W3Schools Tryit Editor

<!DOCTYPE html>
<html>
<title>W3.CSS</title>
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="stylesheet" href="https://www.w3schools.com/w3css/5/w3.css">
<body class="w3-container">

<h2>Code Containers</h2>
<p>The w3-code class create code containers to highlight HTML, JavaScript and CSS code.</p>

<div class="w3-panel w3-card w3-light-grey"> 
<h4>HTML Example</h4>
<div class="w3-code htmlHigh notranslate">
&lt;!DOCTYPE html&gt;<br>&lt;html&gt;<br>
&lt;title&gt;HTML Tutorial&lt;/title&gt;<br>
&lt;body&gt;<br><br>
&lt;h1&gt;This is a heading&lt;/h1&gt;<br>
&lt;p&gt;This is a paragraph.&lt;/p&gt;<br><br>
&lt;/body&gt;<br>
&lt;/html&gt;
</div>
</div>

<div class="w3-panel w3-card w3-light-grey"> 
<h4>CSS Example</h4>
<div class="w3-code cssHigh notranslate">
body {<br>
  background-color: #d0e4fe;<br>}<br><br>
h1 {<br>
  color: orange;<br>
  text-align: center;<br>}<br><br>
p {<br>
  font-family: "Times New Roman";<br>
  font-size: 20px;<br>
}
</div>
</div>

<div class="w3-panel w3-card w3-light-grey"> 
<h4>JavaScript Example</h4>
<div class="w3-code jsHigh notranslate">
var x = 5;        // assign the value 5 to x<br>
var y = 2;        // assign the value 2 to y<br>
var z = x + y;    // assign the value
</div>
</div>

</body>
</html>