html, body {
    margin: 0;
    padding: 0;
    height: 100%;
    overflow: hidden;
}

/* iOS background */
.ios-bg {
    width: 100%;
    height: 100%;
    background-image: url("https://i.imgur.com/IeYaUyf.jpeg");
    background-size: cover;
    background-position: center;
    display: none;
}

/* Android background */
.android-bg {
    width: 100%;
    height: 100%;
    background-image: url("https://i.imgur.com/IeYaUyf.jpeg");
    background-size: cover;
    background-position: center;
    display: none;
}