.block-editor-block-list__block.is-selected .spacer-half {
  background: rgba(255, 255, 255, 0.1);
}

.spacer-half {
  height: var(--height, 50px);
}
@media (max-width: 991.98px) {
  .spacer-half {
    height: calc(var(--height, 50px) / 2);
  }
}