.alert-variant(@background-color; @border-color; @text-color; @alert-icon) {
  position: relative;
  border-color: @border-color;
  background-color: @background-color;
  color: @text-color;
  &:before {
    border-color: @border-color;
    color: @border-color;
    content: @alert-icon;
  }
}