If you are already using LaTeXML, it is also easy to get the ar5iv rendering (example article: https://ar5iv.labs.arxiv.org/html/1910.06709)

You can either copy the CSS asset from: https://github.com/dginev/ar5iv-css

and add "--css=ar5iv.css --nodefaultresources" to the command line options for latexmlpost (or latexmlc).

Or alternatively, for people not interested in learning how to install and configure latexml, they can try the self-contained Dockerfile at:

https://github.com/dginev/ar5ivist/