I haven't done much with this, but I just did a quick test and you can add an animation to the .ia_popup class and it will animate the popup "window" itself.
For example I added the theme/app/popup.css into my custom theme with the below code and it animates the popup itself.
@keyframes popUp_fadeIn {
0% {
transform: scale(0);
opacity: 0.0;
}
60% {
transform: scale(1.1);
}
80% {
transform: scale(0.9);
opacity: 1;
}
100% {
transform: scale(1);
opacity: 1;
}
}
@-webkit-keyframes popUp_fadeIn {
0% {
-webkit-transform: scale(0);
opacity: 0.0;
}
60% {
-webkit-transform: scale(1.1);
}
80% {
-webkit-transform: scale(0.9);
opacity: 1;
}
100% {
-webkit-transform: scale(1);
opacity: 1;
}
}
.ia_popup {
animation-name: popUp_fadeIn;
-webkit-animation-name: popUp_fadeIn;
animation-duration: 0.5s;
-webkit-animation-duration: 0.5s;
animation-timing-function: ease-in-out;
-webkit-animation-timing-function: ease-in-out;
}