* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

#deviceready {
    position: relative;
    height: 1080px;
    background: black;
    text-align: center
}

img {
    position: absolute;
    left: 50%;
    top: 20%;
    transform: translate(-50%, -50%);
}

a {
    text-decoration: none;
}

.btn {
    display: inline-block;
    width: 150px;
    color: whitesmoke;
    border: 2px solid whitesmoke;
    text-align: center;
    margin-top: 20%;
}

.btn-focus {
    border: 2px solid yellow;
    color: yellow;
}