Styling the Categories Module

My client does not like how the categories module displays. I am familiar with creating custom css styles but I am not sure how to target the list style in this case. Can you please help me out with how to target and style this area. Essentially my client wants this category list to not have the dots in front of the subcategories. I was thinking perhaps I could make a custom list style or something and add a module suffix but I'm not sure if this will work. Any help would be appreciated.

To see the double dots I have attached a screenshot.

Here is the url where you can see the categories module on the live site: www.eoriwyoming.org/library

Ideally, I would just like you to provide css that will hide the double dots in front of the subcategories - it would also be ok to just hide all the dots but I cannot have it effect other li styles on the website.

Thanks in advance for your help.