.btn-numpad {
    @apply bg-stone-200 text-stone-900 font-bold text-2xl p-3 rounded shadow hover:bg-white active:bg-stone-300 transition-colors border-b-4 border-stone-400 active:border-b-0 active:translate-y-1;
}

/* High-quality claymation background */
body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image: url('clay_background.png');
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    background-attachment: fixed;
    z-index: -1;
}