body {
    background: #222;
    color: #fff;
    text-align: center;
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
}

h1 {
    margin-top: 30px;
    margin-bottom: 10px;
}

#modeToggle {
    margin-bottom: 5px;
    padding: 10px 18px;
    font-size: 16px;
    background: #333;
    color: #fff;
    border: none;
    border-radius: 7px;
    cursor: pointer;
}

#modeToggle:hover {
    background: #444;
}

#modeText {
    margin-top: 0;
    margin-bottom: 10px;
    font-size: 15px;
    color: #aaa;
}

#pong {
    background: #111;
    display: block;
    margin: 0 auto;
    border: 3px solid #fff;
    box-shadow: 0 0 30px #000;
}