一，效果图。
二，代码。
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>CSS Fonts(字体)</title>
<style>
body {
font-size: 100%;
}
h1 {
font-style: normal;
font-size: 40px;
font-size: 2.5em;
}
p.serif {
font-family: "Times New Roman", Times, serif;
font-style: italic;
font-size: 30px;
font-size: 1.875em;
}
p.sansserif {
font-family: Arial, Helvetica, sans-serif;
font-style: oblique;
font-size: 14px;
font-size: 0.875em;
}
</style>
</head>
<body>
<h1>css font-family</h1>
<p class="serif">this is a paragrapth,shown in the times new Roman font.</p>
<p class="sansserif">this is a paragraph,shown in the arial font.</p>
</body>
</html>
参考资料：《菜鸟教程》