.btn {
font:bold 25px Cabin Sketch; color:#000000;  text-decoration:none;
color: #000;
padding-top: 5px;
font-size: 1.4rem;
font-weight: 600;
border: none;
border-radius: 2rem;
cursor: pointer;
transition-duration: 0.4s;
 box-shadow: 3px 3px  3px rgba(0,0,0,0.6);
-moz-box-shadow: 3px 3px  3px rgba(0,0,0,0.6);
-webkit-box-shadow: 3px 3px  3px rgba(0,0,0,0.6);
-o-box-shadow: 3px 3px  3px rgba(0,0,0,0.6);
    width: 150px;
    height: 100px;
}
.btn:hover {
background: #fff;
box-shadow: 0px 2px 20px 10px #999999;
color: #ff0000;
}
.puzzle {
  width: 100%;
  height: 100%;
  max-width: 100%;
  max-height: 100%;
}