If you are using the C# CSS HTML formatter, I recommend changing the PRE formatting to text wrap. See this site for more information.
I just added this to the top of a .css file:
PRE {white-space: pre-wrap; /* css-3 */white-space: -moz-pre-wrap; /* Mozilla, since 1999 */white-space: -pre-wrap; /* Opera 4-6 */white-space: -o-pre-wrap; /* Opera 7 */word-wrap: break-word; /* Internet Explorer 5.5+ */}