console 命令行工具 X clear
console
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width,initial-scale=1.0">
	<title>盒子模型</title>
	<style type="text/css">
	  body{
	  	margin: 0;
	  	padding: 0;
	  }
	  #box1{
	  	background-color:#9cf;
	  	margin: 20px;
	  	border: 10px solid #039;
	  	padding: 40px;
	  	width: 200px; 
	  }

	  #text{
	  	background-color: #fc0;
	  	height: 100px;
	  }

	  #box2{
	  	background-color: #ccc;
	  	margin: 5px;
	  	height: 100px;
	  	padding-left: 30px;
	  }
	  </style>
</head>
<body>
<div id="box1">
  <div id="text">学习CSS很重要</div>
</div>
<div id="box2">盒子模型需要认真理解</div>

</body>
</html>