body {
    margin: 0px;
    overflow: hidden;
}

#canvas {
    position: absolute;
    width: 100%;
    height: 100%;
    background: #000;
}

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

.alt-message {
    display: none;
}

.error > * {
    display: none;
}

.error > .alt-message {
    display: block;
}