Font-Awesome/less/mixins.less

// Mixins
// --------------------------

.fa-icon-rotate(@degrees, @rotation) {
  filter: progid:DXImageTransform.Microsoft.BasicImage(rotation=@rotation);
  -webkit-transform: rotate(@degrees);
     -moz-transform: rotate(@degrees);
      -ms-transform: rotate(@degrees);
       -o-transform: rotate(@degrees);
          transform: rotate(@degrees);
}

.fa-icon-flip(@horiz, @vert) {
  -webkit-transform: scale(@horiz, @vert);
     -moz-transform: scale(@horiz, @vert);
      -ms-transform: scale(@horiz, @vert);
       -o-transform: scale(@horiz, @vert);
          transform: scale(@horiz, @vert);
}

.fa-icon-stack(@width: 2em, @height: 2em, @top-font-size: 1em, @base-font-size: 2em) {
  .@{fa-css-prefix}-stack {
    position: relative;
    display: inline-block;
    width: @width;
    height: @height;
    line-height: @width;
    vertical-align: -35%;
    .@{fa-css-prefix} {
      position: absolute;
      display: block;
      width: 100%;
      height: 100%;
      font-size: @top-font-size;
      line-height: inherit;
      text-align: center;
    }
    .@{fa-css-prefix}-stack-base {
      font-size: @base-font-size;
    }
  }
}