html,
body {
    background-color: #333333;
    color: #ffffff;
    font-family: Helvetica, Arial, sans-serif;
    margin: 0;
    padding: 0;
    font-size: 14px;
}

#canvas {
    position: absolute;
    left: 0;
    right: 0;
    top: 0;
    bottom: 0;
    margin: auto;
}