/* Centered viewport container so canvas and key icons are auto-centered */
#viewport {
    position: absolute;
    left: 50%;
    top: 50%;
    width: 866px;
    height: 480px;
    transform: translate(-50%, -50%);
    pointer-events: none; /* let interactive elements stay global */
    z-index: 50;
}
canvas {
    display: block;
    cursor: none;
    width: 866px;
    height: 480px;
    /* make canvas fill the centered viewport */
    position: absolute;
    left: 0;
    top: 0;
    pointer-events: auto; /* allow pointer lock / clicks on the canvas */
}