locating css files

Hi,

I am slightly confused. I am trying to edit my Smooth Slider CSS. Some of which is located in smooth_sldr.css but Firefox is saying that there is more CSS at root level ie:

https://www.frametechcontruction.co.uk

I cant locate any CSS files in my root directory and it is that CSS I need to alter as it is overwriting my edits in the smooth_sldr.css

Can anyone tell me where I can access this file???

Cheers
Phil