This is what goes on HTML:
<div>
<div class="red vertical"></div>
<div class="yellow vertical"></div>
<div class="green vertical"></div>
</div>
This is what goes on CSS:
.vertical {
width: 75px;
height: 150px;
float: left;
}
.red {
background-color: red;
}
.yellow {
background-color: yellow;
}
.green {
background-color: green;
}