packages/bolt/app/styles/z-index.scss

$zIndexMax: 999;

.z-logo {
  z-index: $zIndexMax - 1;
}

.z-sidebar {
  z-index: $zIndexMax - 2;
}

.z-prompt {
  z-index: 2;
}

.z-workbench {
  z-index: 3;
}

.z-max {
  z-index: $zIndexMax;
}