.overlay {
  height: 100%;
  width: 0;
  position: fixed;
  z-index: 3;
  left: 0;
  top: 0;
  background-color: rgba(0,0,0, 0.95);
  overflow-x: hidden;
  transition: 0.5s;
}

.overlay-content {
  position: relative;
  top: 15%;
  width: 100%;
  text-align: center;
  margin-top: 30px;
}

.overlay a {
  padding: 8px;
  text-decoration: none;
  font-size: 36px;
  color: #818181;
  display: block;
  transition: 0.3s;
}

.overlay a:hover, .overlay a:focus {
  color: #f1f1f1;
}

.overlay .closebtn {
  position: absolute;
  top: 20px;
  right: 45px;
  font-size: 60px;
}