body {
    background-color: #121212;
    color: white;
    font-family: sans-serif;
    text-align: center;
    padding-top: 50px;
}
.btn {
    display: block;
    width: 200px;
    margin: 10px auto;
    padding: 15px;
    background: #333;
    color: white;
    text-decoration: none;
    border-radius: 25px;
    border: 1px solid #444;
}