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

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

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