body {
 background:#111;
 color:#eee;
 font-family:Arial,sans-serif;
}

.container {
 padding:20px;
}

.card {
 background:#222;
 border-radius:15px;
 padding:15px;
 margin-bottom:15px;
}

button {
 width:100%;
 padding:15px;
 margin-top:10px;
 border-radius:10px;
 border:none;
 font-size:16px;
}