If your theme isn’t wrapping your Preformatted text (spilling over into your sidebar), all you need to do is edit your style.css file.
Within the “pre” section of your style.css file, replace or add the following text
pre {
white-space:pre-wrap;
word-wrap:break-word;
}
Want to add some basic formatting?
pre {
white-space:pre-wrap;
word-wrap:break-word;
border:1px solid #ccc;
padding:5px 10px;
background: #f8f8f8;
font-size: 12px;
margin-right: 50px;
}