/* Desktop background */
body {
background: url('https://example.com/desktop-bg.jpg') no-repeat center center fixed;
background-size: cover;
}
/* Mobile background */
@media (max-width: 767px) {
body {
background: url('https://example.com/mobile-bg.jpg') no-repeat center center fixed;
background-size: cover;
}
}
[id="H0789932467"].page {
background-color: #000000;
}