.overlay {
  height: 0%;
  width: 100vw;
  position: fixed;
  z-index: 1;
  bottom:0;
  left: 0;
  background-color: rgb(0,0,0);
  background-color: rgba(0,0,0, 0.9);
  
  transition: 0.5s;


}

.overlay-content {
  position: relative;
 top: 25%;
  width: 100vw;
  text-align: center;
/*  margin: 60px;*/
/*    background-color: aquamarine*/
}

.overlay a {
  padding: 8px;
  text-decoration: none;
  font-size: 2em;
  color: #fff;
  display: block;
  transition: 0.3s;
/*    margin-bottom: 20px*/
   
}

.overlay a:hover, .overlay a:focus {
  color: #555;
}

.overlay .closebtn {
  position: absolute;
  top: 10px;
  right: 30px;
  font-size: 60px;
/*    margin: 10px;*/
/*    background-color: bisque*/
}

@media screen and (max-height: 450px) {
  .overlay {overflow-y: auto;}
  .overlay a {font-size: 2em}
  .overlay .closebtn {
  font-size: 40px;
/*
  top: 15px;
  right: 35px;
*/
  }
}