.page-about {
  --about-grid-bg: rgba(0, 176, 255, 0.07);
  --about-scrollbar: #3A4157;
}

.page-about .page-head-wrap {
  padding-top: 32px;
  padding-bottom: 12px;
}

.page-about .breadcrumb {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  align-items: center;
  font-size: 13px;
  color: var(--text-dim);
  margin-bottom: 18px;
}

.page-about .breadcrumb a {
  color: var(--primary);
  text-decoration: none;
  border-bottom: 1px solid transparent;
}

.page-about .breadcrumb a:hover {
  border-bottom-color: var(--primary);
}

.page-about .breadcrumb-sep {
  opacity: 0.6;
  font-family: var(--font-mono);
}

.page-about .page-head {
  border-bottom: 1px solid var(--border-line);
  padding-bottom: 20px;
  margin-bottom: 8px;
}

.page-about .page-code {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--primary);
  margin-bottom: 10px;
}

.page-about .page-title {
  font-family: var(--font-head);
  font-weight: 900;
  font-size: clamp(1.7rem, 4vw, 2.8rem);
  line-height: 1.15;
  transform: skewX(-2deg);
  margin: 0 0 12px;
  padding-left: 14px;
  border-left: 6px solid var(--accent-orange);
}

.page-about .page-lead {
  color: var(--text-dim);
  max-width: 68ch;
  font-size: 15px;
  line-height: 1.8;
  margin: 0;
}

.page-about .section-block {
  padding: 36px 0;
  border-top: 1px solid var(--border-line);
}

.page-about .section-block[data-tone="grid"] {
  background: var(--bg-page);
}

.page-about .section-block[data-tone="a"] {
  background: var(--bg-zone-a);
}

.page-about .section-block[data-tone="b"] {
  background: var(--bg-zone-b);
}

.page-about .section-head {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px;
  margin-bottom: 12px;
}

.page-about .section-title {
  font-family: var(--font-head);
  font-weight: 900;
  font-size: clamp(1.4rem, 3vw, 2rem);
  transform: skewX(-2deg);
  margin: 0;
  padding-left: 12px;
  border-left: 5px solid var(--primary);
}

.page-about .section-label {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  background: var(--accent-orange);
  color: #12151F;
  padding: 4px 8px;
  transform: skewX(-6deg);
  display: inline-block;
}

.page-about .section-head .more-link {
  margin-left: auto;
}

.page-about .more-link {
  color: var(--primary);
  font-size: 14px;
  text-decoration: none;
  border-bottom: 1px solid rgba(0, 176, 255, 0.4);
  transition: border-color 0.2s ease, color 0.2s ease;
}

.page-about .more-link:hover {
  color: var(--accent-cyan);
  border-bottom-color: var(--accent-cyan);
}

.page-about .section-desc {
  color: var(--text-dim);
  font-size: 14px;
  line-height: 1.8;
  max-width: 68ch;
  margin: 0 0 24px;
}

.page-about .card {
  background: var(--bg-card);
  border: 1px solid var(--border-line);
  border-radius: 8px;
  transition: transform 0.2s ease, box-shadow 0.2s ease, border-color 0.2s ease;
}

.page-about .card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-pop);
}

.page-about .card-grid {
  display: grid;
  gap: 16px;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
}

.page-about .stat-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
}

.page-about .stat-card {
  position: relative;
  overflow: hidden;
  padding: 20px;
  border-top: 4px solid var(--accent-orange);
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.page-about .stat-card::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(to right, rgba(255, 255, 255, 0.045) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(255, 255, 255, 0.045) 1px, transparent 1px);
  background-size: 16px 16px;
  pointer-events: none;
  z-index: 0;
}

.page-about .stat-card > * {
  position: relative;
  z-index: 1;
}

.page-about .stat-1 {
  border-top-color: var(--accent-orange);
  background: linear-gradient(140deg, #2b1d2b 0%, #222639 70%);
}

.page-about .stat-2 {
  border-top-color: var(--accent-yellow);
  background: linear-gradient(140deg, #2b2818 0%, #222639 70%);
}

.page-about .stat-3 {
  border-top-color: var(--accent-cyan);
  background: linear-gradient(140deg, #143930 0%, #222639 70%);
}

.page-about .stat-4 {
  border-top-color: var(--accent-magenta);
  background: linear-gradient(140deg, #3a2030 0%, #222639 70%);
}

.page-about .stat-5 {
  border-top-color: var(--primary);
  background: linear-gradient(140deg, #12283a 0%, #222639 70%);
}

.page-about .stat-card:hover {
  border-color: var(--border-light);
  box-shadow: 0 6px 26px rgba(0, 0, 0, 0.45);
}

.page-about .stat-index {
  font-size: 12px;
  color: var(--text-dim);
  letter-spacing: 0.12em;
}

.page-about .stat-figure {
  display: flex;
  align-items: baseline;
  gap: 8px;
}

.page-about .stat-num {
  font-family: var(--font-mono);
  font-weight: 900;
  font-size: clamp(2rem, 5vw, 2.7rem);
  line-height: 1;
  color: var(--text-main);
}

.page-about .stat-unit {
  color: var(--text-dim);
  font-size: 14px;
  font-family: var(--font-mono);
}

.page-about .stat-card h3 {
  font-family: var(--font-head);
  font-weight: 800;
  font-size: 17px;
  margin: 4px 0 0;
}

.page-about .stat-desc {
  color: var(--text-dim);
  font-size: 13px;
  line-height: 1.7;
  margin: 0;
}

.page-about .arch-layout {
  display: grid;
  gap: 24px;
}

.page-about .arch-svg-panel {
  overflow-x: auto;
  border: 1px solid var(--border-light);
  border-radius: 8px;
  background: #151A28;
}

.page-about .arch-svg {
  display: block;
  width: 100%;
  min-width: 340px;
  height: auto;
}

.page-about .tree-grid-line,
.page-about .tree-grid-line-v {
  stroke: rgba(0, 176, 255, 0.14);
  stroke-width: 1;
  fill: none;
}

.page-about .tree-grid-mark {
  stroke: rgba(255, 210, 63, 0.32);
  stroke-width: 1;
  fill: none;
}

.page-about .tree-root rect {
  fill: var(--bg-zone-a);
  stroke: var(--primary);
  stroke-width: 1.5;
}

.page-about .tree-root text {
  fill: var(--accent-cyan);
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
}

.page-about .tree-link {
  stroke: var(--primary);
  stroke-width: 1.4;
  fill: none;
  opacity: 0.85;
}

.page-about .tree-link-v {
  stroke-width: 1;
  opacity: 0.55;
}

.page-about .tree-level-1 rect {
  stroke: #12151F;
  stroke-width: 1;
}

.page-about .tree-level-1 text {
  fill: #12151F;
  font-family: var(--font-head);
  font-size: 10px;
  font-weight: 900;
}

.page-about .tree-l1-0 rect {
  fill: var(--accent-orange);
}

.page-about .tree-l1-1 rect {
  fill: var(--accent-yellow);
}

.page-about .tree-l1-2 rect {
  fill: var(--accent-cyan);
}

.page-about .tree-l1-3 rect {
  fill: var(--accent-magenta);
}

.page-about .tree-l1-4 rect {
  fill: #00B0FF;
}

.page-about .tree-level-2 rect {
  fill: var(--bg-card);
  stroke: var(--border-light);
}

.page-about .tree-level-2 text {
  fill: var(--primary);
  font-family: var(--font-mono);
  font-size: 9px;
}

.page-about .tree-level-3 rect {
  fill: #171B29;
  stroke: var(--border-line);
  stroke-dasharray: 3 2;
}

.page-about .tree-level-3 text {
  fill: var(--text-dim);
  font-family: var(--font-mono);
  font-size: 8px;
}

.page-about .arch-matrix {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
}

.page-about .map-tile {
  position: relative;
  padding: 18px;
  border-radius: 8px;
  background: var(--bg-card);
  border: 1px solid var(--border-line);
  border-top: 4px solid currentColor;
  display: flex;
  flex-direction: column;
  gap: 10px;
  min-height: 180px;
  transition: transform 0.2s ease, box-shadow 0.2s ease, border-color 0.2s ease;
}

.page-about .map-tile:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-pop);
  border-color: var(--border-light);
}

.page-about .map-tile .tile-title {
  font-family: var(--font-head);
  font-weight: 900;
  font-size: 18px;
  color: var(--text-main);
  margin: 0;
}

.page-about .map-tile .tile-count {
  font-family: var(--font-mono);
  font-weight: 900;
  font-size: 28px;
  line-height: 1;
  color: currentColor;
}

.page-about .map-tile p {
  color: var(--text-dim);
  font-size: 13px;
  line-height: 1.6;
  margin: 0;
}

.page-about .map-tile .tag-blocks {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.page-about .map-tile .tag-block {
  font-family: var(--font-mono);
  font-size: 12px;
  padding: 3px 8px;
  background: #151A28;
  border: 1px solid var(--border-line);
  border-radius: 3px;
  color: var(--text-main);
}

.page-about .map-tile .tag-block[data-heat="3"] {
  background: var(--accent-yellow);
  color: #12151F;
  border-color: var(--accent-yellow);
}

.page-about .map-tile .tag-block[data-heat="2"] {
  border-color: currentColor;
}

.page-about .btn-sm {
  align-self: flex-start;
  margin-top: auto;
}

.page-about .btn-outline {
  display: inline-block;
  padding: 6px 12px;
  font-size: 13px;
  font-family: var(--font-body);
  font-weight: 700;
  color: var(--primary);
  background: transparent;
  border: 1px solid var(--primary);
  border-radius: 4px;
  text-decoration: none;
  transition: background 0.2s ease, color 0.2s ease, box-shadow 0.2s ease;
}

.page-about .btn-outline:hover {
  background: var(--primary);
  color: #12151F;
  box-shadow: var(--glow-primary);
}

.page-about .arch-note {
  display: grid;
  gap: 18px;
  align-items: start;
  margin-top: 20px;
}

.page-about .arch-art-wrap {
  position: relative;
  border: 1px solid var(--border-line);
  border-radius: 8px;
  overflow: hidden;
}

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

.page-about .tree-expand {
  border: 1px solid var(--border-line);
  border-radius: 8px;
  background: rgba(26, 30, 46, 0.72);
}

.page-about .tree-expand summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 14px 16px;
  cursor: pointer;
  list-style: none;
  font-family: var(--font-head);
  font-weight: 800;
  color: var(--text-main);
  transition: box-shadow 0.2s ease, border-color 0.2s ease;
}

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

.page-about .tree-expand summary::after {
  content: "+";
  font-family: var(--font-mono);
  font-size: 18px;
  color: var(--primary);
}

.page-about .tree-expand[open] summary {
  border-bottom: 1px solid var(--border-line);
  box-shadow: 0 0 0 1px rgba(0, 176, 255, 0.2);
}

.page-about .tree-expand[open] summary::after {
  content: "–";
}

.page-about .tree-expand-title {
  font-size: 15px;
}

.page-about .tree-expand-tag {
  font-size: 12px;
  color: var(--primary);
}

.page-about .tree-expand-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 18px;
  padding: 18px 16px;
}

.page-about .tree-expand-col h4 {
  font-family: var(--font-head);
  font-weight: 800;
  font-size: 14px;
  margin: 0 0 8px;
  color: var(--accent-yellow);
}

.page-about .tree-expand-col ul {
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .tree-expand-col li {
  font-size: 13px;
  color: var(--text-dim);
  line-height: 1.9;
  padding-left: 12px;
  position: relative;
}

.page-about .tree-expand-col li::before {
  content: "▪";
  position: absolute;
  left: 0;
  color: var(--primary);
}

.page-about .timeline-panel {
  position: relative;
  overflow: hidden;
  border: 1px solid var(--border-line);
  border-radius: 10px;
  background: rgba(42, 30, 58, 0.72);
}

.page-about .timeline-bg {
  position: absolute;
  inset: 0;
  z-index: 0;
  opacity: 0.35;
}

.page-about .timeline-bg img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center;
}

.page-about .timeline {
  position: relative;
  z-index: 1;
  list-style: none;
  margin: 0;
  padding: 18px;
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
}

.page-about .tl-item {
  position: relative;
  padding-left: 28px;
}

.page-about .tl-item::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 16px;
  bottom: -18px;
  width: 2px;
  background: var(--border-line);
}

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

.page-about .tl-marker {
  position: absolute;
  left: 0;
  top: 8px;
}

.page-about .tl-dot {
  display: block;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--accent-cyan);
  box-shadow: 0 0 12px currentColor;
}

.page-about .tl-dot[data-state="sync"] {
  background: var(--status-update);
  color: var(--status-update);
}

.page-about .tl-dot[data-state="log"] {
  background: var(--status-refill);
  color: var(--status-refill);
}

.page-about .tl-dot[data-state="batch"] {
  background: var(--status-new);
  color: var(--status-new);
}

.page-about .tl-dot[data-state="range"] {
  background: var(--status-fix);
  color: var(--status-fix);
}

.page-about .tl-dot[data-state="archive"] {
  background: var(--accent-cyan);
  color: var(--accent-cyan);
}

.page-about .tl-card {
  background: rgba(26, 30, 46, 0.92);
  border: 1px solid var(--border-line);
  border-left: 3px solid var(--primary);
  border-radius: 6px;
  padding: 14px;
  display: flex;
  flex-direction: column;
  gap: 6px;
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.page-about .tl-card:hover {
  border-color: var(--border-light);
  box-shadow: 0 4px 18px rgba(0, 0, 0, 0.35);
}

.page-about .tl-batch {
  font-size: 12px;
  color: var(--primary);
  letter-spacing: 0.08em;
}

.page-about .tl-card h3 {
  font-family: var(--font-head);
  font-weight: 800;
  font-size: 16px;
  margin: 0;
  color: var(--text-main);
}

.page-about .tl-card p {
  font-size: 13px;
  color: var(--text-dim);
  line-height: 1.6;
  margin: 0;
}

.page-about .tl-card .status-badge {
  align-self: flex-start;
  margin-top: 2px;
}

.page-about .status-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 12px;
  font-family: var(--font-mono);
  padding: 3px 9px;
  border-radius: 20px;
  background: rgba(77, 255, 77, 0.12);
  border: 1px solid var(--status-update);
  color: var(--status-update);
}

.page-about .status-update {
  background: rgba(77, 255, 77, 0.12);
  border-color: var(--status-update);
  color: var(--status-update);
}

.page-about .status-refill {
  background: rgba(255, 140, 26, 0.12);
  border-color: var(--status-refill);
  color: var(--status-refill);
}

.page-about .status-new {
  background: rgba(255, 210, 63, 0.12);
  border-color: var(--status-new);
  color: var(--status-new);
}

.page-about .status-fix {
  background: rgba(255, 46, 99, 0.12);
  border-color: var(--status-fix);
  color: var(--status-fix);
}

.page-about .guide-layout {
  display: grid;
  gap: 22px;
}

.page-about .steps-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 14px;
  grid-template-columns: 1fr;
}

.page-about .step-card {
  position: relative;
  border: 1px solid var(--border-line);
  border-radius: 8px;
  background: rgba(15, 46, 36, 0.55);
  padding: 20px;
  display: flex;
  flex-direction: column;
  gap: 8px;
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.page-about .step-card:hover {
  border-color: var(--primary);
  box-shadow: var(--glow-primary);
}

.page-about .step-num {
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--accent-cyan);
}

.page-about .step-icon {
  font-size: 34px;
  line-height: 1;
  color: var(--accent-yellow);
}

.page-about .step-card h3 {
  font-family: var(--font-head);
  font-weight: 900;
  font-size: 19px;
  margin: 0;
  color: var(--text-main);
}

.page-about .step-card p {
  color: var(--text-dim);
  font-size: 14px;
  line-height: 1.8;
  margin: 0;
}

.page-about .step-card .more-link {
  margin-top: auto;
  align-self: flex-start;
}

.page-about .guide-art {
  border: 1px solid var(--border-line);
  border-radius: 10px;
  overflow: hidden;
  background: #151A28;
  padding: 10px;
}

.page-about .guide-img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  border-radius: 6px;
}

.page-about .entry-block {
  border-bottom: 1px solid var(--border-line);
}

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

.page-about .entry-card {
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 20px;
  text-decoration: none;
  border-top: 4px solid transparent;
}

.page-about .entry-card:nth-child(1) {
  border-top-color: var(--accent-orange);
}

.page-about .entry-card:nth-child(2) {
  border-top-color: var(--accent-yellow);
}

.page-about .entry-card:nth-child(3) {
  border-top-color: var(--accent-cyan);
}

.page-about .entry-card h3 {
  font-family: var(--font-head);
  font-weight: 900;
  font-size: 20px;
  color: var(--text-main);
  margin: 0;
}

.page-about .entry-card p {
  color: var(--text-dim);
  font-size: 14px;
  line-height: 1.7;
  margin: 0;
}

.page-about .entry-card .more-link {
  margin-top: auto;
}

.page-about .entry-card .label-chip {
  align-self: flex-start;
}

.page-about .label-chip {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 12px;
  padding: 3px 8px;
  background: #151A28;
  border: 1px solid var(--border-line);
  border-radius: 3px;
  color: var(--text-dim);
}

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

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

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

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

@media (min-width: 768px) {
  .page-about .section-block {
    padding: 48px 0;
  }

  .page-about .arch-layout {
    grid-template-columns: 1.05fr 0.95fr;
    gap: 20px;
    align-items: start;
  }

  .page-about .arch-note {
    grid-template-columns: 220px 1fr;
  }

  .page-about .timeline {
    grid-template-columns: repeat(5, 1fr);
    gap: 12px;
    padding: 28px 22px;
  }

  .page-about .tl-item {
    padding-left: 0;
    padding-top: 18px;
  }

  .page-about .tl-item::before {
    left: 0;
    right: 0;
    top: 0;
    bottom: auto;
    width: auto;
    height: 2px;
    background: var(--border-line);
  }

  .page-about .tl-item:first-child::before {
    left: 50%;
  }

  .page-about .tl-item:last-child::before {
    right: 50%;
  }

  .page-about .tl-marker {
    left: 0;
    top: 0;
    right: 0;
    display: flex;
    justify-content: center;
  }

  .page-about .tl-dot {
    position: relative;
    top: -9px;
  }

  .page-about .tl-card {
    border-left: 1px solid var(--border-line);
    border-top: 3px solid var(--primary);
  }

  .page-about .guide-layout {
    grid-template-columns: 1.4fr 0.6fr;
    align-items: start;
  }

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

  .page-about .guide-art {
    padding: 12px;
  }

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

@media (min-width: 992px) {
  .page-about .stat-grid {
    grid-template-columns: repeat(5, 1fr);
  }

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

  .page-about .arch-matrix .map-tile {
    min-height: 200px;
  }

  .page-about .tree-expand-grid {
    grid-template-columns: repeat(5, 1fr);
  }
}

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

  .page-about .arch-matrix .map-tile {
    min-height: 230px;
  }

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