.demo-btn-margin .btn{margin-bottom:6px}
.modal-all {
  display: none;
  background: rgba(20, 20, 20, 0.3);
  position: fixed;
  width: 100%;
  height: 100%;
  top: 0px;
  left: 0px;
  right: 0px;
  bottom: 0px;
  align-items: center;
  align-content: center;
  justify-content: center;
}

.modal {
  width: 200px;
  height: 120px;
  background: white;
  border: 1px solid silver;
  padding: 15px;
}