fbmessenger.css

.fbmessenger{
  position:fixed;
  bottom:15px;
  right:15px;
  z-index:15;
}

.fbmessenger img{
  width:50px;
 filter: drop-shadow(2px 6px 4px rgba(0,0,0,.3));
-webkit-filter: drop-shadow(2px 6px 4px rgba(0,0,0,.3));


}
 
.tooltiptext {
    width: 120px;
    background-color: white;
    color:#2c2c2c; ;
    text-align: center;
    padding: 5px 0;
    border:1px solid #eeeeee;
    border-radius: 6px;
    position: fixed;
    bottom:30px;
	right:75px;
  font-family:'abel';
  text-transform:uppercase;
 filter: drop-shadow(2px 6px 4px rgba(0,0,0,.3));
-webkit-filter: drop-shadow(2px 6px 4px rgba(0,0,0,.3));

    
}
  
.tooltiptext:after {
    content: "";
    position: absolute;
    top: 50%;
    left: 100%;
    margin-top: -5px;
    border-width: 5px;
    border-style: solid;
    border-color: transparent transparent transparent #eeeeee;
}

For more context see here: http://tomcritchlow.com/2016/05/10/facebook-livechat/

Just testing and it works awesome! But either when I change the page URL, stills appears the old page. Great work guys!