  We investigate the structure of the light meson with one dynamical gluon from
the light-front QCD Hamiltonian, determined for their constituent
quark-antiquark and quark-antiquark-gluon Fock sectors, together with a
three-dimensional confinement. After fitting the light meson mass spectroscopy,
the light-front wave functions provide a good quality description of the pion
electromagnetic form factor, and the valence quark distribution functions
following QCD scale evolution.
