html {
    background: url('background.png');
}


#main {
    background-color: rgba(255,255,255,0.7);
    text-align: center;
    width: 65%;
    margin: 0 auto;
    border-radius:10px;
    padding:10px;
}

img {
    margin:20px;
}

ul {
    text-align:left;
    margin-left:100px;
}