In this question use the pseudo element selector.
<!DOCTYPE html>
<html lang='en' xmlns='http://www.w3.org/1999/xhtml'>
<head>
<style>
p::first-letter {
color: red;
font-size: 50px;
}
</style>
</head>
<body>
<p>You can use the ::first-letter pseudo-element to add a special effect to the first character of a text!</p>
</body>
</html>
