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

body {
    background: #111;
    overflow: hidden;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    font-family: 'Segoe UI', Arial, sans-serif;
}

canvas {
    display: block;
    image-rendering: auto;
    cursor: crosshair;
}