<!DOCTYPE html>
<html>
<head>
<style>
p {
border-top-style: dotted;
border-right-style: solid;
border-bottom-style: dotted;
border-left-style: solid;
}
</style>
</head>
<body>
<h1>单独的边框</h1>
<p>两种不同的边框样式。</p>
</body>
</html>