#startbutton
{
  background-image: url(
https://upload.wikimedia.org/wikipedia/commons/thumb/7/72/Triangle.Right.svg/1200px-Triangle.Right.svg.png

);
	width: 85px;
  height: 70px;
  background-size:contain;
  background-position:center;
  
  position:fixed;
  top:60%;
  left:50%;
  transform:translate(-50%, -50%);
  background-color:green;
  border-radius:5%;
  padding:20px;
  
  
}

#widthIn
{
  width: 55px;
  height: 25px;
  
  position:fixed;
  top:50%;
  left:50%;
  transform:translate(-50%, -50%);
  border-radius:5%;
  padding:20px;
}