Typically if users add custom css they include it in the header field of the style which has been applied to the survey.
...answers when you need them
Is there a way to attach a style sheet to a survey instead of using the styles provided or creating styles through the Checkbox interface? One of our users wants to be able to further customize the look and feel of surveys since the GUI options are somewhat limited.
Typically if users add custom css they include it in the header field of the style which has been applied to the survey.