.popup {
    position: fixed;
    z-index: 9;
    top: 50%;
    left: 50%;
    transform: translateX(-50%) translateY(-50%);
    background-color: rgba(0, 0, 0, .5);
    color: #fff;
    padding: 6px 11px;
    font-size: 12px;
    border-radius: 5px;
    opacity: 0;
    animation: showPopup .3s forwards;
}

@keyframes showPopup {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}