border arredondada html
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Bordas Arredondadas</title>
<style type="text/css">
#box{
width:300px;
height:100px;
background-color:#666;
border-radius: 10px;
}
</style>
</head>
<body>
<!-- iremos criar nossa div onde ficará o box arredondado -->
<div id="box"></div>
</body>
</html>