.tab-content {
  display: block;
  position: relative;
  opacity: 0;
  height: 0;
  overflow: hidden;
  visibility: hidden;

  -webkit-transition: .3s ease-in-out;
  -o-transition: .3s ease-in-out;
  transition: .3s ease-in-out;

  -webkit-transition-property: opacity, visibility;
  -o-transition-property: opacity, visibility;
  transition-property: opacity, visibility;
}

.tab-content.active {
  opacity: 1;
  height: auto;
  overflow: visible;
  visibility: visible;
}