body {
    background-image: url('grass.jpg');
    background-repeat: no-repeat;
    background-attachment: fixed;
    background-size: 100% 100%;
}

main {
    text-align: center;
}

#buttons {
    border: 1px solid black;
    background: white;
    padding: 5px;
    margin: 0 35% auto;
}