.spacer-half {
  height: var(--height, 64px);
}
@media (max-width: 991.98px) {
  .spacer-half {
    height: calc(var(--height, 64px) / 2);
  }
}

.block-editor-block-list__block.is-selected .spacer-half {
  background: rgba(0, 0, 0, 0.1);
}