W3Schools Tryit Editor

<!DOCTYPE html>
<html>
<head>
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<style>
body {margin: 0;}

ul.topnav {
  list-style-type: none;
  margin: 0;
  padding: 0;
  overflow: hidden;
  background-color: #333;
}

ul.topnav li {float: left;}

ul.topnav li a {
  display: block;
  color: white;
  text-align: center;
  padding: 14px 16px;
  text-decoration: none;
}

ul.topnav li a:hover:not(.active) {background-color: #111;}

ul.topnav li a.active {background-color: #04AA6D;}

ul.topnav li.right {float: right;}

@media screen and (max-width: 600px) {
  ul.topnav li.right, 
  ul.topnav li {float: none;}
}
</style>
</head>
<body>

<ul class="topnav">
  <li><a class="active" href="#home">Home</a></li>
  <li><a href="#news">News</a></li>
  <li><a href="#contact">Contact</a></li>
  <li class="right"><a href="#about">About</a></li>
</ul>

<div style="padding:0 16px;">
  <h2>Responsive Topnav Example</h2>
  <p>This example use media queries to stack the topnav vertically when the screen size is 600px or less.</p>
  <p>You will learn more about media queries and responsive web design later in our CSS Tutorial.</p>
  <h4>Resize the browser window to see the effect.</h4>
</div>

</body>
</html>

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<!DOCTYPE html><html><head><meta name="viewport" content="width=device-width, initial-scale=1.0"><style>body {margin: 0;}​ul.topnav {  list-style-type: none;  margin: 0;  padding: 0;  overflow: hidden;  background-color: #333;}​ul.topnav li {float: left;}​ul.topnav li a {  display: block;  color: white;  text-align: center;  padding: 14px 16px;  text-decoration: none;}​ul.topnav li a:hover:not(.active) {background-color: #111;}​ul.topnav li a.active {background-color: #04AA6D;}​ul.topnav li.right {float: right;}​@media screen and (max-width: 600px) {  ul.topnav li.right,   ul.topnav li {float: none;}}</style></head><body>​<ul class="topnav">  <li><a class="active" href="#home">Home</a></li>  <li><a href="#news">News</a></li>  <li><a href="#contact">Contact</a></li>  <li class="right"><a href="#about">About</a></li></ul>