<html>
<head>
<style>
#grad1 {
height: 200px;
background-color: #cccccc;
background-image: linear-gradient(red, yellow, green);
}
</style>
</head>
<body>
<h2>Linear Gradient as Background Image</h2>
<p>This linear gradient starts at the top. It starts red, transitioning to yellow, then to green:</p>
<div id="grad1"></div>
</body>
</html>