body{
font-family:Arial;
background:#f2f2f2;
}

.container{
width:80%;
max-width:900px;
margin:30px auto;
background:#fff;
padding:20px;
border-radius:10px;
box-shadow:0 0 10px #ccc;
text-align:center;
}

#preview{
max-width:300px;
display:none;
margin-top:20px;
}

textarea{
width:100%;
height:250px;
padding:10px;
font-family:monospace;
font-size:13px;
}

button{
padding:10px 20px;
margin:10px;
cursor:pointer;
}