// Lightning Design System 2.29.1
.slds-checkbox-button {
  @include square($square-tappable);
}

// Deprecated selectors
@include deprecate("4.0.0", "Use slds-checkbox-button instead") {

  .slds-checkbox_add-button,
  .slds-checkbox--add-button {
    @include square($square-tappable);
    display: flex;
    align-items: center;
    justify-content: center;

    .slds-checkbox_faux,
    .slds-checkbox--faux {
      @include square($square-tappable-small);
    }
  }
}