence-freq {
  font-size: 12px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--gold);
}
.page-about .about-cadence-item .h3 {
  margin: 0;
}
.page-about .about-cadence-item p {
  color: var(--muted);
  line-height: 1.8;
  max-width: 46ch;
}

/* ---- 质量报告 ---- */
.page-about .about-report {
  padding: var(--about-pad) 0;
}
.page-about .about-report-grid {
  display: grid;
  gap: var(--about-gap);
  align-items: start;
}
.page-about .about-report-list {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: var(--hair-light);
}
.page-about .about-report-list li {
  display: grid;
  grid-template-columns: 3ch 1fr;
  gap: 6px 16px;
  padding: 20px 0;
  border-bottom: var(--hair-light);
}
.page-about .about-report-key {
  color: var(--gold);
  font-size: 13px;
  padding-top: 3px;
}
.page-about .about-report-list .h3 {
  margin-bottom: 8px;
}
.page-about .about-report-list p {
  color: rgba(246, 244, 239, 0.78);
  line-height: 1.85;
  max-width: 46ch;
}
.page-about .about-report-side {
  display: grid;
  gap: 0;
  border-top: 1px solid var(--gold);
  padding-top: 18px;
}
.page-about .about-report-side .eyebrow {
  color: var(--gold);
}
.page-about .about-report-link {
  padding: 18px 0;
  border-bottom: var(--hair-light);
}
.page-about .about-report-link p {
  color: rgba(246, 244, 239, 0.72);
  line-height: 1.8;
  margin-bottom: 12px;
  font-size: 14px;
}
.page-about .about-report-link .link-more {
  color: var(--gold);
}

/* ---- 响应式 ---- */
@media (min-width: 760px) {
  .page-about .about-stat-row {
    grid-template-columns: repeat(4, 1fr);
  }
  .page-about .about-cadence-band {
    grid-template-columns: repeat(2, 1fr);
  }
  .page-about .about-taxonomy-row {
    grid-template-columns: 4ch 1fr auto;
    grid-template-areas:
      "num title tag"
      ". .page-about body";
    align-items: baseline;
  }
  .page-about .about-taxonomy-row .tag {
    justify-self: end;
    margin-top: 0;
  }
}

@media (min-width: 1024px) {
  .page-about .about-team-grid {
    grid-template-columns: minmax(0, 1.4fr) minmax(0, 1fr);
    gap: clamp(32px, 4vw, 64px);
  }
  .page-about .about-taxonomy-grid {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    gap: clamp(32px, 4vw, 72px);
  }
  .page-about .about-cadence-band {
    grid-template-columns: repeat(4, 1fr);
  }
  .page-about .about-report-grid {
    grid-template-columns: minmax(0, 1.6fr) minmax(0, 1fr);
    gap: clamp(40px, 5vw, 88px);
  }
}

@media (max-width: 480px) {
  .page-about .about-taxonomy-row {
    grid-template-columns: 3ch 1fr;
  }
  .page-about .about-version-tag {
    display: none;
  }
  .page-about .about-versions .accordion-btn {
    grid-template-columns: 1fr auto;
    grid-template-areas: "key sign";
  }
  .page-about .about-report-list li {
    grid-template-columns: 1fr;
    gap: 8px;
  }
  .page-about .about-report-key {
    padding-top: 0;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-toc .toc-link,
  .page-about .about-versions .accordion-btn,
  .page-about .about-roles .accordion-btn {
    transition: none;
  }
}