#discountPopup {
    position: fixed;
    top:0; left:0;
    width:100%; height:100%;
    background: rgba(0,0,0,0.7);
    display:flex;
    justify-content:center;
    align-items:center;
    z-index:99999;
}
.popup-box {
    background:#fff;
    padding:25px;
    border-radius:10px;
    text-align:center;
    width: 300px;
}