* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font: 13px Roboto, sans-serif;
    background-color: #212121;
}

canvas {
    background-color: #424242;
    position: absolute;
    top: 0;
    bottom: 0;
    left: 0;
    right: 0;
    height: 100vh;
    margin: auto;
}