<html><head> <meta charset="utf-8"> <title>蝴蝶教程（cainiaoya.com）</title> <style> p.serif { font-family: "Times New Roman", Times, serif; } p.sansserif { font-family: Arial, Helvetica, sans-serif; } </style></head><body><h1>CSS font-family</h1><p class="serif">这是一个段落，显示 Times New Roman 字体。</p><p class="sansserif">这是一个段落，显示 Arial 字体。</p></body></html>