#ajax-add-to-cart-popup.hidden {
    display: none;
}

#ajax-add-to-cart-popup {
    position: fixed;
    top: 0; left: 0; right: 0; bottom: 0;
    background: rgba(0,0,0,0.5);
    z-index: 9999;
}

#ajax-add-to-cart-popup .popup-content {
    background: #fff;
    padding: 30px;
    max-width: 400px;
    margin: 100px auto;
    text-align: center;
    position: relative;
    border-radius: 8px;
}

#ajax-add-to-cart-popup .close-popup {
    position: absolute;
    top: 10px; right: 10px;
    cursor: pointer;
    font-size: 20px;
}