console 命令行工具 X clear

console

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <link rel="stylesheet" type="text/css" href="syl.css">
</head>
<body>
    <p>1.</p>
    <div class="container">
     <div class="item"> </div>
    </div>

    <p>2.</p>
    <div class="container2">
     <div class="item2"> </div>
     <div class="item2"> </div>
     <div class="item2"> </div>
     <div class="item2"> </div>
     <div class="item2"> </div>
     <div class="item2"> </div>
    </div>
</body>
</html>

*{
    padding:0;
    margin:0;
}
.container{
    display: flex;
    justify-content: center;
    align-items: center;
    background-color: skyblue;
    width:200px;
    height:200px;
}
.item{
    width:100px;
    height:100px;
    background-color: blue;
}
/*2nd*/
.container2{
    display: flex;
    justify-content: space-around;
  flex-wrap: wrap;
  align-content: space-around;
    width:300px;
    height:300px;
    background-color: skyblue
}
.item2{
    width:80px;
    height:80px;
    background-color: blue;
}