.page-about {
  --about-card-shadow: var(--shadow-hard);
  --about-deep-space: 44px;
  --about-soft-radius: var(--radius-sm);
}

.page-about .about-hero {
  background: var(--section-a);
  color: var(--text-invert);
  padding: 32px 0 42px;
}

.page-about .about-breadcrumb {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  font-size: 13px;
  color: rgba(249, 250, 251, 0.6);
  margin-bottom: 22px;
}

.page-about .about-breadcrumb a {
  color: rgba(249, 250, 251, 0.78);
  text-decoration: none;
  transition: color 0.2s;
}

.page-about .about-breadcrumb a:hover,
.page-about .about-breadcrumb a:focus {
  color: var(--accent);
}

.page-about .crumb-sep {
  color: var(--accent);
  font-weight: 900;
}

.page-about .crumb-current {
  color: var(--accent);
  font-weight: 600;
}

.page-about .about-kicker {
  margin: 0 0 10px;
  color: var(--accent);
  font-size: 12px;
  font-weight: 800;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

.page-about .about-hero h1 {
  margin: 0 0 14px;
  font-size: 28px;
  line-height: 1.2;
  font-weight: 900;
  color: var(--text-invert);
}

.page-about .hero-lead {
  margin: 0 0 24px;
  max-width: 640px;
  font-size: 15px;
  line-height: 1.75;
  color: rgba(249, 250, 251, 0.85);
}

.page-about .hero-metric-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 10px;
  margin-bottom: 26px;
}

.page-about .hero-metric {
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid rgba(255, 255, 255, 0.14);
  border-radius: var(--about-soft-radius);
  padding: 14px 16px;
  display: flex;
  flex-direction: column;
}

.page-about .metric-num {
  font-size: 24px;
  line-height: 1.1;
  font-weight: 900;
  color: var(--accent);
}

.page-about .metric-label {
  margin-top: 4px;
  font-size: 12px;
  color: rgba(249, 250, 251, 0.7);
}

.page-about .about-toc {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-size: 13px;
}

.page-about .about-toc > span {
  color: rgba(249, 250, 251, 0.55);
  margin-right: 2px;
}

.page-about .about-toc a {
  background: rgba(255, 255, 255, 0.1);
  border: 1px solid rgba(255, 255, 255, 0.2);
  color: var(--text-invert);
  text-decoration: none;
  padding: 5px 14px;
  border-radius: 999px;
  transition: background 0.2s, color 0.2s, border 0.2s;
}

.page-about .about-toc a:hover,
.page-about .about-toc a:focus {
  background: var(--accent);
  border-color: var(--accent);
  color: var(--text-main);
  outline: none;
}

.page-about .about-section {
  padding: var(--about-deep-space) 0;
}

.page-about .about-section .section-head {
  margin-bottom: 22px;
}

.page-about .about-section h2 {
  margin: 0;
  display: inline-block;
  font-size: 24px;
  line-height: 1.25;
  font-weight: 900;
  border-left: 6px solid var(--accent);
  padding-left: 12px;
}

.page-about .section-head-desc {
  margin: 8px 0 0 18px;
  font-size: 14px;
  color: var(--text-main);
}

.page-about .about-scope {
  background: var(--page-bg);
}

.page-about .about-taxonomy {
  background: var(--section-b);
  color: var(--text-invert);
}

.page-about .about-taxonomy h2,
.page-about .about-updates h2 {
  color: var(--text-invert);
}

.page-about .about-taxonomy .section-head-desc,
.page-about .about-updates .section-head-desc {
  color: rgba(249, 250, 251, 0.68);
}

.page-about .scope-grid {
  display: grid;
  gap: 20px;
  align-items: start;
}

.page-about .scope-media {
  background: var(--card-bg);
  border: 3px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--about-card-shadow);
  overflow: hidden;
}

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

.page-about .media-caption {
  display: block;
  padding: 8px 12px;
  font-size: 12px;
  font-weight: 700;
  color: var(--text-main);
  background: var(--accent);
  border-top: 3px solid var(--border);
}

.page-about .scope-item-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 12px;
}

.page-about .scope-item {
  display: flex;
  gap: 14px;
  background: var(--card-bg);
  border: 3px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--about-card-shadow);
  padding: 16px;
}

.page-about .scope-badge {
  flex-shrink: 0;
  width: 52px;
  height: 52px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 12px;
  font-size: 10px;
  font-weight: 900;
  letter-spacing: 0.08em;
  border: 2px solid var(--border);
  color: var(--text-main);
}

.page-about .scope-badge-live {
  background: var(--tag-live);
}

.page-about .scope-badge-sched {
  background: var(--tag-replay);
}

.page-about .scope-badge-arch {
  background: var(--tag-feature);
  color: var(--text-invert);
}

.page-about .scope-item-text h3 {
  margin: 0 0 6px;
  font-size: 16px;
  font-weight: 800;
  color: var(--text-main);
}

.page-about .scope-item-text p {
  margin: 0;
  font-size: 13px;
  line-height: 1.7;
  color: var(--text-main);
  opacity: 0.82;
}

.page-about .scope-params {
  margin-top: 16px;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  background: var(--accent);
  border: 3px solid var(--border);
  border-radius: var(--radius);
  padding: 12px 14px;
}

.page-about .param-item {
  font-size: 13px;
  font-weight: 600;
  color: var(--text-main);
  background: rgba(255, 255, 255, 0.35);
  border-radius: 6px;
  padding: 4px 10px;
}

.page-about .param-item strong {
  margin-right: 6px;
  font-weight: 900;
  text-decoration: underline;
  text-decoration-thickness: 2px;
  text-decoration-color: var(--border);
}

.page-about .taxonomy-layout {
  display: grid;
  gap: 20px;
  align-items: start;
}

.page-about .taxonomy-tree {
  background: rgba(255, 255, 255, 0.08);
  border: 2px solid rgba(249, 250, 251, 0.3);
  border-radius: var(--radius);
  padding: 18px;
}

.page-about .tree-root {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  background: var(--accent);
  color: var(--text-main);
  border: 2px solid var(--border);
  border-radius: 10px;
  padding: 10px 14px;
  font-weight: 900;
  font-size: 16px;
}

.page-about .tree-node-count {
  font-size: 13px;
  background: rgba(17, 24, 39, 0.14);
  border-radius: 999px;
  padding: 2px 10px;
}

.page-about .tree-branch {
  margin-top: 14px;
}

.page-about .tree-node-main {
  display: inline-block;
  background: rgba(249, 250, 251, 0.14);
  border-left: 4px solid var(--accent);
  color: var(--text-invert);
  font-size: 14px;
  font-weight: 800;
  border-radius: 6px;
  padding: 6px 12px;
}

.page-about .tree-children {
  margin: 12px 0 0 14px;
  padding-left: 16px;
  border-left: 2px dashed rgba(249, 250, 251, 0.3);
  display: grid;
  gap: 6px;
}

.page-about .tree-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 6px;
  background: rgba(255, 255, 255, 0.07);
  border-radius: 8px;
  padding: 8px 12px;
  font-size: 14px;
  transition: background 0.2s;
}

.page-about .tree-row:hover,
.page-about .tree-row:focus-within {
  background: rgba(255, 255, 255, 0.14);
}

.page-about .tree-part {
  font-weight: 800;
  color: var(--text-invert);
}

.page-about .tree-tags {
  font-size: 12px;
  color: rgba(249, 250, 251, 0.68);
}

.page-about .tree-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 14px;
}

.page-about .meta-tile {
  background: rgba(255, 255, 255, 0.13);
  border: 1px solid rgba(255, 255, 255, 0.2);
  color: var(--text-invert);
  font-size: 12px;
  font-weight: 700;
  border-radius: 999px;
  padding: 4px 12px;
}

.page-about .taxonomy-media {
  background: rgba(255, 255, 255, 0.06);
  border: 2px solid rgba(249, 250, 251, 0.24);
  border-radius: var(--radius);
  overflow: hidden;
}

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

.page-about .about-updates {
  background: var(--section-a);
  color: var(--text-invert);
}

.page-about .updates-grid {
  display: grid;
  gap: 20px;
  align-items: start;
}

.page-about .timeline {
  display: grid;
  gap: 10px;
}

.page-about .timeline-row {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 10px;
  background: var(--card-bg);
  border: 3px solid var(--border);
  border-radius: 12px;
  box-shadow: var(--about-card-shadow);
  padding: 12px 14px;
  transition: transform 0.2s, box-shadow 0.2s;
}

.page-about .timeline-row:hover,
.page-about .timeline-row:focus-within {
  transform: translateY(-2px);
  box-shadow: 6px 6px 0 rgba(0, 0, 0, 0.85);
}

.page-about .timeline-row.is-current {
  border-color: var(--border);
  background: #fffef0;
}

.page-about .timeline-index {
  font-size: 15px;
  font-weight: 900;
  color: var(--text-main);
  font-variant-numeric: tabular-nums;
  min-width: 72px;
}

.page-about .timeline-desc {
  font-size: 13px;
  color: var(--text-main);
  opacity: 0.78;
  flex: 1;
}

.page-about .timeline-tag-next {
  background: var(--accent);
  color: var(--text-main);
  border: 2px solid var(--border);
  font-size: 12px;
  font-weight: 900;
  padding: 3px 12px;
  border-radius: 999px;
}

.page-about .updates-side {
  display: grid;
  gap: 12px;
}

.page-about .updates-img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: cover;
  border: 2px solid rgba(249, 250, 251, 0.3);
  border-radius: var(--radius);
}

.page-about .update-facts {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 8px;
}

.page-about .update-facts li {
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid rgba(255, 255, 255, 0.16);
  border-radius: 10px;
  padding: 10px 12px;
  font-size: 13px;
  color: rgba(249, 250, 251, 0.85);
  font-weight: 600;
}

.page-about .fact-num {
  color: var(--accent);
  font-size: 16px;
  font-weight: 900;
}

.page-about .about-usage {
  background: var(--page-bg);
}

.page-about .usage-steps {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 14px;
}

.page-about .usage-step {
  display: flex;
  gap: 16px;
  background: var(--card-bg);
  border: 3px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--about-card-shadow);
  padding: 18px 16px;
}

.page-about .step-num {
  flex-shrink: 0;
  width: 46px;
  height: 46px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--accent);
  border: 2px solid var(--border);
  border-radius: 12px;
  font-size: 16px;
  font-weight: 900;
  color: var(--text-main);
}

.page-about .step-body h3 {
  margin: 0 0 6px;
  font-size: 16px;
  font-weight: 800;
  color: var(--text-main);
}

.page-about .step-body p {
  margin: 0;
  font-size: 13px;
  line-height: 1.7;
  color: var(--text-main);
  opacity: 0.82;
}

.page-about .step-body a {
  color: var(--tag-live);
  text-decoration: underline;
  text-decoration-thickness: 2px;
  text-underline-offset: 2px;
  font-weight: 700;
}

.page-about .step-body a:hover,
.page-about .step-body a:focus {
  background: var(--accent);
  color: var(--text-main);
  text-decoration: none;
  outline: none;
}

@media (min-width: 600px) {
  .page-about .hero-metric-grid {
    grid-template-columns: repeat(4, 1fr);
  }

  .page-about .about-hero h1 {
    font-size: 34px;
  }

  .page-about .hero-lead {
    font-size: 16px;
  }

  .page-about .update-facts {
    grid-template-columns: repeat(4, 1fr);
  }

  .page-about .scope-item {
    padding: 18px 20px;
  }
}

@media (min-width: 992px) {
  .page-about .about-hero {
    padding: 48px 0 56px;
  }

  .page-about .about-hero h1 {
    font-size: 42px;
  }

  .page-about .hero-lead {
    font-size: 17px;
  }

  .page-about .scope-grid {
    grid-template-columns: 400px 1fr;
    gap: 24px;
  }

  .page-about .taxonomy-layout {
    grid-template-columns: 1fr 500px;
    gap: 24px;
  }

  .page-about .updates-grid {
    grid-template-columns: 1fr 400px;
    gap: 24px;
  }

  .page-about .about-section {
    padding: 56px 0;
  }

  .page-about .about-section h2 {
    font-size: 28px;
  }

  .page-about .usage-steps {
    grid-template-columns: repeat(2, 1fr);
  }
}