ul {
  list-style-type: none;
  margin: 0;
  padding: 0;
  background-color: grey;
}

body {
  background-color: white;
  font-size: 14px;
  color: black;
}

li {
  float: left;
}

li a {
  display: block;
  color: white;
  padding: 8px;
  background-color: grey;
}

/* Change the link color to #111 (black) on hover */
li a:hover {
  background-color: #3336FF;
}

.active {
  background-color: #04AA6D;
}

ul {
  position: fixed;
  top: 0;
  width: 100%;
}

.center {
  display: block;
  margin-left: auto;
  margin-right: auto;
  width: 50%;
  height: 50%;
}

.navbar {
  overflow: hidden;
  background-color: #333;
  position: fixed; 
  top: 0; 
  width: 100%;
}

.main {
  margin-top: 400px;
}