.modal {
    position: fixed;
    z-index: 99;
    top: 0;
    left: 0;
    bottom: 0;
    right: 0;
    display: flex;
    justify-content: center;
    align-items: center;
    background: rgba(127, 127, 127, .5);
}

.modal-content {
    background-color: #fff;
    max-width: 600px;
    border: solid 1px #ccc;
    padding: 20px;
}

.modal button {
    margin: 3px;
}