body {
     margin:0 auto;
     max-width: 450px;
     max-height: 450px;
}
#container{
    width: 380px;
    min-height: 400px;
    margin: 50% auto;
    text-align: center;
    background: #2c3e50;
    color:#ecf0f1;
    font: bold 20px Futura, sans-serif;
    
}

.titlebar{
    text-align: center;
    font: bold 16px/44px sans-serif;
    margin: 0;
    background: gray;
}

#titlebar-dark{
    text-align: center;
    font: bold 16px/44px sans-serif;
    margin: 0;
    color: white;
    background: #e67e22;
}

 button{
     font: bold 20px Futura, sans-serif;
     color: #8e44ad;
     background: #ecf0f1;
     border: none;
     border-radius: 6px;
     padding: 5px 20px;
     margin: 5px;
 }