body {
    margin: 0;
    padding: 0;
    background-color: #0c1618;
    display: flex;
    flex-direction: column; /* Üstten alta doğru diz */
    align-items: center;    /* Ortala */
}
canvas {
    display: block;
    position: fixed;
    top: 0; left: 0;
    z-index: -1; /* Arkada kalsın */
}