代码示例：（标识：css_buttons_font）
<!DOCTYPE html>
<html>
<head>
<style>
.button {
background-color: #4CAF50; /* 绿色 */
border: none;
color: white;
padding: 15px 32px;
text-align: center;
text-decoration: none;
display: inline-block;
margin: 4px 2px;
cursor: pointer;
}
.button1 {font-size: 10px;}
.button2 {font-size: 12px;}
.button3 {font-size: 16px;}
.button4 {font-size: 20px;}
.button5 {font-size: 24px;}
</style>
</head>
<body>
<h1>按钮大小</h1>
<p>通过 font-size 属性改变按钮的字体大小：</p>
<button class="button button1">10px</button>
<button class="button button2">12px</button>
<button class="button button3">16px</button>
<button class="button button4">20px</button>
<button class="button button5">24px</button>
</body>
</html>
