body{
    background-image: url("marvel image.jpg");
    background-repeat: no-repeat;
    background-attachment: fixed;
    background-position: center;
    background-size: cover;
}
h1{
    text-align: center;
    background: linear-gradient(to right, skyblue, white  );
    background-repeat: no-repeat;
    background-attachment: fixed;
}