CSS - Measurement Units

 <!DOCTYPE html>
<html>
<head>
    <title>CSS Units</title>
    <style>
        .ex2 {
            font-size: 2ex;
        }
        
        .ex4 {
            font-size: 4ex;
        }
        
        .ex6 {
            font-size: 6ex;
        }
    </style>
</head>
<body>
    <h1 class="ex2">This is a heading with font-size 2ex</h1>
    <p class="ex4">This is a paragraph with font-size 4ex</p>
    <div class="ex6">This is a div with font-size 6ex</div>
</body>
</html>

CSS - Measurement Units

Example -Demo ex unit