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:yellow;
            margin:20px;
            border:10px solid #039;
            padding:40px;
            width:200px;
        }

        #text{
            background-color:pink;
            height:100px;
        }
        #box2{
            background-color:#ccc;
            margin:5px;
            height:100px;
            padding-left:30px;
        </style>
    </head>
    <body>
        <div id="box1">
            <div id="text"><h2 align="center">学习很重要</h2></div>
        </div>
        <div id="bxo2">盒子模型需要认真理解</div>
    </body>
</html>