body,
html {
    margin: 0;
    height: 100%;
    background: #41A2FF;
    background-size: 100% 100%;
}

.center {
    margin: 0;
    position: absolute;
    top: 50%;
    left: 50%;
    -ms-transform: translate(-50%, -50%);
    transform: translate(-50%, -50%);
}

#canvas {
    height: 50vh;
}