.heart {
    width: 200px;
    height: 200px;
    background-image: url('/images/favicon.png');
    background-size: cover;
    animation: pulse 1s infinite;
    margin: 0 auto;
}

@keyframes pulse {
    0% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.1);
    }
    100% {
        transform: scale(1);
    }
}