<html>
<head>
<title>标题</title>
</head>
<body>
<header>头部内容</header>
<section>主体内容</section>
<footer>底部内容</footer>
</body>
</html>
* {
margin: 0;
padding: 0;
box-sizing: border-box;
padding: 10px;
}
html {
background: red;
}
body {
background: yellow;
}
header {
background: green;
}
section{
background: greenyellow;
}