.heart {
    background-color: red;
    display: inline-block;
    height: 50px;
    margin: 0 10px;
    position: relative;
    top: 0;
    transform: rotate(-45deg);
    position: absolute; 
    left: 45%; top: 45%;
    width: 50px;
  }
  
  .heart:before,
  .heart:after {
    content: "";
    background-color: red;
    border-radius: 50%;
    height: 50px;
    position: absolute;
    width: 50px;
  }
  
  .heart:before {
    top: -25px;
    left: 0;
  }
  
  .heart:after {
    left: 25px;
    top: 0;
  }

  @keyframes heartbeat {
    0% {
      transform: scale( 1 );    
    }
    20% {
      transform: scale( 1.25 ) 
        translateX(5%) 
        translateY(5%);
    } 
    40% {
      transform: scale( 1.5 ) 
        translateX(9%) 
        translateY(10%);
    }
  }

  .heart {
    animation: heartbeat 1s infinite; // our heart has infinite heartbeat :)
    ...
  }