body{
    margin: 0;
}
/* navigation bar */
.navbar {
  position: sticky;
  width: 100%;
  margin: auto;
}
.navbar ul {
  width: 100%;
  list-style-type: none;
  background-color: #000000;
  padding: 0px;
  margin: 0px;
  overflow: hidden;
}
.navbar a {
  color: white;
  text-decoration: none;
  padding: 20px;
  display: block;
  text-align: center;
}
.navbar a:hover {
  background-color: #303030;
}
.navbar li {
  float: left;
}