.page-about {
  --about-section-gap: clamp(3rem, 7vw, 5.5rem);
  --about-border: rgba(160, 168, 163, 0.18);
  --about-card-border: rgba(160, 168, 163, 0.16);
  --about-lime-soft: rgba(183, 255, 63, 0.08);
  --about-blue-soft: rgba(0, 229, 255, 0.08);
  background: var(--color-ink);
  color: var(--color-cream);
  font-family: var(--font-sans);
  line-height: 1.7;
  padding-top: var(--header-total);
  min-width: 0;
}

.page-about a {
  color: var(--color-blue);
  text-decoration: none;
}

.page-about a:hover,
.page-about a:focus-visible {
  text-decoration: underline;
}

.page-about img {
  max-width: 100%;
  height: auto;
}

.page-about__context,
.page-about__hero,
.page-about__layout {
  max-width: var(--container-max);
  margin-left: auto;
  margin-right: auto;
  padding-inline: var(--container-pad);
}

.page-about__context {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem 1rem;
  padding-top: 1.5rem;
  padding-bottom: 0.5rem;
}

.page-about__crumb-list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  list-style: none;
  padding: 0;
  margin: 0;
  font-size: 0.85rem;
  color: var(--color-mist);
}

.page-about__crumb-item + .page-about__crumb-item::before {
  content: " / ";
  color: var(--color-mist);
  opacity: 0.6;
  margin-right: 0.5rem;
}

.page-about__crumb-item a {
  color: var(--color-mist);
  transition: color var(--transition-fast);
}

.page-about__crumb-item a:hover {
  color: var(--color-lime);
  text-decoration: none;
}

.page-about__context-meta {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.12em;
  color: var(--color-mist);
  border: 1px solid var(--about-border);
  padding: 0.35rem 0.7rem;
}

.page-about__hero {
  display: grid;
  gap: 2rem;
  padding-top: clamp(2rem, 6vw, 4.5rem);
  padding-bottom: 1rem;
  position: relative;
}

.page-about__hero-text {
  min-width: 0;
}

.page-about__eyebrow {
  margin: 0 0 1rem;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  letter-spacing: 0.18em;
  color: var(--color-lime);
  text-transform: uppercase;
}

.page-about__hero h1 {
  margin: 0 0 1.25rem;
  font-size: clamp(2rem, 5vw, 4rem);
  font-weight: 900;
  letter-spacing: -0.02em;
  line-height: 1.1;
}

.page-about__lede {
  margin: 0 0 1.5rem;
  max-width: 62ch;
  font-size: clamp(1rem, 1.4vw, 1.125rem);
  color: var(--color-mist);
}

.page-about__hero-text::after {
  content: "";
  display: block;
  width: 120px;
  height: 4px;
  margin-top: 1.5rem;
  background: linear-gradient(90deg, var(--color-blue), transparent);
  transform: skewX(-20deg);
}

.page-about__hero-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 1.25rem;
}

.page-about__hero-tag {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  letter-spacing: 0.06em;
  color: var(--color-cream);
  border: 1px solid var(--about-card-border);
  background: var(--color-rock);
  padding: 0.4rem 0.75rem;
}

.page-about__hero-tag:nth-child(1) {
  color: var(--color-lime);
  border-color: rgba(183, 255, 63, 0.35);
}

.page-about__hero-tag:nth-child(2) {
  color: var(--color-clay);
  border-color: rgba(255, 107, 74, 0.35);
}

.page-about__hero-tag:nth-child(3) {
  color: var(--color-blue);
  border-color: rgba(0, 229, 255, 0.35);
}

.page-about__dossier {
  margin: 1.25rem 0 0;
  padding: 1rem 1.25rem;
  background: var(--color-rock);
  border-left: 4px solid var(--color-pine);
}

.page-about__dossier-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.25rem 1rem;
  font-size: 0.9rem;
}

.page-about__dossier-row + .page-about__dossier-row {
  margin-top: 0.4rem;
  padding-top: 0.4rem;
  border-top: 1px solid var(--about-border);
}

.page-about__dossier-row dt {
  min-width: 5.5em;
  color: var(--color-mist);
}

.page-about__dossier-row dd {
  margin: 0;
  color: var(--color-cream);
  font-weight: 500;
}

.page-about__hero-figure {
  position: relative;
  margin: 0;
  border: 1px solid rgba(183, 255, 63, 0.3);
  background: var(--color-rock);
}

.page-about__hero-figure::before {
  content: "框景 01 / 数据面板";
  position: absolute;
  top: -11px;
  left: 16px;
  padding: 0 0.5rem;
  background: var(--color-ink);
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.12em;
  color: var(--color-lime);
}

.page-about__hero-img {
  display: block;
  width: 100%;
  height: auto;
}

.page-about__figure-caption {
  margin-top: 0.5rem;
  font-size: 0.8rem;
  color: var(--color-mist);
  border-bottom: 1px solid var(--about-border);
  padding-bottom: 0.75rem;
}

.page-about__layout {
  display: grid;
  gap: 2rem;
  padding-top: var(--about-section-gap);
  padding-bottom: clamp(3rem, 7vw, 5rem);
}

.page-about__index {
  background: var(--color-rock);
  border: 1px solid var(--about-card-border);
  padding: 1.5rem;
  align-self: start;
  min-width: 0;
}

.page-about__index-title {
  margin: 0 0 1rem;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  letter-spacing: 0.15em;
  color: var(--color-lime);
}

.page-about__index-list {
  list-style: none;
  margin: 0 0 1.25rem;
  padding: 0;
  display: grid;
  gap: 0.35rem;
}

.page-about__index-link {
  display: flex;
  align-items: baseline;
  gap: 0.75rem;
  padding: 0.5rem 0.65rem;
  border-left: 2px solid transparent;
  color: var(--color-cream);
  text-decoration: none;
  transition: border-color var(--transition-fast), background-color var(--transition-fast);
}

.page-about__index-link:hover,
.page-about__index-link:focus-visible {
  border-left-color: var(--color-lime);
  background: var(--about-lime-soft);
  text-decoration: none;
}

.page-about__index-num {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--color-blue);
}

.page-about__index-name {
  font-weight: 500;
}

.page-about__index-foot {
  margin: 0;
  font-size: 0.8rem;
  color: var(--color-mist);
  border-top: 1px solid var(--about-border);
  padding-top: 0.75rem;
}

.page-about__body {
  min-width: 0;
}

.page-about__section {
  scroll-margin-top: calc(var(--header-total) + 16px);
  border-top: 1px solid var(--about-border);
  padding-top: clamp(2.5rem, 6vw, 4rem);
  margin-bottom: var(--about-section-gap);
}

.page-about__section:target {
  background: var(--about-lime-soft);
}

.page-about__section-head {
  display: flex;
  align-items: flex-end;
  flex-wrap: wrap;
  gap: 0.5rem 1rem;
  border-bottom: 1px solid var(--about-border);
  padding-bottom: 0.75rem;
  margin-bottom: 1.25rem;
  min-width: 0;
}

.page-about__section-head::after {
  content: "";
  flex: 1;
  min-width: 40px;
  height: 3px;
  background: linear-gradient(90deg, var(--color-pine), var(--color-lime));
  transform: skewX(-20deg);
}

.page-about__section-num {
  font-family: var(--font-mono);
  font-size: clamp(3rem, 8vw, 5.5rem);
  font-weight: 600;
  line-height: 0.9;
  color: var(--color-lime);
  opacity: 0.85;
}

.page-about__section-head h2 {
  margin: 0;
  font-size: clamp(1.75rem, 3vw, 2.5rem);
  font-weight: 800;
  letter-spacing: -0.01em;
  line-height: 1.15;
}

.page-about__section-sub {
  margin: 0 0 0.75rem;
  font-family: var(--font-mono);
  font-size: 0.9rem;
  letter-spacing: 0.06em;
  color: var(--color-blue);
}

.page-about__prose-lead {
  margin: 0 0 1.5rem;
  max-width: 70ch;
  font-size: 1.05rem;
  color: var(--color-cream);
}

.page-about__split {
  display: grid;
  gap: 1.5rem;
  align-items: start;
}

.page-about__prose p {
  margin: 0 0 1rem;
  color: var(--color-mist);
}

.page-about__prose p:first-child {
  color: var(--color-cream);
  font-size: 1.05rem;
}

.page-about__brand-note {
  background: var(--color-pine);
  border: 1px solid rgba(0, 229, 255, 0.3);
  padding: 1.5rem;
}

.page-about__brand-note-label {
  display: inline-block;
  margin-bottom: 0.75rem;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  letter-spacing: 0.1em;
  color: var(--color-blue);
}

.page-about__brand-note p {
  margin: 0 0 1rem;
  font-size: 1.15rem;
  line-height: 1.5;
}

.page-about__brand-note-sign {
  font-size: 0.85rem;
  color: var(--color-mist);
}

.page-about__filter-scope {
  margin: 1.5rem 0 2rem;
}

.page-about__filter-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 1.25rem;
}

.page-about__filter-btn {
  background: transparent;
  border: 1px solid var(--about-card-border);
  color: var(--color-mist);
  font-family: var(--font-mono);
  font-size: 0.8rem;
  letter-spacing: 0.06em;
  padding: 0.45rem 1rem;
  cursor: pointer;
  transition: color var(--transition-fast), border-color var(--transition-fast), background-color var(--transition-fast);
}

.page-about__filter-btn:hover,
.page-about__filter-btn:focus-visible {
  border-color: var(--color-lime);
  color: var(--color-lime);
}

.page-about__filter-btn[data-active],
.page-about__filter-btn[aria-pressed="true"] {
  border-color: var(--color-lime);
  color: var(--color-lime);
  background: var(--about-lime-soft);
}

.page-about__content-cluster {
  display: grid;
  gap: 1rem;
}

.page-about__type-card {
  background: var(--color-rock);
  border: 1px solid var(--about-card-border);
  padding: 1.25rem;
  margin: 0;
  min-width: 0;
  transition: transform var(--transition-fast), border-color var(--transition-fast);
}

.page-about__type-card:hover,
.page-about__type-card:focus-within {
  transform: translateY(-4px);
  border-color: rgba(0, 229, 255, 0.35);
}

.page-about__type-tag {
  display: inline-flex;
  align-items: center;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.08em;
  color: var(--color-lime);
  border: 1px solid rgba(183, 255, 63, 0.35);
  padding: 0.2rem 0.5rem;
}

.page-about__type-card[data-filter-item="replay"] .page-about__type-tag {
  color: var(--color-clay);
  border-color: rgba(255, 107, 74, 0.35);
}

.page-about__type-card[data-filter-item="search"] .page-about__type-tag {
  color: var(--color-blue);
  border-color: rgba(0, 229, 255, 0.35);
}

.page-about__type-card h3 {
  margin: 0.75rem 0 0.5rem;
  font-size: 1.05rem;
}

.page-about__type-card p {
  margin: 0;
  color: var(--color-mist);
  font-size: 0.92rem;
}

.page-about__coverage-figure,
.page-about__timeline-figure {
  margin: 1.5rem 0 0;
}

.page-about__coverage-figure img,
.page-about__timeline-figure img {
  display: block;
  width: 100%;
  height: auto;
  border: 1px solid var(--about-card-border);
  background: var(--color-rock);
}

.page-about__coverage-stats {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 0.75rem;
  margin-top: 1.75rem;
}

.page-about__coverage-stat {
  background: var(--color-rock);
  border: 1px solid var(--about-card-border);
  padding: 1.1rem 0.75rem;
  text-align: center;
  min-width: 0;
}

.page-about__coverage-stat-value {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(1.75rem, 4vw, 2.75rem);
  font-weight: 600;
  line-height: 1;
  color: var(--color-lime);
}

.page-about__coverage-stat:nth-child(2) .page-about__coverage-stat-value,
.page-about__coverage-stat:nth-child(3) .page-about__coverage-stat-value {
  color: var(--color-blue);
}

.page-about__coverage-stat:nth-child(4) .page-about__coverage-stat-value {
  color: var(--color-clay);
}

.page-about__coverage-stat-label {
  display: block;
  margin-top: 0.5rem;
  font-size: 0.85rem;
  color: var(--color-mist);
}

.page-about__timeline-list {
  position: relative;
  list-style: none;
  margin: 1.5rem 0 0;
  padding: 0;
}

.page-about__timeline-list::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 8px;
  bottom: 8px;
  width: 2px;
  background: linear-gradient(to bottom, var(--color-lime) 0%, var(--color-blue) 60%, var(--color-clay) 100%);
}

.page-about__timeline-node {
  position: relative;
  padding-left: 2.25rem;
  margin-bottom: 1.25rem;
}

.page-about__timeline-node::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.75rem;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--color-ink);
  border: 3px solid var(--color-lime);
  box-sizing: border-box;
}

.page-about__timeline-node:nth-child(3)::before {
  border-color: var(--color-blue);
}

.page-about__timeline-node:nth-child(4)::before {
  border-color: var(--color-clay);
}

.page-about__timeline-node:nth-child(5)::before {
  border-color: var(--color-blue);
}

.page-about__timeline-details {
  background: var(--color-rock);
  border: 1px solid var(--about-card-border);
  transition: border-color var(--transition-fast), background-color var(--transition-fast), transform var(--transition-fast);
}

.page-about__timeline-details:hover,
.page-about__timeline-details:focus-within {
  border-color: rgba(183, 255, 63, 0.4);
  background: rgba(183, 255, 63, 0.04);
  transform: translateX(4px);
}

.page-about__timeline-summary {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  gap: 0.75rem;
  align-items: center;
  padding: 1rem 1.25rem;
  cursor: pointer;
  list-style: none;
}

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

.page-about__timeline-summary::after {
  content: "−";
  flex-shrink: 0;
  font-family: var(--font-mono);
  color: var(--color-lime);
  font-size: 1.2rem;
  line-height: 1;
}

.page-about__timeline-details:not([open]) .page-about__timeline-summary::after {
  content: "+";
}

.page-about__timeline-tag {
  display: inline-flex;
  align-items: center;
  white-space: nowrap;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.1em;
  color: var(--color-blue);
  border: 1px solid rgba(0, 229, 255, 0.35);
  padding: 0.2rem 0.5rem;
}

.page-about__timeline-node:nth-child(4) .page-about__timeline-tag {
  color: var(--color-clay);
  border-color: rgba(255, 107, 74, 0.4);
}

.page-about__timeline-title {
  font-weight: 700;
  font-size: 1.05rem;
  color: var(--color-cream);
  min-width: 0;
}

.page-about__timeline-body {
  padding: 0 1.25rem 1.25rem;
  color: var(--color-mist);
  font-size: 0.95rem;
}

.page-about__timeline-body p {
  margin: 0;
}

.page-about__trust-panel {
  display: grid;
  gap: 1rem;
  background: rgba(14, 59, 60, 0.45);
  border: 1px solid rgba(0, 229, 255, 0.18);
  padding: 1.25rem;
}

.page-about__trust-item {
  background: rgba(11, 15, 14, 0.6);
  padding: 1.25rem;
  border-top: 3px solid var(--color-clay);
  min-width: 0;
  transition: transform var(--transition-fast), background-color var(--transition-fast);
}

.page-about__trust-item:nth-child(2) {
  border-top-color: var(--color-lime);
}

.page-about__trust-item:nth-child(3) {
  border-top-color: var(--color-blue);
}

.page-about__trust-item:nth-child(4) {
  border-top-color: var(--color-lime);
}

.page-about__trust-item:hover,
.page-about__trust-item:focus-within {
  transform: translateY(-2px);
  background: rgba(183, 255, 63, 0.05);
}

.page-about__trust-item h3 {
  margin: 0 0 0.5rem;
  font-size: 1.05rem;
}

.page-about__trust-item p {
  margin: 0;
  color: var(--color-mist);
  font-size: 0.95rem;
}

.page-about__trust-statement {
  margin: 1.25rem 0 0;
  padding: 1rem 1.25rem;
  border-left: 4px solid var(--color-clay);
  background: var(--color-rock);
  color: var(--color-mist);
  font-size: 0.9rem;
}

.page-about__more {
  border-top: 1px solid var(--about-border);
  padding-top: 2rem;
  margin-top: var(--about-section-gap);
}

.page-about__more > h2 {
  margin: 0 0 1.25rem;
  font-size: 1.5rem;
}

.page-about__more-grid {
  display: grid;
  gap: 1rem;
}

.page-about__more-card {
  display: block;
  background: var(--color-rock);
  border: 1px solid var(--about-card-border);
  padding: 1.25rem;
  color: inherit;
  text-decoration: none;
  transition: transform var(--transition-fast), border-color var(--transition-fast);
}

.page-about__more-card h3 {
  margin: 0 0 0.5rem;
  font-size: 1.1rem;
  color: var(--color-lime);
}

.page-about__more-card p {
  margin: 0;
  color: var(--color-mist);
  font-size: 0.9rem;
}

.page-about__more-card:hover,
.page-about__more-card:focus-visible {
  transform: translateY(-4px);
  border-color: rgba(183, 255, 63, 0.35);
  text-decoration: none;
}

@media (min-width: 640px) {
  .page-about__content-cluster {
    grid-template-columns: repeat(2, 1fr);
  }

  .page-about__coverage-stats {
    grid-template-columns: repeat(4, 1fr);
  }

  .page-about__trust-panel {
    grid-template-columns: repeat(2, 1fr);
  }

  .page-about__more-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

@media (min-width: 992px) {
  .page-about__hero {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: 2.5rem;
    align-items: end;
  }

  .page-about__hero-text {
    padding-bottom: 1rem;
  }

  .page-about__hero-figure {
    margin: 0;
  }

  .page-about__layout {
    grid-template-columns: 240px minmax(0, 1fr);
    gap: clamp(2rem, 5vw, 4rem);
    align-items: start;
  }

  .page-about__index {
    position: sticky;
    top: calc(var(--header-total) + 24px);
  }

  .page-about__split {
    grid-template-columns: minmax(0, 1fr) 240px;
    gap: 2rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about__type-card,
  .page-about__more-card,
  .page-about__trust-item,
  .page-about__timeline-details {
    transition: none;
  }

  .page-about__hero-text::after {
    transform: none;
  }
}