<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title></title>
<style type="text/css">
.a{
width:98%;
column-count:2;
column-gap: 10px;
margin: 0 auto;
border: 1px solid red;
}
.a div{
margin: 10px;
}
</style>
</head>
<body>
<div class="a">
<div style="height: 100px;background-color: red;"></div>
<div style="height: 300px;background-color: yellow;"></div>
<div style="height: 500px;background-color: gray;"></div>
<div style="height: 200px;background-color: cyan;"></div>
<div style="height: 400px;background-color: orange;"></div>
<div style="height: 50px;background-color: pink;"></div>
</div>
</body>
</html>
