body {
    background: #202028;
    color: #fff;
    font-family: sans-serif;
    font-size: 2em;
    text-align: center;
}
canvas {
    border: solid .2em #fff;
    height: 90vh;
}
button {
    background: #fff;
    border: none;
    border-radius: 0.3em;
    color: #202028;
    cursor: pointer;
    font-size: 0.7em;
    margin-top: 0.4em;
    padding: 0.4em 0.8em;
}
button:active {
    transform: translateY(1px);
}