  We present a light-front model calculation of the pion parton distribution
functions (PDFs) and the pion electromagnetic form factor. The pion state is
modeled in terms of light-front wave functions (LFWFs) for the $q\bar q$,
$q\bar q q\bar q$, $q\bar q g$, and $q\bar q gg$ components. We design the
LFWFs so that the parameters in the longitudinal and transverse momentum space
enter separately in the fit of the pion PDFs and the electromagnetic form
factor, respectively. We extract the pion PDFs within the xFitter framework
using available Drell-Yan and photon-production data. With the obtained
parameters in the longitudinal-momentum space, we then fit the available
experimental data on the pion electromagnetic form factor to constrain the
remaining parameters in the transverse-momentum space. The results for the pion
PDFs are compatible with existing extractions and lattice calculations, and the
fit to the pion electromagnetic form factor data works quite successfully. The
obtained parametrization for the LFWFs marks a step forward towards a unified
description of different hadron distribution functions in both the
longitudinal- and transverse-momentum space and will be further applied to a
phenomenological study of transverse-momentum dependent parton distribution
functions and generalized parton distributions.
