body:has(#diagram-builder) {
  background: light-dark(#f9fafb, #0a0a0a);
}

@media (min-width: 761px) {
  body:has(#diagram-builder) > header {
    /* Keep the navigation aligned while its background spans the full bar. */
    margin-left: 0;
    padding-left: calc(var(--outer-gutter) + var(--sidebar-width) + 2.5rem);
  }
}

body:has(#diagram-builder) .site-footer {
  background: transparent;
}