body{
    background:#0a0f2c;
    font-family:Arial;
    color:#fff;
}

/* Device Frame */
.device-frame{
    margin:auto;
    background:#000;
    border-radius:40px;
    padding:20px;
    box-shadow:0 0 40px #000;
    transition:0.4s;
}

iframe{
    width:100%;
    height:100%;
    border:none;
    border-radius:25px;
}

/* Sizes */
.mobile{ width:320px; height:600px;}
.tablet{ width:768px; height:800px;}
.desktop{ width:100%; height:700px; border-radius:10px;}

.controls button{
    margin:5px;
}