Например так
<!DOCTYPE html>
<html>
<head>
<style>
.boxes {
max-width: 400px;
}
.box {
display: block;
float: left;
width: 80px;
height: 80px;
margin-right: 20px;
margin-bottom: 20px;
}
.box-blue {
background-color: blue;
}
.box-red {
background-color: red;
}
</style>
<body>
<div class="boxes">
<div class="box box-blue"></div>
<div class="box box-blue"></div>
<div class="box box-blue"></div>
<div class="box box-blue"></div>
<div class="box box-red"></div>
<div class="box box-red"></div>
<div class="box box-red"></div>
<div class="box box-red"></div>
</div>
</body>
</html>
