.page-about {
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-sans);
  min-height: calc(100vh - var(--header-h));
}

.page-about .about-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 20px;
  max-width: 1440px;
  margin: 0 auto;
  padding: 20px 16px 64px;
}

.page-about .about-aside {
  position: relative;
  background: linear-gradient(135deg, var(--bg-index), #292929);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 16px;
  order: -1;
}

.page-about .about-aside__panel {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.page-about .about-aside__kicker {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.2em;
  color: var(--accent);
  text-transform: uppercase;
  margin: 0;
}

.page-about .about-aside__title {
  font-size: 1.4rem;
  font-weight: 900;
  margin: 0;
  line-height: 1.2;
  color: var(--text);
}

.page-about .about-nav {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 6px;
}

.page-about .about-nav__link {
  display: block;
  padding: 9px 12px;
  color: var(--text-dim);
  font-size: 0.95rem;
  border-radius: var(--radius-sm);
  border: 1px solid transparent;
  text-decoration: none;
  transition: background-color 0.2s, color 0.2s;
}

.page-about .about-nav__link--active {
  background: rgba(255, 107, 0, 0.14);
  color: var(--primary);
  border-color: rgba(255, 107, 0, 0.3);
  font-weight: 600;
}

.page-about .about-aside__goto {
  display: grid;
  gap: 8px;
  border-top: 1px solid var(--border);
  padding-top: 14px;
  margin-top: 2px;
}

.page-about .about-aside__goto-label {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.12em;
  color: var(--text-dim);
  text-transform: uppercase;
}

.page-about .about-main {
  min-width: 0;
  display: flex;
  flex-direction: column;
  gap: 26px;
}

.page-about .about-hero {
  padding: 4px 0 2px;
}

.page-about .about-hero__title {
  font-size: 2rem;
  line-height: 1.15;
  font-weight: 900;
  margin: 0 0 12px;
  transform: skewX(-3deg);
  transform-origin: left center;
}

.page-about .about-hero__dim {
  display: inline-block;
  color: var(--accent);
  margin-left: 6px;
}

.page-about .about-hero__lead {
  font-size: 1rem;
  line-height: 1.7;
  color: var(--text-dim);
  max-width: 860px;
  margin: 0;
}

.page-about .about-section {
  padding: 22px 18px;
  border-radius: var(--radius-lg);
  background: var(--bg-elevated);
  border: 1px solid var(--border);
}

.page-about .about-section--tree {
  background: linear-gradient(135deg, #4a00e0 0%, #1a1a1a 78%);
  border: none;
  color: #fff;
}

.page-about .about-section--tags {
  background: linear-gradient(135deg, #0d3b1f 0%, #1a1a1a 78%);
  border: none;
  color: #fff;
}

.page-about .about-section--update {
  background: var(--bg-card);
  border: 1px solid var(--border);
}

.page-about .about-section--retrieval {
  background: linear-gradient(135deg, #1e1e1e 0%, #241b2e 100%);
  border: 1px solid var(--border);
}

.page-about .page-head {
  display: flex;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 8px 14px;
  margin-bottom: 4px;
}

.page-about .page-head__title {
  font-size: 1.6rem;
  font-weight: 900;
  margin: 0;
  display: flex;
  align-items: baseline;
  gap: 10px;
}

.page-about .page-head__index {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--primary);
  font-weight: 700;
  background: rgba(255, 107, 0, 0.12);
  padding: 3px 8px;
  border-radius: 6px;
}

.page-about .page-head__subtitle {
  font-size: 0.85rem;
  color: var(--text-dim);
}

.page-about .page-head--light .page-head__title {
  color: #fff;
}

.page-about .page-head--light .page-head__subtitle {
  color: rgba(255, 255, 255, 0.72);
}

.page-about .page-head--light .page-head__index {
  background: rgba(0, 212, 255, 0.18);
  color: var(--accent);
}

.page-about .about-stats {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 16px;
  margin-top: 16px;
}

.page-about .stat-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
}

.page-about .stat-card {
  position: relative;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 14px 12px;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  gap: 6px;
  min-width: 0;
}

.page-about .stat-card__icon {
  font-family: var(--font-mono);
  font-size: 0.62rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  width: fit-content;
  padding: 2px 7px;
  border-radius: 999px;
  color: #1a1a1a;
  text-transform: uppercase;
}

.page-about .stat-card--orange .stat-card__icon {
  background: var(--primary);
}

.page-about .stat-card--cyan .stat-card__icon {
  background: var(--accent);
}

.page-about .stat-card--yellow .stat-card__icon {
  background: var(--status-live);
}

.page-about .stat-card--pink .stat-card__icon {
  background: var(--status-done);
}

.page-about .stat-card--lime .stat-card__icon {
  background: var(--tag-lime);
}

.page-about .stat-card__number {
  font-family: var(--font-mono);
  font-size: 2rem;
  font-weight: 800;
  line-height: 1;
  color: var(--primary);
  white-space: nowrap;
}

.page-about .stat-card__label {
  font-size: 0.82rem;
  font-weight: 700;
  color: var(--text);
  letter-spacing: 0.02em;
}

.page-about .stat-card__hint {
  font-size: 0.72rem;
  color: var(--text-dim);
  line-height: 1.4;
}

.page-about .about-figure {
  margin: 18px 0 0;
  border-radius: var(--radius-md);
  overflow: hidden;
  background: rgba(10, 10, 10, 0.45);
  border: 1px solid var(--border);
}

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

.page-about .about-figure figcaption {
  padding: 8px 12px;
  font-size: 0.78rem;
  color: var(--text-dim);
  background: rgba(0, 0, 0, 0.25);
  border-top: 1px solid rgba(255, 255, 255, 0.06);
}

.page-about .about-section--tree .about-figure,
.page-about .about-section--tags .about-figure {
  margin-top: 18px;
  border-color: rgba(255, 255, 255, 0.16);
}

.page-about .tree-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 12px;
  margin-top: 18px;
}

.page-about .tree-node {
  background: rgba(20, 10, 40, 0.55);
  border: 1px solid rgba(255, 255, 255, 0.16);
  border-top: 3px solid var(--accent);
  border-radius: var(--radius-md);
  padding: 14px 14px 12px;
  backdrop-filter: blur(4px);
}

.page-about .tree-node:nth-child(3n + 1) {
  border-top-color: var(--primary);
}

.page-about .tree-node:nth-child(3n + 2) {
  border-top-color: var(--accent);
}

.page-about .tree-node:nth-child(3n) {
  border-top-color: var(--status-live);
}

.page-about .tree-node__head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 10px;
  margin-bottom: 10px;
}

.page-about .tree-node__name {
  font-weight: 900;
  font-size: 1.2rem;
  color: #fff;
}

.page-about .tree-node__name::before {
  content: "";
  display: inline-block;
  width: 8px;
  height: 8px;
  border-radius: 2px;
  margin-right: 8px;
  background: var(--accent);
  transform: skewX(-10deg);
}

.page-about .tree-node:nth-child(3n + 1) .tree-node__name::before {
  background: var(--primary);
}

.page-about .tree-node:nth-child(3n + 2) .tree-node__name::before {
  background: var(--accent);
}

.page-about .tree-node:nth-child(3n) .tree-node__name::before {
  background: var(--status-live);
}

.page-about .tree-node__count {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--accent);
  background: rgba(0, 212, 255, 0.15);
  padding: 2px 8px;
  border-radius: 999px;
  white-space: nowrap;
}

.page-about .tree-node__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.page-about .tree-node__list li {
  font-size: 0.78rem;
  color: rgba(255, 255, 255, 0.85);
  background: rgba(255, 255, 255, 0.1);
  border-radius: 6px;
  padding: 3px 9px;
}

.page-about .about-tag-table {
  margin-top: 16px;
  overflow-x: auto;
  border: 1px solid rgba(255, 255, 255, 0.14);
  border-radius: var(--radius-md);
  background: rgba(10, 30, 18, 0.5);
}

.page-about .about-tag-table table {
  width: 100%;
  border-collapse: collapse;
  min-width: 520px;
}

.page-about .about-tag-table th,
.page-about .about-tag-table td {
  padding: 10px 14px;
  text-align: left;
  border-bottom: 1px solid rgba(255, 255, 255, 0.12);
  font-size: 0.9rem;
}

.page-about .about-tag-table th {
  background: rgba(0, 230, 118, 0.1);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--status-new);
}

.page-about .about-tag-table td:last-child {
  color: rgba(255, 255, 255, 0.75);
  font-size: 0.85rem;
}

.page-about .about-tag-table a {
  color: #fff;
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-color: rgba(255, 255, 255, 0.3);
}

.page-about .about-tag-table .tag {
  font-size: 0.72rem;
  padding: 3px 8px;
  border-radius: 6px;
  font-weight: 700;
  color: #1a1a1a;
  white-space: nowrap;
}

.page-about .about-tag-table .tag--lime {
  background: var(--tag-lime);
}

.page-about .about-tag-table .tag--yellow {
  background: var(--status-live);
}

.page-about .about-timeline {
  margin-top: 18px;
  display: flex;
  flex-direction: column;
}

.page-about .timeline-item {
  position: relative;
  padding-left: 42px;
  padding-bottom: 30px;
}

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

.page-about .timeline-item::before {
  content: "";
  position: absolute;
  left: 13px;
  top: 18px;
  bottom: 0;
  width: 2px;
  background: var(--border);
}

.page-about .timeline-item:last-child::before {
  display: none;
}

.page-about .timeline-item__dot {
  position: absolute;
  left: 7px;
  top: 6px;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--primary);
  box-shadow: 0 0 0 4px rgba(255, 107, 0, 0.18);
}

.page-about .timeline-item:nth-child(1) .timeline-item__dot {
  background: var(--primary);
  box-shadow: 0 0 0 4px rgba(255, 107, 0, 0.18);
}

.page-about .timeline-item:nth-child(2) .timeline-item__dot {
  background: var(--accent);
  box-shadow: 0 0 0 4px rgba(0, 212, 255, 0.18);
}

.page-about .timeline-item:nth-child(3) .timeline-item__dot {
  background: var(--status-live);
  box-shadow: 0 0 0 4px rgba(255, 214, 0, 0.18);
}

.page-about .timeline-item:nth-child(4) .timeline-item__dot {
  background: var(--status-done);
  box-shadow: 0 0 0 4px rgba(255, 93, 177, 0.18);
}

.page-about .timeline-item:nth-child(5) .timeline-item__dot {
  background: var(--tag-lime);
  box-shadow: 0 0 0 4px rgba(192, 255, 0, 0.18);
}

.page-about .timeline-item__body h3 {
  margin: 0 0 4px;
  font-size: 1.05rem;
  font-weight: 800;
  color: var(--text);
}

.page-about .timeline-item__body p {
  margin: 0;
  font-size: 0.9rem;
  line-height: 1.6;
  color: var(--text-dim);
}

.page-about .retrieval-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
  margin-top: 16px;
}

.page-about .retrieval-item {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 18px 16px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.page-about .retrieval-item__mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  border-radius: 12px;
  font-family: var(--font-mono);
  font-weight: 800;
  font-size: 1.1rem;
  color: #1a1a1a;
}

.page-about .retrieval-item--orange .retrieval-item__mark {
  background: var(--primary);
}

.page-about .retrieval-item--cyan .retrieval-item__mark {
  background: var(--accent);
}

.page-about .retrieval-item--yellow .retrieval-item__mark {
  background: var(--status-live);
}

.page-about .retrieval-item--pink .retrieval-item__mark {
  background: var(--status-done);
}

.page-about .retrieval-item__title {
  margin: 0;
  font-size: 1.05rem;
  font-weight: 800;
}

.page-about .retrieval-item__desc {
  margin: 0;
  font-size: 0.88rem;
  line-height: 1.6;
  color: var(--text-dim);
}

@media (min-width: 640px) {
  .page-about .about-nav {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .tree-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .retrieval-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 768px) {
  .page-about .about-hero__title {
    font-size: 3rem;
  }

  .page-about .about-hero__lead {
    font-size: 1.06rem;
  }

  .page-about .about-stats {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr);
    align-items: center;
  }
}

@media (min-width: 1024px) {
  .page-about .about-layout {
    grid-template-columns: 250px minmax(0, 1fr);
    gap: 28px;
    padding: 24px 28px 80px;
    align-items: start;
  }

  .page-about .about-aside {
    position: sticky;
    top: calc(var(--header-h) + 16px);
    max-height: calc(100vh - var(--header-h) - 32px);
    overflow-y: auto;
    padding: 20px;
  }

  .page-about .about-nav {
    grid-template-columns: 1fr;
  }

  .page-about .about-main {
    gap: 30px;
  }

  .page-about .about-hero {
    padding: 8px 0 2px;
  }

  .page-about .about-section {
    padding: 26px 24px;
  }

  .page-about .stat-list {
    gap: 12px;
  }
}

@media (min-width: 1200px) {
  .page-about .stat-list {
    grid-template-columns: repeat(5, minmax(0, 1fr));
  }

  .page-about .tree-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .stat-card__number {
    font-size: 2.4rem;
  }
}