#open-btn {
  font-size: 3rem;
  right: 18px;
  position: absolute;
  top: 27px;
}
#slide-nav {
  width: 0;
  opacity: 0;
  height: 100%;
  top: 0;
  left: 0;
  position: fixed;
  transition: 0.1s;
  z-index: -1;
}
#slide-nav ul {
  list-style-type: none;
  padding: 12px;
}
#slide-nav li {
  margin-bottom: 7px;
}
#slide-nav a {
  color: #fff;
  text-decoration: none;
  font-size: 1.2em;
}
#slide-nav a:hover {
  text-decoration: underline;
}
#close-btn {
  color: #fff;
  font-size: 2.4rem;
  margin-left: 7px;
}
#open-btn,
#close-btn {
  cursor: pointer;
}