.collapse.in {
  height: auto; }

.collapse {
  -webkit-transition: height 0.35s ease;
  -moz-transition: height 0.35s ease;
  -ms-transition: height 0.35s ease;
  -o-transition: height 0.35s ease;
  transition: height 0.35s ease;
  position: relative;
  overflow: hidden;
  height: 0; }