[Spaced]

I forgot one part of this.
With the float on <p> tag the border will go only the length of the text. The "clearyourclass" class is to push any text that is suppose to be underneath "yourclassname" you can do this with a <br clear="all" /> but you have less control of the final product.

Code:

CSS:
.clearyourclass{width: 100%; float: left;}
.yourclassname{margin: 2px; padding: 5px; border: 1px solid #000; float: left; clear: both;}

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<div class="clearyourclass">
     <p class="yourclassname">Your text Here</p>
</div>