.overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.7);
    justify-content: center;
    align-items: center;
    z-index: 9999;
}

.popup {
    background-color: #81b64c;
    color: #fff;
    padding: 20px;
    border-radius: 5px;
    box-shadow: 0px 0px 10px 0px rgba(0,0,0,0.5);
    text-align: center;
}