#simple-popup-overlay {
    display: none;
    position: fixed;
    top: 0; left: 0;
    width: 100%; height: 100%;
    background: rgba(0,0,0,0.6);
    z-index: 9998;
}

#simple-popup {
    display: none;
    position: fixed;
    top: 50%; left: 50%;
    transform: translate(-50%, -50%);
    background: #fff;
    padding: 20px;
    max-width: 400px;
    width: 90%;
    z-index: 9999;
    border-radius: 10px;
    box-shadow: 0 4px 15px rgba(0,0,0,0.3);
}

#simple-popup-close {
    float: right;
    cursor: pointer;
    font-size: 20px;
}