.line(@num: 1) {
    overflow: hidden;
    text-overflow: ellipsis;
}
  
.line(@num: 1) when(@num = 1 ){
    white-space: nowrap;
}

.line(@num: 1) when not(@num = 1 ){
    display: -webkit-box;
    -webkit-line-clamp: $num;
    -webkit-box-orient: vertical;
}