<html>
<head>
<style>
img.background {
width: 100%;
height: 100%;
position: absolute;
left: 0px;
top: 0px;
z-index: -1;
filter: blur(35px);
}
</style>
</head>
<body>
<h1>The blur() Function</h1>
<p>Blurred background:</p>
<img class="background" src="pineapple.jpg" alt="Pineapple" width="300" height="300">
</body>
</html>