flex:
<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>Flex</title>
<style type="text/css">
html, body {
width: 100%;
}
.flex-container {
display: flex;
flex-wrap: wrap;
justify-content: center;
width: 80%;
margin: auto;
}
.flex-container {
background-color: #F0f0f0;
}
.flex-container .flex-item{
padding: 20px;
background-color: #B1FF84;
}
</style>
</head>
<body>
<div class="flex-container">
<div class="flex-item">01</div>
<div class="flex-item">02</div>
<div class="flex-item">03</div>
<div class="flex-item">04</div>
<div class="flex-item">05</div>
<div class="flex-item">06</div>
<div class="flex-item">07</div>
<div class="flex-item">08</div>
<div class="flex-item">09</div>
<div class="flex-item">10</div>
<div class="flex-item">11</div>
<div class="flex-item">12</div>
<div class="flex-item">13</div>
<div class="flex-item">14</div>
<div class="flex-item">15</div>
<div class="flex-item">16</div>
</body>
</html>