Let's say you need six different 100px square boxes with different characteristics:

• Red with Border
• Blue with Border
• Green with Border
• Red without Border
• Blue without Border
• Green without Border

You COULD create a unique class for each of these, like so:

.redwithborder {
	width: 100px;
	height: 100px;
	margin: 10px;
	float: left;
	background-color: red;
	border: 3px solid black;
}
.bluewithborder {
	width: 100px;
	height: 100px;
	margin: 10px;
	float: left;
	background-color: blue;
	border: 3px solid black;
}
...etc

BUT that's called CSS Bloat because it includes a bunch of unnecessary repetitive code. Instead, create just five classes with simple, identifiable names that each handle something very specific:

.box {
	width: 100px;
	height: 100px;
	margin: 10px;
	float: left;
}
.red {
	background-color: red;
}
.blue {
	background-color: blue;
}
.green {
	background-color: green;
}
.border {
	border: 3px solid black;
}

In your HTML, things look just as clean, just put a space between each of the classes you wish to apply to the div:

	<div class="red border box">
	</div>

	<div class="blue border box">
	</div>

	<div class="green border box">
	</div>

	<div class="red box">
	</div>

	<div class="blue box">
	</div>

	<div class="green box">
	</div>

This method allows better future flexibility as well. If you wanted to create an orange box, or even a box with a background-image or some completely separate characteristic, you could. And then adding a border to that new box is simple adding a space and the "border" class name.

[EXAMPLE PAGE]