Looking for a way to read .epub LNs on web browser

I recently downloaded the さくら荘のペットな彼女 light novels as epub files. I've been trying to look for a web browser epub reader so that I can use Yomitan for mining, however, the websites I've found seem to be having trouble loading the format properly. Does anybody have any alternatives? If not, is there something that I could set up that acts as an alternative to Yomitan which can be used on any PC app for mining/autocards instead of only the browser?