.fade {
  opacity: 0;
  -webkit-transition: opacity 0.15s linear;
  -moz-transition: opacity 0.15s linear;
  -o-transition: opacity 0.15s linear;
  transition: opacity 0.15s linear;
}
.fade.in {
  opacity: 1;
}
/*.collapse {
  position: relative;
  height: 0;
  overflow: hidden;
  .transition(height .35s ease);
  &.in {
    height: auto;
  }
}*/
.collapse {
  position: relative;
  height: 0;
  overflow: hidden;
  -webkit-transition: height 0.35s ease;
  -moz-transition: height 0.35s ease;
  -o-transition: height 0.35s ease;
  transition: height 0.35s ease;
}
.collapse.in {
  height: auto;
}