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<!DOCTYPE html>
<html>
<head>
<style>
h1, h2, div {
  background-color: lightgreen;
}
h1 {
  border-block: 5px solid red;
}
h2 {
  border-block: 4px dotted blue;
}
div {
  border-block: double;
}
</style>
</head>
<body>
<h1>在块方向上带有实线红色边框的标题</h1>
<h2>在块方向上带有点状蓝色边框的标题</h2>
<div>在块方向上带有双线边框的 div 元素。</div>
</body>
</html>