.fade {

@include transition($transition-fade);

&:not(.show) {
  opacity: 0;
}

}

// scss-docs-start collapse-classes .collapse {

&:not(.show) {
  display: none;
}

}

.collapsing {

height: 0;
overflow: hidden;
@include transition($transition-collapse);

} // scss-docs-end collapse-classes