.fade { opacity: 0; @include transition($transition-fade); &.show { opacity: 1; } } .collapse { display: none; &.show { display: block; } } tr { &.collapse.show { display: table-row; } } tbody { &.collapse.show { display: table-row-group; } } .collapsing { position: relative; height: 0; overflow: hidden; @include transition($transition-collapse); }