body,
a {
  color: #808080;
}
ul.sidenav {
  list-style-type: none;
  margin: 0;
  padding: 0;
  width: 10%;
  background-color: #f1f1f1;
  height: 100%;
  position: fixed;
  overflow: auto;
}
ul.sidenav li a {
  display: block;
  color: #000;
  padding: 8px 16px;
  text-decoration: none;
  transition: 0.3s;
}
ul.sidenav li a.active {
  background-color: #4caf50;
  color: #fff;
}
ul.sidenav li a:hover:not(.active) {
  background-color: #555;
  color: #fff;
}
#content {
  margin-left: 25%;
  padding: 1px 16px;
  height: 100%;
}