.puzzle-tile {
    box-sizing: border-box;
    border: 1px solid #fff;
    cursor: pointer;
    transition: all 0.2s ease;
}

@keyframes fadein {
    from { opacity: 0; transform: translate(-50%, -60%); }
    to { opacity: 1; transform: translate(-50%, -50%); }
}

@media screen and (max-width: 500px) {
    #slide-puzzle-container {
        width: 90vw !important;
        height: auto !important;
    }
}