定义两个盒子div 要求两个盒子设置宽200px 高200px 背景颜色为蓝色和绿色 盒子之间的垂直间距30px
<!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>
</head>
<body>
<div style="width: 200px;height:200px;background-color: blue;">
</div>
<div style="width: 200px;height:200px;background-color: green;margin-top: 30px;">
</div>
</body>
</html>