body {
        background-color: whitesmoke;
        font-family: Tahoma, Verdana, Segoe, sans-serif;
        margin: 10px;
    }
    
h1 {
    font-size: 1.8em;
    margin-bottom: 20px;
    }

h2 {
    font-size: 1.6em;
}
    
.main {
    margin: auto;
    max-width: 680px;
    padding: 10px 20px 10px 20px;
    background-color:#fff;
    border-radius: 0.25em;
    box-shadow: 0 .125em .25em rgba(0,0,0,.075)!important;
    }
    
.hint-hidden {
    display: none;
    }
    
.footer {
    text-align: center;
    font-size: 0.7em;
    color: gray;
}