I want to underline links in the default template for the List Category Posts plugin. I can't find where to do this in the template & styles. Any assistance would be gratefully accepted.
If you want to do this for every link from List Category Posts, you can add this to your theme's css file:
Check this answer for more details on new features that can help you customize even more:
If you just want to add this underline, then the best would be to use this new feature instead of a template.