body {
    font-family: Arial, sans-serif;
    background-color: #45a049 !important;
    background-image: url(../img/conversor-de-unidades.jpg);
    background-repeat: repeat;
    background-size: cover;
    background-blend-mode: multiply;
}

.container {
    border-radius: 0.25rem;
}

@keyframes pulse {
    0%, 100% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.3);
    }
}

#heart {
    display: inline-block;
    animation: pulse 0.6s infinite;
    color: red;
}