body {
    text-align: center;
    font-size: 12px;
    font-family: Trebuchet Ms, Arial;
}
h1 {
    color: #333;
}

#koan {
    margin: 10px;
    background: #555;
    color: #fff;
    width: 400px;
    font-size: 1.1em;
    text-align: center;
}

#koan_title {
    font-size: 18px;
}