core mixins

mixins.less

.transition(@time) {
  -webkit-transition: all @time;
  -moz-transition: all @time;
  -o-transition: all @time;
  transition: all @time;
}

.line-height(@px) {
  line-height: @px;
  @rem: unit(@px, rem);
  line-height: @rem / 16px;
}

.font-size(@px) {
  font-size: @px;
  @rem: unit(@px, rem);
  font-size: @rem / 16;
}