Recently I was setting up the reporting for our acceptance tests that I noticed two issues.
(1) it's terribly simple in style! (2) it's missing some info such as namespaces (for when you have many folders in which you have tests) and categories.
So I edited the existing XSLT and rectified those two issues for me by adding twitter bootstrap style, prismJs syntax highlighting and adding the missing information to the output.
I hope this could be helpful for you too.
P.S. in case you have your own special-purpose report XSLT why not share it with others in the project?
Show HN: generate nicer nunit/specflow test reports using this new XSLT template
github.com