<html><head><style> .box { border: 2px solid green; background-color: beige; font-family: monospace; font-size: 20px;}.box > a { color: green;}.box > a:hover { color: white; background-color: salmon;}</style></head><body><h1>嵌套之前</h1><div class="box">这段文本包含一个 <a href="#">链接</a>。将鼠标悬停在链接上可查看效果。</div></body></html>