.popup-window {
    position: fixed;
    top: 0;
    left: 0;
    margin: 0;
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: rgba(0,0,0,.8);
}
.popup-window input, .popup-window select {
    width: auto;
}
.popup-window > .pane > div {
    display: flex;
    align-items: center;
    justify-content: space-around;
}