Contour And Older Mac Mini/Safari

I just hooked up my old Mac Mini, (mid 2011) with

2.5 GHz core i5

OS 10.11.6

4GB RAM

Safari version 11.1.2

Contour doesn't work, and I'm not really surprised, but should it? It seems to meet the system requirements, although I haven't seen anything about minimum memory. 4GB may be the problem? Or Safari? I haven't tried another browser.

Thanks for any help