ul {
    list-style-type: none;
    margin: 0;
    padding: 0;
    overflow: hidden;
    background-color: #333;
}
li {
  float: left;
}
li a {
  display: block;
  color: white;
  text-align: center;
  padding: 14px 16px;
  text-decoration: none;
}
li a:hover:not(.active) {
  background-color: #111;
}
.active {
  background-color: #4CAF50;
}
header {
    text-align: center;
    margin: 0px auto;
}
footer {
    min-width: 1024px;
    margin: 10px auto;
    text-align: center;
}
article {
    min-width: 1024px;
    margin: 0px auto;
    text-align: center;
}
.clip-circle {
    clip-path: circle(200px at center);
}