#alertMessage {
    position: fixed;
    top: 30%;
    left: 20%;
    right: 20%;
    padding: 20px 30px;
    background: rgba(0, 0, 0, 0.6);
    color: #ffffff;
    font-size: 20px;
    text-align: center;
    z-index: 999;
    display: none;
}