body {
    margin: 0;
    padding: 20px;
    background-color: #1a1a1a;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: flex-start;
    box-sizing: border-box;
}

#gameCanvas {
    display: block;
    border: 2px solid #333;
}