body {
    font-family: system-ui, sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    margin: 0;
    background: #f5f5f5;
}

.warp-container {
    text-align: center;
}

#photo {
    width: 300px;
    max-width: 80%;
    display: block;
    margin: 0 auto 20px;
    transform-origin: center;

    /* transition sur transform : l’image se déforme progressivement
       à chaque changement de matrice fait en JS */
    transition: transform 0.5s ease;
}

.controls button {
    padding: 8px 16px;
    margin: 0 6px;
    border-radius: 4px;
    border: none;
    cursor: pointer;
}

#btnStart {
    background: #c0392b;
    color: #fff;
}

#btnStop {
    background: #bdc3c7;
}