flags/less/flag-icon-base.less

.flag-icon-background {
  background-size: contain;
  background-position: 50%;
  background-repeat: no-repeat;
}

.flag-icon {
  .flag-icon-background;
  position: relative;
  display: inline-block;
  width: unit(4 / 3, em);
  line-height: 1em;
  &:before {
    content: "\00a0";
  }
  &.flag-icon-squared {
    width: 1em;
  }
}

.flag-icon(@country) {
  .flag-icon-@{country} {
    background-image: ~"url(@{flag-icon-css-path}@{flag-icon-rect-path}/@{country}.svg)";
    &.flag-icon-squared {
      background-image: ~"url(@{flag-icon-css-path}@{flag-icon-square-path}/@{country}.svg)";
    }
  }
}