Bootstrap media queries

media-queries.less

@media(max-width:767px){}                         // xs
@media(min-width:768px) and (max-width:991px){}   // sm
@media(min-width:992px) and (max-width:1199px){}  // md
@media(min-width:1200px){}                        // lg

@media(max-width:991px){}                         // xs - sm 
@media(max-width:1199px){}                        // xs - md 
@media(min-width:768px) and (max-width:1199px){}  // sm - md
@media(min-width:768px){}                         // sm - lg
@media(min-width:992px){}                         // md - lg