Dcat-Admin/resources/assets/sass/bootstrap-extended/mixins/_buttons.scss

@mixin button-square-variant($border) {
    @include border-radius($border);
}
@mixin button-round-variant($border) {
    @include border-radius($border);
}

// Button sizes
@mixin button-size($padding-y, $padding-x, $font-size, $line-height, $border-radius) {
  padding: $padding-y $padding-x;
  font-size: $font-size;
  // line-height: $line-height-base;
  @include border-radius($border-radius);
}