html {
    background: url('/../images/b1.jpg') no-repeat center center fixed;
    -webkit-background-size: cover;
    -moz-background-size: cover;
    -o-background-size: cover;
    background-size: cover;
}
.date {margin: 50px; color: #ccc; font-size: 2em}
#date {font-size: 5em}
@media (max-width: 1080px) {
    #date {font-size: 4em}
}