body {
    margin: 0;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    height: 100vh;
    background-color: #f0f0f0;
}

.toolbar {
    position: fixed;
    top: 10px;
    display: flex;
    gap: 10px;
}

canvas {
    border: 1px solid black;
    cursor: crosshair;
}