#spp-popup {
    display: none;
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background: white;
    border: 1px solid #ccc;
    box-shadow: 0 2px 10px rgba(0,0,0,0.2);
    padding: 20px;
    z-index: 1000;
}
#spp-popup.show {
    display: block;
}
#spp-popup-close {
    position: absolute;
    top: 5px;
    right: 10px;
    cursor: pointer;
    font-size: 18px;
}