body {
    display: flex; 
    justify-content: center; 
    align-items: center; 
    min-height: 100vh; 
    background-color: azure;
    /* Use public/bg.png if present (served at /bg.png). Falls back to azure. */
    background-image: url('/rbbg.jpg');
    background-repeat: no-repeat;
    background-position: center center;
    background-size: cover;
}