body {
    padding: 0;
    margin: 0;
    height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
}

#challenge8 .coracao {
    position: relative;
    width: 200px;
    height: 150px;
    background-color: transparent;
    animation: coracaoBatendo 5s infinite linear;
}

#challenge8 .coracao .parte-coracao {
    position: absolute;
    width: 45%;
    height: 100%;
    border-radius: 60px 60px 0 0;
    background-color: #ff9999;
}

#challenge8 .parte-coracao:nth-child(1) {
    transform: rotate(-45deg)
}

#challenge8 .parte-coracao:nth-child(2) {
    transform: rotate(45deg);
    right: 34%;
}

@keyframes coracaoBatendo {
    0%, 40%, 100% {
        transform: scale(1)
    }
    10%, 30%, 50%, 70%, 90% {
        transform: scale(1.1)
    }
    20%, 60% {
        transform: scale(1.08)
    }
    80% {
        transform: scale(1.05)
    }
}