Use the align-content property with value space-around to add space around the flex lines.
Example
You can try to run the following code to implement the space-around value:
<!DOCTYPE html>
<html>
<head>
<style>
.mycontainer {
display: flex;
height: 200px;
background-color: red;
align-content: space-around;
flex-wrap: wrap;
}
.mycontainer > div {
background-color: yellow;
text-align: center;
line-height: 60px;
font-size: 30px;
width: 100px;
margin: 5px;
}
</style>
</head>
<body>
<h1>Queue</h1>
<div class = "mycontainer">
<div>Q1</div>
<div>Q2</div>
<div>Q3</div>
<div>Q4</div>
<div>Q5</div>
<div>Q6</div>
<div>Q7</div>
<div>Q8</div>
</div>
</body>
</html>