//

 // 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;

   .transition(opacity .15s linear);

   &.in {

     opacity: 1;

   }

 }

 .collapse {

   display: none;

   &.in {

     display: block;

   }

 }

 .collapsing {

   position: relative;

   height: 0;

   overflow: hidden;

   .transition(height .35s ease);

 }