.page-about {
  --about-col: 46rem;
  --about-wide: 64rem;
  padding-bottom: clamp(2rem, 6vw, 4rem);
}

.page-about [id] {
  scroll-margin-top: 7rem;
}

/* ---------- 首屏 ---------- */

.page-about .about-hero {
  max-width: var(--about-col);
  padding-block: clamp(1.75rem, 5vw, 3.5rem) clamp(1.25rem, 3vw, 2rem);
}

.page-about .about-hero h1 {
  font-family: var(--font-display);
  font-size: var(--type-h1);
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.15;
  color: var(--chalk);
  margin: 0.85rem 0 0;
  text-wrap: balance;
}

.page-about .about-lede {
  font-family: var(--font-body);
  font-size: clamp(1.02rem, 1.5vw, 1.15rem);
  line-height: 1.85;
  color: var(--chalk-dim);
  margin: 1.15rem 0 0;
}

.page-about .about-facts {
  list-style: none;
  margin: 1.75rem 0 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 1.5rem;
}

.page-about .about-facts li {
  display: inline-flex;
  align-items: baseline;
  gap: 0.5rem;
  font-family: var(--font-body);
  font-size: 0.9375rem;
  color: var(--chalk);
  padding: 0.3rem 0.85rem;
  border: 1px solid var(--line-soft);
  border-radius: var(--radius-pill);
  background: var(--turf-panel);
}

.page-about .about-facts .mono {
  font-size: var(--type-meta);
  letter-spacing: 0.08em;
  color: var(--chalk-dim);
}

.page-about .about-facts b {
  font-weight: 600;
  color: var(--glow-blue);
  font-variant-numeric: tabular-nums;
}

/* ---------- 媒体 ---------- */

.page-about .about-herofig {
  margin: clamp(1.5rem, 4vw, 2.75rem) 0 0;
}

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

.page-about .media-caption {
  font-family: var(--font-mono);
  font-size: var(--type-meta);
  letter-spacing: 0.06em;
  line-height: 1.7;
  color: var(--chalk-dim);
  margin: 0.75rem 0 0;
}

.page-about .about-herofig .media-caption {
  padding-top: 0.5rem;
}

/* ---------- 章节索引 ---------- */

.page-about .about-toc {
  border-top: 1px solid var(--line-soft);
  border-bottom: 1px solid var(--line-soft);
  padding-block: 0.9rem;
  margin-top: clamp(1.5rem, 4vw, 2.5rem);
}

.page-about .about-toc-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem 0.75rem;
}

.page-about .about-toc-list a {
  display: inline-flex;
  align-items: baseline;
  gap: 0.45rem;
  font-family: var(--font-body);
  font-size: var(--type-meta);
  letter-spacing: 0.06em;
  color: var(--chalk-dim);
  text-decoration: none;
  padding: 0.3rem 0.75rem;
  border: 1px solid transparent;
  border-radius: var(--radius-pill);
  transition: color 0.2s var(--ease), border-color 0.2s var(--ease);
}

.page-about .about-toc-list a .mono {
  color: var(--glow-blue-deep);
}

.page-about .about-toc-list a:hover,
.page-about .about-toc-list a:focus-visible {
  color: var(--glow-blue);
  border-color: var(--glow-blue-deep);
  outline: none;
}

.page-about .about-toc-list a:focus-visible {
  box-shadow: 0 0 0 2px var(--focus-ring);
}

/* ---------- 章节头 ---------- */

.page-about .about-section {
  padding-block: clamp(2.25rem, 6vw, 4.5rem);
}

.page-about .about-head {
  max-width: var(--about-col);
}

.page-about .about-head h2 {
  font-family: var(--font-display);
  font-size: clamp(1.5rem, 3.2vw, 2.1rem);
  font-weight: 700;
  letter-spacing: -0.015em;
  line-height: 1.25;
  color: var(--chalk);
  margin: 0.9rem 0 0;
  text-wrap: balance;
}

.page-about .about-head-lead {
  font-family: var(--font-body);
  font-size: 1rem;
  line-height: 1.85;
  color: var(--chalk-dim);
  margin: 0.9rem 0 0;
}

/* ---------- 01 范围对照 ---------- */

.page-about .about-scope {
  display: grid;
  gap: 1.25rem;
  margin-top: clamp(1.75rem, 4vw, 2.75rem);
}

.page-about .about-scope-col h3 {
  position: relative;
  padding-left: 1.1rem;
  margin: 0 0 1rem;
  font-family: var(--font-display);
  font-size: 1.0625rem;
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--chalk);
}

.page-about .about-scope-col h3::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.25em;
  bottom: 0.25em;
  width: 3px;
  border-radius: 3px;
  background: var(--glow-blue);
}

.page-about .about-scope-no h3 {
  color: var(--ink-solid);
}

.page-about .about-scope-no h3::before {
  background: var(--amber-flag);
}

.page-about .about-scope-col ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0.85rem;
}

.page-about .about-scope-col li {
  position: relative;
  padding-left: 1.15rem;
  font-family: var(--font-body);
  font-size: 0.9375rem;
  line-height: 1.75;
  color: var(--chalk-dim);
}

.page-about .about-scope-col li::before {
  content: "—";
  position: absolute;
  left: 0;
  color: var(--glow-blue-deep);
}

.page-about .about-scope-no li {
  color: var(--ink-solid);
}

.page-about .about-scope-no li::before {
  color: var(--amber-flag);
}

.page-about .about-scope-col li strong {
  color: var(--chalk);
  font-weight: 600;
}

.page-about .about-scope-no li strong {
  color: var(--ink-solid);
}

@media (min-width: 820px) {
  .page-about .about-scope {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    gap: 2rem;
  }
}

/* ---------- 02 版本序列 ---------- */

.page-about .about-versions {
  list-style: none;
  margin: clamp(1.75rem, 4vw, 2.75rem) 0 0;
  padding: 0;
}

.page-about .ver-item {
  position: relative;
  display: grid;
  grid-template-columns: 3.75rem minmax(0, 1fr);
  column-gap: 0.5rem;
  row-gap: 0.35rem;
  padding: 1.35rem 0.75rem 1.35rem 1.35rem;
  border-left: 1px solid var(--line-soft);
  border-top: 1px solid var(--line-soft);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  transition: background 0.25s var(--ease), border-color 0.25s var(--ease);
}

.page-about .ver-item:last-child {
  border-bottom: 1px solid var(--line-soft);
}

.page-about .ver-item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 1.85rem;
  width: 8px;
  height: 8px;
  margin-left: -4.5px;
  border-radius: 50%;
  background: var(--bg-night-turf);
  border: 1px solid var(--glow-blue-deep);
  transition: background 0.25s var(--ease), box-shadow 0.25s var(--ease);
}

.page-about .ver-item:hover {
  background: linear-gradient(90deg, rgba(79, 227, 255, 0.05), transparent 72%);
}

.page-about .ver-item:target {
  background: linear-gradient(90deg, rgba(79, 227, 255, 0.11), transparent 76%);
  border-left-color: var(--glow-blue);
}

.page-about .ver-item:target::before {
  background: var(--glow-blue);
  box-shadow: 0 0 0 5px rgba(79, 227, 255, 0.16);
}

.page-about .ver-tag {
  grid-column: 1;
  grid-row: 1;
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  letter-spacing: 0.12em;
  color: var(--glow-blue);
  text-decoration: none;
  padding-top: 0.25rem;
  border-bottom: 1px solid transparent;
}

.page-about .ver-tag:hover,
.page-about .ver-tag:focus-visible {
  border-bottom-color: var(--glow-blue);
  outline: none;
}

.page-about .ver-title {
  grid-column: 2;
  grid-row: 1;
  margin: 0;
  font-family: var(--font-display);
  font-size: 1.0625rem;
  font-weight: 700;
  letter-spacing: 0.01em;
  color: var(--chalk);
}

.page-about .ver-body {
  grid-column: 2;
  grid-row: 2;
  margin: 0;
  max-width: 42rem;
  font-family: var(--font-body);
  font-size: 0.9375rem;
  line-height: 1.8;
  color: var(--chalk-dim);
}

.page-about .about-version-note {
  max-width: var(--about-col);
  margin: 1.5rem 0 0;
  padding-left: 1rem;
  border-left: 2px solid var(--amber-flag);
  font-family: var(--font-body);
  font-size: 0.9375rem;
  line-height: 1.8;
  color: var(--chalk-dim);
}

.page-about .about-version-note b {
  color: var(--amber-flag);
  font-weight: 600;
  font-variant-numeric: tabular-nums;
}

/* ---------- 03 维护分工 ---------- */

.page-about .about-flow {
  margin-top: clamp(1.75rem, 4vw, 2.75rem);
  display: grid;
  gap: 2rem;
}

.page-about .about-roles {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .about-role {
  display: grid;
  grid-template-columns: 2.75rem minmax(0, 1fr);
  column-gap: 0.5rem;
  row-gap: 0.3rem;
  padding-block: 1.15rem;
  border-bottom: 1px solid var(--line-soft);
}

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

.page-about .about-role-idx {
  grid-column: 1;
  grid-row: 1;
  font-size: 0.8125rem;
  letter-spacing: 0.12em;
  color: var(--glow-blue-deep);
  padding-top: 0.28rem;
}

.page-about .about-role-name {
  grid-column: 2;
  grid-row: 1;
  margin: 0;
  font-family: var(--font-display);
  font-size: 1.0625rem;
  font-weight: 700;
  letter-spacing: 0.01em;
  color: var(--chalk);
}

.page-about .about-role-desc {
  grid-column: 2;
  grid-row: 2;
  margin: 0;
  max-width: 40rem;
  font-family: var(--font-body);
  font-size: 0.9375rem;
  line-height: 1.8;
  color: var(--chalk-dim);
}

.page-about .about-details {
  margin-top: 1.5rem;
  border: 1px solid var(--line-soft);
  border-radius: var(--radius-md);
  background: var(--turf-panel);
  overflow: hidden;
}

.page-about .about-details summary {
  cursor: pointer;
  list-style: none;
  display: flex;
  align-items: center;
  gap: 0.65rem;
  padding: 1rem 1.15rem;
  font-family: var(--font-display);
  font-size: 0.9375rem;
  font-weight: 600;
  letter-spacing: 0.03em;
  color: var(--chalk);
  transition: color 0.2s var(--ease);
}

.page-about .about-details summary::-webkit-details-marker {
  display: none;
}

.page-about .about-details summary::before {
  content: "+";
  flex: none;
  width: 1.1rem;
  text-align: center;
  font-family: var(--font-mono);
  font-size: 1rem;
  color: var(--glow-blue);
}

.page-about .about-details[open] summary::before {
  content: "−";
}

.page-about .about-details summary:hover,
.page-about .about-details summary:focus-visible {
  color: var(--glow-blue);
  outline: none;
}

.page-about .about-details summary:focus-visible {
  box-shadow: inset 0 0 0 2px var(--focus-ring);
}

.page-about .about-details-body {
  padding: 0 1.15rem 1.25rem;
  font-family: var(--font-body);
  font-size: 0.9375rem;
  line-height: 1.85;
  color: var(--chalk-dim);
}

.page-about .about-details-body p {
  margin: 0 0 0.75rem;
}

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

.page-about .about-flow-media {
  margin: 0;
}

.page-about .about-flow-media .media-caption {
  margin-top: 0.6rem;
}

/* ---------- 数字带 ---------- */

.page-about .about-numbers {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1.75rem 1rem;
  margin-top: clamp(2rem, 5vw, 3rem);
  padding-top: 1.5rem;
  padding-bottom: 0.5rem;
  border-top: 1px solid var(--line-soft);
}

.page-about .about-num {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.page-about .about-num-value {
  font-family: var(--font-display);
  font-size: clamp(2rem, 5vw, 3rem);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--chalk);
  font-variant-numeric: tabular-nums;
}

.page-about .about-num:nth-child(3) .about-num-value {
  color: var(--glow-blue);
}

.page-about .about-num-label {
  font-family: var(--font-body);
  font-size: 0.875rem;
  line-height: 1.6;
  color: var(--chalk-dim);
}

@media (min-width: 720px) {
  .page-about .about-numbers {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 1.5rem;
  }

  .page-about .about-num:nth-child(even) {
    transform: translateY(1.25rem);
  }
}

/* ---------- 中部横图 ---------- */

.page-about .about-midfig {
  margin: clamp(2rem, 5vw, 3.5rem) auto;
}

/* ---------- 04 跨地域 ---------- */

.page-about .about-region {
  margin-top: clamp(1.75rem, 4vw, 2.5rem);
  border-top: 1px solid var(--line-soft);
}

.page-about .about-region-row {
  display: grid;
  gap: 0.35rem;
  padding-block: 1.1rem;
  border-bottom: 1px solid var(--line-soft);
}

.page-about .about-region-name {
  font-family: var(--font-display);
  font-size: 1.0625rem;
  font-weight: 700;
  letter-spacing: 0.01em;
  color: var(--chalk);
}

.page-about .about-region-note {
  font-family: var(--font-body);
  font-size: 0.9375rem;
  line-height: 1.8;
  color: var(--chalk-dim);
}

@media (min-width: 760px) {
  .page-about .about-region-row {
    grid-template-columns: 13rem minmax(0, 1fr);
    gap: 1.5rem;
    align-items: baseline;
  }
}

.page-about .about-cross-notes {
  max-width: var(--about-col);
  margin-top: clamp(1.5rem, 4vw, 2.25rem);
}

.page-about .about-cross-notes p {
  font-family: var(--font-body);
  font-size: 0.9688rem;
  line-height: 1.85;
  color: var(--chalk-dim);
  margin: 0 0 0.9rem;
}

.page-about .about-cross-notes p:last-child {
  margin-bottom: 0;
  padding-top: 0.9rem;
  border-top: 1px solid var(--line-soft);
}

/* ---------- 05 纠错通道 ---------- */

.page-about .about-routes {
  list-style: none;
  margin: clamp(1.75rem, 4vw, 2.5rem) 0 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line-soft);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius-lg);
  overflow: hidden;
}

.page-about .about-route {
  background: var(--turf-panel);
  padding: 1.35rem 1.25rem;
}

.page-about .about-route-idx {
  display: block;
  font-size: 0.8125rem;
  letter-spacing: 0.12em;
  color: var(--glow-blue-deep);
  margin-bottom: 0.5rem;
}

.page-about .about-route-name {
  margin: 0 0 0.45rem;
  font-family: var(--font-display);
  font-size: 1.0625rem;
  font-weight: 700;
  letter-spacing: 0.01em;
  color: var(--chalk);
}

.page-about .about-route p {
  margin: 0;
  font-family: var(--font-body);
  font-size: 0.9375rem;
  line-height: 1.8;
  color: var(--chalk-dim);
}

@media (min-width: 860px) {
  .page-about .about-routes {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .about-route:first-child {
    background: var(--turf-raise);
  }

  .page-about .about-route:first-child .about-route-idx {
    color: var(--amber-flag);
  }
}

.page-about .about-feedback-tip {
  max-width: var(--about-col);
  margin-top: clamp(1.5rem, 4vw, 2.25rem);
  padding: 1.35rem 1.25rem;
  border: 1px solid var(--line-soft);
  border-radius: var(--radius-md);
  background: linear-gradient(150deg, rgba(255, 180, 84, 0.07), transparent 62%);
}

.page-about .about-feedback-title {
  margin: 0 0 0.85rem;
  font-family: var(--font-display);
  font-size: 1rem;
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--chalk);
}

.page-about .about-feedback-tip ul {
  list-style: none;
  margin: 0 0 1.25rem;
  padding: 0;
  display: grid;
  gap: 0.6rem;
}

.page-about .about-feedback-tip li {
  position: relative;
  padding-left: 1.1rem;
  font-family: var(--font-body);
  font-size: 0.9375rem;
  line-height: 1.75;
  color: var(--chalk-dim);
}

.page-about .about-feedback-tip li::before {
  content: "·";
  position: absolute;
  left: 0.2rem;
  color: var(--amber-flag);
  font-weight: 700;
}

/* ---------- 收束 ---------- */

.page-about .about-coda {
  padding-block: clamp(2rem, 5vw, 3.5rem);
}

.page-about .about-coda-inner {
  max-width: var(--about-wide);
  padding: clamp(1.5rem, 4vw, 2.5rem);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius-lg);
  background: linear-gradient(165deg, var(--turf-panel), var(--bg-night-turf) 78%);
}

.page-about .about-coda-list {
  list-style: none;
  margin: 1.1rem 0 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 0.65rem;
}

.page-about .about-coda-list li {
  display: inline-flex;
  align-items: baseline;
  gap: 0.45rem;
  padding: 0.35rem 0.85rem;
  border: 1px solid var(--line-soft);
  border-radius: var(--radius-pill);
  font-family: var(--font-body);
  font-size: var(--type-meta);
  letter-spacing: 0.05em;
  color: var(--chalk);
}

.page-about .about-coda-list .mono {
  color: var(--glow-blue);
}

.page-about .about-coda-note {
  max-width: 46rem;
  margin: 1.5rem 0 0;
  font-family: var(--font-body);
  font-size: 0.9375rem;
  line-height: 1.85;
  color: var(--chalk-dim);
}

.page-about .about-coda-note b {
  color: var(--glow-blue);
  font-weight: 600;
  font-variant-numeric: tabular-nums;
}

.page-about .about-coda-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.65rem;
  margin-top: 1.5rem;
}

/* ---------- 桌面加宽与错位 ---------- */

@media (min-width: 960px) {
  .page-about .about-flow {
    grid-template-columns: minmax(0, 1.6fr) minmax(0, 1fr);
    gap: 3rem;
    align-items: start;
  }

  .page-about .about-flow-media {
    margin-top: -3.5rem;
    transform: rotate(var(--tilt-b));
  }
}

@media (min-width: 1200px) {
  .page-about .about-toc-list {
    gap: 0.4rem 1.5rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-flow-media,
  .page-about .about-num:nth-child(even) {
    transform: none;
  }
}
</final>
</final>