body::before {
    content: "";
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
    background-image: url('background.jpg');
    background-repeat: repeat;
    filter: blur(5px);
  }

div.error {
    text-align: center;
    font-size: xx-large;
    color: red;
}

#back {
    text-align: center;
    margin-top: 200px;

}

#copyright {
    text-align: center;
    margin-top: 400px;
    padding: 20px;
    color: rgb(0, 0, 0);
}