body {
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

#canvas {
    max-width: 100%;
    height: auto;
    object-fit: contain;
}

.checkerboard {
    background-image:
        linear-gradient(45deg, #ccc 25%, transparent 25%), 
        linear-gradient(135deg, #ccc 25%, transparent 25%),
        linear-gradient(45deg, transparent 75%, #ccc 75%),
        linear-gradient(135deg, transparent 75%, #ccc 75%);
    background-size: 20px 20px;
    background-position: 0 0, 10px 0, 10px -10px, 0px 10px;
}