//// Component animations// -------------------------------------------------- // Heads up!//// We don't use the `.opacity()` mixin here since it causes a bug with text// fields in IE7-8. Source: https://github.com/twitter/bootstrap/pull/3552. .fade { opacity: 0; @include transition(opacity .15s linear); &.in { opacity: 1; }} .collapse { display: none; &.in { display: block; }}.collapsing { position: relative; height: 0; overflow: hidden; @include transition(height .35s ease);}