<!DOCTYPE html>
<html>
<head>
<style>
p::first-line {
font-size: 20px;
text-decoration: underline;
background-color: lightgreen;
}
</style>
</head>
<body>
<h1>Demo of ::first-line</h1>
<h2>WWF's Mission Statement</h2>
<p>To stop the degradation of the planet's natural environment and to build a future in which humans live in harmony with nature, by; conserving the world's biological diversity, ensuring that the use of renewable natural resources is sustainable, and promoting the reduction of pollution and wasteful consumption.</p>
</body>
</html>