style.css

*{
    padding: 0;
    margin: 0;
    box-sizing: border-box;
}


.wrapper{
    height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
}
#heart{
    display: inline-block;
    margin: 100px;
    position: relative;
    animation: xx 1000ms linear infinite alternate paused;
    
}
@keyframes xx{
    0%{
        transform: scale(1)
    }
    100%{
        transform: scale(1.5)
    }
}

#heart>div{
    height: 50px;
    width: 50px;
    position: absolute;
    background:red;
}
.bottom{
    transform: rotate(45deg);
}
.left{bottom: 100%;
    left: -50px;
    transform: rotate(45deg) translateX(31px);
    border-radius: 50% 0 0 50%;
 
}

.right{
    bottom: 100%;
    left: 50px;transform: rotate(45deg) translateY(31px);
    border-radius: 50% 50% 0 0;
}
#start{
    margin-left: 50px;
}