body {
    color: #ecf0f1;
    background-color: #2c3e50;
}

#start, #game-over {
    font-family: Arial, Helvetica, sans-serif;
    color: #ecf0f1;
    padding:20px;
    position: fixed;
    top: 50%;
    left: 50%;
    margin-top: -50px;
    margin-left: -100px;
    width:200px;
    text-align: center;
}

#start a, #game-over a {
    border: 1px solid #ecf0f1;
    color: #ecf0f1;
    text-decoration:none;
    padding: 10px;
    border-radius: 5px;
    cursor: pointer;
    display: block;
    width: 200px;
    text-align: center;
}

#start a:hover, #game-over a:hover { background-color:#ecf0f1; color:#2c3e50; }