  The possibility to reanalyse data taken by the HERA experiments offers the
chance to study modern QCD jet and event-shape observables in deep-inelastic
scattering production. In this contribution we present resummed and matched
predictions for the groomed invariant-mass event shape in neutral-current DIS
including the effect of grooming the hadronic final state using the soft-drop
technique. Non-perturbative corrections from hadronisation are taken into
account through parton-to-hadron level transfer matrices extracted from
dedicated Monte Carlo simulations with SHERPA, including uncertainties
extracted from replica tunes to data from the HERA experiments.
