W3Schools Tryit Editor

<!DOCTYPE html>
<html>
<head>
<style> 
#main {
  width: 140px;
  height: 300px;
  border: 1px solid #000000;
  display: flex;
  flex-flow: row wrap;
  align-content: space-around; 
}

#main div {
  width: 70px;
  height: 70px;
}
</style>
</head>
<body>

<p>Click the button to set the value of the alignContent property to "space-between"</p>
<button onclick="myFunction()">Try it</button>

<p><b>Note:</b> Internet Explorer 10 and earlier versions do not support the alignContent property.</p>

</body>

</html>