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

canvas {
    border: 1px solid #ccc;
    background-color: #fff;
}

.toolbar {
    margin-bottom: 10px;
}