JSFiddle - React, Tailwind, and code Playground

HTML

<a href="#"><div id="feedback">Feedback</div></a>

CSS

#feedback{
  color:#FFF;
  position:fixed;
  bottom:200px; right:-56px;
  width:140px; 
  height:35px; 
  line-height:40px;
  background:#727948;
  text-align:center;
  font-size:18px;
  border-bottom-left-radius:5px;
  border-bottom-right-radius:5px;
  -webkit-box-shadow: 0 8px 6px -6px black;
     -moz-box-shadow: 0 8px 6px -6px black;
          box-shadow: 0 8px 6px -6px black;
  opacity:0.8;
  -webkit-transform: rotate(90deg);/* Safari and Chrome */
  -moz-transform: rotate(90deg); /* Firefox */
  -ms-transform: rotate(90deg); /* ie9 */
  -o-transform: rotate(90deg); /* Opera */
  filter: progid:DXImageTransform.Microsoft.BasicImage(rotation=2); /* ie8 */
  writing-mode:tb-rl; /* ie8 */ 
}
  
#feedback:hover{
  opacity:1;
}