I totally feel your pain, as most sites seem to forget that people actually use their phones for this. You should definitely take a look at https://ninewins.uk/ and how it scales to your screen size. I’ve been using it on my iPhone for a while now and the touch response is incredibly sharp, which makes a huge difference. The interface is clean and doesn't feel cramped even on a smaller display, so you can actually enjoy the experience without constantly zooming in and out. It’s probably one of the most fluid mobile-first designs I’ve come across recently for casual gaming on the move.