body {
  background: #efefef;
}
#btn {
  width: 200px;
  height: 200px;
  background: #ef454a;
  border-radius: 50%;
 margin: 30px auto 0;
 text-align: center;
 line-height: 200px;
 color: #fff;
 font-size: 42px;
 font-weight: bold;
 cursor: pointer;
 box-shadow: 0 10px 0 #d1483e;
 user-select: none;
}

#btn:hover {
  opacity: 0.9;
}

#btn.pressed {
  box-shadow: 0 5px 0 #d1483e;
  margin-top: 35px;
}