The jet quenching phenomena in heavy ion collisions provide a strong evidence of the modification of parton shower in the quark-gluon plasma (QGP). Jet substructure observables can probe various aspects of the jet formation mechanism and allow us to study the medium properties in great details. Here we focus on the hard probes using jets and present theoretical calculations of jet shapes and cross sections in proton-proton and lead-lead collisions at the LHC using soft-collinear effective theory, with Glauber gluon interactions in the medium. Resumming large logarithms in the jet substructure calculation is necessary for precise theoretical predictions, and it can be performed using renormalization group evolution between characteristic jet scales. Also, the medium induces power corrections to jet shapes due to the Landau-Pomeranchuk-Migdal effect. We present the comparison between our calculations with the recent measurements at the LHC with very good agreement. Our calculations help initiate precise jet modification studies in heavy ion collisions.