代码示例：（标识：css_buttons_image）
<!DOCTYPE html>
<html>
<head>
<style>
.container {
position: relative;
width: 100%;
max-width: 400px;
}
.container img {
width: 100%;
height: auto;
}
.container .btn {
position: absolute;
top: 50%;
left: 50%;
transform: translate(-50%, -50%);
-ms-transform: translate(-50%, -50%);
background-color: #f1f1f1;
color: black;
font-size: 16px;
padding: 16px 30px;
border: none;
cursor: pointer;
border-radius: 5px;
text-align: center;
}
.container .btn:hover {
background-color: black;
color: white;
}
</style>
</head>
<body>
<h1>图像上的按钮</h1>
<p>为图像添加按钮：</p>
<div class="container">
<img src="/static/demo/images/coffee.jpg" alt="Snow" style="width:100%">
<button class="btn">按钮</button>
</div>
</body>
</html>
