html,body{
  overflow:hidden;
}

#demo{
  position:relative;
  top:0;
  left:0;
}
#demo img{
  position:absolute;
  top:0;
  left:0;
  transform-origin: center;
  cursor:pointer;
  user-select:none;
}
#demo img.coin{
  border-radius:50%;
}

#demo em{
  position:absolute;
  top:0;
  right:0;
  font-size:64px;
  font-weight:bold;
}
#demo input{
  position:absolute;
  bottom:1vmin;
  left:0;
  height:8vmin;
  width:calc(100vw - 20px);
  opacity:0.6;
  z-index:99;
  font-size:32px;
  border:8px solid #000;
}

#demo input.ng{
  border:8px solid #a00;
}
#demo input.ok{
  border:8px solid #0a0;
}

#demo input:hover{
  opacity:1;
}