  We demonstrate sideband-resolved Si$_3$N$_4$ optomechanical crystals
supporting $10^5$ quality factor optical modes at 980 nm, coupled to $\approx4$
GHz frequency mechanical modes with quality factors of $\approx3000$.
Optomechanical electromagnetically induced transparency and absorption are
observed at room temperature and in atmosphere with intracavity photon numbers
of the order of $10^4$.
