.modal {
    background-color: rgba(0, 0, 0, .8);
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
}

.modal-content {
  margin: 0 auto;
  margin-top: 5%;
  max-width: 900px;
  background-color: #eee;
  padding: 0;
  box-shadow: 0 0 2px #fff;  
}

.modal-header, .modal-body, .modal-footer {
    padding: 10px;
}

.modal-header {
    background-color: #ccc;
}

.modal-footer {
    background-color: #ccc;
}
#msg_gravar {
    text-align:center;
    width: 100vw;
    height: 100vh;
    
}