Create css in existing website to allow for pretty formatted python code snippets

I have a teaching website in which I would like to insert python code snippets, with the formatting (coloured) intact. Ideally, it would be good if the css of the website could be altered so that all code inside the <pre></pre> tags would contain pretty formatted python code. This is probably a 5 minute job for someone who knows what they are doing and in the interest of developing a long term relationship, would be interested in a quick resolution and explanation. Unfortunately we are unable to provide cpanel access, so it would require a very well laid out and carefully explained tutorial so that I can implement this myself. As an introductory line, please tell me what further information you need from me to proceed. Thanks in advance. (e.g. all the css files of the site, which was created using bootstrap. I am not sure which one contains the necessary information for the <pre> code </pre>) Some files attached for reference. Obviously we would pay when the instructions provided by the freelancer work on the site in question. Current code on website: [login to view URL] What we want it to look like: (see the code if you scroll down on this web page) [login to view URL]