pre{
  position: relative;
  font-size: 15px;

}
pre code{
  display: inline-block;
  
  height: 0;
  padding: 0 ;
  margin: 0;
  
}
.copy-button{
  position: absolute;
  top: 0;
  right: 0;
  display: flex;
  justify-content: center;
  align-items: center;
  appearance: none;
  -moz-appearance: none;
  -webkit-appearance: none;
  margin: 0 auto;
  padding: 0 1em;
  height: 24px;
  border: none;
  line-height: 1;
  font-weight: bold;
  background: #666;
  color: #fff;
  cursor: pointer;
}
.copy-button:hover{
  background: #999;
}