transform navbar to responsive html css code example

Example: css schöne navbar

nav ul {
    margin: 0;
    padding: 0;
    text-align: center;
  }

  nav li {
    list-style: none;
    position: relative;
    margin: 0; 
    padding: 0;
  }

  nav ul ul {
    position: absolute;
    top: -0.4em; 
    left: 8em;
  }