:root { color-scheme: light dark; }
* { box-sizing: border-box; }
body { margin: 0; font: 15px/1.5 system-ui, sans-serif; }

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  padding: 16px 24px;
  background: Canvas;
  border-bottom: 1px solid #8884;
}
.header-actions { display: flex; justify-content: flex-end; gap: 12px; margin-bottom: 4px; }
.site-header h1 { margin: 0 0 4px; font-size: 22px; }
.repo-link { display: inline-flex; align-items: center; gap: 6px; color: inherit; text-decoration: none; font-size: 13px; opacity: 0.8; }
.repo-link:hover { opacity: 1; }
.repo-link svg { width: 18px; height: 18px; }
.tagline { margin: 0 0 10px; opacity: 0.75; }

#toc {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 4px 12px;
}
#toc a {
  font-size: 13px;
  color: inherit;
  text-decoration: none;
  padding: 3px 6px;
  border-radius: 4px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
#toc a:hover { background: #4b7bec22; }

main {
  padding: 16px 24px 32px;
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.example {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  align-items: stretch; /* left source and right diagram share the row's height */
}
.example:target .panel { border-color: #4b7bec; }

.panel { border: 1px solid #8884; border-radius: 8px; padding: 12px 14px; min-width: 0; }
.panel h2 { margin: 0 0 6px; font-size: 17px; }
.panel .num { color: #4b7bec; font-variant-numeric: tabular-nums; margin-right: 4px; }
.explanation { margin: 0 0 10px; opacity: 0.85; }
.panel pre { overflow: auto; background: #8881; padding: 10px; border-radius: 6px; margin: 0; }

.panel.output { display: flex; align-items: center; justify-content: center; overflow: auto; }
.panel.output .diagram { max-width: 100%; }
.panel.output svg { max-width: 100%; height: auto; }

.error { color: #c0392b; white-space: pre-wrap; }

@media (max-width: 900px) {
  #toc { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .example { grid-template-columns: 1fr; }
}