Vertically centering Bootstrap modal window

Question

I would like to center my modal on the viewport (middle) I tried to add some css properties

 .modal { position: fixed; top:50%; left:50%; }   

Answer 1

this Works for me perfectly:

.modal {
text-align: center;
padding: 0!important;
}

.modal:before {
content: '';
display: inline-block;
height: 100%;
vertical-align: middle;
margin-right: -4px;
}

.modal-dialog {
display: inline-block;
text-align: left;
vertical-align: middle;
}

complete Demo URL : https://codepen.io/dimbslmh/full/mKfCc