body {
    background-image: url('black.jpg');
      background-size: cover;
      background-repeat: no-repeat;
      background-position: center;
}
h1 {
    color: aliceblue;
    text-align: center;
    margin-top: 50px;
    position: relative;
    font-family: Archivo;
}
#example {
    color: aliceblue;
    font-size: x-large;
    text-align: center;
    margin-top: 50px;
    font-family: Archivo;
}
img {
    display: block;
    margin-left: auto;
    margin-right: auto;
}