.user-select(@select: all) {
    -webkit-user-select: @select;
     -khtml-user-select: @select;
       -moz-user-select: @select;
         -o-user-select: @select;
            user-select: @select;
}

.transform(@transform: none) {
    -webkit-transform: @transform;
       -moz-transform: @transform;
         -o-transform: @transform;
            transform: @transform;
}

.transition(@transition: none) {
    -webkit-transition: @transition;
       -moz-transition: @transition;
         -o-transition: @transition;
            transition: @transition;
}

.border-radius(@radius: 0px) {
    -webkit-border-radius: @radius;
       -moz-border-radius: @radius;
         -o-border-radius: @radius;
            border-radius: @radius;
}

.box-shadow(@shadow: none) {
    -webkit-box-shadow: @shadow;
       -moz-box-shadow: @shadow;
         -o-box-shadow: @shadow;
            box-shadow: @shadow;
}

.box-sizing(@box-sizing: none) {
    -webkit-box-sizing: @box-sizing;
       -moz-box-sizing: @box-sizing;
         -o-box-sizing: @box-sizing;
            box-sizing: @box-sizing;
}

.backface-visibility(@backface-visibility: hidden) {
    -webkit-backface-visibility: @backface-visibility;
       -moz-backface-visibility: @backface-visibility;
        -ms-backface-visibility: @backface-visibility;
}

.font-size(@font-size: 16) {
    @rem: (@font-size / 16);
    font-size: @font-size * 1px;
    font-size: ~"@{rem}rem";
}