Modal to slide up from bottom in Bootstrap 4

Question

I'm trying to set up a modal to slide up from bottom but there's no tutorial for Bootstrap 4 that actually works. Here's an attempt:

JSFiddle DEMO

HTML

<button type="submit" class="btn btn-block btn-default footer__btn" data-toggle="modal" data-target="#myModal2"> Open Modal</button>
<div class="modal fade" id="myModal2" tabindex="-1" role="dialog" aria-labelledby="myModalLabel">
  <div class="modal-dialog" role="document">
    <div class="modal-content">
      <div class="modal-body">
        Body of the modal.
      </div>
      <div class="modal-footer">
        <button type="button" class="btn btn-default" data-dismiss="modal">Close</button>
      </div>
    </div>
  </div>
</div>

CSS

.modal.fade .modal-dialog {
    -webkit-transform: translate(0,100%);
    -ms-transform: translate(0,100%);
    -o-transform: translate(0,100%);
    transform: translate(0,100%);
}

Answer 1

Since you don't want to add another framework on top of Bootstrap 4, I just changed the CSS :

.animate-bottom {
  position: relative;
  animation: animatebottom 0.4s;
}

@keyframes animatebottom {
  from {
    bottom: -300px;
    opacity: 0;
  }

  to {
    bottom: 0;
    opacity: 1;
  }
}

Then just add the class animate-bottom after the modal-content in the <div>

<button type="submit" class="btn btn-block btn-default footer__btn" data-toggle="modal" data-target="#myModal2"> Open Modal</button>
<div class="modal fade animate" id="myModal2" tabindex="-1" role="dialog" aria-labelledby="myModalLabel">
  <div class="modal-dialog" role="document">
    <div class="modal-content animate-bottom"> <!-- Here you have the juicy hahah -->
      <div class="modal-header">
        <button type="button" class="close" data-dismiss="modal" aria-label="Close"><span aria-hidden="true">&times;</span></button>
        <h4 class="modal-title" id="myModalLabel"> ABOUT </h4>
      </div>
      <div class="modal-body">
        CONTEÚDO
      </div>
      <div class="modal-footer">
        <button type="button" class="btn btn-default" data-dismiss="modal">Close</button>

      </div>
    </div>
  </div>
</div>

Here's the Fiddle :

JSFiddle DEMO

Make sure you make it cross-browser, but this is just the base of the animation, hope it'll fit your request.